[Show abstract][Hide abstract] ABSTRACT: Purpose
To identify mechanisms of disease in a child born to consanguineous parents, who presented with Omenn syndrome (OS) and was found to carry a heterozygous RAG1 mutation in peripheral blood DNA.
Mutation analysis was performed on whole blood and buccal swab DNA. Recombination activity of the mutant RAG1 protein and diversity of T cell repertoire were tested.
Apparent heterozygosity for a novel, functionally null RAG1 mutation in peripheral blood DNA from a patient with OS was shown to be secondary to true somatic reversion. Analysis of T cell repertoire demonstrated expression of various TCRBV families, but an overall restricted pattern.
This is the first case of true somatic reversion of a RAG1 mutation in a patient with OS. The reversion event likely occurred at a stage where only a limited pool of T cell progenitors capable of performing V(D)J recombination could be generated. This work emphasizes the importance of performing functional studies to investigate the significance of novel genetic variants, and to consider somatic reversion as a possible disease modifier in SCID.
Journal of Clinical Immunology 07/2014; 34(5). · 3.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Information about patients with primary immune deficiencies can be scarce because of the rarity of the disorders. Individual centers rarely have sufficient patients to educate trainees and garner collective wisdom. Registries for many diseases have proven their worth by providing essential information on disease spectrum, treatments and natural history. This study describes the construction and use of a registry for patients with primary immune deficiencies and other efforts to improve knowledge and care for affected patients and their families.
Registry demographics and data were extracted using proprietary reporting tools. Educational efforts and cell repository data were collected from centralized source material.
The USIDNET Registry contains 3,459 patients, with common variable immune deficiency being the most represented. Pilot studies identified strengths and weaknesses of the data. Visiting Professor and Visiting Scholar Programs have been successful, encouraging trainees at all levels to pursue a career in Immunology.
USIDNET's comprehensive and integrated approach provides resources that strengthen the field of primary immune deficiencies, as shown by utilization by 312 distinct sites or individuals. The reach of USIDNET's efforts is extended through the educational resources.
Journal of Clinical Immunology 04/2014; · 3.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background/Purpose:T regulatory (Treg) function has been shown to be impaired in juvenile idiopathic arthritis (JIA) as synovial fluid (SF) Tregs are unable to suppress T effector cells (Teffs) found in the joint. The cause of this breach in immunologic tolerance is not fully understood, meriting the further study of Tregs and Teffs in JIA. The T cell receptor (TCR) endows T lymphocytes with antigen specificity and mediates interactions between T cells and their environment. Yet, little is known about the comparative specificities, clonality, and diversity of Tregs and Teffs in JIA. Further, the Treg repertoire has not been studied in adult or pediatric inflammatory arthritis. Therefore, we endeavored to characterize these TCR repertoires in JIA through deep sequencing technology.Methods:Mononuclear cells were isolated by Ficoll gradient centrifugation from paired peripheral blood (PB) and SF samples. Tregs (CD4+CD25+CD127low) and Teffs (CD4+CD25−) were sorted by flow cytometry. The TCRβ chain was amplified by multiplex PCR with genomic DNA serving as the template and then deep sequenced (ImmunoSEQ™). Sequences were aligned to the reference International ImMunoGeneTics information system. Further analysis utilizing Immunoglobulin Analysis Tool software was done to assess clonality, diversity, and variable (V), diversity (D), and joining (J) usage. Statistical analysis was completed with paired/unpaired Wilcoxon signed-rank and Kruskal-Wallis tests.Results:Three girls and 2 boys with oligoarticular (n = 2), extended oligoarticular (n = 2), and psoriatic (n = 1) arthritis were studied. Patients were similar in age (7–12 yrs) and ANA status (negative n = 4). Treatment consisted of NSAIDs (n = 2), methotrexate (n = 1), leflunomide (n = 1), and leflunomide with etanercept (n = 1). Tregs, measured as % of CD4+ cells, were enriched in the SF compared to PB (mean ± SEM: SF Tregs 13.2 ± 1.8; PB Tregs 5.1 ± 0.6). SF Teff repertoire was less diverse (p = 0.008) and more clonal (p = 0.008) than PB Teffs. In SF Teffs, a single complementarity determining region 3 (CDR3) was shared across all patients, though different V and J genes were used to create this CDR3, suggesting antigen selection. SF Tregs had the largest clonal expansions compared to PB Tregs (p = 0.016), PB Teffs (p = 0.008) and SF Teffs (p = 0.032). The degree of SF Treg clonality correlated with the active joint count. V gene usage, particularly Vβ29, in unique clonotypes was skewed in SF Tregs compared to PB Teffs, PB Tregs, and SF Teffs (p = 0.022); Vβ29 gene overuse was most prominent in patients with more active joints.Conclusion:We report on the first deep sequencing analysis of T cells in JIA. An antigen-driven process was suggested by the clonality and shared CDR3 clonotypes in SF Teffs. This study is the first to demonstrate abnormalities in the Treg repertoire in inflammatory arthritis. The SF Treg repertoire had the most pronounced clonality and skewing of V gene usage, and these abnormalities correlated with disease severity. These results suggest that Treg insufficiency in JIA may be partially due to an aberrant Treg repertoire in the arthritic joint. Studies of additional patients with functional correlates are needed to augment these findings.
