Article

Nonclonal Mast Cell Activation Syndrome

If you want to read the PDF, try requesting it from the authors.

Abstract

Patients who present with typical features of mast cell activation with laboratory confirmation and without evidence of a clonal mast cell disorder or other medical condition should be initiated on medical treatment to block mast cells and their mediators. If a major response is achieved, a diagnosis of nonclonal mast cell activation syndrome (NC-MCAS) is likely and treatment should be optimized, including management of any associated conditions. In this review, the latest evidence with regard to the diagnosis and treatment of NC-MCAS is presented.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the author.

... Mast cell activation syndrome (MCAS) is a chronic multisystem disease of abnormal mast cell (MC) activation leading to inflammatory and allergic symptoms [1][2][3]. Gastrointestinal (GI) manifestations are common, with nausea, heartburn, abdominal pain, and altered bowel habits being the most frequently reported (Table 1) [2][3][4]. Unrecognized and untreated MCAS may account for refractory GI symptoms which may be attributed to functional GI disorders including irritable bowel syndrome (IBS) [5,6]. ...
... Mast cell activation syndrome (MCAS) is a chronic multisystem disease of abnormal mast cell (MC) activation leading to inflammatory and allergic symptoms [1][2][3]. Gastrointestinal (GI) manifestations are common, with nausea, heartburn, abdominal pain, and altered bowel habits being the most frequently reported (Table 1) [2][3][4]. Unrecognized and untreated MCAS may account for refractory GI symptoms which may be attributed to functional GI disorders including irritable bowel syndrome (IBS) [5,6]. Presently, no one has studied a large group of patients with IBS to determine prevalence of MCAS and/or MC activation as the primary etiology. ...
... MCAS patients pose a considerable management challenge due to their pathophysiological heterogeneity, numerous systemic symptoms and triggers, comorbid conditions, and varied responses to therapy. Triggers for MC activation include stress, food, alcohol, excipients in medications, infections, altered microbiome, and environmental stimuli including heat, chemical, and mold exposure [2,3,6,[18][19][20][21]. A multidisciplinary approach is optimal for diagnosis and management. ...
Article
Full-text available
Mast cell activation syndrome is thought to be a common, yet under-recognized, chronic multi-system disorder caused by inappropriate mast cell activation. Gastrointestinal symptoms are frequently reported by these patients and are often mistaken by physicians as functional gastrointestinal disorders. This syndrome can be diagnosed by the medical history and measurable biomarkers. Gastroenterologists manage diseases associated with active inflammatory cells including neutrophils, lymphocytes, macrophages, and eosinophils. The mast cell has only recently been recognized as a major player in our specialty. Gastrointestinal disorders from mast cell mediators often present with apparent irritable bowel syndrome, dyspepsia, chronic or cyclical nausea, and heartburn. Individuals with mast cell activation syndrome experience significant delays in diagnosis. The gastrointestinal symptoms are often refractory to symptom-targeted prescription medications. Beyond avoiding triggers, the best therapy is directed at modulating mast cell activation and the effects of the mediators. Many of these therapies are simple over-the-counter medications. In this article, we review mast cell function and dysfunction and the gastrointestinal symptoms, comorbid conditions, diagnosis, and management of mast cell activation syndrome. Gastroenterologists who become aware of this syndrome can dramatically improve the quality of life for their patients who previously have been labeled with a functional gastrointestinal disorder.
... hEDS and the hEDS variant, hypermobility spectrum disorder (HSD) are characteristically defined by the combination of the following three criteria: between hEDS/HSD and immune-mediated disorders may be explained by recurrent or chronic release of mast cell (MC)-derived factors. MCs have shown to contribute to barrier function and homeostasis within the connective tissue of multiple organ systems and are native to the epithelium of the gastrointestinal, urogenital and respiratory tracts, among others [17,18]. While MCs are normally under tight regulation, aberrant immune activation of these cells results in mast cell activation disorders (MCAD) [17,18]. ...
... MCs have shown to contribute to barrier function and homeostasis within the connective tissue of multiple organ systems and are native to the epithelium of the gastrointestinal, urogenital and respiratory tracts, among others [17,18]. While MCs are normally under tight regulation, aberrant immune activation of these cells results in mast cell activation disorders (MCAD) [17,18]. Due to the intertwined relationship between MC and connective tissue, shared clinical features between MCAD and hEDS/ HSD have been described in the literature [9,[19][20][21]. ...
... MCs develop in the bone marrow and continue to mature at their site of residence in the connective tissue through the interaction of Kit tyrosine kinase receptor on MC surfaces with stem cell factor [18,22]. While the exact mechanism of action of MC is out of the scope of this review, it is important to note that MC express a multitude of receptors such as high-affinity IgE and low-affinity IgG receptors, complement receptors, and toll-like receptors [17,18,[22][23][24]. Upon the binding of these various receptors to their target, MCs release preformed granule mediators such as histamine, protease, as well as lipid mediators such as prostaglandins and leukotrienes [17,18,23,24]. ...
Article
Full-text available
Ehlers–Danlos syndrome (EDS) is a group of related connective tissue disorders consisting of 13 subtypes, each with its own unique phenotypic and genetic variation. The overlap of symptoms and multitude of EDS variations makes it difficult for patients to achieve a diagnosis early in the course of their disease. The most common form, hypermobile type EDS (hEDS) and its variant, hypermobile spectrum disorder (HSD), are correlated with rheumatologic and inflammatory conditions. Evidence is still needed to determine the pathophysiology of hEDS; however, the association among these conditions and their prevalence in hEDS/HSD may be explained through consideration of persistent chronic inflammation contributing to a disruption of the connective tissue. Aberrant mast cell activation has been shown to play a role in disruption of connective tissue integrity through activity of its mediators including histamine and tryptase which affects multiple organ systems resulting in mast cell activation disorders (MCAD). The overlap of findings associated with MCAD and the immune-mediated and rheumatologic conditions in patients with hEDS/HSD may provide an explanation for the relationship among these conditions and the presence of chronic inflammatory processes in these patients. It is clear that a multidisciplinary approach is required for the treatment of patients with EDS. However, it is also important for clinicians to consider the summarized symptoms and MCAD-associated characteristics in patients with multiple complaints as possible manifestations of connective tissue disorders, in order to potentially aid in establishing an early diagnosis of EDS.
... In those that exhibit two or more MCA disorders, the diagnosis of MCAS should be considered. A MCAD subtype, MCAS is typically defined by the combination of (a) typical symptoms, (b) laboratory abnormalities, and (c) response to treatment (Akin, 2017;Hamilton, 2018). Patients often present with episodic MCA signs and symptoms, such as abdominal cramping, asthma, pruritic rashes, hypotensive episodes, tachycardia, anaphylaxis, unexplained arrhythmias, and neurologic/psychiatric symptoms. ...
... Yet many of these patients report beneficial responses to anti-MC mediator therapies. Thus, recent recommendations suggest ongoing treatment in these patients with MCAD (Hamilton, 2018). This can provide symptomatic relief while allowing further investigation to identify associated and often overlooked medical conditions such as PID, HDCT, and disorders of the autonomic neurological systems (Arkwright & Gennery, 2014;Doherty & White, 2018;Seneviratne, Maitland, & Afrin, 2017). ...
... As observed in other cohort studies, most of the patients with MCAD were female, with males comprising only 26% of the study participants (Hamilton, 2018). Among those with MCAD and hEDS/ HSD, the female-to-male ratio of 4:1 observed in our study is similar to other studies (Hamonet et al., 2018;Seneviratne et al., 2017;Tinkle et al., 2017). ...
Article
Mast cell activation disease (MCAD) includes single organ disease such as asthma, urticaria, and gastroenteritis, as well as multiorgan system involvement such as mast cell activation syndrome and anaphylaxis. Reports link MCAD with hypermobile Ehlers‐Danlos syndrome (hEDS), hypermobility spectrum disorder (HSD), and with primary immune deficiencies such as complement and immunoglobulin deficiencies (Ig Def). This study assesses the concurrence of these syndromes. We undertook a cohort analysis of patients seen in a community‐based Allergy/Immunology clinic from 2015 to 2019. We searched for diagnostic codes for Ig Def disorders, hypermobility syndrome, hypermobile/Ehlers‐Danlos syndrome, and MCADs. Of 974 patients with suspected MCAD, 449 (46%) had a diagnosis of MCAD; 496 (51%) of cases had a combination of at least two of hEDS/HSD, MCAD, and Ig Def. Ig Def was present in 417 (43%) of patients; 188 (19.3%) had hEDS/HSD with an Ig Def with or without MCAD and accounted for 45% of all the cases with Ig Def. Of 974 cases, 101 (10%) had hEDS/HSD and MCAD; 207 (21%) had Ig Def and MCAD; 7 (0.7%) had Ig Def and hEDS/HSD; and 181 (19%) had a combination of all three syndromes. Most patients (74%) with these comorbidities were female. The presence of MCAD and Ig Def should be explored in patients with hEDS/HSD. Identifying underlying contributors to recurrent/chronic inflammation and tissue injury is needed to tailor and personalize therapies. This, in turn, can reduce tissue damage, iatrogenic intervention, and optimize health outcomes.
... Following containment of the pathogen-induced damage, MC activation must be down regulated in a timely fashion, to prevent the pathology of unnecessary or excessive inflammation. Recent studies highlight the role of endothelial and epithelial-derived products as key immuno modulators of MC activation (MCA) [1,2]. ...
... Direct engagement of MCs, via TLRs, results in de-novo production and secretion of pro-inflammatory cytokines, such as and IL-1 and IL-6. While indirect activation of MC, by Ig R or CR engagement, not only leads denovo production and secretion of pro-inflammatory cytokines, but rapid release of prestored proteases, heparin, platelet-activating factor, and histamine [1,2,10]. Moreover, MCs have been shown to initiate then curb different inflammatory cascades, with influence over nearby lymph node composition, the recruitment of innate and adaptive immune responses to site of infection, such as macrophages and lymphocytes, respectively, and then suppression of recruited components of the immune system, upon detection of contained or subsiding infection. ...
... Given the key role that MC play in the orchestration and resolution of inflammation, MC activation must be tightly regulated. This is to not only coordinate a tailored, effective response to impending dangers, but also to prevent pathology associated with inappropriate or excessive inflammation, such as NC-MCAS and COVID-19 associated hyper-inflammatory syndrome [1,10]. Recent reports highlight the role of chemical mediators derived from the surrounding epithelium and endothelium as crucial regulators of MC activation, such as IL-33 and Thymic Stromal Lymphopoietin [11]. ...
Article
Full-text available
Coronavirus disease (COVID-19) is a heterogeneous syndrome following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of the upper respiratory tract. ln adults, the clinical condition can range from asymptomatic cases to severe acute respiratory syndrome and multi-organ dysfunction. Those at risk of developing COVID-19 related hyper inflammatory syndrome likely had an ineffective, innate immune response to this novel pathogen. Mast cells are associated with the epithelium, contributing to tissue homeostasis and epithelial barrier defense. Equipped with an array of pathogen receptors, mast cells exhibit distinct cytokine profiles, dependent on the tissue and the triggered pathogen receptors. Following viral infections, mast cells produce pro-inflammatory chemical mediators, such as Interleukin-1 (IL-1) and IL-6, and these cytokines has been shown to be elevated in severe COVID-19 cases. Here, we present a case of a 32-year-old Caucasian woman, with Postural Orthostatic Tachycardia Syndrome (POTS), hypermobile type Ehlers Danlos Syndrome (hEDS), and a cluster of mast cell activation disorders, worrisome for a Mast Cell Activation Syndrome (MCAS), but never had laboratory confirmation of this non-clonal mast cell activation disorder, until she contracted COVID-19 in late March 2020. This case illustrates the need to recognize the rate of mast cell activation in SARS-CoV-2 infection, not only to optimize anti-SARS-CoV-2 therapy, including the development of vaccine, but to potentially curb the risk of SARS CoV-2 triggered hyper inflammatory syndrome.
