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Increased susceptibility to develop severe forms of Epstein-Barr virus (EBV) infection in early age is a significant hallmark of an underlying primary immunodeficiency (PID). Here, we present immunologic and genetic evaluations of a 3-year-old child who was born to first-cousins parents and presented with recurrent infections, failure to thrive, and severe EBV-related infection and proliferation. A diagnosis of diffuse large B cell lymphoma was made and the immunological workup was suggestive of T cell immunodeficiency. Unfortunately, the patient succumbed to EBV-related lymphoma. Whole-exome sequencing revealed a novel homozygous mutation, c.991del.C; p. Q331Sfs*6 in the SLP76 gene. The SLP76 protein, a TCR signaling molecule, was recently linked to a human disease of the immune system. In order to examine the effect of this new SLP76 mutation on T cell signaling, a SLP76-deficient Jurkat-derived T cell line was transduced either with wild-type (WT), or with the specific SLP76 mutant, or with a mock vector. Downstream TCR signaling events, including ERK1/2 phosphorylation, CD69 expression, and Ca2 + mobilization, were reduced in cells harboring the reported mutation, linking this novel mutation to the expected immunological outcome. SLP76 deficiency should be added to the growing list of monogenetic diseases that predispose affected individuals to acquire severe and uncontrolled EBV infections and to develop substantial complications. This case further links mutations in the SLP76 gene to a significant human immunodeficiency and extends its clinical phenotype.

The International Union of Immunological Societies (IUIS) expert committee (EC) on Inborn Errors of Immunity (IEI) reports here the 2022 updated phenotypic classification, which accompanies and complements the most-recent genotypic classification. This phenotypic classification is aimed for clinicians at the bedside and focuses on clinical features and laboratory phenotypes of specific IEI. In this classification, 485 IEI underlying phenotypes as diverse as infection, malignancy, allergy, auto-immunity and auto-inflammation are described, including 55 novel monogenic defects and 1 autoimmune phenocopy. Therefore, all 485 diseases of the genetic classification are presented in this paper in the form of colored tables with essential clinical or immunological phenotype entries.

PurposePatients with X-linked agammaglobulinemia (XLA) are characterized by humoral impairment and are routinely treated with intravenous immunoglobulin (IVIG). In this study, we aimed to investigate the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in IVIG preparations harvested globally and evaluate the transfer of SARS-CoV-2 antibodies to the XLA patient.MethodsA single-center, prospective cohort study was conducted in the period of November 2020 to November 2022. Clinical and laboratory data, specifically, SARS-CoV-2 spike IgG levels from the serum of 115 IVIG preparations given to 5 XLA patient were collected. Concurrently, SARS-CoV-2 spike IgG levels from the serum of the 5 XLA was collected monthly.ResultsFive XLA patients were evaluated within the study period. All were treated monthly with commercial IVIG preparations. A total of 115 IVIG treatments were given over the study period. The origin country and the date of IVIG harvesting was obtained for 111 (96%) of the treatments. Fifty-four IVIG preparations (49%) were harvested during the COVID-19 pandemic of which 76% were positive (>50AU/mL) for SARS-CoV-2 spike antibodies which were subsequently transmitted to the XLA patients in an approximate 10-fold reduction. SARS-CoV2 spike IgG was first detected in IVIG batches that completed their harvest date by September 2021. Positive products were harvested from origin countries with a documented prevalence over 2,000 per 100,000 population.ConclusionAs the prevalence of COVID-19 infections rises, detection of SARS-CoV-2 spike IgG in commercial IVIG products increases and is then transmitted to the patient. Future studies are needed to investigate the neutralizing capabilities of SARS-CoV-2 IgG and whether titer levels in IVIG remain consistent as the incidence of infection and vaccination rates in the population changes.

BackgroundPatients 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.ObjectiveTo describe a cohort of patients with PIDs with atypical presentations of skin infections, who posed a diagnostic and/or therapeutic challenge.MethodsThis 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.ResultsEight 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.ConclusionsIn 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.

