Genotype-phenotype correlations in chronic granulomatous disease: insights from a large national cohort.

ABSTRACT: Neutrophils are the first line of defense against invading pathogens. Neutrophils execute and modulate immune responses by generating reactive oxygen species (ROS). Chronic granulomatous disease (CGD) is a primary immune deficiency disorder of phagocytes, caused by inherited mutations in the genes of the nicotinamide adenine dinucleotide phosphate reduced oxidase enzyme. These mutations lead to failure of ROS generation followed by recurrent bacterial and fungal infections, frequently associated with hyperinflammatory manifestations. We report a multicenter cumulative experience in diagnosing and treating patients with CGD. From 1986 to 2021, 2918 patients experiencing frequent infections were referred for neutrophil evaluation. Among them, 110 patients were diagnosed with CGD: 56 of Jewish ancestry, 48 of Arabic ancestry, and 6 of non-Jewish/non-Arabic ancestry. As opposed to other Western countries, the autosomal recessive (AR) CGD subtypes were predominant in Israel (71/110 patients). Thirty-nine patients had X-linked CGD, in most patients associated with severe infections (clinical severity score ≥3) and poor outcomes, presenting at a significantly earlier age than AR-CGD subtypes. The full spectrum of infections and hyperinflammatory manifestations is described. Six patients had hypomorphic mutations with significantly milder phenotype, clinical severity score ≤2, and better outcomes. Hematopoietic stem cell transplantation was implemented in 39 of 110 patients (35.5%). Successful engraftment was achieved in 92%, with 82% long-term survival and 71% full clinical recovery. CGD is a complex disorder requiring a multiprofessional team. Early identification of the genetic mutation is essential for prompt diagnosis, suitable management, and prevention.

Combined Immunodeficiency Caused by a Novel Nonsense Mutation in LCK.

Mutations affecting T-cell receptor (TCR) signaling typically cause combined immunodeficiency (CID) due to varying degrees of disturbed T-cell homeostasis and differentiation. Here, we describe two cousins with CID due to a novel nonsense mutation in LCK and investigate the effect of this novel nonsense mutation on TCR signaling, T-cell function, and differentiation. Patients underwent clinical, genetic, and immunological investigations. The effect was addressed in primary cells and LCK-deficient T-cell lines after expression of mutated LCK. RESULTS: Both patients primarily presented with infections in early infancy. The LCK mutation led to reduced expression of a truncated LCK protein lacking a substantial part of the kinase domain and two critical regulatory tyrosine residues. T cells were oligoclonal, and especially naïve CD4 and CD8 T-cell counts were reduced, but regulatory and memory including circulating follicular helper T cells were less severely affected. A diagnostic hallmark of this immunodeficiency is the reduced surface expression of CD4. Despite severely impaired TCR signaling mTOR activation was partially preserved in patients' T cells. LCK-deficient T-cell lines reconstituted with mutant LCK corroborated partially preserved signaling. Despite detectable differentiation of memory and effector T cells, their function was severely disturbed. NK cell cytotoxicity was unaffected. Residual TCR signaling in LCK deficiency allows for reduced, but detectable T-cell differentiation, while T-cell function is severely disturbed. Our findings expand the previous report on one single patient on the central role of LCK in human T-cell development and function.

CD137 deficiency causes immune dysregulation with predisposition to lymphomagenesis.

Dysregulated immune responses are essential underlying causes of a plethora of pathologies including cancer, autoimmunity, and immunodeficiency. We here investigated 4 patients from unrelated families presenting with immunodeficiency, autoimmunity, and malignancy. We identified 4 distinct homozygous mutations in TNFRSF9 encoding the tumor necrosis factor receptor superfamily member CD137/4-1BB, leading to reduced, or loss of, protein expression. Lymphocytic responses crucial for immune surveillance, including activation, proliferation, and differentiation, were impaired. Genetic reconstitution of CD137 reversed these defects. CD137 deficiency is a novel inborn error of human immunity characterized by lymphocytic defects with early-onset Epstein-Barr virus (EBV)-associated lymphoma. Our findings elucidate a functional role and relevance of CD137 in human immune homeostasis and antitumor responses.

Genotype and functional correlates of disease phenotype in deficiency of adenosine deaminase 2 (DADA2).

