X-linked agammaglobulinemia (XLA) is caused by mutations in the Bruton tyrosine kinase)
BTK
) gene. Affected patients have severely reduced amounts of circulating B cells. Patients with atypical XLA ...may have residual circulating B cells, and there are few studies exploring these cells’ repertoire. We aimed to study the B cell repertoire of a novel hypomorphic mutation in the
BTK
gene, using the next generation sequencing (NGS) technology. Clinical data was collected from our clinical records. Real-time PCR was used to determine KREC copies, and NGS was used to determine the immunoglobulin (Ig) heavy chain (IgH) repertoire diversity. Both patients had a relatively mild clinical and laboratory phenotype, residual BTK protein expression, and the same novel mutation in the
BTK
gene, c.1841 T > C, p. L614P. Signal-joint kappa-deleting recombination excision circles (sj-KREC) for both patients were completely absent reflecting lack of naïve B cells. The intron RSS-Kde coding joints (cj) were significantly reduced, reflecting residual replicating B cells. NGS displayed restricted IgH repertoire with highly uneven distribution of clones, especially for Pt2. We report a novel
BTK
mutation, c.1841 T > C (p. L614P) that is associated with a relatively mild phenotype. We conclude that the IgH repertoire in atypical XLA is restricted with highly uneven distribution of clones. This phenomenon may be explained by extremely reduced to non-existent levels of BTK in B cells. This report sheds further light on atypical cases of XLA.
Biallelic mutations in the zeta-associated protein 70 (
ZAP70
) gene cause combined immunodeficiency (CID). Neonatal screening for severe CID in Israel is implemented since 2015. We report on ...clinical, flow cytometry, and genetic data of an unusual ZAP70 deficiency patient. A 10-week-old Bedouin female presented with severe autoimmune hemolytic anemia. Cytomegalovirus (CMV) negative packed cell therapy was given without improvement; indexes of hemolysis worsened. At this time, thrombocytopenia was noted. The patient was treated with single dose of 1 g/kg intravenous immunoglobulin with rapid resolution of hemolysis. Serum immunoglobulin concentrations were normal; flow cytometry revealed severe CD8 lymphocytopenia. Lymphocyte proliferation test demonstrated reduced response to concanavalin A and phytohemagglutinin. Gated T cells were negative for intracellular ZAP70. A genetic analysis revealed a missense homozygous c.1388C > T (p.A463V) mutation, confirming the diagnosis of ZAP70 deficiency. She later on developed urinary tract infection due to ESBL producing
E. coli
treated with amikacin and severe CMV infection that partially responded to ganciclovir therapy and at 7 months of age, she successfully underwent allogeneic hematopoietic stem cell transplantation. Neonatal screening by T cell receptor excision circles (TRECs) for SCID was normal, yet very low TRECs were recorded at the time of CID diagnosis. Normal neonatal screening for SCID does not rule out the diagnosis of CID due to ZAP70 deficiency. This type of CID can present with autoimmunity as the sole initial manifestation of the disease.
Autosomal dominant hyper-IgE syndrome (AD-HIES) caused by dominant negative (DN) variants in the signal transducer and activator of transcription 3 gene (
) is characterized by recurrent ...Staphylococcal abscesses, severe eczema, chronic mucocutaneous candidiasis (CMC), and non-immunological facial and skeletal features.
To describe our experience with the diagnosis and treatment of adult patients with AD-HIES induced by DN-
variants.
The medical records of adult patients (>18 years) treated at the Allergy and Clinical Immunology Clinic of Hadassah Medical Center, Jerusalem, Israel, were retrospectively analyzed. Immune and genetic workups were used to confirm diagnosis.
Three adult patients (2 males; age 29-41 years) were diagnosed with DN-
variants. All patients had non-immunological features, including coarse faces and osteopenia. Serious bacterial infections were noted in all patients, including recurrent abscesses, recurrent pneumonia, and bronchiectasis. CMC and diffuse dermatophytosis were noted in two patients. Two patients had severe atopic dermatitis refractory to topical steroids and phototherapy. Immune workup revealed elevated IgE in three patients and eosinophilia in two patients. Whole exome sequencing revealed DN-
variants (c.1166C>T; p.Thr389Ile in two patients and c.1268G>A; p. Arg423Gln in one patient). Variants were located in DNA-binding domain (DBD) and did not hamper STAT3 phosphorylation Treatment included antimicrobial prophylaxis with trimethoprim/sulfamethoxazole (n=2) and amoxycillin-clavulanic acid (n=1), and anti-fungal treatment with fluconazole (n=2) and voriconazole (n=1). Two patients who had severe atopic dermatitis, were treated with dupilumab with complete resolution of their rash. No adverse responses were noted in the dupilumab-treated patients.