RAG2-SCID is a primary immunodeficiency caused by mutations in Recombination-activating gene 2 (RAG2), a gene intimately involved in the process of lymphocyte maturation and function. ex-vivo manipulation of a patient’s own hematopoietic stem and progenitor cells (HSPCs) using CRISPR-Cas9/rAAV6 gene editing could provide a therapeutic alternative to the only current treatment, allogeneic hematopoietic stem cell transplantation (HSCT). Here we show a first-of-its-kind RAG2 correction strategy that replaces the entire endogenous coding sequence (CDS) to preserve the critical endogenous spatiotemporal gene regulation and locus architecture. Expression of the corrective transgene led to successful development into CD3+TCRαβ+ and CD3+TCRγδ+ T cells and promoted the establishment of highly diverse TRB and TRG repertoires in an in-vitro T-cell differentiation platform. We believe that a CDS replacement technique to correct tightly regulated genes, like RAG2, while maintaining critical regulatory elements and conserving the locus structure could bring safer gene therapy techniques closer to the clinic.

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.

PurposeReceptor-interacting serine/threonine-protein kinase 1 (RIPK1) is an important regulator of necroptosis and inflammatory responses. We present the clinical features, genetic analysis and immune work-up of two patients with infantile-onset inflammatory bowel disease (IBD) resulting from RIPK1 mutations.MethodsWhole exome and Sanger sequencing was performed in two IBD patients. Mass cytometry time of flight (CyTOF) was conducted for in-depth immunophenotyping on one of the patient’s peripheral blood mononuclear cells, and compared to control subjects and patients with Crohn’s disease.ResultsThe patients presented with severe colitis and perianal fistulas in the first months of life, without severe/atypical infections. Genetic studies identified pathogenic genetic variants in RIPK1 (Patient 1, A c.1934C>T missense mutation in Exon 11; Patient 2, c.580G>A missense mutation residing in Exon 4). Protein modeling demonstrated that the mutation in Patient 1 displaces a water molecule, potentially disrupting the local environment, and the mutation in Patient 2 may lead to disruption of the packing and conformation of the kinase domain. Immunofluorescence RIPK1 staining in rectal biopsies demonstrated no expression for Patient 1 and minimal expression for Patient 2, compared to controls and patients with active Crohn’s disease. Using CyTOF unbiased clustering analysis, we identified peripheral immune dysregulation in one of these patients, characterized by an increase in IFNγ CD8+ T cells along with a decrease in monocytes, dendritic cells and B cells. Moreover, RIPK1-deficient patient’s immune cells exhibited decreased IL-6 production in response to lipopolysaccharide (LPS) across multiple cell types including T cells, B cells and innate immune cells.ConclusionsMutations in RIPK1 should be considered in very young patients presenting with colitis and perianal fistulas. Given RIPK1’s role in inflammasome activation, but also in epithelial cells, it is unclear whether IL1 blockade or allogeneic hematopoietic stem cell transplantation can suppress or cure the hyper-inflammatory response in these patients. Additional studies in humans are required to better define the role of RIPK1 in regulating intestinal immune responses, and how treatment can be optimized for patients with RIPK1 deficiency.

We report the updated classification of inborn errors of immunity, compiled by the International Union of Immunological Societies Expert Committee. This report documents the key clinical and laboratory features of 55 novel monogenic gene defects, and 1 phenocopy due to autoantibodies, that have either been discovered since the previous update (published January 2020) or were characterized earlier but have since been confirmed or expanded in subsequent studies. While variants in additional genes associated with immune diseases have been reported in the literature, this update includes only those that the committee assessed that reached the necessary threshold to represent novel inborn errors of immunity. There are now a total of 485 inborn errors of immunity. These advances in discovering the genetic causes of human immune diseases continue to significantly further our understanding of molecular, cellular, and immunological mechanisms of disease pathogenesis, thereby simultaneously enhancing immunological knowledge and improving patient diagnosis and management. This report is designed to serve as a resource for immunologists and geneticists pursuing the molecular diagnosis of individuals with heritable immunological disorders and for the scientific dissection of cellular and molecular mechanisms underlying monogenic and related human immune diseases. ispartof: JOURNAL OF CLINICAL IMMUNOLOGY vol:42 issue:7 pages:1473-1507 ispartof: location:Netherlands status: published