BACKGROUND: Deficiency of adenosine deaminase 2 (DADA2) is a syndrome with pleiotropic manifestations including vasculitis and hematologic compromise. A systematic definition of the relationship between adenosine deaminase 2 (ADA2) mutations and clinical phenotype remains unavailable. OBJECTIVE: We sought to test whether the impact of ADA2 mutations on enzyme function correlates with clinical presentation. METHODS: Patients with DADA2 with severe hematologic manifestations were compared with vasculitis-predominant patients. Enzymatic activity was assessed using expression constructs reflecting all 53 missense, nonsense, insertion, and deletion genotypes from 152 patients across the DADA2 spectrum. RESULTS: We identified patients with DADA2 presenting with pure red cell aplasia (n = 5) or bone marrow failure (BMF, n = 10) syndrome. Most patients did not exhibit features of vasculitis. Recurrent infection, hepatosplenomegaly, and gingivitis were common in patients with BMF, of whom half died from infection. Unlike patients with DADA2 with vasculitis, patients with pure red cell aplasia and BMF proved largely refractory to TNF inhibitors. ADA2 variants associated with vasculitis predominantly reflected missense mutations with at least 3% residual enzymatic activity. In contrast, pure red cell aplasia and BMF were associated with missense mutations with minimal residual enzyme activity, nonsense variants, and insertions/deletions resulting in complete loss of function. CONCLUSIONS: Functional interrogation of ADA2 mutations reveals an association of subtotal function loss with vasculitis, typically responsive to TNF blockade, whereas more extensive loss is observed in hematologic disease, which may be refractory to treatment. These findings establish a genotype-phenotype spectrum in DADA2.

Atypical immune phenotype in severe combined immunodeficiency patients with novel mutations in IL2RG and JAK3.

Mutations in the common gamma chain of the interleukin 2 receptor (IL2RG) or the associated downstream signaling enzyme Janus kinase 3 (JAK3) genes are typically characterized by a T cell-negative, B cell-positive, natural killer (NK) cell-negative (T-B+NK-) severe combined immunodeficiency (SCID) immune phenotype. We report clinical course, immunological, genetic and proteomic work-up of two patients with different novel mutations in the IL-2-JAK3 pathway with a rare atypical presentation of T-B+NK- SCID. Lymphocyte subpopulation revealed significant T cells lymphopenia, normal B cells, and NK cells counts (T-B+NK+SCID). Despite the presence of B cells, IgG levels were low and IgA and IgM levels were undetectable. T-cell proliferation in response to mitogens in patient 1 was very low and T-cell receptor V-beta chain repertoire in patient 2 was polyclonal. Whole-exome sequencing revealed novel mutations in both patients (patient 1-c.923delC frame-shift mutation in the IL2RG gene, patient 2-c.G172A a homozygous missense mutation in the JAK3 gene). Bioinformatic analysis of the JAK3 mutation indicated deleterious effect and 3D protein modeling located the mutation to a surface exposed alpha-helix structure. Our findings help to link between genotype and phenotype, which is a key factor for the diagnosis and treatment of SCID patients.

Whole exome sequencing (WES) approach for diagnosing primary immunodeficiencies (PIDs) in a highly consanguineous community.

Primary immunodeficiencies (PIDs) are a heterogeneous group of monogenic inborn errors of immunity. The genetic causes of these diseases can be identified using whole exome sequencing (WES). Here, DNA samples from 106 patients with a clinical suspicion of PID were subjected to WES in order to test the diagnostic yield of this test in a highly consanguineous community. A likely genetic diagnosis was achieved in 70% of patients. Several factors were considered to possibly influence the diagnostic rate of WES among our cohort including early age, presence of consanguinity, family history suggestive of PID, the number of family members who underwent WES and the clinical phenotype of the patient. The highest diagnostic rate was in patients with combined immunodeficiency or with a syndrome. Notably, WES findings altered the clinical management in 39% (41/106) of patients in our cohort. Our findings support the use of WES as an important diagnostic tool in patients with suspected PID, especially in highly consanguineous communities.

A Large Cohort of RAG1/2-Deficient SCID Patients-Clinical, Immunological, and Prognostic Analysis.