... There are two schools of thought on the role of bioactive food chemicals to treat chronic diarrhoea. The low-histamine approach is advocated as a treatment for mast cell activation syndrome (MCAS) [60], and the low-food chemical approach, developed at the Royal Prince Alfred Hospital allergy unit in Sydney, Australia and commonly known at the Royal Prince Alfred Hospital (RPAH) diet, is used to treat chronic diarrhoea in the presence of nongastrointestinal-related symptoms including urticaria, asthma or rhinosinusitis [61]. The prevalence of food chemical or histamine intolerance is unclear. ...
... There are two schools of thought on the role of bioactive food chemicals to treat chronic diarrhoea. The low-histamine approach is advocated as a treatment for mast cell activation syndrome (MCAS) [60], and the low-food chemical approach, developed at the Royal Prince Alfred Hospital allergy unit in Sydney, Australia and commonly known at the Royal Prince Alfred Hospital (RPAH) diet, is used to treat chronic diarrhoea in the presence of non-gastrointestinal-related symptoms including urticaria, asthma or rhinosinusitis [61]. The prevalence of food chemical or histamine intolerance is unclear. ...
... Histamine intolerance is driven by reduced histamine degradation resulting in histamine accumulation [67]. A reduction in the enzyme diamine oxidase (DAO), needed to degrade histamine, along with dietary sources of histamine-containing foods results in an overload of histamine, resulting in symptoms, including diarrhoea [60]. ...
Article
Full-text available
Chronic diarrhoea affects up to 14% of adults, it impacts on quality of life and its cause can be variable. Patients with chronic diarrhoea are presented with a plethora of dietary recommendations, often sought from the internet or provided by those who are untrained or inexperienced. In this review, we summarise the possible causes of chronic diarrhoea that can be managed by diet, the symptom improvement and quality of life benefits but also the potential risks of such dietary treatments. Clinicians need to consider both the benefits and risks of dietary treatments before making dietary recommendations to manage chronic diarrhoea. The pivotal role that dietitians have in ensuring optimal symptom improvement without jeopardising nutritional and overall health is discussed.
... Non-clonal mast cell activation disorder (syndrome) (NC-MCAD) and autoimmune/inflammatory syndrome induced by adjuvants (ASIA) have garnered attention over the last decade albeit with much debate and indeed some skepticism [1,2]. While initially capturing the attention of allergists, immunologists, and rheumatologists, the discussion is clearly entering the mainstream of medicine, and the public especially, given the broad definitions of such disorders and their potentially considerable application to the general populace. ...
... Distributed throughout the body, mast cells are unified by their functions and their hematopoietic origin. With presence in the gastrointestinal tract, in the airways, and in the skin, mast cells function in host defense and have various modulatory activities in other immune and non-immune functions [1]. There are very few body compartments, however, in which mast cells are absent. ...
... Secondary and idiopathic definitions were united by nonclonal proliferations of mast cell activation, but was there sufficient to clearly differentiate the two despite a defined putative causation for the former? This rational and important approach towards the understanding of NC-MCAD must nevertheless be placed in the more contemporary reality as expressed by Hamilton-there are no yet reliable subclassifications of NC-MCAD, and there is even less consensus with the diagnostic criteria for NC-MCAD [1]. The call to collaboration in this regard and a next-order proposal to exact more science for the creation of diagnostic algorithms point towards some well-needed consistencies [42,43]. ...
Article
Full-text available
Non-clonal mast cell activation disorder (syndrome) (NC-MCAD) and autoimmune/inflammatory syndrome induced by adjuvants (ASIA) are complex syndromic and spectral clinical entities which have contemporaneously garnered considerable attention and rightfully so. NC-MCAD presents with a predominantly allergic profile, and causative clinical variables may or may not be identified. Manifest NC-MCAD illnesses can be complex and involve several organ systems. Such diversity may be in part explained by the ubiquity and plasticity of the mast cell. ASIA, due to its broad definition, continues to expand as a clinical entity, especially with the greater recognition of what might constitute adjuvancy. Such diversity has the potential to overly stretch the boundaries for scientific investigation. For both NC-MCAD and ASIA, the inciting molecular mechanisms require elucidation. Future research would benefit from greater precision for clinical diagnosis and risk factor identification, and the latter would be potentially facilitated by the discovery of reliable laboratory markers. Some patients with ASIA may present with clinical features that may be identified as NC-MCAD. This review examines the potential spectral nexus of NC-MCAD and ASIA and considers the role of the mast cell in such a possible interface.
... Mast cell activation syndrome (MCAS) is a common disorder of uncontrolled mast cell (MC) activation with multi-systemic inflammatory and allergic symptoms [1][2][3]. In a study in Germans, the prevalence of MCAS was estimated to be 17% of the population [4]. ...
... Owing to the clinical nature of this unfunded research project not all subjects had uniform testing (e.g. insurance did not cover and allow for MC mediator testing in 25% of the subjects). Another criticism might include the fact that these patients were diagnosed with MCAS in the setting of the evaluation for refractory intestinal symptoms, yet this scenario is extremely common for the undiagnosed MCAS patient [1][2][3][4][5][6][7]29]. Although the specific MC mediators measured in our MCAS subjects did not correlate with a risk for SIBO, this is not unexpected. ...
... Mast cell activation disorder (MCAD) is a family of immunological disorders in which mast cells degranulate, i.e., release their granules containing histamine and other substances, unusually easily (Hamilton, 2018). Mast cells are derived from multipotential hematopoietic stem cells (MHSCs) which then differentiate into mast cell progenitors (MCPs). ...
... However, the MCAS-hEDS association has not been robustly supported with clinical evidence partly due to changing criteria of hEDS classification (Kohn and Chang, 2020). MCAS causes allergic symptoms when a patient is exposed to 'a trigger' (Hamilton, 2018). The antigen within the trigger promotes immunoglobulin E production. ...
Article
Full-text available
Ehlers-Danlos Syndromes (EDSs) are a group of connective tissue disorders, characterized by skin stretchability, joint hypermobility and instability. Mechanically, various tissues from EDS patients exhibit lowered elastic modulus and lowered ultimate strength. This change in mechanics has been associated with EDS symptoms. However, recent evidence points toward a possibility that the comorbidities of EDS could be also associated with reduced tissue stiffness. In this review, we focus on mast cell activation syndrome and impaired wound healing, comorbidities associated with the classical type (cEDS) and the hypermobile type (hEDS), respectively, and discuss potential mechanobiological pathways involved in the comorbidities.
... Unlike clonal activation (e.g., in mastocytosis), mast cell activation syndrome is characterized by normal basophils and mast cells, which may increase in response to a trigger ("reactive hyperplasia"). The triggers can be IgE complexes with various ligands, including allergen, drugs (nonsteroidal anti-inflammatory drugs, vancomycin), complement components, aberrant IFNγ, and infectious agents acting on toll-like receptors [86,87]. ...
Article
Full-text available
Histamine is a natural amine derived from L-histidine. Although it seems that our knowledge about this molecule is wide and diverse, the importance of histamine in many regulatory processes is still enigmatic. The interplay between different types of histamine receptors and the compound may cause ample effects, including histamine intoxication and so-called histamine intolerance or non-allergic food intolerance, leading to disturbances in immune regulation, manifestation of gastroenterological symptoms, and neurological diseases. Most cases of clinical manifestations of histamine intolerance are non-specific due to tissue-specific distribution of different histamine receptors and the lack of reproducible and reliable diagnostic markers. The diagnosis of histamine intolerance is fraught with difficulties, in addition to challenges related to the selection of a proper treatment strategy, the regular course of recovery, and reduced amelioration of chronic symptoms due to inappropriate treatment prescription. Here, we reviewed a history of histamine uptake starting from the current knowledge about its degradation and the prevalence of histamine precursors in daily food, and continuing with the receptor interactions after entering and the impacts on the immune, central nervous, and gastrointestinal systems. The purpose of this review is to build an extraordinarily specific method of histamine cycle assessment in regard to non-allergic intolerance and its possible dire consequences that can be suffered.
... Mast cell activation syndrome (MCAS) is the most common variant of mast cell activation disease (MCAD) and causes chronic inflammatory and allergic symptoms and syndromes (Hamilton 2018;Afrin et al. 2017). In a German study, the prevalence of MCAD was 17% (Molderings et al. 2013). ...
Article
Full-text available
Determine efficacy and adverse events (AEs) of hydroxyurea (HU) in mast cell activation syndrome (MCAS) patients who were refractory to standard medical therapy. An electronic chart review was performed to find MCAS patients who received HU in a MCAS medical practice. Diagnosis of MCAS was established on the basis of mast cell (MC) activation symptoms in ≥ 5 systems plus ≥ 1 abnormal MC mediators and/or ≥ 20 MC/high power field on duodenal biopsies. Medicines not providing significant clinical improvement prior to HU were tabulated. The following symptoms were evaluated by patients on a 0–10 scale prior to and at the study conclusion: bone pain, abdominal pain, diarrhea, bloating, and nausea. Safety labs were obtained on a regular basis. Twenty out of three hundred ten (8.4%) MCAS patients received HU. Patients included 22 females, average age 42.4 years. Dysautonomia was present in 60%. An average of 10.6 (SD 1.7, range 8–13) medications were used prior to adding HU to various concomitant medications. Average dose of HU was 634 mg. In 20 patients who continued therapy for ≥ 2 months, there was statistically significant reduction of bone pain, abdominal pain, diarrhea, bloating, and nausea. Fourteen patients noted prolonged success with therapy. Six patients stopped HU within 6 weeks owing to AEs. Four patients treated ≥ 2 months had AEs and 2 led to HU cessation. All AEs were reversible. Refractory MCAS patients showed clear significant improvement in bone pain and gastrointestinal symptoms on HU. Systematic monitoring was effective in preventing the occurrence of severe HU-induced adverse events.
... The clinical symptomatology of HI, although diverse and hence confusing, has a remarkable similarity to non-clonal mast cell activation syndrome (NC-MCAS) which is gathering increasing attention, but especially in North America. [4][5][6][7] Whereas patients with severe NC-MCAS are a more definitive subset, the majority of patients with the NC-MCAS diagnosis are difficult to understand, and the entity is considerably heterogeneous from a clinical perspective. 8 NC-MCAS can be relapsing or indolent, but not as severe as more aggressive forms of mastocytosis. ...
Article
Systemic mastocytosis results from proliferation and activation of an abnormal mast cell clone. It is a heterogeneous disorder with clinical manifestations ranging from skin lesions alone to aggressive multi-organ infiltration and decreased survival. Given these varied manifestations, diagnosis can be difficult. We describe the case of a woman who presented with rash and diarrhoea and had a history of anaphylactic reactions. Over a protracted period, the patient’s symptoms were investigated by a number of specialties including gastroenterology, dermatology, immunology and haematology. Morphological, immunohistochemical and molecular analysis of bone marrow samples ultimately led to a diagnosis of systemic mastocytosis. Management with leukotriene and histamine antagonists resulted in significant improvement in symptoms and quality of life. The case serves to highlight the protean manifestations of systemic mastocytosis, the tests available to diagnose it and the agents available to treat it.
Article
Full-text available
Objectives: Idiopathic mast cell disorders, a recently defined and recognised syndrome in clinical practice, are similar to the previously termed non-clonal mast cell disorder. Patients with idiopathic mast cell activation syndrome (MCAS) suffer all the classical signs of mast cell activation but do not have evidence of mast cell clonality. Furthermore, treatment of these patients can be limited and burdensome in those with refractory symptoms. Methods: Here, we describe treatment of a patient with idiopathic MCAS utilising a single monthly subcutaneous injection of omalizumab and review the current classification and therapeutic options for clonal and non-clonal MCAS. Results: Low-dose omalizumab treatment has successfully led to a 5-year, sustained clinical response, controlled debilitating symptoms of mast cell activation and allowed for reintroduction and long-term maintenance of bee venom subcutaneous immunotherapy. Conclusion: Low-dose omalizumab of 150 mg monthly should be considered for maintenance management of patients with idiopathic MCAS for its cost and quality-of-life benefits.