Kabuki syndrome (KS) is a genetic disorder caused mainly by de novo pathogenic variants in KMT2D or KDM6A, characterized by recognizable facial features, intellectual disability, and multi-systemic involvement, including short stature, microcephaly, hearing loss, cardiac defects, and additional congenital anomalies. While congenital anomalies of the kidneys and urinary tract (CAKUT) are known manifestations of this disorder, studies focused solely on kidney involvement are scarce, and its prevalence is most likely underestimated. This study aimed to describe the prevalence and nature of CAKUT and other renal manifestations, in a cohort of KS patients followed at a single tertiary center. All patients who were evaluated at the Sheba Medical Center and received a clinical and/or molecular diagnosis of KS, over a 16-year period (2004–2020), were included. Digital medical records, including ultrasound studies, were reviewed by a team of pediatric nephrologists. Thirteen patients were included in the study, at ages ranging from the neonatal period to 20 years. In eight patients, a pathogenic variant in KMT2D was established. CAKUT were detected in 8/13 (61.5%) of patients and varied from hypospadias, hydronephrosis, or double collecting systems to pelvic kidney, kidney asymmetry, horseshoe kidney, or kidney agenesis. One patient experienced kidney failure necessitating transplantation at 20 years of age. Our findings underscore the high prevalence of CAKUT and genitourinary involvement in patients with KS and suggest that assessment by pediatric nephrology specialists is warranted as part of the routine multidisciplinary evaluation of newly diagnosed patients. A higher resolution version of the Graphical abstract is available as Supplementary information

Background and aimAnti-TNFα is measurable in infants exposed in utero up to 12 months of age. Data about the exposure effect on the infant’s adaptive immunity are limited. We aimed to prospectively evaluate the distribution and function of T and B cells, in infants of females with inflammatory bowel disease, in utero exposed to anti-TNFα or azathioprine.MethodsA prospective multi-center study conducted 2014–2017. Anti-TNFα levels were measured in cord blood, and at 3 and 12 months. T-cell repertoire and function were analyzed at 3 and 12 months by flow-cytometry, expression of diverse T cell receptors (TCR) and T-cell receptor excision circles (TREC) quantification assay. Serum immunoglobulins and antibodies for inactivated vaccines were measured at 12 months. Baseline clinical data were retrieved, and 2-monthly telephonic interviews were performed regarding child infections and growth.Results24 pregnant females, age 30.6 (IQR 26.5–34.5) years were recruited, 20 with anti-TNFα (infliximab 8, adalimumab 12), and 4 with azathioprine treatment. Cord blood anti-TNFα was higher than maternal blood levels [4.3 (IQR 2.3–9.2) vs. 2.5 (IQR 1.3–9.7) mcg/ml], declining at 3 and 12 months. All infants had normal number of B-cells (n = 17), adequate levels of immunoglobulins (n = 14), and protecting antibody levels to Tetanus, Diphtheria, Hemophilus influenza-B and hepatitis B (n = 17). All had normal CD4+, CD8+ T-cells, and TREC numbers. TCR repertoire was polyclonal in 18/20 and slightly skewed in 2/20 infants. No serious infections requiring hospitalization were recorded.ConclusionWe found that T-cell and B-cell immunity is fully mature and immune function is normal in infants exposed in utero to anti-TNFα, as in those exposed to azathioprine. Untreated controls and large-scale studies are needed to confirm these results.

BackgroundDuring 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 theNHEJ1gene, cause severe combined immunodeficiency syndrome (SCID) along with neurodevelopmental disease and sensitivity to ionizing radiation.ObjectiveTo provide new clinical and immunological insights on NHEJ1 deficiency arising from a newly diagnosed patient with severe immunodeficiency.Materials and methodsA 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 Vβ repertoireviaflow cytometry analysis, and TCR and BCR repertoire analysisvianext-generation sequencing (NGS).ResultsClinical findings included microcephaly, recurrent pneumonia, and failure to thrive. An immune workup revealed lymphopenia, reduced T cell function, and hypogammaglobulinemia. Skewed TCR Vβ repertoire, TCR gamma (TRG) repertoire, and BCR repertoire were determined in the patient. Genetic analysis identified a novel homozygous missense pathogenic variant inXLF/Cernunnos: c.A580Ins.T; p.M194fs. The patient underwent a successful hematopoietic stem cell transplantation (HSCT).ConclusionA novelNHEJ1pathogenic 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.