INTRODUCTION: Severe combined immunodeficiency (SCID) is a fatal disorder resulting from various genetic defects. In the Middle East, where consanguineous marriage is prevalent, autosomal recessive mutations in recombination-activating genes (RAG) are a leading cause of SCID. We present a large cohort of SCID patients due to RAG1 or RAG2 mutations. METHODS: Twenty-six patients with RAG1 or RAG2 deficiency, diagnosed at Sheba Medical Center, were retrospectively investigated. Clinical presentation, immunologic phenotype, genetic analysis, treatment, and outcome were analyzed. RESULTS: Majority of patients were referred from the Palestinian Authority. Most patients were males of Muslim Arab descent, 77% were born to consanguineous parents, and 65% had family history of immunodeficiency. Nearly all patients suffered from various infections before turning 2 months old, eight patients (31%) presented with Omenn and Omenn-like syndrome, and three patients (11%) had maternal engraftment. Notably, seven patients (27%) suffered from vaccine-derived infections, including a rare case of measles encephalitis. Nineteen patients underwent hematopoietic stem cell transplantation (HSCT) at a median age of 6 months, with a successful outcome for 72% of them. Genetic analysis revealed 11 different mutations (7 RAG2, 4 RAG1), two of them novel. CONCLUSIONS: Consanguineous marriages account for a genetic "founder effect." SCID is a pediatric emergency that dictates immediate precautions and curative treatment with HSCT. Due to lack of newborn screening for SCID within the Palestinian population, most patients in this cohort were diagnosed upon clinical symptoms, which led to a delayed diagnosis, harmful administration of contra-indicated live vaccines, delay in HSCT, and poor outcome.

An RTEL1 Mutation Links to Infantile-Onset Ulcerative Colitis and Severe Immunodeficiency.

PURPOSE: More than 50 different monogenic disorders causing inflammatory bowel disease (IBD) have been identified. Our goal was to characterize the clinical phenotype, genetic workup, and immunologic alterations in an Ashkenazi Jewish patient that presented during infancy with ulcerative colitis and unique clinical manifestations. METHODS: Immune workup and whole-exome sequencing were performed, along with Sanger sequencing for confirmation. Next-generation sequencing of the TCRB and IgH was conducted for immune repertoire analysis. Telomere length was evaluated by in-gel hybridization assay. Mass cytometry was performed on patient's peripheral blood mononuclear cells, and compared with control subjects and patients with UC. RESULTS: The patient presented in infancy with failure to thrive and dysmorphic features, consistent with a diagnosis of dyskeratosis congenita and Hoyeraal-Hreidarsson syndrome. Severe ulcerative colitis manifested in the first year of life and proceeded to the development of a primary immunodeficiency, presenting as Pneumocystis jiroveci pneumonia and hypogammaglobulinemia. Genetic studies identified a deleterious homozygous C.3791G>A missense mutation in the helicase regulator of telomere elongation 1 (RTEL1), leading to short telomeres in the index patient. Immune repertoire studies showed polyclonal T and B cell receptor distribution, while mass cytometry analysis demonstrated marked immunological alterations, including a predominance of naïve T cells, paucity of B cells, and a decrease in various innate immune subsets. CONCLUSIONS: RTEL1 mutations are associated with significant alterations in immune landscape and can manifest with infantile-onset IBD. A high index of suspicion is required in Ashkenazi Jewish families where the carriage rate of the C.3791G>A variant is high.

Novel MALT1 Mutation Linked to Immunodeficiency, Immune Dysregulation, and an Abnormal T Cell Receptor Repertoire.