[Show abstract][Hide abstract] ABSTRACT: The present uncertainty of which live viral or bacterial vaccines can be given to immunodeficient patients and the growing neglect of societal adherence to routine immunizations has prompted the Medical Advisory Committee of the Immune Deficiency Foundation to issue recommendations based on published literature and the collective experience of the committee members. These recommendations address the concern for immunodeficient patients acquiring infections from healthy subjects who have not been immunized or who are shedding live vaccine–derived viral or bacterial organisms. Such transmission of infectious agents can occur within the hospital, clinic, or home or at any public gathering. Collectively, we define this type of transmission as close-contact spread of infectious disease that is particularly relevant in patients with impaired immunity who might have an infection when exposed to subjects carrying vaccine-preventable infectious diseases or who have recently received a live vaccine. Immunodeficient patients who have received therapeutic hematopoietic stem transplantation are also at risk during the time when immune reconstitution is incomplete or while they are receiving immunosuppressive agents to prevent or treat graft-versus-host disease. This review recommends the general education of what is known about vaccine-preventable or vaccine-derived diseases being spread to immunodeficient patients at risk for close-contact spread of infection and describes the relative risks for a child with severe immunodeficiency. The review also recommends a balance between the need to protect vulnerable subjects and their social needs to integrate into society, attend school, and benefit from peer education.
The Journal of allergy and clinical immunology 01/2014; 133(4):961–966. · 12.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Thymocytes and thymic epithelial cells (TECs) cross-talk is essential to support T cell development and preserve thymic architecture and maturation of TECs and Foxp3(+) natural regulatory T cells. Accordingly, disruption of thymic lymphostromal cross-talk may have major implications on the thymic mechanisms that govern T cell tolerance. Several genetic defects have been described in humans that affect early stages of T cell development [leading to severe combined immune deficiency (SCID)] or late stages in thymocyte maturation (resulting in combined immunodeficiency). Hypomorphic mutations in SCID-causing genes may allow for generation of a limited pool of T lymphocytes with a restricted repertoire. These conditions are often associated with infiltration of peripheral tissues by activated T cells and immune dysregulation, as best exemplified by Omenn syndrome (OS). In this review, we will discuss our recent findings on abnormalities of thymic microenvironment in OS with a special focus of defective maturation of TECs, altered distribution of thymic dendritic cells and impairment of deletional and non-deletional mechanisms of central tolerance. Here, taking advantage of mouse models of OS and atypical SCID, we will discuss how modifications in stromal compartment impact and shape lymphocyte differentiation, and vice versa how inefficient T cell signaling results in defective stromal maturation. These findings are instrumental to understand the extent to which novel therapeutic strategies should act on thymic stroma to achieve full immune reconstitution.
[Show abstract][Hide abstract] ABSTRACT: The Primary Immune Deficiency Treatment Consortium (PIDTC) is a network of 33 centers in North America that study the treatment of rare and severe primary immunodeficiency diseases. Current protocols address the natural history of patients treated for severe combined immunodeficiency (SCID), Wiskott-Aldrich syndrome, and chronic granulomatous disease through retrospective, prospective, and cross-sectional studies. The PIDTC additionally seeks to encourage training of junior investigators, establish partnerships with European and other International colleagues, work with patient advocacy groups to promote community awareness, and conduct pilot demonstration projects. Future goals include the conduct of prospective treatment studies to determine optimal therapies for primary immunodeficiency diseases. To date, the PIDTC has funded 2 pilot projects: newborn screening for SCID in Navajo Native Americans and B-cell reconstitution in patients with SCID after hematopoietic stem cell transplantation. Ten junior investigators have received grant awards. The PIDTC Annual Scientific Workshop has brought together consortium members, outside speakers, patient advocacy groups, and young investigators and trainees to report progress of the protocols and discuss common interests and goals, including new scientific developments and future directions of clinical research. Here we report the progress of the PIDTC to date, highlights of the first 2 PIDTC workshops, and consideration of future consortium objectives.