Background Cutaneous manifestations of dedicator of cytokinesis 8 gene (DOCK8) deficiency, a combined type of T and B cell immunodeficiency, previously designated as autosomal recessive hyper IgE syndrome, includes dermatitis and skin infections. There are limited treatment options for dermatitis related to the syndrome. Objective To describe a cohort of patients with DOCK8 deficiency with a focus on the treatment of their cutaneous manifestations. Methods A retrospective study on all children with the genetic diagnosis of DOCK8 deficiency treated at the Sheba Medical Center between 1/1/2003 and 1/1/2021 was preformed. Collected data included: demographic features, family history, laboratory, genetic testing, skin manifestations, treatment, and disease course. Description of two cases of severe recalcitrant dermatitis treated with dupilumab is detailed. Results Nine children with a genetic diagnosis of DOCK8 deficiency were included, of whom six were girls (66%) with a median age of 8.5 (±2.2 SD) years. The median age at diagnosis was 2.8 (±2.6 SD) years. Six patients were born to consanguineous parents. Five out of six patients who received hematopoietic stem cell transplantation (HSCT) had a complete response, and one was recently transplanted. Of note, two patients, while awaiting HSCT, were treated with dupilumab for their severe dermatitis resulting in a marked improvement of the cutaneous manifestations and pruritus. Conclusions Hematopoietic stem cell transplantation is the gold standard and most effective therapy for patients with DOCK8 deficiency. Dupilumab, a biological therapy indicated for atopic dermatitis and other Th2 derived dermatoses, is an excellent option for dermatitis in patients with DOCK8 deficiency and can be used as a bridge before HSCT. Larger studies are needed to confirm this observation.

Vacuolar protein sorting 45 homolog (VPS45), a member of the Sec1/Munc18 (SM) family, has been implicated in the regulation of endosomal trafficking. VPS45 deficiency in human patients results in congenital neutropenia, bone marrow fibrosis, and extramedullary renal hematopoiesis. Detailed mechanisms of the VPS45 function are unknown. Here, we show an essential role of mammalian VPS45 in maintaining the intracellular organization of endolysosomal vesicles and promoting recycling of cell-surface receptors. Loss of VPS45 causes defective Rab5-to-Rab7 conversion resulting in trapping of cargos in early endosomes and impaired delivery to lysosomes. In this context, we demonstrate aberrant trafficking of the granulocyte colony-stimulating factor receptor in the absence of VPS45. Furthermore, we find that lack of VPS45 in mice is not compatible with embryonic development. Thus, we identify mammalian VPS45 as a critical regulator of trafficking through the endosomal system and early embryogenesis of mice.

Severe combined immunodeficiency (SCID) is a group of monogenic primary immunodeficiencies caused by mutations in genes involved in the process of lymphocyte maturation and function. CRISPR-Cas9 gene editing of the patient’s own hematopoietic stem and progenitor cells (HSPCs) ex vivo could provide a therapeutic alternative to allogeneic hematopoietic stem cell transplantation (HSCT), the current gold standard for treatment of SCID. Using CRISPR-Cas9/rAAV6 gene-editing, we engineered genotypes in healthy donor (HD)-derived CD34+ HSPCs, thus eliminating the need for rare patient samples, to model both SCID and the therapeutic outcomes of gene-editing therapies for SCID via multiplexed homology directed repair (HDR). Firstly, we developed a SCID disease model via knock-out of both alleles of genes critical to the development of lymphocytes; and secondly, we established a knock-in/knock-out (KI-KO) strategy to develop a proof-of-concept single-allelic gene correction. Since SCID is a recessive disorder, correction of only one allele is enough to cure the patient. Based on these results, we performed gene correction of RAG2-SCID patient-derived CD34+ HSPCs that successfully developed into CD3+ T cells with diverse TCR repertoires in an in vitro T-cell differentiation (IVTD) platform. By using CRISPR-Cas9, multiplexed HDR, HD-derived CD34+ HSPCs, and an IVTD system we outline an approach for the study of human lymphopoiesis. We present both a way for researchers to determine the optimal configuration for CRISPR-Cas9 gene correction of SCID and other recessive blood disorders, and the feasibility of translating these techniques to perform gene correction in patient-derived CD34+ HSPCs.