MALT1 (mucosa-associated lymphoid tissue lymphoma-translocation gene 1) is an intracellular signaling protein that activates NFκB and is crucial for both the adaptive and innate immune responses. Only 6 patients with immune deficiencies secondary to inherited mutations in the MALT1 gene have been described. PURPOSE: To provide clinical and immunological insights from 2 patients diagnosed with MALT1 immunodeficiency syndrome due to a novel MALT1 mutation. METHODS: Two cousins with suspected combined immunodeficiency underwent immunological and genetic work-up, including lymphocyte phenotyping, lymphocyte activation by mitogen stimulation, and next-generation sequencing (NGS) of T cell receptor gamma chain (TRG) repertoire. Whole exome sequencing was performed to identify the underlying genetic defect. RESULTS: Clinical findings included recurrent infections, failure to thrive, lymphadenopathy, dermatitis, and autoimmunity. Immune work-up revealed lymphocytosis, low to normal levels of immunoglobulins, absence of regulatory T cells, and low Th17 cells. A normal proliferative response was induced by phytohemagglutinin and IL-2 but was diminished with anti-CD3. TRG repertoire was diverse with a clonal expansion pattern. Genetic analysis identified a novel autosomal recessive homozygous c.1799T>A; p. I600N missense mutation in MALT1. MALT1 protein expression was markedly reduced, and in vitro IL-2 production and NFκB signaling pathway were significantly impaired. CONCLUSIONS: Two patients harboring a novel MALT1 mutation presented with signs of immune deficiency and dysregulation and were found to have an abnormal T cell receptor repertoire. These findings reinforce the link between MALT1 deficiency and combined immunodeficiency. Early diagnosis is crucial, and curative treatment by hematopoietic stem cell transplantation may be warranted.

A structured graduated protocol with heat denatured eggs in the treatment of egg allergy.

BACKGROUND: Most children with egg allergy (EA) can tolerate extensively heated and baked egg (EHBE). Consumption of EHBE may promote faster resolution of EA; however, no consensus exists as to the required amounts and treatment protocols. OBJECTIVE: To evaluate the efficacy and safety of a structured graduated exposure protocol (SGEP) with EHBE in promoting tolerance to eggs in EA children under 2 years of age. METHODS: In a case-control study, EA children aged < 2 years who were treated with SGEP including EHBE were compared to children treated with strict avoidance. Data were collected from records and telephone questionnaires. Analysis was performed using non-parametric Kaplan-Meier and Cox proportional hazard regression models. RESULTS: Thirty-nine egg-allergic children with a median age at intervention of 16 months (interquartile range: 13-19) were treated with SGEP and followed to a median age of 39 months (26.8-50.0). The median age at resolution of EA was compared to a matched group of 80 children treated with strict avoidance at least until 2 years of age or earlier natural resolution and followed to a median age of 69 months (46-104). The median estimated age at EA resolution in the SGEP group was 24 months (95% CI, 19.5-28.5 months), compared to 78 months (95% CI, 53-102) in the control group, P < .001. At last follow-up, 82% of treated children were tolerant to lightly cooked eggs vs 54% of controls, P = .001. CONCLUSION: A structured protocol with EHBE appears to promote faster resolution of EA.

Correction to: Novel Mutations in RASGRP1 Are Associated with Immunodeficiency, Immune Dysregulation, and EBV-Induced Lymphoma.

The original version of this article unfortunately contained mistakes in Author's name, in Table 1 and in result section.

Novel Mutations in RASGRP1 are Associated with Immunodeficiency, Immune Dysregulation, and EBV-Induced Lymphoma.

PURPOSE: RAS guanyl-releasing protein 1 (RASGRP1) deficiency has recently been shown to cause a primary immunodeficiency (PID) characterized by CD4+ T cell lymphopenia and Epstein-Barr virus (EBV)-associated B cell lymphoma. Our report of three novel patients widens the scope of RASGRP1 deficiency by providing new clinical and immunological insights on autoimmunity, immune cell development, and predisposition to lymphoproliferative disease. METHODS: One patient of Turkish origin (P1) and two Palestinian patients (P2, P3) were evaluated for immunodeficiency. To decipher the molecular cause of disease, whole exome sequencing was conducted. Identified mutations were validated by immunological and biochemical assays. RESULTS: We report three patients presenting with similar clinical characteristics of immunodeficiency and EBV-associated lymphoproliferative disease. In addition, P2 and P3 exhibited overt autoimmune manifestations. Genetic screening identified two novel loss-of-function mutations in RASGRP1. Immunoblotting and active Ras pull-down assays confirmed perturbed ERK1/2 signaling and reduced Ras-GTPase activity in heterologous Jurkat cells with ectopic expression of RASGRP1 mutants. All three patients had CD4+ T cell lymphopenia. P2 and P3 showed decreased mitogen-induced lymphocyte proliferation, reduced T cell receptor excision circles, abnormal T cell receptor (TCR) Vß repertoires, and increased frequencies of TCRγδ cells. TCR gamma repertoire diversity was significantly reduced with a remarkable clonal expansion. CONCLUSIONS: RASGRP1 deficiency is associated with life-threatening immune dysregulation, severe autoimmune manifestations, and susceptibility to EBV-induced B cell malignancies. Early diagnosis is critical and hematopoietic stem cell transplantation might be considered as curative treatment.