Article
Idiopathic anaphylaxis is a condition caused by paroxysmal episodes of sudden-onset multiorgan involvement variably including laryngeal edema, urticaria, bronchoconstriction, dyspnea, hypoxia, abdominal pain, nausea, vomiting, diarrhea, and hypotension. Rarely, the episodes can lead to cardiovascular collapse and death in the absence of a clear trigger, especially in the presence of other cardiovascular comorbidities. Elevated mast cell mediators such as tryptase and histamine have been reported during episodes, and mast cells are considered the primary cells responsible for driving anaphylaxis in humans. Basophils also secrete histamine and LTC4 when activated and theoretically can contribute to symptoms. As our understanding of mast cell disorders continue to grow, the classification for these disorders evolves. The purpose of this article was 2-fold: to review the epidemiology, clinical manifestations, and diagnosis of idiopathic anaphylaxis and to discuss the classification of idiopathic anaphylaxis within the broader context of mast cell activation disorders.
Article
Mast cells are the central cells in the pathogenesis of many conditions that are associated with mediator release. New information is emerging about the role of mast cells in a number of conditions. This review summarises current knowledge on the topic. Some conditions such as mastocytosis have a confirmed genetic background; however, the genetic background of hereditary α-tryptasemia has only recently been described, and routine testing is yet to be set up in genetic laboratories. It is still unknown whether there is a genetic predisposition leading to the development of mast cell activation syndrome as well as urticaria and angioedema, and research is under way in this direction. The best known mediator contained in mast cells is histamine 2-(4-imidazolyl)-ethylamine, but it is not the only one. The effects of other mediators are significant in mast cell-mediated conditions, and can be future therapeutic targets. Diamine oxidase deficiency is responsible for digestive issues in some people, and although not directly linked with mast cell pathology, it falls under this umbrella due to symptoms related to the effects of externally consumed histamine. Mast cell-mediated diseases are usually defined through the detection of an elevation of mast cell mediators, response to antihistamines, mast cell stabilisers, and, in some cases, anti-IgE treatment when indicated. They comprise of mastocytosis, hereditary α-tryptasemia, mast cell activation syndrome, urticaria, and angioedema.
Chapter
Anaphylaxis often includes cutaneous, respiratory, gastrointestinal, and cardiovascular manifestations. It often occurs after ingestion or injection of an exogenous substance. There are many conditions which can mimic the symptoms and situational setting of anaphylaxis and thereby be mistaken for anaphylaxis. The main masqueraders of anaphylaxis are urticaria/angioedema, flushing syndromes, asthma, vocal cord dysfunction, aspiration, other forms of transient loss of consciousness including vasovagal syncope, seizures and strokes, other forms of shock, gastrointestinal and postprandial syndromes, and non-organic causes.
Chapter
Primary eosinophilic, mastocytic, and histiocytic disorders of the gastrointestinal (GI) tract comprise a spectrum of poorly understood and rare entities. Despite their extremely low prevalence in the general population, these diagnoses are commonly considered in the differential diagnosis when evaluating GI biopsies in daily practice. Surgical pathologists will often encounter biopsies with a prominence of one or more of these cell types. The question that then arises is whether the patient actually has one of these rare disorders or the findings are a secondary manifestation of mucosal injury due to an unrelated etiology. The aim of this chapter is to provide a pragmatic approach to interpretation of GI biopsies when faced with an inflammatory process with prominence of these cell types and to highlight our evolving understanding of these disorders that affects clinical practice.
Article
Hypermobile Ehlers–Danlos syndrome (hEDS) is the most common type of EDS, yet has remained steadfastly inscrutable vis‐à‐vis efforts to identify its cellular, molecular, and pathophysiologic roots. Once thought to principally affect just connective tissues, hEDS is now appreciated to be a multisystem disease of great heterogeneity with many symptoms and findings difficult to attribute solely to disordered connective tissue development. In the last decade, there has been growth in the appreciation of the existence of a wide range of disorders of chronic inappropriate mast cell (MC) activation (a large heterogeneous pool of MC activation syndromes [MCAS]) distinguishable from other MC disorders such as rare neoplastic mastocytosis. Via chronic aberrant release of the MC's vast repertoire of potent mediators, MCAS can drive extraordinary arrays of pathologies, most commonly of inflammatory, allergic, and dystrophic natures. Although hEDS is seen in only a minority of MCAS cases, limited studies have identified an association between hEDS and MCAS, fueling speculation that certain variants of MCAS may drive hEDS. No laboratory studies probing cellular or molecular linkages between hEDS and MCAS have been conducted yet, and research efforts to identify the genetic roots of hEDS should also consider those of MCAS.
Article
Full-text available
Background Mast cells are closely associated with epithelium, serving as sentinels responsible for the recognition of tissue injury and coordination of the initial inflammatory response. Upon detection of the injured cell content, mast cells then tailor the release of preformed and newly produced chemical mediators to the detected challenge, via an array of pathogen receptors. In addition to immunoglobulin E receptor-triggered mast cell activation, commonly referred to as allergic or atopic disorders, non-immunoglobulin E receptor mediated mast cell activation follows engagement of toll-like receptors, immunoglobulin G receptors, and complement receptors. Upon containment of the extrinsic challenge, acute inflammation is downregulated, and repair of the injured tissue ensues. The mast cell compartments must return to a baseline steady state to remain tolerant towards self-antigens and harmless entities, including environmental conditions, to prevent unnecessary immune activation and chronic hypersensitivity disorders. Over the past 50 years, an increasing number of patients are experiencing episodes of aberrant mast cell activation, not associated with allergen-specific mast cell disease or systemic mastocytosis. This led to proposed diagnostic criteria of mast cell activation syndrome. Mast cell activation syndrome is a heterogeneous disorder, defined by a combination of (1) recurrent symptoms typical of mast cell activation, (2) an increase of validated mast cell derived mediators, and (3) response to treatment with mast cell stabilizing or mast cell mediator-targeted therapies. Onset of mast cell activation syndrome ostensibly reflects the loss of tolerance in the mast cell compartment to nonthreatening entities and nonhazardous environmental conditions. The etiology of chronic mast cell dysregulation and associated intolerance to self-antigens or harmless entities is not well understood, but a growing number of studies point to exposure of the epithelial borders, which leads to inappropriate or excessive mast cell activation or impaired resolution of acute inflammation following neutralization of the identified pathogen. Case presentation Here we present a case of adult onset mast cell activation syndrome following scombroid poisoning. Scombroid toxicity is usually a self-limited illness, but there are individuals who have been shown to have severe symptoms or persistent illness following histamine fish poisoning. We describe a 74-year-old Caucasian woman, with a history of drug-induced urticaria, who developed a constellation of hypersensitivity illnesses consistent with the diagnosis of mast cell activation syndrome after ingestion of tainted fish. Conclusion Mast cell activation disease causes problems of increased complexity in children and adults. The increased prevalence and severity of mast cell activation disease has been attributed to dramatic changes in our lifestyles and modern living environments. These changes likely impact the integrity of the epithelial barriers, leading to loss of tolerance in the mast cell compartment. Here, we present a case of a nonatopic, 74-year-old female who developed mast cell activation disease after exposure to a potent environmental toxin. Mast cell activation disease commonly involves several organ systems, with patients often referred to a succession of different specialists. This results in delayed diagnosis and suboptimal care. Instead, early recognition of mast cell activation disease would lead to better outcomes. We review the literature, describing the diagnostic criteria for mast cell activation disorders that can improve recognition of this multiorgan system syndrome. Further research is needed into the interaction of epithelial barrier disruption and the dysregulation of the immune system.
Article
Our current recommendations for diagnosing and treating primary mast cell (MC) activation syndrome make use of the latest studies and consensus guidelines for clinically recognizing systemic anaphylaxis in real time, regardless of whether allergen-triggered or other pathways are involved; our current understanding of the biomarkers secreted by activated MCs that best discriminate this disorder from other conditions; and the therapeutic drugs that might selectively affect those mediators or MCs themselves. Finding familial or somatic mutations of genes that cause MCs to be hyperactivatable would extend our diagnostic tools and potentially indicate new therapeutic interventions, targeting either the mutated gene product or the associated molecular pathway. In conclusion, we trust that the clinical, laboratory, and therapeutic criteria for primary MC activation syndromes described herein will provide clinicians with practical criteria of sufficient sensitivity and specificity to diagnose most cases without overdiagnosing the disorder in patients who likely have other conditions.
Article
Full-text available
Elevated basal serum tryptase levels are present in 4-6% of the general population, but the cause and relevance of such increases are unknown. Previously, we described subjects with dominantly inherited elevated basal serum tryptase levels associated with multisystem complaints including cutaneous flushing and pruritus, dysautonomia, functional gastrointestinal symptoms, chronic pain, and connective tissue abnormalities, including joint hypermobility. Here we report the identification of germline duplications and triplications in the TPSAB1 gene encoding α-tryptase that segregate with inherited increases in basal serum tryptase levels in 35 families presenting with associated multisystem complaints. Individuals harboring alleles encoding three copies of α-tryptase had higher basal serum levels of tryptase and were more symptomatic than those with alleles encoding two copies, suggesting a gene-dose effect. Further, we found in two additional cohorts (172 individuals) that elevated basal serum tryptase levels were exclusively associated with duplication of α-tryptase-encoding sequence in TPSAB1, and affected individuals reported symptom complexes seen in our initial familial cohort. Thus, our findings link duplications in TPSAB1 with irritable bowel syndrome, cutaneous complaints, connective tissue abnormalities, and dysautonomia.
Article
Full-text available
IgE antibodies and mast cells play critical roles in the establishment of allergic responses to food antigens. Curcumin, the active ingredient of the curry spice turmeric, has anti-inflammatory properties, and thus may have the capacity to regulate Th2 cells and mucosal mast cell function during allergic responses. We assessed whether curcumin ingestion during oral allergen exposure can modulate the development of food allergy using a murine model of ovalbumin (OVA)-induced intestinal anaphylaxis. Herein, we demonstrate that frequent ingestion of curcumin during oral OVA exposure inhibits the development of mastocytosis and intestinal anaphylaxis in OVA-challenged allergic mice. Intragastric (i.g.) exposure to OVA in sensitized BALB/c mice induced a robust IgE-mediated response accompanied by enhanced OVA-IgE levels, intestinal mastocytosis, elevated serum mMCP-1, and acute diarrhea. In contrast, mice exposed to oral curcumin throughout the experimental regimen appeared to be normal and did not exhibit intense allergic diarrhea or a significant enhancement of OVA-IgE and intestinal mast cell expansion and activation. Furthermore, allergic diarrhea, mast cell activation and expansion, and Th2 responses were also suppressed in mice exposed to curcumin during the OVA-challenge phase alone, despite the presence of elevated levels of OVA-IgE, suggesting that curcumin may have a direct suppressive effect on intestinal mast cell activation and reverse food allergy symptoms in allergen-sensitized individuals. This was confirmed by observations that curcumin attenuated the expansion of both adoptively transferred bone marrow-derived mast cells (BMMCs), and inhibited their survival and activation during cell culture. Finally, the suppression of intestinal anaphylaxis by curcumin was directly linked with the inhibition of NF-κB activation in curcumin-treated allergic mice, and curcumin inhibited the phosphorylation of the p65 subunit of NF-κB in BMMCs. In summary, our data demonstrates a protective role for curcumin during allergic responses to food antigens, suggesting that frequent ingestion of this spice may modulate the outcome of disease in susceptible individuals.