Anti-TNFα is measurable in infants exposedA prospective multi-center study conducted 2014-2017. Anti-TNFα levels were measured in cord blood, and at 3 and 12 months. T-cell repertoire and function were analyzed at 3 and 12 months by flow-cytometry, expression of diverse T cell receptors (TCR) and T-cell receptor excision circles (TREC) quantification assay. Serum immunoglobulins and antibodies for inactivated vaccines were measured at 12 months. Baseline clinical data were retrieved, and 2-monthly telephonic interviews were performed regarding child infections and growth.24 pregnant females, age 30.6 (IQR 26.5-34.5) years were recruited, 20 with anti-TNFα (infliximab 8, adalimumab 12), and 4 with azathioprine treatment. Cord blood anti-TNFα was higher than maternal blood levels [4.3 (IQR 2.3-9.2) vs. 2.5 (IQR 1.3-9.7) mcg/ml], declining at 3 and 12 months. All infants had normal number of B-cells (We found that T-cell and B-cell immunity is fully mature and immune function is normal in infants exposed

Hemophilia A (HA) therapy requires intravenous replacement infusions of factor (F) VIII concentrate. Inhibitors are high-affinity immunoglobulin G that are directed against FVIII and thereby render replacement therapy ineffective. This complication has significant prognostic implications. We aimed to examine the immune system involvement in inhibitor formation specifically T-cell excision circles (TRECs) and B-cell excision circles (KRECs), markers of new T and B cells, respectively, and examine them as surrogate markers for inhibitor formation.Blood samples were collected from 35 children with severe HA. Children were divided into two groups: with FVIII inhibitors and without FVIII inhibitors. TRECs and KRECs were measured in peripheral blood.A total of 11 patients with inhibitors and 24 without were evaluated. Children with inhibitors had higher levels of TRECs however not statistically significant (p = 0.085). CjKREC levels were higher in the inhibitor patients (p = 0.003). Moreover, the sj/cjKREC ratio was lower in the inhibitor patients (p = 0.015).Our findings may add to the notion that inhibitor formation is attributed to humoral immunity due to peripheral B-cell expansion and loss of peripheral tolerance. Improved knowledge regarding the involvement of the immune system in the formation of FVIII inhibitors will enable better therapy tailoring in the era of non-replacement therapies.The etiology of FVIII inhibitor formation is multifactorial, in which the immune system plays a pivotal role. Our findings may add to the notion that inhibitor formation is attributed to humoral immunity due to peripheral B-cell expansion and production of antibodies against FVIII. Improved knowledge regarding the involvement of the immune system in the development of FVIII inhibitors will enable the identification of patients prone to inhibitor development and better therapy tailoring in the new era of non-replacement therapies.

Background Pediatric research is a diverse field that is constantly growing. Current machine learning advancements have prompted a technique termed text-mining. In text-mining, information is extracted from texts using algorithms. This technique can be applied to analyze trends and to investigate the dynamics in a research field. We aimed to use text-mining to provide a high-level analysis of pediatric literature over the past two decades. Methods We retrieved all available MEDLINE/PubMed annual data sets until December 31, 2018. Included studies were categorized into topics using text-mining. Results Two hundred and twenty-five journals were categorized as Pediatrics, Perinatology, and Child Health based on Scimago ranking for medicine journals. We included 201,141 pediatric papers published between 1999 and 2018. The most frequently cited publications were clinical guidelines and meta-analyses. We found that there is a shift in the trend of topics. Epidemiological studies are gaining more publications while other topics are relatively decreasing. Conclusions The topics in pediatric literature have shifted in the past two decades, reflecting changing trends in the field. Text-mining enables analysis of trends in publications and can serve as a high-level academic tool. Impact Text-mining enables analysis of trends in publications and can serve as a high-level academic tool. This is the first study using text-mining techniques to analyze pediatric publications. Our findings indicate that text-mining techniques enable better understanding of trends in publications and should be implemented when analyzing research.