A Structured Gradual Exposure Protocol to Baked and Heated Milk in the Treatment of Milk Allergy.

OBJECTIVE: To evaluate the efficacy and safety of a structured gradual exposure protocol (SGEP) with extensively heated and baked milk in promoting allergy resolution in children with cow milk allergy (CMA). STUDY DESIGN: In a case control study, children with CMA aged 1-4 years who were treated with SGEP including extensively heated and baked milk, were compared with children treated with strict avoidance. Data were collected from medical records and from validated telephone questionnaires. Data analysis was performed using a nonparametric Kaplan-Meier and proportional hazard Cox regression model, after evaluation of the adequacy of the case control matching. RESULTS: There were 43 children with milk allergy-26 (62%) males with a mean age at intervention of 21 months (range, 12-47 months)-who were treated with SGEP and followed to a mean age of 40 months (range, 20-82 months). The median age at resolution of CMA was compared with a matched group of 67 children treated with strict avoidance at least until 4 years of age or followed until earlier resolution, with a mean age at follow-up of 71 months (range, 11-176 months). The median estimated age at CMA resolution in the SGEP group was 36 months (95% CI, 34.5-49.7) compared with 98 months (95% CI, 82.4-114.1) in controls (P < .001). At last follow-up, 86% of treated children were tolerant to unheated milk proteins vs 52% of controls (P = .003). CONCLUSION: A structured protocol with extensively heated and baked milk seems to promote faster resolution of CMA.

[THE SERUM LEVELS OF MILK AND PEANUT-SPECIFIC IGE: ROLE IN THE EVALUATION OF THE RISK FOR ALLERGIC REACTION IN CHILDREN IN ISRAEL].

BACKGROUND: The performance characteristics of the ImmunoCAP assay for detecting specific IgE antibodies in the evaluation of milk and peanut allergy have been established. However, the results are not comparable to the IMMULITE 2000, another FDA-approved assay available in Israel, owing to differences in the extracts used, technical method, and population studied. OBJECTIVES: To establish the performance characteristics and predictive values for the IMMULITE 2000 assay in Israel. METHODS: The database of the Allergy Clinic at Schneider Children's Medical Center in Israel was searched for all patients referred for evaluation of allergies in 2006-2009. The results of the milk- and peanut-specific IgE antibody tests were collected and correlated with the clinical diagnoses of milk and peanut allergy or tolerance. Sensitivity, specificity and positive and negative predictive values were calculated as well as receiver operating characteristic (ROC) plots. RESULTS: The prevalence of milk allergy was 30% (111/369 patients), and peanut allergy, 6% (31/505 patients). The area under the ROC curve was 0.954 for milk allergy and 0.956 for peanut allergy. The levels with a positive predictive value of ≥95% were 10 kU/L and 3 kU/L, respectively. The level of peanut-specific IgE antibodies with a ≥95% positive predictive value was lower than found for the ImmunoCAP in the USA and Europe. CONCLUSIONS: These findings indicate that the decision points used for predicting the risk of future allergic reactions must be calculated separately for different assay methods and different populations. Our findings may assist the allergists in Israel to decide whether to perform a supervised oral challenge in order to verify if the patient has developed tolerance to milk or peanuts.

Prolonged excretion of type-2 poliovirus from a primary immune deficient patient during the transition to a type-2 poliovirus-free world, Israel, 2016.

Wild poliovirus type-2 has been eradicated, use of live type-2 vaccine has been terminated globally, and all type-2 polioviruses are under strict laboratory containment protocols. Re-emergence may arise from prolonged asymptomatic excretion of poliovirus by hospitalised primary immune deficient (PID) patients, as described here, through repeated exposure of close contacts to high titres of infected material. At this transition time, PID patients should be screened and hospital containment protocols updated in parallel with laboratory containment.