Article
Full-text available
β-Lactam antibiotics (mainly amoxicillin, AX) are the drugs that most frequently induce systemic drug allergy reactions. We attempted to identify the risk factors associated with systemic reactions to AX. All patients who were referred to our department for suspected hypersensitivity reactions to AX over a 6-month period were evaluated for anti-AX immunoglobulin E (IgE) levels and skin-test positivity for β-lactams. Age, sex, concomitant diseases, therapies, total IgE, serum tryptase levels and signs and symptoms suggesting mast cell activation syndrome (MCAS) were analyzed in relation to the severity of the reaction in accordance with the Mueller classification. Sixty-seven patients were selected: 39 with mild reactions such as cutaneous or gastrointestinal symptoms (grades I and II) and 28 with severe systemic reactions (grades III and IV). Anti-AX IgE levels and total IgE were significantly higher in severe reactions than in mild ones (p < 0.00005, p = 0.0037). Treatment with histamine-2 receptor antagonists (anti-H2) was significantly related to severe reactions (p = 0.007). No significant correlations were found between the severity of the reactions and dyslipidemia or levels of angiotensin-converting enzyme and tryptase. Anti-AX IgE levels were the most significant immunological parameter distinguishing patients who presented with severe reactions to AX and those with mild reactions. Higher values of total IgE, the use of gastroprotective drugs and signs and symptoms suggesting an MCAS significantly increased the odds ratio of having a severe reaction. The risk of serious adverse reactions to AX increased in older patients and in males, but this trend was not significant. © 2015 S. Karger AG, Basel.
Article
Full-text available
Diagnosis of mast cell activation disease (MCAD), i.e. systemic mastocytosis (SM) and idiopathic systemic mast cell activation syndrome (MCAS), usually requires demonstration of increased mast cell (MC) mediator release. Since only a few MC mediators are currently established as biomarkers of MCAD, the sensitivity of plasma heparin level (pHL) as an indicator of increased MC activation was compared with that of serum tryptase, chromogranin A and urinary N-methylhistamine levels in 257 MCAD patients. Basal pHL had a sensitivity of 41% in MCAS patients and 27% in SM patients. Non-pharmacologic stimulation of MC degranulation by obstruction of venous flow for 10 minutes increased the sensitivity of pHL in MCAS patients to 59% and in SM patients to 47%. In MCAS patients tryptase, chromogranin A, and N-methylhistamine levels exhibited low sensitivities (10%, 12%, and 22%, respectively), whereas sensitivities for SM were higher (73%, 63%, and 43%, respectively). Taken together, these data suggest pHL appears more sensitive than the other mediators for detecting systemic MC activity in patients with MCAS. The simple, brief venous occlusion test appears to be a useful indicator of the presence of pathologically irritable MCs, at least in the obstructed compartment of the body.
Article
Full-text available
Background: Mast cells (MCs) are hematopoietic cells that mature in tissues and are involved in allergy, immunity, and inflammation by secreting multiple mediators. The natural flavone luteolin has anti-inflammatory actions and inhibits human mast cells (MCs). Objective: We sought to investigate the ability of luteolin and its novel structural analog 3',4',5,7-tetramethoxyluteolin (methlut) to inhibit human MC mediator expression and release in vitro and in vivo. Methods: Human LAD2 cells and umbilical primary human cord blood-derived cultured mast cells were stimulated with substance P (SP) or IgE/anti-IgE with or without preincubation with luteolin, methlut, or cromolyn (1-100 μmol/L) for 2 or 24 hours, after which mediator secretion was measured. The effect of the compounds on MC intracellular calcium levels and nuclear factor κB activation was also investigated. Pretreatment with methlut was also studied in mice passively sensitized with dinitrophenol-human serum albumin and challenged intradermally. Results: Methlut is a more potent inhibitor than luteolin or cromolyn for β-hexosaminidase and histamine secretion from LAD2 cells stimulated by either SP or IgE/anti-IgE, but only methlut and luteolin significantly inhibit preformed TNF secretion. Methlut is also a more potent inhibitor than luteolin of de novo-synthesized TNF from LAD2 cells and of CCL2 from human cord blood-derived cultured MCs. This mechanism of action for methlut might be due to its ability to inhibit intracellular calcium level increases, as well as nuclear factor κB induction, at both the transcriptional and translational levels in LAD2 cells stimulated by SP without affecting cell viability. Intraperitoneal treatment with methlut significantly decreases skin vascular permeability of Evans blue dye in mice passively sensitized to dinitrophenol-human serum albumin and challenged intradermally. Conclusion: Methlut is a promising MC inhibitor for the treatment of allergic and inflammatory conditions.
Article
Full-text available
Counting mast cells in gastrointestinal (GI) mucosal biopsies is becoming an increasingly common practice. The primary reason for this exercise is to evaluate for possible involvement by systemic mastocytosis (SM). However, the features of mastocytosis in GI biopsies are not well described. In addition, recent studies have suggested that increased mast cells may be involved in the pathogenesis of some cases of diarrhea-predominant irritable bowel syndrome (IBS); the term "mastocytic enterocolitis" has been proposed for such cases. As the baseline mast cell density in colonic biopsies from normal patients has not been established in large cohorts, there is no widely accepted threshold for what constitutes increased mucosal mast cells. The aims of this study were (1) to determine the utility of GI biopsies for the diagnosis of SM, (2) to characterize the clinical, histologic, and immunohistochemical features of mastocytosis in the GI tract, (3) to determine mast cell density in normal colonic mucosa from a large cohort of asymptomatic patients, and (4) to compare these findings with those from patients with diarrhea-predominant IBS. Twenty-four patients with SM involving the GI tract, 100 asymptomatic patients, and 100 patients with IBS (the latter 2 groups with histologically normal colonic biopsies) were included. For the mastocytosis group, 107 biopsies (70 involved by mastocytosis; 67 mucosal, 3 liver) from 20 women and 4 men were evaluated (median age 59 y). The most commonly involved site was the colon (19 patients, 95%), followed by ileum (86%), duodenum (80%), and stomach (54%). In 16 cases (67%), the first diagnosis of SM was made on the basis of GI biopsies. Seventeen patients had documented cutaneous mastocytosis. Fifteen of 17 patients who underwent bone marrow biopsy had marrow involvement by SM. Eighteen patients had indolent disease, and 6 had aggressive disease (including all 3 with liver involvement). The most common GI symptom was diarrhea, followed by abdominal pain, nausea, weight loss, bloating, vomiting, or reflux. Liver disease presented with hepatomegaly and ascites. Endoscopic abnormalities (observed in 62%) included erythema, granularity, and nodules. Histologically, involved biopsies were characterized by infiltrates of ovoid to spindle-shaped mast cells in aggregates or sheets in the lamina propria, sometimes forming a confluent band underneath the surface epithelium; 25% of biopsies had only focal involvement (single aggregate). Prominent eosinophils were seen in 44% of involved colonic/ileal biopsies and 16% of duodenal biopsies. Mast cells were highlighted by diffuse membranous staining for KIT and CD25. In the nonmastocytosis groups, all biopsies contained singly dispersed mast cells with no aggregates. The mean highest mast cell counts (in a single high-power field) for asymptomatic patients and IBS patients were 26 (range, 11 to 55) and 30 (range, 13 to 59), respectively. In summary, GI (especially colonic) biopsies can establish a diagnosis of SM in patients with GI symptoms. GI involvement is usually subtle and is often associated with prominent eosinophils, which may obscure the mast cell infiltrate. KIT and CD25 are invaluable markers for the diagnosis. Mast cell density in colonic mucosa from asymptomatic patients is highly variable. Although patients with diarrhea-predominant IBS on average have mildly increased mast cells, the overlap in range with that of control patients is too great for this difference to be clinically useful. These findings argue against the utility of counting GI mucosal mast cell in patients with chronic diarrhea.
Article
Full-text available
Mast cells (MCs) are active participants in blood coagulation and innate and acquired immunity. This review focuses on the development of mouse and human MCs, as well as the involvement of their granule serine proteases in inflammation and the connective tissue remodeling that occurs during the different phases of the healing process of wounded skin and other organs. The accumulated data suggest that MCs, their tryptases, and their chymases play important roles in tissue repair. While MCs initially promote healing, they can be detrimental if they are chronically stimulated or if too many MCs become activated at the same time. The possibility that MCs and their granule serine proteases contribute to the formation of keloid and hypertrophic scars makes them potential targets for therapeutic intervention in the repair of damaged skin.
Article
Full-text available
Background Mast cell diseases include mastocytosis and mast cell activation syndromes, some of which have been shown to involve clonal defects in mast cells that result in abnormal cellular proliferation or activation. Numerous clinical studies of mastocytosis have been published, but no population-based comprehensive surveys of patients in the United States have been identified. Few mast cell disease specialty centers exist in the United States, and awareness of these mast cell disorders is limited among nonspecialists. Accordingly, information concerning the experiences of the overall estimated population of these patients has been lacking. Objective To identify the experiences and perceptions of patients with mastocytosis, mast cell activation syndromes, and related disorders, The Mastocytosis Society (TMS), a US based patient advocacy, research, and education organization, conducted a survey of its members and other people known or suspected to be part of this patient population. Methods A Web-based survey was publicized through clinics that treat these patients and through TMS's newsletter, Web site, and online blogs. Both online and paper copies of the questionnaire were provided, together with required statements of consent. Results The first results are presented for 420 patients. These results include demographics, diagnoses, symptoms, allergies, provoking factors of mast cell symptoms, and disease impact. Conclusion Patients with mastocytosis and mast cell activation syndromes have provided clinical specialists, collaborators, and other patients with information to enable them to explore and deepen their understanding of the experiences and perceptions of people coping with these disorders.
Article
Full-text available
Mast cells are immune cells critical in the pathogenesis of allergic, but also inflammatory and autoimmune diseases through release of many pro-inflammatory cytokines such as IL-8 and TNF. Contact dermatitis and photosensitivity are skin conditions that involve non-immune triggers such as substance P (SP), and do not respond to conventional treatment. Inhibition of mast cell cytokine release could be effective therapy for such diseases. Unfortunately, disodium cromoglycate (cromolyn), the only compound marketed as a mast cell "stabilizer", is not particularly effective in blocking human mast cells. Instead, flavonoids are potent anti-oxidant and anti-inflammatory compounds with mast cell inhibitory actions. Here, we first compared the flavonoid quercetin (Que) and cromolyn on cultured human mast cells. Que and cromolyn (100 µM) can effectively inhibit secretion of histamine and PGD(2). Que and cromolyn also inhibit histamine, leukotrienes and PGD(2) from primary human cord blood-derived cultured mast cells (hCBMCs) stimulated by IgE/Anti-IgE. However, Que is more effective than cromolyn in inhibiting IL-8 and TNF release from LAD2 mast cells stimulated by SP. Moreover, Que reduces IL-6 release from hCBMCs in a dose-dependent manner. Que inhibits cytosolic calcium level increase and NF-kappa B activation. Interestingly, Que is effective prophylactically, while cromolyn must be added together with the trigger or it rapidly loses its effect. In two pilot, open-label, clinical trials, Que significantly decreased contact dermatitis and photosensitivity, skin conditions that do not respond to conventional treatment. In summary, Que is a promising candidate as an effective mast cell inhibitor for allergic and inflammatory diseases, especially in formulations that permit more sufficient oral absorption.
Article
Full-text available
Activation of tissue mast cells (MCs) and their abnormal growth and accumulation in various organs are typically found in primary MC disorders also referred to as mastocytosis. However, increasing numbers of patients are now being informed that their clinical findings are due to MC activation (MCA) that is neither associated with mastocytosis nor with a defined allergic or inflammatory reaction. In other patients with MCA, MCs appear to be clonal cells, but criteria for diagnosing mastocytosis are not met. A working conference was organized in 2010 with the aim to define criteria for diagnosing MCA and related disorders, and to propose a global unifying classification of all MC disorders and pathologic MC reactions. This classification includes three types of 'MCA syndromes' (MCASs), namely primary MCAS, secondary MCAS and idiopathic MCAS. MCA is now defined by robust and generally applicable criteria, including (1) typical clinical symptoms, (2) a substantial transient increase in serum total tryptase level or an increase in other MC-derived mediators, such as histamine or prostaglandin D(2), or their urinary metabolites, and (3) a response of clinical symptoms to agents that attenuate the production or activities of MC mediators. These criteria should assist in the identification and diagnosis of patients with MCAS, and in avoiding misdiagnoses or overinterpretation of clinical symptoms in daily practice. Moreover, the MCAS concept should stimulate research in order to identify and exploit new molecular mechanisms and therapeutic targets.
