[Show abstract][Hide abstract] ABSTRACT: Allergen exposure via the respiratory tract and in particular via the nasal mucosa boosts systemic allergen-specific IgE production. Intranasal corticosteroids (INCS) represent a first line treatment of allergic rhinitis but their effects on this boost of allergen-specific IgE production are unclear.
Here we aimed to determine in a double-blind, placebo-controlled study whether therapeutic doses of an INCS preparation, i.e., nasal fluticasone propionate, have effects on boosts of allergen-specific IgE following nasal allergen exposure.
Subjects (n = 48) suffering from grass and birch pollen allergy were treated with daily fluticasone propionate or placebo nasal spray for four weeks. After two weeks of treatment, subjects underwent nasal provocation with either birch pollen allergen Bet v 1 or grass pollen allergen Phl p 5. Bet v 1 and Phl p 5-specific IgE, IgG1-4, IgM and IgA levels were measured in serum samples obtained at the time of provocation and one, two, four, six and eight weeks thereafter.
Nasal allergen provocation induced a median increase to 141.1% of serum IgE levels to allergens used for provocation but not to control allergens 4 weeks after provocation. There were no significant differences regarding the boosts of allergen-specific IgE between INCS- and placebo-treated subjects.
In conclusion, the application of fluticasone propionate had no significant effects on the boosts of systemic allergen-specific IgE production following nasal allergen exposure.
[Show abstract][Hide abstract] ABSTRACT: Background: A 29-year-old female presented with a first-time anaphylactic reaction.
History revealed the intake of “Schwarzbeernocken”, a Tyrolean speciality containing
blueberries, 1 hour prior to the onset of symptoms. We aimed to identify the culprit
allergen. Methods: Serum from a blueberry allergic donor was studied for IgE reactivity
to blueberry, mugwort (Artemisia vulgaris) and birch (Betula verrucosa) pollen extract
in IgE immunoblot experiments. IgE inhibition experiments and N-terminal sequencing
were performed to further identify the putative blueberry allergen. In addition, blueberry
extract was evaluated for cross-reactive allergens with sera from a Bet v 1- and a monosensitized
mugwort pollen-allergic patient.
Results: Blueberries contain a 9 kDa allergen which cross-reacts with Pru p 3, the nonspecific lipid transfer protein from peach, and shows sequence homology with cabbage lipid transfer protein. No allergen homologous to Bet v 1 could be identified in blueberries.
Conclusion: Blueberry lipid transfer protein represents a relevant food allergen which can cause severe anaphylactic reactions. However, blueberries apparently do not contain any Bet v 1-homologue. This protein family is found in many other foods and known as the most common cause of oral allergy syndrome in the Northern hemisphere.
[Show abstract][Hide abstract] ABSTRACT: Nowadays, clinical and evidence based guidelines are considered one of the major efforts to improve patient care in medical practices as well as hospital settings. In the literature, clinical guidelines have been defined as "systematically developed statements to assist practitioner and patient decisions about appropriate healthcare for specific clinical circumstances", which promote both clinically effective standards and cost-effective care [1–4]. Despite controversial discussion about the clinical impact of guidelines [5, 6], they may provide workable recommendations that may thus be important for improving the individual patient's care [1, 4]. Adverse drug reactions (drug allergies, drug hypersensitivities) often represent a major hazard for the affected patient, and a definite diagnosis is important for further drug therapies in most cases. In this context, any diagnostic procedure must be preceded by an individual risk-benefit assessment. Drug provocation testing is regarded as the gold standard, but this kind of testing should be performed in accordance with established criteria and, in the vast majority of cases, in a hospital setting. In this paper we present a clinical guideline for drug provocation testing in Austria.
Full-text · Article · Oct 2011 · Wiener klinische Wochenschrift
[Show abstract][Hide abstract] ABSTRACT: Nowadays, clinical and evidence based guidelines are considered one of the major efforts to improve patient care in medical practices as well as hospital settings. In the literature, clinical guidelines have been defined as "systematically developed statements to assist practitioner and patient decisions about appropriate healthcare for specific clinical circumstances", which promote both clinically effective standards and cost-effective care. Despite controversial discussion about the clinical impact of guidelines, they may provide workable recommendations that may thus be important for improving the individual patient's care. Adverse drug reactions (drug allergies, drug hypersensitivities) often represent a major hazard for the affected patient, and a definite diagnosis is important for further drug therapies in most cases. In this context, any diagnostic procedure must be preceded by an individual risk-benefit assessment. Drug provocation testing is regarded as the gold standard, but this kind of testing should be performed in accordance with established criteria and, in the vast majority of cases, in a hospital setting. In this paper we present a clinical guideline for drug provocation testing in Austria.
Full-text · Article · Sep 2011 · Wiener klinische Wochenschrift
[Show abstract][Hide abstract] ABSTRACT: Patients with birch pollen allergy often develop allergic reactions to plant foods.