A horse or a zebra? Unusual manifestations of common cutaneous infections in primary immunodeficiency pediatric patients.

Background: Patients with primary immunodeficiency disorders (PIDs) often suffer from recurrent infections because of their inappropriate immune response to both common and less common pathogens. These patients may present with unique and severe cutaneous infectious manifestations that are not common in healthy individuals and may be more challenging to diagnose and treat. Objective: To describe a cohort of patients with PIDs with atypical presentations of skin infections, who posed a diagnostic and/or therapeutic challenge. Methods: This is a retrospective study of pediatric patients with PID with atypical presentations of infections, who were treated at the immunodeficiency specialty clinic and the pediatric dermatology clinic at the Sheba Medical Center between September 2012 and August 2022. Epidemiologic data, PID diagnosis, infectious etiology, presentation, course, and treatment were recorded. Results: Eight children with a diagnosis of PID were included, five of whom were boys. The average age at PID diagnosis was 1.7 (±SD 3.2) years. The average age of cutaneous infection was 6.9 (±SD 5.9) years. Three patients were born to consanguineous parents. The PIDs included the following: common variable immunodeficiency, severe combined immunodeficiency, DOCK8 deficiency, ataxia telangiectasia, CARD11 deficiency, MALT1 deficiency, chronic granulomatous disease, and a combined cellular and humoral immunodeficiency syndrome of unknown etiology. The infections included the following: ulcerative-hemorrhagic varicella-zoster virus (two cases) atypical fungal and bacterial infections, resistant Norwegian scabies, giant perianal verrucae (two cases), and diffuse molluscum contagiosum. Conclusions: In this case series, we present unusual manifestations of infectious skin diseases in pediatric patients with PID. In some of the cases, recognition of the infectious process prompted life-saving treatment. Increasing familiarity with these dermatological manifestations, as well as keeping a high index of suspicion, is important to enabling early diagnosis of cutaneous infections in PIDs and initiation of prompt suitable treatment.

Novel NHEJ1 pathogenic variant linked to severe combined immunodeficiency, microcephaly, and abnormal T and B cell receptor repertoires.

Background: During the process of generating diverse T and B cell receptor (TCR and BCR, respectively) repertoires, double-strand DNA breaks are produced. Subsequently, these breaks are corrected by a complex system led by the non-homologous end-joining (NHEJ). Pathogenic variants in genes involved in this process, such as the NHEJ1 gene, cause severe combined immunodeficiency syndrome (SCID) along with neurodevelopmental disease and sensitivity to ionizing radiation. Objective: To provide new clinical and immunological insights on NHEJ1 deficiency arising from a newly diagnosed patient with severe immunodeficiency. Materials and methods: A male infant, born to consanguineous parents, suspected of having primary immunodeficiency underwent immunological and genetic workup. This included a thorough assessment of T cell phenotyping and lymphocyte activation by mitogen stimulation tests, whole-exome sequencing (WES), TCR repertoire Vß repertoire via flow cytometry analysis, and TCR and BCR repertoire analysis via next-generation sequencing (NGS). Results: Clinical findings included microcephaly, recurrent pneumonia, and failure to thrive. An immune workup revealed lymphopenia, reduced T cell function, and hypogammaglobulinemia. Skewed TCR Vß repertoire, TCR gamma (TRG) repertoire, and BCR repertoire were determined in the patient. Genetic analysis identified a novel homozygous missense pathogenic variant in XLF/Cernunnos: c.A580Ins.T; p.M194fs. The patient underwent a successful hematopoietic stem cell transplantation (HSCT). Conclusion: A novel NHEJ1 pathogenic variant is reported in a patient who presented with SCID phenotype that displayed clonally expanded T and B cells. An adjusted HSCT was safe to ensure full T cell immune reconstitution.

Underperformed and Underreported Testing for Persistent Oropharyngeal Poliovirus Infections in Primary Immune Deficient Patients-Risk for Reemergence of Polioviruses.