Article
Full-text available
Systemic mast cell activation syndrome is a mast cell disorder characterized by an unregulated increased activation of mast cells leading to a pathologically enhanced release of mediators. Mutations in tyrosine kinase kit which crucially determines mast cell activity have been suggested as a necessary condition for the development of a clinically symptomatic mast cell disease. At the level of mRNA in mast cell progenitor cells of 20 patients with systemic mast cell activation syndrome and of 20 gender- and age-matched healthy volunteers, the tyrosine kinase kit was investigated for genetic alterations by means of RT-PCR and direct sequencing of the amplificates. In mast cells of 13 out of these 20 patients, multiple predominantly novel potential functionally activating point mutations or complex alterations of the mRNA sequence encoding the tyrosine kinase kit were detected. In contrast, in 19 of the 20 healthy subjects, no functionally relevant alterations of c-kit transcripts were detected. The present findings support the idea that the systemic mast cell activation syndrome is a clonal disease most commonly associated with variable activating mutations in the tyrosine kinase kit.
Article
Full-text available
Mastocytosis is a rare disease consisting of a group of disorders characterized by a pathologic increase in the number of mast cells in one or more organ system. Treatment is symptomatic. Oral sodium cromoglicate (SCG) is the only treatment licensed for the treatment of mastocytosis. In this case we report how in a mastocytosis patient being treated with H1 and H2 antihistamines, and oral sodium cromoglicate, the addition of inhaled sodium cromoglicate resulted in further improvement. This is the first report of this use of the drug in this disease. The subject is a Caucasian woman aged 40 years. Symptoms of mastocytosis began when she was aged 13 years, but the diagnosis was not made until after her first pregnancy aged 33 years. Symptoms improved with H1 and H2 antihistamines, and oral sodium cromoglicate, but it required the addition of inhaled sodium cromoglicate to produce further improvement, specifically in the symptoms of bone pain, fatigue and headache. Doses of oral sodium cromoglicate had to be increased if challenged with a food to which the subject was sensitive. Doses of inhaled sodium cromoglicate had to be increased during the menstrual period. Patients suffering from the rare disease of mastocytosis have symptoms affecting many body systems. Symptoms result from the release of inflammatory mediators from mast cells. Sodium cromoglicate, a drug that reduces the release of mediators from mast cells, is effective in controlling gastrointestinal symptoms, but less effective in those affecting other body systems. In this case report we have shown that the addition of inhaled sodium cromoglicate controls the symptoms of bone pain, fatigue and headache and also that the doses have to be increased during the menstrual period.
Article
Full-text available
Increased numbers of mast cells and mast cell activation in distal gut segments are associated with symptom onset and severity in irritable bowel syndrome (IBS). Although upper gut symptoms are common, mast cells have not been thoroughly evaluated in proximal gut in IBS patients. Jejunal biopsies obtained by Watson's capsule, aspiration of intestinal fluid and one blood sample were obtained in 20 diarrhoea-predominant patients with IBS (D-IBS) and 14 healthy volunteers (H). Psychological stress (Holmes-Rahe Scale) and depression (Beck's Depression Inventory) were evaluated at baseline and food and respiratory allergy excluded. Biopsies were processed for H&E staining and microscopic inflammation assessed by counting intraepithelial lymphocytes. Mast cells in lamina propria were counted by immunohistochemistry with CD117 (c-kit). Tryptase concentration was measured in intestinal fluid and serum. D-IBS patients showed higher psychological stress than healthy volunteers (D-IBS: 203 (SD 114) v H: 112 (SD 99); p = 0.019). Immunohistochemical staining of jejunal mucosa revealed mild increase in intraepithelial CD3+ cells in D-IBS patients (D-IBS: 15.3 (SD 5.5; 95% CI 12.7 to 17.9) v H: 10.3 (SD 3.9; 95% CI 8.0 to 12.5); p = 0.006). Moreover, D-IBS patients showed marked increase in mast cells numbers (D-IBS: 34 (SD 9.3); H: 15.3 (SD 4.4) mast cells/hpf; p<0.001) and higher tryptase concentration in jejunal fluid (D-IBS: 0.45 (SD 0.38); H: 0.09 (SD 0.10) microg/l; p = 0.005). Upper gut symptoms were not associated with gender, mast cell counts, jejunal tryptase or basal stress. This jejunal mucosal inflammatory profile may help identify diarrhoea-predominant IBS, a stress-related disorder.
Article
Background: Patients with systemic mastocytosis (SM) may suffer from mast cell (MC) mediator-related symptoms insufficiently controlled by conventional therapy. Omalizumab is an established treatment in other MC-driven diseases, but experiences in SM are limited. Objective: To assess the efficacy and safety of omalizumab in SM. Methods: In our patient cohort we evaluated all SM patients treated with omalizumab. A physician global assessment of type and severity of symptoms was performed at baseline, at 3 and 6 months and at latest follow-up. Quality-of-life was assessed by visual analogue scale. S-tryptase and KIT D816V allele burden were monitored. Results: A total of 14 adult SM patients (10 ISM, 2 BMM, 1 SSM and 1 ASM-AHN) received omalizumab with a median duration of 17 months (range: 1-73 months). One patient was excluded due to concomitant cytoreductive therapy. In the remaining 13 patients we observed a significant reduction of symptoms, with complete symptom control in five (38.5%), major response in three (23.1%) and a partial response in three (23.1%) patients, whereas two patients (15.4%) withdrew due to subjective side-effects at first dose. The treatment was most effective for recurrent anaphylaxis and skin symptoms, less for gastrointestinal, musculoskeletal and neuropsychiatric symptoms. Patient-reported quality-of-life showed significant improvement. No significant changes in s-tryptase/KIT D816V allele burden were observed. No severe adverse events were recorded. Conclusions: Omalizumab appears to be a promising treatment option in SM, effectively preventing anaphylaxis and improving chronic MC mediator-related symptoms, insufficiently controlled by conventional therapy. Controlled studies are needed to substantiate findings. This article is protected by copyright. All rights reserved.
Article
Mast cells (MC) are hemopoietically-derived tissue immune cells that are ubiquitous in the body, including neuroendocrine organs such as the hypothalamus, pineal, pituitary, ovaries, pancreas and uterus where their action is not well understood. Mast cells have historically been associated with allergies because of their rich content of histamine and tryptase, but more recently with regulation of immunity and inflammation due their synthesis and release of numerous cytokines and chemokines. Mast cells are located perivascularly and express numerous receptors for diverse ligands such as allergens, pathogens, neurotransmitters, neuropeptides and hormones including acetylcholine, calcitonin gene-related peptide (CGRP), corticosteroids, corticotropin-releasing hormone (CRH), β-endorphin, epinephrine, 17β-estradiol, gonadotrophins, hemokinin-A (HKA), leptin, melatonin, neurotensin (NT), parathyroid hormone (PTH), substance P (SP) and vasoactive instestinal peptide (VIP). Moreover, MC can synthesize and release most of their neurohormonal triggers, including adrenocorticotropin hormone (ACTH), CRH, endorphins, HKA, leptin, melatonin, NT, SP and VIP. Animal experiments have shown that diencephalic MC increase in number during courting in doves, while stimulation of brain and nasal MC leads to activation of the hypothalamic-pituitary-adrenal (HPA) axis. Recent evidence indicates that MC reactivity exhibits diurnal variations and it is interesting that melatonin appears to regulate MC secretion. However, the way MC change their phenotype or secrete specific molecules selectively at different pathophysiological settings still remains unknown. Mast cells developed over 500 million years ago and may have served as the original prototype neuroimmunoendocrine cell and then evolved into a master regulator of such interactions, especially since most of the known diseases involve neuroinflammation that worsens with stress. This article is protected by copyright. All rights reserved.
Article
Systemic mastocytosis is a rare heterogeneous myeloproliferative neoplasm characterized by abnormal proliferation and activation of mast cells. We describe a large multicentre series of 460 adult patients with systemic mastocytosis, with a diagnosis based on WHO 2008 criteria, in a "real-life" setting of ten Italian centers with dedicated multidisciplinary programs. Included were indolent forms with (n=255) and without (n=165) skin lesions, smouldering (n=20), aggressive (n=28), associated with other hematological diseases mastocytosis (n=21) and mast cell leukemia (n=1). This series was uniquely characterized by a substantial proportion of patients with low burden of neoplastic mast cells; notably, 38% of cases were diagnosed using only minor diagnostic criteria according to WHO 2008 classification, underlying the feasibility of early diagnosis where all diagnostic approaches are made available. This has particular clinical relevance for prevention of anaphylaxis manifestations, that were typically associated with indolent forms. In multivariate analysis, the most important features associated with shortened overall survival were disease subtype and age at diagnosis >60 years. Disease progression was correlated with mastocytosis subtype and thrombocytopenia. As many as 32% of patients with aggressive mastocytosis suffered from early evolution into acute leukemia. Overall, this study provides novel information about diagnostic approaches and current presentation of patients with SM and underlines the importance of networks and specialized centers to facilitate early diagnosis and prevent disease-associated manifestations. This article is protected by copyright. All rights reserved.
Article
Objectives: Systemic mastocytosis (SM) is a disorder characterized by the excessive accumulation of clonally derived mast cells in various tissues. When triggered, mast cells release large amounts of histamine, prostaglandins and leukotrienes. Leukotriene E4 (LTE4) is the primary stable metabolite of total cysteinyl leukotrienes. We hypothesized that secretion of LTE4 would be increased in SM and could be used alone or in combination with current urinary biomarkers to optimize screening for SM. Design and methods: LTE4 was measured by liquid chromatography followed by tandem mass spectrometry (LC-MS/MS). Analytical assay validation was performed using residual urine specimens. LTE4 results were normalized to urine creatinine for clinical use. Reference interval was established using a healthy volunteer cohort. Clinical sensitivity and specificity for SM detection were determined by measuring urinary biomarkers (LTE4, n-methyl histamine [NMH] and 11ß-prostaglandin F2α [BPG]) in a cohort of 409 patients referred to allergy specialists, 66 (16%) of which were diagnosed with SM. Results: Urinary LTE4 measurement was accurate, precise and linear across a range of 31-3020pg/mL. The 95th percentile of the reference interval population was <104pg/mg creatinine. Median urine LTE4 concentrations were significantly higher among patients with SM (97pg/mg cr. vs. 50pg/mg cr.; P<0.01). Elevated urinary LTE4 was 48% sensitive and 84% specific for SM. Clinical sensitivity was 53% for BPG (>1000ng/mL) and 71% for NMH (>200ng/mL). Incorporating all three urinary metabolites improved the SM diagnostic sensitivity to 97%, with minimal change in specificity. Conclusions: We have developed a sensitive and precise LC-MS/MS assay for quantitation of LTE4 in urine. Incorporating LTE4 into a panel including BPG and NMH provides a much-needed screening tool for a complicated disease with non-specific symptoms and invasive confirmatory testing.
Article
Anaphylaxis results from severe systemic mast cell activation. In addition to IgE-mediated and physical triggers, it may occur with a clonal mast cell disease and in an idiopathic fashion without clear provoking factors. Disorders of mast cell activation are classified into primary (clonal), secondary, and idiopathic. Mast cell activation syndrome (MCAS) is a multisystem disorder characterized by objective documentation of elevated mast cell mediators during attacks and a favorable response to antimediator therapy. It should be considered in the differential diagnosis of patients presenting with recurrent anaphylaxis without a clear cause. This article discusses the diagnosis of MCAS.
Article
This article provides an overview of recent developments concerning the physiology and pathobiology of mast cells and discusses current diagnostic and therapeutic approaches to mast-cell disorders, with an emphasis on mastocytosis.