Genetic diagnostic tools including whole-exome sequencing (WES) have advanced our understanding in human diseases and become common practice in diagnosing patients with suspected primary immune deficiencies. Establishing a genetic diagnosis is of paramount importance for tailoring adequate therapeutic regimens, including identifying the need for hematopoietic stem cell transplantation (HSCT) and genetic-based therapies. Here, we genetically studied two adult patients who were clinically diagnosed during infancy with severe combined immune deficiency (SCID). Two unrelated patients, both of consanguineous kindred, underwent WES in adulthood, 2 decades after their initial clinical manifestations. Upon clinical presentation, immunological workup was performed, which led to a diagnosis of SCID. The patients presented during infancy with failure to thrive, generalized erythematous rash, and recurrent gastrointestinal and respiratory tract infections, including episodes of Pneumocystis pneumonia infection and Candida albicans fungemia. Hypogammaglobulinemia and T-cell lymphopenia were detected. Both patients were treated with a 10/10 HLA matched sibling donor unconditioned HSCT. Retrospective genetic workup revealed homozygous bi-allelic mutations in IL7RA in one patient and in RAG2 in the other. Our study exemplifies the impact of retrospectively establishing a genetic diagnosis. Pinpointing the genetic cause raises several issues including optimized surveillance and treatment, understanding disease mechanisms and outcomes, future family planning, and social and psychological considerations.

A disease-specific, patient-reported outcome instrument suitable for evaluation of prodromes and attacks of hereditary angioedema (HAE) is a clinical unmet need. We constructed such instrument and examined its validity, acceptability, and discriminative ability. Sixty-six patients participated in a survey addressing their demographics, social, and medical status. Discriminant content validity involved: (1) construct definition by in-depth cognitive debriefing interviews, (2) item selection identifying relevant categories, and (3) judgment of the format whereby questionnaires were tested on experienced patients and its content/reliability was validated. Prodromes and attacks affecting certain body systems (domains) were organized in “clusters”. Internal consistency, content, and convergent validities were analyzed. Analyses of variance and regression models were used to evaluate the discriminative ability of the instrument to differentiate between attacks and prodromes. The study demonstrates very high internal consistency (Cronbach’s α: attacks 0.88–0.98, prodromes 0.78–0.98). Analysis of variance confirmed significant differences between all dimensions and in pre-defined clusters (F (4, 61) = 45.74, p

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.

The transcription factor GATA2 plays a key role in the survival and self-renewal of hematopoietic stem and progenitor cells. Autosomal dominant variants in GATA2 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 GATA2 (n=1). Novel heterozygous GATA2 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.

Purpose: Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is an important regulator of necroptosis and inflammatory responses. We present the clinical features, genetic analysis and immune work-up of two patients with infantile-onset inflammatory bowel disease (IBD) resulting from novel RIPK1 mutations.Methods: Whole exome and Sanger sequencing was performed in two IBD patients. Mass cytometry time of flight (CyTOF) was conducted for in-depth immunophenotyping on one of the patient’s peripheral blood mononuclear cells, and compared to control subjects and patients with Crohn’s disease.Results: The patients presented with severe colitis and perianal fistulas in the first months of life, without severe/atypical infections. Genetic studies identified novel and pathogenic genetic variants in RIPK1. Using CyTOF unbiased clustering analysis, we identified peripheral immune dysregulation in one of these patients, characterized by an increase in IFNγ CD8+ T cells along with a decrease in monocytes, dendritic cells and B cells. Moreover, RIPK1-deficient patient’s immune cells exhibited decreased IL-6 production in response to LPS across multiple cell types including T cells, B cells and innate immune cells. Summary: Mutations in RIPK1 should be considered in very young patients presenting with colitis and perianal fistulas. Given RIPK1’s role in inflammasome activation, but also in epithelial cells, it is unclear whether IL1 blockade or allogeneic hematopoietic stem cell transplantation can suppress or cure the hyper-inflammatory response in these patients. Additional studies in humans are required to better define the role of RIPK1 in regulating intestinal immune responses, and how treatment can be optimized for patients with RIPK1 deficiency.