BACKGROUND: Individuals with primary immune deficiencies (PIDs) may excrete poliovirus for extended periods and remain a major reservoir for polio after eradication. Poliovirus can spread by fecal-oral or oral-oral transmission. In middle- and high-income countries, oral-oral transmission may be more prevalent than fecal-oral transmission of polioviruses where PIDs patients survive longer. Our aim was to determine the prevalence of prolonged or persistent oropharyngeal poliovirus infections in PIDs. METHODS: We performed a literature search for reports of prolonged (excreting poliovirus for ≥6 months and ≤5 years) or persistent (excreting poliovirus for >5 years) poliovirus infections in PIDs. RESULTS: There were 140 PID cases with prolonged or persistent poliovirus infections. All had poliovirus-positive stools. Testing of oropharyngeal mucosa was only reported for 6 cases, 4 of which were positive. Molecular analyses demonstrated independent evolution of poliovirus in the gut and oropharyngeal mucosa in 2 cases. Seven PIDs had multiple lineages of the same poliovirus serotype in stools without information about polioviruses in oropharyngeal mucosa. CONCLUSIONS: Testing for persistence of poliovirus in oropharyngeal mucosa of PID patients is rare, with virus recovered in 4 of 5 cases in whom stools were positive. Multiple lineages or serotypes in 7 additional PID cases may indicate separate foci of infection, some of which might be in oropharyngeal mucosa. We recommend screening throat swabs in addition to stools for poliovirus in PID patients. Containment protocols for reducing both oral-oral and fecal-oral transmission from PID patients must be formulated for hospitals and community settings.

Inherited SLP76 deficiency in humans causes severe combined immunodeficiency, neutrophil and platelet defects.

The T cell receptor (TCR) signaling pathway is an ensemble of numerous proteins that are crucial for an adequate immune response. Disruption of any protein involved in this pathway leads to severe immunodeficiency and unfavorable clinical outcomes. Here, we describe an infant with severe immunodeficiency who was found to have novel biallelic mutations in SLP76. SLP76 is a key protein involved in TCR signaling and in other hematopoietic pathways. Previous studies of this protein were performed using Jurkat-derived human leukemic T cell lines and SLP76-deficient mice. Our current study links this gene, for the first time, to a human immunodeficiency characterized by early-onset life-threatening infections, combined T and B cell immunodeficiency, severe neutrophil defects, and impaired platelet aggregation. Hereby, we characterized aspects of the patient's immune phenotype, modeled them with an SLP76-deficient Jurkat-derived T cell line, and rescued some consequences using ectopic expression of wild-type SLP76. Understanding human diseases due to SLP76 deficiency is helpful in explaining the mixed T cell and neutrophil defects, providing a guide for exploring human SLP76 biology.

Bacille Calmette-Guerin (BCG) complications in children with severe combined immunodeficiency (SCID).

Background: Bacille Calmette-Guerin (BCG) is included in the routine vaccination program in Gaza and the West Bank. Although safe, complications can occur and include local, extra-regional and disseminated BCG infection. Therefore it is contraindicated in immunodeficiencies. However, most infants are immunized prior to diagnosis of immunodeficiency. We report clinical and immunological characteristics of patients referred with severe combined immunodeficiency (SCID) who suffered from BCG complications. Methods: Files of patients referred for evaluation of immunodeficiency from January 2008 to February 2016 were retrieved. All patients have received BCG. Cell surface markers of peripheral blood mononuclear cells (PBMCs) were measured by immunofluorescent staining and flow cytometry. Serum concentrations of immunoglobulins were measured using nephelometry. Genetic diagnosis of SCID was made by direct Sanger sequencing of candidate genes. BCG complications were classified as: a) local; b) regional; c) distant; and d) disseminated disease. Results: Twenty-one children were diagnosed with SCID. BCG complications were diagnosed in 12 (57.1%). Eight patients developed local and regional disease (67%) and 4 (33%) had disseminated infection. Patients received at least three drugs: isoniazid, ethambutol and rifampicin. Outcome was relatively favorable with eight patients surviving (66.6%). No death related to BCG infection was observed. Disseminated disease was associated with reduced numbers of total lymphocytes, CD3 and CD8 levels (p < .05). Conclusions: Although high rates of BCG complications were observed, mortality was not increased and outcomes were good. Increased awareness in countries where BCG vaccine is not routinely administered and newborn screening programs for SCID could reduce complication rates.