Article
Primary mast cell activation syndromes (MCAS) are a group of disorders presenting with symptoms of mast cell mediator release. To assess the effectiveness and safety of orally-administered H1 -antihistamines in the treatment of primary MCAS compared with placebo and other pharmacologic treatments. We systematically searched five databases, three trial repositories and contacted an international panel of experts to identify published and unpublished trials, enrolling a total of 71 patients (63 adults). 36 potentially relevant studies were identified. Of these, five crossover trials met the eligibility criteria. Five of these studies were judged to be at moderate or high risk of bias. Two studies compared an H1 -antihistamine with placebo, two compared two different H1 - antihistamines, and one study compared H1 - and H2 -antihistamines with oral cromolyn sodium. Four of the five RCTs were historic (reported from 1983-93), small (enrolling 8-15 patients), and used agents and/or dosing regimens that are now uncommonly used in clinical practice (i.e. azelastine, chlorpheniramine, hydroxyzine and ketotifen). The fifth trial, which enrolled 33 adults with cutaneous and systemic mastocytosis found four weeks of treatment with the second-generation H1 -antihistamine rupatadine, compared with placebo, resulted in significant improvements in quality of life, symptom control (itching, wheals and flares, flushing, tachycardia, and headache, but not gastrointestinal symptoms), and reduction of itching and whealing after standardized skin provocation to elicit Darier's sign. There is an urgent need for large, well-designed, double-blind, placebo-controlled randomized trials investigating the effectiveness, cost-effectiveness and safety of second-generation H1 -antihistamines in treatment of primary MCAS. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Article
Mast cells are primary effectors in allergic reactions, and may have important roles in disease by secreting histamine and various inflammatory and immunomodulatory substances. Although they are classically activated by immunoglobulin (Ig)E antibodies, a unique property of mast cells is their antibody-independent responsiveness to a range of cationic substances, collectively called basic secretagogues, including inflammatory peptides and drugs associated with allergic-type reactions. The pathogenic roles of these substances have prompted a decades-long search for their receptor(s). Here we report that basic secretagogues activate mouse mast cells in vitro and in vivo through a single receptor, Mrgprb2, the orthologue of the human G-protein-coupled receptor MRGPRX2. Secretagogue-induced histamine release, inflammation and airway contraction are abolished in Mrgprb2-null mutant mice. Furthermore, we show that most classes of US Food and Drug Administration (FDA)-approved peptidergic drugs associated with allergic-type injection-site reactions also activate Mrgprb2 and MRGPRX2, and that injection-site inflammation is absent in mutant mice. Finally, we determine that Mrgprb2 and MRGPRX2 are targets of many small-molecule drugs associated with systemic pseudo-allergic, or anaphylactoid, reactions; we show that drug-induced symptoms of anaphylactoid responses are significantly reduced in knockout mice; and we identify a common chemical motif in several of these molecules that may help predict side effects of other compounds. These discoveries introduce a mouse model to study mast cell activation by basic secretagogues and identify MRGPRX2 as a potential therapeutic target to reduce a subset of drug-induced adverse effects.
Article
Mast cell activation syndrome (MCAS) describes patients with episodes of mast cell mediator release, with negative bone marrow biopsy results, and the failure to meet the criteria for systemic mastocytosis. Identify elevation of mast cell mediators of patients with MCAS. We performed a retrospective study of 25 patients with MCAS who were evaluated at Mayo Clinic from 2006 to 2012. Patients were reviewed for MCAS symptoms and mast cell mediators, including serum tryptase and 24-hour urine N-methyl histamine (N-MH) and 11β-prostaglandin-F2α (11β-PGF2α). The study was approved by the institutional review board. Urinary 11β-PGF2α was the most frequently elevated product in MCAS of our 25-patient cohort. Flushing and pruritus had the greatest correlation with elevation of 24-hour urine 11β-PGF2α value at baseline. The serum tryptase level was elevated in 10 patients, whereas the N-MH level was elevated with 2 patients. Eight of 9 patients with MCAS and with elevated 24-hour urine 11β-PGF2α who underwent aspirin therapy and follow-up urinary studies had normalization of this mediator (1 patient did not have a follow-up urine study). Six of these 9 patients with MCAS who underwent aspirin therapy had symptomatic improvement. We recommend measurement of 24-hour urine 11β-PGF2α and serum tryptase levels of patients with symptoms suggestive of MCAS. Measurement of 24-hour urine 11β-PGF2α and serum tryptase levels can help avoid misdiagnosis and overinterpretation of MCAS symptoms in clinical practice. Given that an elevation of 24-hour urine N-MH level was found only in 2 patients, measurement of this mediator may be less helpful in diagnosing MCAS. We recommend aspirin therapy for patients with MCAS and with elevated 24-hour urine 11β-PGF2α levels. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Article
During the past few years, a number of molecular markers have been developed in clinical hematology, most of them related to specific gene defects. However, there is also an unmet need to develop novel serologic parameters to improve diagnostics and prognostication in daily practice. Among these, the serum tryptase appears to be a most reliable biomarker of myeloid neoplasms. Elevated tryptase levels are found in subgroups of patients with mastocytosis, myelodysplastic syndrome, myeloproliferative neoplasm, acute myeloid leukemia, chronic myeloid leukemia and chronic eosinophilic leukemia. In these patients, the tryptase level is of diagnostic and/or prognostic significance. In mastocytosis, an elevated tryptase level is a minor criterion of systemic disease and in BCR-ABL1+ chronic myeloid leukemia, elevated tryptase at diagnosis correlates with treatment responses and overall survival. In patients with elevated tryptase, the enzyme also serves as follow-up parameter and can be employed to measure treatment-responses. In the current article, we review and update the perspectives of tryptase and provide recommendations for use of this conventional biomarker in daily practice.
Article
The recent progress in sensitive KIT D816V mutation analysis suggests that mutation analysis of peripheral blood (PB) represents a promising diagnostic test in mastocytosis. However, there is a need for systematic assessment of the analytical sensitivity and specificity of the approach in order to establish its value in clinical use. We therefore evaluated sensitive KIT D816V mutation analysis of PB as a diagnostic test in an entire case-series of adults with mastocytosis. We demonstrate for the first time that by using a sufficiently sensitive KIT D816V mutation analysis, it is possible to detect the mutation in PB in nearly all adult mastocytosis patients. The mutation was detected in PB in 78 of 83 systemic mastocytosis (94%) and 3 of 4 cutaneous mastocytosis patients (75%). The test was 100% specific as determined by analysis of clinically relevant control patients who all tested negative. Mutation analysis of PB was significantly more sensitive than serum tryptase >20 ng/ml. Of 27 patients with low tryptase, 26 tested mutation positive (96%). The test is furthermore readily available and we consider the results to serve as a foundation of experimental evidence to support the inclusion of the test in diagnostic algorithms and clinical practice in mastocytosis.
Article
Glia and microglia in particular elaborate pro-inflammatory molecules which play key roles in CNS disorders from neuropathic pain and epilepsy to neurodegenerative diseases. Microglia respond also to pro-inflammatory signals released from other non-neuronal cells, mainly those of immune origin such as mast cells. The latter are found in most tissues, are CNS resident, and traverse the blood-spinal cord and blood-brain barriers when barrier compromise results from CNS pathology. Growing evidence of mast cell - glia communication opens new perspectives for development of therapies targeting neuroinflammation by differentially modulating activation of non-neuronal cells normally controlling neuronal sensitization - both peripherally and centrally. Mast cells and glia possess endogenous homeostatic mechanisms/molecules that can be up-regulated as a result of tissue damage or stimulation of inflammatory responses. Such molecules include the N-acylethanolamine family. One such member, N-palmitoylethanolamine is proposed to have a key role in maintenance of cellular homeostasis in the face of external stressors provoking, for example, inflammation. N-palmitoylethanolamine has proven efficacious in mast-cell mediated experimental models of acute and neurogenic inflammation. This review will provide an overview of recent progress relating to the pathobiology of neuroinflammation, the role of microglia, neuro-immune interactions involving mast cells and the possibility that mast cell-microglia cross talk contributes to the exacerbation of acute symptoms of chronic neurodegenerative disease and accelerate disease progression, as well as promote pain transmission pathways. We will conclude by considering the therapeutic potential of treating systemic inflammation or blockade of signalling pathways from the periphery to the brain in such settings. This article is protected by copyright. All rights reserved.
Article
Mastocytosis is a heterogeneous disease characterized by mast cell accumulation in 1 or more organs. Gastrointestinal manifestations of systemic mastocytosis have been previously studied in small cohorts of patients, and no specific histologic description is available. We sought to assess the clinical and pathologic features of gastrointestinal manifestations in patients with mastocytosis. Medical history and gastrointestinal symptoms of patients with mastocytosis (n = 83) were compared with those of matched healthy subjects (n = 83) by means of patient questionnaire. Data were analyzed for epidemiologic, clinical, biological, and genetic factors associated with gastrointestinal symptoms for patients with mastocytosis. A comparative analysis of gastrointestinal histology from patients with mastocytosis (n = 23), control subjects with inflammatory bowel disease (n = 17), and healthy subjects (n = 19) was performed. The following gastrointestinal symptoms occurred more frequently and were more severe in patients with mastocytosis than in healthy subjects: bloating (33% vs 7.2%, P < .0001), abdominal pain (27.3% vs 4.8%, P < .0001), nausea (23% vs 8.4%, P = .02), and diarrhea (33.85% vs 1.2%, P < .0001). Patients with mastocytosis had a significantly higher incidence of personal history of duodenal ulcer (P = .02). Wild-type (WT) c-Kit was associated with diarrhea (P = .03). Specific histologic lesions were present in patients with mastocytosis but were not correlated with clinical symptoms. Gastrointestinal manifestations in patients with mastocytosis are highly prevalent and often severe. Clinical symptoms do not correspond to histologic findings, are nonspecific, and can simulate irritable bowel syndrome.
Article
Background: Mastocytosis is frequently associated with mast cell-mediated symptoms which require relieving medication. While second generation antihistamines (sgAHs) are the first line therapeutic strategy to treat mast cell mediator-related symptoms, controlled clinical trials on how they improve quality of life have not been performed. Methods: This randomized, double-blind, placebo-controlled, cross-over trial assessed rupatadine 20 mg daily in the treatment of mastocytosis symptoms in 30 adult patients. Symptoms were assessed by a visual analogue scale (VAS) and symptom specific quality of life questionnaire (ItchyQoL). Results: The mean ItchyQoL total score and VAS symptom score were significantly improved in the rupatadine treatment phase compared with placebo. There were also significant reductions from placebo in the severity of itch, wheal and flare, flushing, tachycardia and headache but not gastrointestinal symptoms. Conclusions: In this first comprehensive trial of a sgAH in mastocytosis, rupatadine 20 mg daily for 4 weeks significantly controlled symptoms and improved patients' quality of life.
Article
One hundred and seventeen coded intestinal biopsies were examined by electron microscopy and evaluated for morphological evidence of mast cell and basophil secretion in situ. Sixty percent of the biopsies had evidence of secretion. Mast cell secretion was evident in control biopsies, many of which were obtained from uninvolved tissues of patients with inflammatory bowel disease. Biopsies of inflamed continent pouches from ulcerative colitis (UC) patients showed more mast cell secretion than noninflamed UC pouch biopsies. This evidence of mast cell secretion supports recent work that documents high constitutive levels of histamine in jejunal fluids of Crohn’s disease patients and suggests a proinflammatory role for mast cells in inflammation associated with pouchitis.
Article
A variable percentage of patients with systemic mast cell (MC) activation symptoms meet criteria for systemic mastocytosis (SM). We prospectively evaluated the clinical utility of the REMA score versus serum baseline tryptase (sBt) levels for predicting MC clonality and SM in 158 patients with systemic MC activation symptoms in the absence of mastocytosis in the skin (MIS). World Health Organization criteria for SM were applied in all cases. MC clonality was defined as the presence of KIT-mutated MC or by a clonal HUMARA test. The REMA score consisted of the assignment of positive or negative points as follows: male (+1), female (-1), sBt <15 μg/l (-1) or >25 μg/l (+2), presence (-2) or absence (+1) of pruritus, hives or angioedema and presence (+3) of presyncope or syncope. Efficiency of the REMA score for predicting MC clonality and SM was assessed by receiver operating characteristic (ROC) curve analyses and compared to those obtained by means of sBt levels alone. Molecular studies revealed the presence of clonal MC in 68/80 SM cases and in 11/78 patients who did not meet the criteria for SM. ROC curve analyses confirmed the greater sensitivity and a similar specificity of the REMA score versus sBt levels (84 vs. 59% and 74 vs. 70% for MC clonality and 87 vs. 62% and 73 vs. 71% for SM, respectively). Our results confirm the clinical utility of the REMA score to predict MC clonality and SM in patients suffering from systemic MC activation symptoms without MIS.