Dupilumab can be used safely as a biotherapy for atopic dermatitis in these patients as it can effectively alleviate eczema-related symptoms. Immunologists and dermatologists treating AD-HIES adult patients should be aware of demodicosis as a possible manifestation. DN-
variants in DBD do not hamper STAT3 phosphorylation.
The transcription factor GATA2 plays a key role in the survival and self-renewal of hematopoietic stem and progenitor cells. Autosomal dominant variants in
cause a broad spectrum of heterogeneous ...phenotypes. Here, we present our experience with GATA2 deficiency in a retrospective multicenter analysis of computerized medical records of adult patients (age ≥18 years) treated between 2018 and 2022 at Shaare Zedek Medical Center in Jerusalem and Sheba Tel-Hashomer Medical Center in Ramat Gan, Israel. Two male and two female patients with GATA2 deficiency were identified. Three of the patients presented with symptoms in adult life and all patients were diagnosed as adults. Age at presentation was 10.5-36 years and age at diagnosis 24-47 years. Diagnosis was delayed in all patients by 1-24.5 years. The phenotypic diversity was notable. Patients presented with myelodysplastic syndrome (n=2), pulmonary alveolar proteinosis (n=1), and recurrent viral (n=1), bacterial (n=3), and mycobacterial (n=1) infections. Bone marrow biopsy revealed cytogenetic abnormalities in one patient (monosomy 7). Patients were diagnosed by exome sequencing (n=3) and Sanger sequencing of the coding exons in
(n=1). Novel heterozygous
variants (c.177C>A, p.Y59* and c.610dup, p.R204Pfs*78) were identified in two patients. Immune workup revealed B cell lymphopenia and monocytopenia in all tested patients. One patient died from overwhelming sepsis despite all patients being treated with antibiotics and anti-mycobacterials. Our cohort highlights the phenotypic diversity, late presentation, and delayed diagnosis of GATA2 deficiency. Increased awareness of this primary immune deficiency presenting in adult life is needed and should involve a high index of suspicion.
Infants with severe combined immunodeficiency (SCID) are at risk of developing severe life-threatening infections if they are inadvertently given attenuated live vaccines. Concomitant appearance of ...two live vaccine-associated complications in one person is rarely reported. In this study, we present two SCID infants, who received BCG and oral polio vaccines according to their local immunization schedule early in life, before the diagnosis of immunodeficiency was made. Their clinical presentation, extensive immunological workup, genetic tests, and clinical disease course are presented. Both patients developed localized and disseminated infections originating from the BCG vaccine (BCGitis and BCGiosis, respectively) and in addition suffered from diarrhea and chronic fecal secretion of vaccine-derived poliovirus. Alarmingly, in case 2, the poliovirus was a type 2 vaccine-derived poliovirus in which both neurovirulence attenuation sites reverted to the neurovirulent genotype. These cases highlight the importance of early recognition of SCID by neonatal screening or thorough family anamnesis, and the need to further defer the timing of administration of attenuated live vaccines.
Patients with loss-of-function mutations in IL10 or IL10 receptor (IL10R) genes develop severe, medical-refractory, infantile-onset inflammatory bowel disease (IBD). We have previously reported ...significant alterations in innate and adaptive immune responses in these patients. Next generation sequencing platforms enable a comprehensive assessment of T cell receptor (TCR) and B cell receptor (BCR) repertoire patterns. We aimed to characterize TCR and BCR features in peripheral blood of patients with deleterious IL10 signaling defects. DNA was isolated from blood of seven patients with IL10R mutations and one with an IL10 mutation, along with eight controls, and subjected to next generation sequencing of
and
loci. A significant increase in clonality was observed in both TCR and BCR repertoires in circulating lymphocytes of IL10/IL10R-deficient patients, but to a much greater extent in T cells. Furthermore, short CDR3β length and altered hydrophobicity were demonstrated in T cells of patients, but not in B cells, secondary to lower rates of insertions of nucleotides, but not deletions, at the V-, D-, or J-junctions. We were unable to observe specific T or B clones that were limited only to the patients or among controls. Moreover, the expanded T cells clones were unique to each patient. In conclusion, next generation sequencing of the TCR and BCR is a powerful tool for characterizing the adaptive immune cell phenotype and function in immune-mediated disorders. The oligoclonality observed among IL10/IL10R-deficient patients may suggest specialization of unique clones that likely have a role in mediating tissue damage. Nevertheless, the lack of shared clones between patients provides another piece of evidence that the adaptive immune response in IBD is not triggered against common antigens. Additional studies are required to define the specific antigens that interact with the expanded IL10/IL10R-deficient clones.