The Journal of allergy and clinical immunology 10/2013; · 12.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: For many years, severe combined immune deficiency diseases, which are characterized by virtual lack of circulating T cells and severe predisposition to infections since early in life, have been considered the prototypic forms of genetic defects of T-cell development. More recently, advances in genome sequencing have allowed identification of a growing number of gene defects that cause severe but incomplete defects in T-cell development, function, or both. Along with recurrent and severe infections, especially cutaneous viral infections, the clinical phenotype of these conditions is characterized by prominent immune dysregulation.
The Journal of allergy and clinical immunology 03/2013; · 12.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The characterization of primary immunodeficiencies (PIDs) in human subjects is crucial for a better understanding of the biology of the immune response. New achievements in this field have been possible in light of collaborative studies; attention paid to new phenotypes, infectious and otherwise; improved immunologic techniques; and use of exome sequencing technology. The International Union of Immunological Societies Expert Committee on PIDs recently reported on the updated classification of PIDs. However, new PIDs are being discovered at an ever-increasing rate. A series of 19 novel primary defects of immunity that have been discovered after release of the International Union of Immunological Societies report are discussed here. These new findings highlight the molecular pathways that are associated with clinical phenotypes and suggest potential therapies for affected patients.
The Journal of allergy and clinical immunology 02/2013; 131(2):314-23. · 12.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Severe combined immunodeficiency (SCID) comprises a group of disorders that are fatal owing to genetic defects that abrogate T cell development. Numerous related defects have recently been identified that allow T cell development but that compromise T cell function by affecting proximal or distal steps in intracellular signaling. These functional T cell immunodeficiencies are characterized by immune dysregulation and increased risk of malignancies, in addition to infections. The study of patients with these rare conditions, and of corresponding animal models, illustrates the importance of intracellular signaling to maintain T cell homeostasis. Expected final online publication date for the Annual Review of Immunology Volume 31 is March 19, 2013. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
Annual Review of Immunology 01/2013; · 36.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We report the clinical description and molecular dissection of a new fatal human inherited disorder characterized by chronic autoinflammation, invasive bacterial infections and muscular amylopectinosis. Patients from two kindreds carried biallelic loss-of-expression and loss-of-function mutations in HOIL1 (RBCK1), a component of the linear ubiquitination chain assembly complex (LUBAC). These mutations resulted in impairment of LUBAC stability. NF-κB activation in response to interleukin 1β (IL-1β) was compromised in the patients' fibroblasts. By contrast, the patients' mononuclear leukocytes, particularly monocytes, were hyper-responsive to IL-1β. The consequences of human HOIL-1 and LUBAC deficiencies for IL-1β responses thus differed between cell types, consistent with the unique association of autoinflammation and immunodeficiency in these patients. These data suggest that LUBAC regulates NF-κB-dependent IL-1β responses differently in different cell types.
[Show abstract][Hide abstract] ABSTRACT: Deficiency of the purine salvage enzyme adenosine deaminase leads to SCID (ADA-SCID). Hematopoietic cell transplantation (HCT) can lead to a permanent cure of SCID; however, little data are available on outcome of HCT for ADA-SCID in particular. In this multicenter retrospective study, we analyzed outcome of HCT in 106 patients with ADA-SCID who received a total of 119 transplants. HCT from matched sibling and family donors (MSDs, MFDs) had significantly better overall survival (86% and 81%) in comparison with HCT from matched unrelated (66%; P < .05) and haploidentical donors (43%; P < .001). Superior overall survival was also seen in patients who received unconditioned transplants in comparison with myeloablative procedures (81% vs 54%; P < .003), although in unconditioned haploidentical donor HCT, nonengraftment was a major problem. Long-term immune recovery showed that regardless of transplant type, overall T-cell numbers were similar, although a faster rate of T-cell recovery was observed after MSD/MFD HCT. Humoral immunity and donor B-cell engraftment was achieved in nearly all evaluable surviving patients and was seen even after unconditioned HCT. These data detail for the first time the outcomes of HCT for ADA-SCID and show that, if patients survive HCT, long-term cellular and humoral immune recovery is achieved.