Article
Mast-cell activation mediated by the high-affinity receptor for IgE (FcepsilonRI) is considered to be a key event in the allergic inflammatory response. However, in a physiological setting, other receptors, such as KIT, might also markedly influence the release of mediators by mast cells. Recent studies have provided evidence that FcepsilonRI-dependent degranulation is regulated by two complementary signalling pathways, one of which activates phospholipase Cgamma and the other of which activates phosphatidylinositol 3-kinase, using specific transmembrane and cytosolic adaptor molecules. In this Review, we discuss the evidence for these interacting pathways and describe how the capacity of KIT, and other receptors, to influence FcepsilonRI-dependent mast-cell-mediator release might be a function of the relative abilities of these receptors to activate these alternative pathways.
Article
Diagnostic criteria for mast cell (MC) activation syndrome have been recently proposed, but clinical studies to validate these criteria are lacking. We sought to determine the clinical manifestations of this newly recognized syndrome in a cohort of patients. We prospectively evaluated 18 patients seen at our institution with MC activation syndrome from 2006 to 2009. Patients enrolled had at least 4 of the signs and symptoms of abdominal pain, diarrhea, flushing, dermatographism, memory and concentration difficulties, or headache. Response to treatment with anti-MC mediator medications was assessed based on established criteria. Laboratory tests indicating MC mediator release and histopathology and immunohistochemical studies on gastrointestinal biopsy samples were performed. Ninety-four percent of the patients had abdominal pain, 89% had dermatographism, 89% had flushing, and 72% had the constellation of all 3 symptoms. Patients additionally had headache, diarrhea, and memory and concentration difficulties. All patients had at least 1 positive laboratory test result for an increased MC mediator level. On the basis of the response to treatment criteria, 67% of the patients in the cohort had either a complete or major regression in symptoms while taking medications targeting MC mediators. There was no significant difference in the numbers of intestinal mucosal MCs between our patients and healthy control subjects. MC activation syndrome might be the underlying cause of unexplained symptoms when several organ systems are involved, such as the gastrointestinal tract and the skin. It is especially important to be able to recognize the constellation of clinical features because response to anti-MC mediator medications is often excellent.
Article
We report on the outcome of 4 patients with therapy-resistant systemic mast cell activation disease (MCAD) treated with the anti-IgE monoclonal antibody omalizumab in compassionate use. Two patients achieved an impressive persistent clinical response to treatment with omalizumab. In the third patient symptoms gradually improved. In the fourth patient omalizumab treatment had to be discontinued due to intolerable mast cell mediator-induced symptoms. In conclusion, omalizumab can lessen the intensity of the symptoms of systemic MCAD. Hence, omalizumab should be considered as a therapeutic option in cases of systemic MCAD that are resistant to evidence-based therapy.
Article
The term mast cell activation syndrome (MCAS) is finding increasing use as a diagnosis for subjects who present with signs and symptoms involving the dermis, gastrointestinal track, and cardiovascular system frequently accompanied by neurologic complaints. Such patients often have undergone multiple extensive medical evaluations by different physicians in varied disciplines without a definitive medical diagnosis until the diagnosis of MCAS is applied. However, MCAS as a distinct clinical entity has not been generally accepted, nor do there exist definitive criteria for diagnosis. Based on current understanding of this disease "syndrome" and on what we do know about mast cell activation and resulting pathology, we will explore and propose criteria for its diagnosis. The proposed criteria will be discussed in the context of other disorders involving mast cells or with similar presentations and as a basis for further scientific study and validation.
Article
Mast cell activation is thought to be involved in visceral hypersensitivity, one of the main characteristics of the irritable bowel syndrome (IBS). A study was therefore undertaken to investigate the effect of the mast cell stabiliser ketotifen on rectal sensitivity and symptoms in patients with IBS. 60 patients with IBS underwent a barostat study to assess rectal sensitivity before and after 8 weeks of treatment. After the initial barostat, patients were randomised to receive ketotifen or placebo. IBS symptoms and health-related quality of life were scored. In addition, mast cells were quantified and spontaneous release of tryptase and histamine was determined in rectal biopsies and compared with biopsies from 22 age- and gender-matched healthy volunteers. Ketotifen but not placebo increased the threshold for discomfort in patients with IBS with visceral hypersensitivity. This effect was not observed in normosensitive patients with IBS. Ketotifen significantly decreased abdominal pain and other IBS symptoms and improved quality of life. The number of mast cells in rectal biopsies and spontaneous release of tryptase were lower in patients with IBS than in healthy volunteers. Spontaneous release of histamine was mostly undetectable but was slightly increased in patients with IBS compared with healthy volunteers. Histamine and tryptase release were not altered by ketotifen. This study shows that ketotifen increases the threshold for discomfort in patients with IBS with visceral hypersensitivity, reduces IBS symptoms and improves health-related quality of life. Whether this effect is secondary to the mast cell stabilising properties of ketotifen or H(1) receptor antagonism remains to be further investigated. Trial Registration Number NTR39, ISRCTN22504486.
Article
We report that the asthma drugs cromolyn disodium and nedocromil sodium are potent G-protein-coupled receptor 35 (GPR35) agonists. We utilized calcium flux and inositol phosphate accumulation assays to examine the pharmacology of these asthma drugs on the human, mouse and rat GPR35. The compounds were more potent on the human GPR35 than on mouse and rat receptors. In contrast, zaprinast, a known GPR35 agonist, was more potent on mouse and rat GPR35 than the human ortholog. We show by quantitative PCR that GPR35 is expressed in human mast cells, human basophils and human eosinophils. We also demonstrate that GPR35 mRNA is upregulated upon challenge with IgE antibodies. We show that, unlike zaprinast, a potent phosphodiesterase 5 (PDE5) inhibitor, cromolyn disodium and nedocromil sodium lack inhibitory activity towards PDE5. These findings suggest that GPR35 may play an important role in mast cell biology and be a potential target for the treatment of asthma.
Article
Systemic mast cell activation disorders (MCADs) are characterized by severe and systemic mast cell (MC) mediators-related symptoms frequently associated with increased serum baseline tryptase (sBt). To analyze the clinical, biological, and molecular characteristics of adult patients presenting with systemic MC activation symptoms/anaphylaxis in the absence of skin mastocytosis who showed clonal (c) versus nonclonal (nc) MCs and to provide indication criteria for bone marrow (BM) studies. Eighty-three patients were studied. Patients showing clonal BM MCs were grouped into indolent systemic mastocytosis without skin lesions (ISMs(-); n = 48) and other c-MCADs (n = 3)-both with CD25(++) BM MCs and either positive mast/stem cell growth factor receptor gene (KIT) mutation or clonal human androgen receptor assay (HUMARA) tests-and nc-MCAD (CD25-negative BM MCs in the absence of KIT mutation; n = 32) and compared for their clinical, biological, and molecular characteristics. Most clonal patients (48/51; 94%) met the World Health Organization criteria for systemic mastocytosis and were classified as ISMs(-), whereas the other 3 c-MCAD and all nc-MCAD patients did not. In addition, although both patients with ISMs(-) and patients with nc-MCAD presented with idiopathic and allergen-induced anaphylaxis, the former showed a higher frequency of men, cardiovascular symptoms, and insect bite as a trigger, together with greater sBt. Based on a multivariate analysis, a highly efficient model to predict clonality before BM sampling was built that includes male sex (P = .01), presyncopal and/or syncopal episodes (P = .009) in the absence of urticaria and angioedema (P = .003), and sBt >25 microg/L (P = .006) as independent predictive factors. Patients with c-MCAD and ISMs(-) display unique clinical and laboratory features different from nc-MCAD patients. A significant percentage of c-MCAD patients can be considered as true ISMs(-) diagnosed at early phases of the disease.
Article
Recent data suggest that tryptase, a mast cell enzyme, is expressed in neoplastic cells in myeloid leukaemias. In several of these patients, increased serum tryptase levels are detectable. We have determined serum tryptase levels in 914 patients with haematological malignancies, including myeloproliferative disorders (n = 156), myelodysplastic syndromes (MDS, n = 241), acute myeloid leukaemia (AML, n = 317), systemic mastocytosis (SM, n = 81), non-Hodgkin's lymphoma (n = 59) and acute lymphoblastic leukaemia (n = 26). Moreover, tryptase was measured in 136 patients with non-neoplastic haematological disorders, 102 with non-haematological disorders and 164 healthy subjects. In healthy subjects, the median serum tryptase was 5.2 ng mL(-1). Elevated serum tryptase levels were found to cluster in myeloid neoplasm, whereas almost all patients with lymphoid neoplasms exhibited normal tryptase. Among myeloid neoplasms, elevated tryptase levels (> 15 ng mL(-1)) were recorded in > 90% of patients with SM, 38% with AML, 34% with CML and 25% with MDS. The highest tryptase levels, often > 1000 ng mL(-1), were found in advanced SM and core-binding-factor leukaemias. In most patients with non-neoplastic haematological disorders and non-haematological disorders analysed in our study, tryptase levels were normal, the exception being a few patients with end-stage kidney disease and helminth infections, in whom a slightly elevated tryptase was found. In summary, tryptase is a new diagnostic marker of myeloid neoplasms and a useful test in clinical haematology.
Article
A multicenter, double-blind, placebo-controlled trial of the efficacy of oral cromolyn sodium (200 mg orally four times per day) was conducted in 11 patients with systemic mastocytosis who had been maintained with the drug on an individualized compassionate-need basis. Efficacy was measured by physician assessment of overall disease severity based on history and physical examination at specified intervals and by the average daily patient symptom diary scores for each of three mastocytosis-related symptoms that had previously appeared to be alleviated by the use of this drug. Efficacy variables were compared for a 4-week baseline period, during which patients received open-labeled cromolyn sodium, and at 4-week intervals during a 16-week period of random assignment to cromolyn sodium or placebo. Overall disease severity and symptoms recorded in patient diaries were graded on a scale of 0 (absent) to 5 (incapacitating). The average physician assessment of disease severity and symptom scores of the patients in the placebo-treated group increased significantly during the randomization phase relative to patients in the cromolyn sodium-treated group, reflecting an exacerbation of symptoms with drug withdrawal (p less than 0.05 and less than 0.028, respectively). When the symptom scores were analyzed separately for gastrointestinal manifestations of disease (diarrhea, abdominal pain, nausea, and vomiting), cromolyn sodium treatment was significantly beneficial relative to placebo (p less than 0.02), whereas the benefit for nongastrointestinal manifestations did not reach statistical significance.
Article
The aim of this study was to clarify the role of eosinophils and mast cells in the small bowel in celiac disease. Patients with celiac disease (n = 10) were investigated by perfusion of a closed jejunal segment. The concentrations of certain granule constituents from eosinophils, eosinophil cationic protein (ECP), and from mast cells/basophils, histamine, were measured and the jejunal secretion rates of these cellular markers were calculated. Compared with findings in healthy control subjects (n = 14), increased secretion rates were observed under basal conditions in patients with histopathologically active celiac disease. Gliadin, administered by perfusion to the jejunal segment, induced a fourfold increase in ECP secretion and a twofold increase of histamine secretion in patients with celiac disease (n = 7), but did not influence the secretion rates of these substances in healthy controls (n = 3). The secretion rate of ECP started to increase 20 minutes after challenge of the perfused segment with gliadin and reached maximum levels 40 minutes later. The secretion rate of histamine started to increase 40 minutes after gliadin administration. Concurrently with these inflammatory events, the secretion of albumin was doubled as a sign of increased mucosal leakage. These data indicate that eosinophils and mast cells are both involved in the early gliadin-induced reactions of the small intestine, and suggest that these cells are effector cells participating in the celiac lesion of the mucosa.