The kinetics of T and B cell immune recovery after bone marrow transplantation (BMT) is affected by many pre- and post-transplant factors. Because of the profoundly depleted baseline T and B cell ...immunity in recombination activating gene 2 (RAG-2)-deficient severe combined immunodeficiency (SCID) patients, some of these factors are eliminated, and the immune recovery after BMT can then be clearly assessed. This process was followed in ten SCID patients in parallel to their associated transplant-related complications. Early peripheral presence of T and B cells was observed in 8 and 4 patients, respectively. The latter correlated with pre-transplant conditioning therapy. Cells from these patients carried mainly signal joint DNA episomes, indicative of newly derived B and T cells. They were present before the normalization of the T cell receptor (TCR) and the B cell receptor (BCR) repertoire. Early presentation of the ordered TCR gene rearrangements after BMT occurred simultaneously, but this pattern was heterogeneous over time, suggesting different and individual thymic recovery processes. Our findings early after transplant could suggest the long-term patients' clinical outcome. Early peripheral presence of newly produced B and T lymphocytes from their production and maturation sites after BMT suggests donor stem cell origin rather than peripheral expansion, and is indicative of successful outcome. Peripheral detection of TCR excision circles and kappa-deleting recombination excision circles in RAG-2-deficient SCID post-BMT are early markers of T and B cell reconstitution, and can be used to monitor outcome and tailor specific therapy for patients undergoing BMT.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Mutations in dedicator of cytokinesis 8 gene (DOCK8) gene cause a combined immunodeficiency that can be diagnosed as a hyper IgE syndrome and DOCK8 plays a role in reorganization of the F-actin ...cytoskeleton in NK and dentritic cells. Neutrophil functions, including chemotaxis, phagocytosis and superoxide generation were studied in neutrophils from DOCK8 deficient patients compared to neutrophils from healthy controls.
The alpha subunit of IL-7 receptor (IL7R7α) is critical for the differentiation of T cells, specifically for the development and maintenance of γδT cells. Mutations in
are associated with Severe ...Combined Immunodeficiency (SCID). Infants with
deficiency can be identified through newborn screening program. We aimed at defining the immunological and genetic parameters that are directly affected by the
mutation on the immune system of five unrelated patients which were identified by our newborn screening program for SCID. The patients were found to have a novel identical homozygote mutation in
(n.c.120 C>G; p.F40L). Both surface expression of IL7Rα and functionality of IL-7 signaling were impaired in patients compared to controls. Structural modeling demonstrated instability of the protein structure due to the mutation. Lastly the
immune repertoire of the patients showed reduced diversity, increased clonality and differential CDR3 characteristics. Interestingly, the patients displayed significant different clinical outcome with two displaying severe clinical picture of immunodeficiency and three had spontaneous recovery. Our data supports that the presented
mutation affects the IL-7 signaling and shaping of the
repertoire, reinforcing the role of
in the immune system, while non-genetic factors may exist that attribute to the ultimate clinical presentation and disease progression.
Thymic function in MHC class II–deficient patients Lev, Atar, MSc; Simon, Amos J., BSc; Broides, Arnon, MD ...
Journal of allergy and clinical immunology,
03/2013, Letnik:
131, Številka:
3
Journal Article
Recenzirano
Background MHC class II (MHC-II) molecules play a pivotal role in the development, activation, and homeostasis of CD4+ TH cells in the thymus. The absence of MHC-II molecules causes severe T-cell ...immunodeficiency. Objective We sought to study thymic function, including T-cell receptor excision circle (TREC) quantification, in patients with MHC-II deficiency. Methods Eight MHC-II–deficient patients underwent a thorough T-cell immunologic work-up, including thymic activity, which was estimated based on TREC levels and T-cell receptor (TCR) genes, as well as analysis of several sequential human TCR gene rearrangements. Results In vitro responses to mitogens were normal or only slightly reduced, and flow cytometric evaluations of the TCR-Vβ repertoires of total CD3+ lymphocytes were normal in all patients. However, both the flow cytometric evaluation of the TCR-Vβ repertoire on CD4+ cells and spectratyping evaluation of the TCR-Vγ repertoire on total CD3+ lymphocytes showed clonal abnormalities. TRECs were present in all patients in both total lymphocytes and sorted CD4+ cells. Additionally, TRECs were detected in genomic DNA obtained from Guthrie cards with dried blood spots. Quantitative RT-PCR assessment of different TCR gene rearrangement events revealed lower levels in MHC-II–deficient patients compared with levels seen in healthy control subjects. This was irrespective of the total lymphocyte numbers, suggesting a reduced global thymic activity. Conclusions Our report highlights potential pitfalls in diagnosing MHC-II deficiency and emphasizes the probable importance of MHC-II molecules in the normal thymic maturation process of T cells. Patients with MHC-II deficiency have detectable TRECs and might therefore be missed by a TREC-based newborn screening program.
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