To evaluate the prevalence, main symptoms, and triggers of birch pollen-related food allergy and the role of food-specific IgG(4) antibodies in food tolerance.
Food-induced symptoms were evaluated in 225 individuals with birch pollen allergy by using a standardized questionnaire. IgE and IgG(4) levels specific for the major birch pollen allergen Bet v 1 and birch profilin Bet v 2 and the Bet v 1 homologs in apple (Mal d 1) and hazelnut (Cor a 1) were quantified by ImmunoCAP. Mock-treated and IgG-depleted sera from patients tolerating hazelnuts in food challenges were compared for their inhibitory activity for binding of Cor a 1-IgE complexes to B cells.
In total, 73% of the study population experienced food allergy, which was perennial in 86% of the affected individuals. The oral allergy syndrome was the main clinical manifestation. However, more than 58% of the patients also experienced food-induced rhinoconjunctivitis. Apples and hazelnuts were identified as the most frequent triggers. Food allergy correlated with IgE reactivity to Bet v 1 but not to Bet v 2. Mal d 1-specific and Cor a 1-specific IgG(4)/IgE ratios were significantly higher in food-tolerant individuals than individuals with food allergy. Sera from IgG(4)-positive food-tolerant patients possessed IgG-dependent IgE-inhibitory activity.
Birch pollen-related food allergy is highly prevalent and often perennial. High food allergen-specific IgG(4)/IgE ratios seem associated with food tolerance, potentially because specific IgG(4) blocks IgE binding to food allergens. Thus, the presence of food allergen-specific IgG(4) antibodies is no diagnostic marker for birch pollen-related food allergy.
No preview · Article · Mar 2011 · The Journal of allergy and clinical immunology
[Show abstract][Hide abstract] ABSTRACT: Severe side effects during venom immunotherapy (VIT) are associated with a variety of risk factors.
Our aim was to evaluate the association of baseline serum tryptase concentration (BTC) and of other parameters, which are routinely recorded during patient evaluation, with the frequency of severe reactions requiring an emergency intervention during the buildup phase of VIT.
In this observational prospective multicenter study, we enrolled 680 patients with established honeybee or vespid venom allergy who underwent VIT. Data were collected on tryptase concentration, age, sex, culprit insect, cardiovascular medication, degree of preceding sting reaction, preventive antiallergic medication before therapy, time between last preceding sting reaction and VIT, venom specific IgE concentration, and type of buildup procedure. Relative rates were calculated with generalized additive models.
Fifty-seven patients (8.4%) required an emergency intervention during buildup because of a severe systemic reaction. The frequency of interventions increased significantly with higher BTC (log-linear association; adjusted odds ratio, 1.56; 95% CI, 1.15-2.11; P < .005). The predictive power of BTC was markedly greater when VIT was performed for vespid venom allergy than for bee venom (for bee VIT, no significant association; for vespid VIT, log-linear association; adjusted odds ratio, 2.33; 95% CI, 1.28-4.26; P = .005). The most important other factor significantly associated with severe reactions during the buildup phase of VIT was bee venom allergy.
Before vespid VIT, measurement of baseline serum tryptase concentration should be used to identify patients with a high risk for side effects. Patients with bee venom allergy require a particularly high degree of surveillance during VIT.
Full-text · Article · Jul 2010 · The Journal of allergy and clinical immunology
[Show abstract][Hide abstract] ABSTRACT: Severe anaphylaxis to honeybee or vespid stings is associated with a variety of risk factors, which are poorly defined.
Our aim was to evaluate the association of baseline serum tryptase concentrations and other variables routinely recorded during patient evaluation with the frequency of past severe anaphylaxis after a field sting.
In this observational multicenter study, we enrolled 962 patients with established bee or vespid venom allergy who had a systemic reaction after a field sting. Data were collected on tryptase concentration, age, sex, culprit insect, cardiovascular medication, and the number of preceding minor systemic reactions before the index field sting. A severe reaction was defined as anaphylactic shock, loss of consciousness, or cardiopulmonary arrest. The index sting was defined as the hitherto first, most severe systemic field-sting reaction. Relative rates were calculated with generalized additive models.
Two hundred six (21.4%) patients had a severe anaphylactic reaction after a field sting. The frequency of this event increased significantly with higher tryptase concentrations (nonlinear association). Other factors significantly associated with severe reactions after a field sting were vespid venom allergy, older age, male sex, angiotensin-converting enzyme inhibitor medication, and 1 or more preceding field stings with a less severe systemic reaction.
In patients with honeybee or vespid venom allergy, baseline serum tryptase concentrations are associated with the risk for severe anaphylactic reactions. Preventive measures should include substitution of angiotensin-converting enzyme inhibitors.