Article
To asses the efficacy of ketotifen (Zaditen; Sandoz Pharmaceuticals, Basel, Switzerland) for the treatment of pediatric mastocytosis, eight children who exhibited symptoms as a result of mastocytosis were enrolled in a 12-week, double-blind, placebo-controlled, crossover trial of ketotifen versus hydroxyzine (Atarax; Roerig, New York, N.Y.). Efficacy of each drug was assessed by daily symptom scores and plasma- and 24-hour urine-histamine levels. After completion of the study, symptom scores revealed that seven of the eight children exhibited a greater reduction in symptoms while they were receiving hydroxyzine (p less than 0.05). The symptoms most likely to improve with treatment with hydroxyzine were flushing and abdominal pain. Analysis of plasma- and 24-hour urine-histamine levels at the beginning and end of each trial period of each drug revealed no significant differences (p greater than 0.20). Changes in 24-hour urine-histamine levels, but not plasma-histamine levels, correlated with changes in symptom scores. We conclude that ketotifen offers no advantage over hydroxyzine in the treatment of pediatric mastocytosis.
Article
In 16 consecutive patients with systemic mastocytosis, we prospectively evaluated a variety of gastrointestinal functions and examined how they relate to the occurrence of gastrointestinal symptoms. Nine patients had either a duodenal ulcer or duodenitis. Hypersecretion of gastric acid was present in 6 patients, and in these patients the mean basal acid output was 20.7 +/- 4.1 mEq/h (range 14-39 mEq/h). Impaired small intestinal absorption occurred in 5 patients, although this was usually mild. The mean fractional emptying rate of liquids for all patients (14.7% +/- 2.3% per minute) did not differ from that for controls (10.7% +/- 0.6% per minute). Mean mouth-to-cecum transit time measured by breath hydrogen testing was the same among patients (87.7 +/- 6.7 min) and controls (86.7 +/- 8.0 min). Plasma histamine concentrations were increased in all patients (mean 1886 pg/ml, range 480-7450) and correlated with the basal acid output (r = 0.64, p less than 0.02) but not maximal acid output or the presence or absence of pain or diarrhea. Mean fasting plasma concentrations of motilin, substance P, and neurotensin from 6 patients did not differ significantly from controls, whereas gastrin and vasoactive intestinal peptide were significantly less than in controls (p less than 0.01). Gastrointestinal symptoms, consisting of abdominal pain or diarrhea, occurred in 80% of patients. Abdominal pain classified as dyspeptic was usually associated with acid-peptic disease of the duodenum and hypersecretion of gastric acid, whereas abdominal pain of a nondyspeptic character was not. Only in those cases of diarrhea consisting of greater than 200 g stool/day was gastric acid hypersecretion frequently found. Neither fecal urgency nor nondyspeptic pain could be accounted for by alterations of gastrointestinal transit. These results demonstrate that gastrointestinal symptoms, peptic disease, and mild malabsorption are much more common than described previously in patients with systemic mastocytosis. Furthermore, the results provide no evidence for the contention that altered gastrointestinal transit is involved in the pathogenesis of these symptoms.
Article
Mast cells and basophils are implicated as major effector cells in allergic disease. However, both mast cell and basophil involvement in clinical events have been difficult to assess heretofore because of localization of mast cells in tissues and the small numbers of basophils in the circulatory system. Tryptase has been found to be a discriminating marker for the participation of human mast cells in immediate allergic responses, and therefore provides precise assessment of mast cell activation. High tryptase levels in serum, plasma, and other biologic fluids are consistent with mast cell activation in systemic anaphylaxis and other immediate hypersensitivity allergic reactions. Although basophil activation has been implicated in late phase response to allergen challenge, sensitive specific indicators of basophil activation are still under investigation.
Article
Histamine is a critical messenger molecule in times of stress, promoting alertness, blood flow, and healing (Kahlson et al., 1960; Schayer, 1962; White and Rumbold, 1988). Excess histamine, however, has a negative impact on circulatory and immunologic homeostasis (Schayer, 1962; Falus and Merétey, 1992) and aggravates inflammatory conditions of the gut (Rangachari, 1992) and respiratory tract (Doyle et al., 1994). Thus, antihistamine therapy is used for systematic treatment of certain diseases, including acid-peptic disorders (Feldman and Burton, 1990b), allergy (howarth, 1983; Schata et al., 1991; Naclerio, 1993), and inflammatory skin disorders (Giacosa et al.,1978).
Article
Patients with systemic mastocytosis present symptoms related to the tissue response to the release of mediators from mast cells and to the local mast cell burden. Such patients often have a history of chronic and acute mediator-related symptoms. Most patients have indolent disease with a good prognosis and a normal life span. Symptoms can include pruritus, flushing, syncope, gastric distress, nausea and vomiting, diarrhea, bone pain and neuropsychiatric symptoms, most of which are controlled by medication. Because there is no current cure for mastocytosis, successful therapeutic interventions rely on the recognition of mediator-related symptoms and their treatment, and established intervention approaches for the relatively uncommon leukemic concomitants. Efforts to link a particular mast cell-derived mediator to some aspect of the symptom complex depend on the known actions of the mediator and the efficacy of target-based interventions.
Article
Postural tachycardia syndrome (POTS) is a disabling condition that commonly affects otherwise normal young females. Because these patients can present with a flushing disorder, we hypothesized that mast cell activation (MCA) can contribute to its pathogenesis. Here we describe POTS patients with MCA (MCA+POTS), diagnosed by episodes of flushing and abnormal increases in urine methylhistamine, and compared them to POTS patients with episodic flushing but normal urine methylhistamine and to normal healthy age-matched female controls. MCA+POTS patients were characterized by episodes of flushing, shortness of breath, headache, lightheadedness, excessive diuresis, and gastrointestinal symptoms such as diarrhea, nausea, and vomiting. Triggering events include long-term standing, exercise, premenstrual cycle, meals, and sexual intercourse. In addition, patients were disabled by orthostatic intolerance and a characteristic hyperadrenergic response to posture, with orthostatic tachycardia (from 79+/-4 to 114+/-6 bpm), increased systolic blood pressure on standing (from 117+/-5 to 126+/-7 mm Hg versus no change in POTS controls), increased systolic blood pressure at the end of phase II of the Valsalva maneuver (157+/-12 versus 117+/-9 in normal controls and 119+/-7 mm Hg in POTS; P=0.048), and an exaggerated phase IV blood pressure overshoot (50+/-10 versus 17+/-3 mm Hg in normal controls; P<0.05). In conclusion, MCA should be considered in patients with POTS presenting with flushing. These patients often present with a typical hyperadrenergic response, but beta-blockers should be used with great caution, if at all, and treatment directed against mast cell mediators may be required.
Article
The recovery of mediator metabolites from urine has the potential to provide a rapid, safe, and easily available index of release of mediators. We aimed to determine urinary metabolites of both histamine and leukotrienes (LTs) in patients affected by chronic urticaria (CU). Twenty patients with CU were studied. They were selected on the basis of double-blind placebo-controlled challenge (DBPC) with acetyl salicylic acid (ASA) and food additives. Ten patients (group B) were negative to both challenges. Ten patients (group C) presented urticaria and/or the appearance of angioedema during or 24 h after challenge, with reactions to ASA (five patients) or food additives (five patients). We recruited 15 healthy volunteers as controls (group A). During a second challenge, groups B and C were challenged double-blind with a single dose of ASA, or a specific food additive, or placebo. The healthy group was challenged only with a placebo (talc capsule). Patients in groups B and C were challenged twice: with placebo (as groups B1 and C1) and with ASA (groups B2 and C2) or food additives (C2). Four samples of urine were collected; one during the night before the specific or sham challenge (baseline), and three at 2, 6 and 24 h after the challenge. Urinary methylhistamine (N-MH) and LTE4 were analyzed and normalized for urinary creatinine. For urinary N-MH at baseline, there was a significant difference only between group A and groups B1, B2, C1 and C2 (A vs. B1, P < 0.0001; A vs. B2, P < 0.0001; A vs. C1, P < 0.0001; A vs. C2, P < 0.0001). We detected a significant variation in urinary methylhistamine excretion only in group C2 after 2 h, 6 h and 24 h (P < 0.0001). However, no variations were observed in N-MH excretion rate in the other groups (A, B1, C1) after challenge with placebo, and in B2 after challenge with ASA 20 mg. For urinary LTE4 at baseline no differences were found between the mean values for the different groups. After specific challenge, only C2 patients showed significantly increased excretion rates of urinary LTE4 compared with the other groups challenged with placebo (A, B1, C1), or ASA (B2) (P < 0.0001). No significant correlation was seen between urinary LTE4 and methylhistamine excretion rate in any patients. Our results show that urinary excretion of N-MH and LTE4 is different for CU patients without ASA or food hypersensitivity, compared to those with CU with ASA or food additive hypersensitivity after specific challenge.
Article
Mast cells produce symptoms by local and remote effects of mediator release and by their presence in increased numbers in normal tissue and bone marrow, where they damage and impair normal organ function. Moreover, mast cells are long-lived and heterogeneous in their response to secretagogues and to inhibitors of mediator release. Clinicians sorting out the diagnosis of SM on the basis of presenting signs and symptoms continue to have their diagnostic skills challenged because of the rarity of this disorder, the fact that many symptoms of SM are present in more common disorders, and the multiple guises that SM may assume at the time of presentation.
Article
Serum (or plasma) levels of total and mature tryptase measurements are recommended in the diagnostic evaluation of systemic anaphylaxis and systemic mastocytosis, but their interpretation must be considered in the context of a complete workup of each patient. Total tryptase levels generally reflect the increased burden of mast cells in patients with all forms of systemic mastocytosis (indolent systemic mastocytosis, smoldering systemic mastocytosis, systemic mastocytosis associated with a hematologic clonal non-mast cell disorder, aggressive systemic mastocytosis, and mast cell leukemia) and the decreased burden of mast cells associated with cytoreductive therapies in these disorders. Causes of an elevated total tryptase level other than systemic mastocytosis must be considered, however, and include systemic anaphylaxis, acute myelocytic leukemia, various myelodysplastic syndromes, hypereosinophilic syndrome associated with the FLP1L1-PDGFRA mutation, end-stage renal failure, and treatment of onchocerciasis. Mature (beta) tryptase levels generally reflect the magnitude of mast cell activation and are elevated during most cases of systemic anaphylaxis, particularly with parenteral exposure to the inciting agent.
Article
Intestinal mast cell infiltration may participate to abdominal pain in irritable bowel syndrome (IBS) patients. However, the underlying mechanisms remain unknown. We assessed the effect of mast cell mediators released from the colonic mucosa of IBS patients on the activation of rat sensory neurons in vitro. Colonic mast cell infiltration and mediator release were assessed with quantitative immunofluorescence and immunoenzymatic assays. The effect of mucosal mediators was tested on mesenteric sensory nerve firing and Ca(2+) mobilization in dorsal root ganglia in rats. Mediators from IBS patients, but not controls, markedly enhanced the firing of mesenteric nerves (14.7 +/- 3.2 imp/sec vs 2.8 +/- 1.5 imp/sec; P < .05) and stimulated mobilization of Ca(2+) in dorsal root ganglia neurons (29% +/- 4% vs 11% +/- 4%; P < .05). On average, 64% of dorsal root ganglia responsive to mediators were capsaicin-sensitive, known to mediate nociception. Histamine and tryptase were mainly localized to mucosal mast cells. IBS-dependent nerve firing and Ca(2+) mobilization were correlated with the area of the colonic lamina propria occupied by mast cells (r = 0.74; P < .01, and r = 0.78; P < .01, respectively). IBS-dependent excitation of dorsal root ganglia was inhibited by histamine H(1) receptor blockade and serine protease inactivation (inhibition of 51.7%; P < .05 and 74.5%; P < .05; respectively). Mucosal mast cell mediators from IBS patients excite rat nociceptive visceral sensory nerves. These results provide new insights into the mechanism underlying visceral hypersensitivity in IBS.