Full-text · Article · Nov 2009 · The Journal of allergy and clinical immunology
[Show abstract][Hide abstract] ABSTRACT: Allergen-specific subcutaneous immunotherapy (SCIT) is an antigen-specific therapy of IgE-mediated allergies. In the present study, we analyze the epitope specificities of antibody responses induced by SCIT with allergen extracts from pollen of trees belonging to the order Fagales (birch, alder, hazel) adsorbed onto aluminum hydroxide.
The IgE, IgG1-4 and IgA responses to defined recombinant allergens (birch pollen: Bet v 1; alder pollen: Aln g 1; hazel pollen: Cor a 1; apple: Mal d 1) as well as to Bet v 1-derived recombinant fragments and synthetic peptides were analyzed in sera from patients who had undergone SCIT for different periods of time.
Long-term SCIT (>1 year; cumulative dose >1,000,000 SQ units) induced more pronounced IgG1, IgG2 and IgG4 responses to Bet v 1 and Bet v 1-related allergens according to the degree of sequence homology (Bet v 1>Aln g 1>Cor a 1>Mal d 1) than short-term SCIT (<1 year; cumulative dose <1,000,000 SQ units). In contrast to patients treated for <1 year, patients treated for >1 year mounted distinct IgG1, IgG2 and IgG4 responses against sequential Bet v 1 epitopes. No relevant allergen-specific IgA or IgG3 responses were induced by short- or long-term SCIT. Using a competitive ELISA assay, it could be shown that serum IgG from patients undergoing long-term SCIT inhibited IgE reactivity to Bet v 1 better than IgG from patients undergoing short-term SCIT.
SCIT with allergen extracts adsorbed onto aluminum hydroxide induces IgG responses against new epitopes that block IgE binding and cross-react with structurally related allergens depending, among other factors, on duration of treatment and cumulative injected dose.
No preview · Article · Sep 2009 · International Archives of Allergy and Immunology
[Show abstract][Hide abstract] ABSTRACT: Beech and oak pollen are potential allergen sources with a world-wide distribution.
We aimed to characterize the allergen profile of beech and oak pollen and to study cross-reactivities with birch and grass pollen allergens.
Sera from tree pollen-allergic patients with evidence for beech and oak pollen sensitization from Basel, Switzerland, (n=23) and sera from birch pollen-allergic patients from Vienna, Austria, (n=26) were compared in immunoblot experiments for IgE reactivity to birch (Betula pendula syn. verrucosa), beech (Fagus sylvatica) and oak (Quercus alba) pollen allergens. Subsequently, beech and oak pollen allergens were characterized by IgE inhibition experiments with purified recombinant and natural allergens and with allergen-specific antibody probes. Birch-, beech- and oak pollen-specific IgE levels were determined by ELISA.
Beech and oak pollen contain allergens that cross-react with the birch pollen allergens Bet v 1, Bet v 2 and Bet v 4 and with the berberine bridge enzyme-like allergen Phl p 4 from timothy grass pollen. Sera from Swiss and Austrian patients exhibited similar IgE reactivity profiles to birch, beech and oak pollen extracts. IgE levels to beech and oak pollen allergens were lower than those to birch pollen allergens.
IgE reactivity to beech pollen is mainly due to cross-reactivity with birch pollen allergens, and a Phl p 4-like molecule represented another predominant IgE-reactive structure in oak pollen. The characterization of beech and oak pollen allergens and their cross-reactivity is important for the diagnosis and treatment of beech and oak pollen allergy.
[Show abstract][Hide abstract] ABSTRACT: Previously, we have constructed recombinant derivatives of the major birch pollen allergen, Bet v 1, with a more than 100-fold reduced ability to induce IgE-mediated allergic reactions. These derivatives differed from each other because the two recombinant Bet v 1 fragments represented unfolded molecules whereas the recombinant trimer resembled most of the structural fold of the Bet v 1 allergen. In this study, we analyzed the Ab (IgE, IgG subclass, IgA, IgM) response to Bet v 1, recombinant and synthetic Bet v 1-derived peptides in birch pollen allergic patients who had been vaccinated with the derivatives or adjuvant alone. Furthermore, we studied the induction of IgE-mediated skin responses in these patients using Bet v 1 and Bet v 1 fragments. Both types of vaccines induced a comparable IgG1 and IgG4 response against new sequential epitopes which overlap with the conformational IgE epitopes of Bet v 1. This response was 4- to 5-fold higher than that induced by immunotherapy with birch pollen extract. Trimer more than fragments induced also IgE responses against new epitopes and a transient increase in skin sensitivity to the fragments at the beginning of therapy. However, skin reactions to Bet v 1 tended to decrease one year after treatment in both actively treated groups. We demonstrate that vaccination with folded and unfolded recombinant allergen derivatives induces IgG Abs against new epitopes. These data may be important for the development of therapeutic as well as prophylactic vaccines based on recombinant allergens.
Full-text · Article · Nov 2007 · The Journal of Immunology