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 theTo provide new clinical and immunological insights on NHEJ1 deficiency arising from a newly diagnosed patient with severe immunodeficiency.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 Vβ repertoireClinical findings included microcephaly, recurrent pneumonia, and failure to thrive. An immune workup revealed lymphopenia, reduced T cell function, and hypogammaglobulinemia. Skewed TCR Vβ repertoire, TCR gamma (TRG) repertoire, and BCR repertoire were determined in the patient. Genetic analysis identified a novel homozygous missense pathogenic variant inA novel

Patients with Wiskott-Aldrich syndrome (WAS) harbor mutations in the WAS gene and suffer from immunodeficiency, microthrombocytopenia, and eczema. T-cells play an important role in immune response in the skin and the γδT-cells have an important role in skin homeostasis. Since WAS patients often present with eczema, we wanted to examine whether the T-cell receptor gamma (TRG) repertoire of the γδT-cells is affected in these patients. In addition, the immunoglobulin heavy chain (IGH) repertoire from genomic DNA of WAS patients was not yet studied. Thus, we sought to determine the effects that specific WAS mutations from our patients have in shaping the TRG and IGH immune repertoires. We collected clinical and genetic data on four WAS patients, each harboring a different mutation in the WAS gene. Using next-generation sequencing (NGS), we analyzed their TRG and IGH repertoires using genomic DNA isolated from their peripheral blood. We analyzed the TRG and IGH repertoire sequences to show repertoire restriction, clonal expansions, preferential utilization of specific V genes, and unique characteristics of the antigen binding region in WAS patients with eczema compared to healthy controls. Both the TRG and IGH repertoire showed diverse repertoire comparable to healthy controls on one the hand, and on the other hand, the IGH repertoire showed increased diversity, more evenly distributed repertoire and immaturity of the antigen binding region. Thus, we demonstrate by analyzing the repertoire based on genomic DNA, the various effect that WAS mutations have in shaping the TRG and IGH adaptive immune repertoires.

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.

Summary Capping protein regulator and myosin 1 linker 2 (CARMIL2) deficiency is characterized by impaired T cell activation, which is attributed to defective CD28-mediated co-signaling. Herein, we aimed to analyze the effect of exogenous interleukin (IL)-2 on in-vitro T cell activation and proliferation in a family with CARMIL2 deficiency. This study included four children (one male and three females; aged 2·5–10 years at presentation). The patients presented with inflammatory bowel disease and recurrent viral infections. Genetic analysis revealed a novel homozygous 25-base pairs deletion in CARMIL2. Immunoblotting demonstrated the absence of CARMIL2 protein in all four patients and confirmed the diagnosis of CARMIL2 deficiency. T cells were activated in-vitro with the addition of IL-2 in different concentrations. CD25 and interferon (IFN)-γ levels were measured after 48 h and 5 days of activation. CD25 surface expression on activated CD8+ and CD4+ T cells was significantly diminished in all patients compared to healthy controls. Additionally, CD8+ T cells from all patients demonstrated significantly reduced IFN-γ production. When cells derived from CARMIL2-deficient patients were treated with IL-2, CD25 and IFN-γ production increased in a dose-dependent manner. T cell proliferation, as measured by Cell Trace Violet, was impaired in one patient and it was also rescued with IL-2. In conclusion, we found that IL-2 rescued T cell activation and proliferation in CARMIL2-deficient patients. Thus, IL-2 should be further studied as a potential therapeutic modality for these patients.

Patients with Down syndrome (DS) are at increased risk for infections and autoimmune disorders. Although several immunological abnormalities were previously found, differences in T cell receptor repertoire have never been shown. Thus we compared the T cell receptor gamma (TRG) repertoire in DS and non-syndromic pediatric patients by next-generation sequencing, in addition to other immunological markers. Genomic DNA was extracted from thymuses of pediatric patients who underwent heart surgery, where six were with DS and six were non-syndromic patients. Peripheral blood counts, T cell subpopulations, thymus TCR excision circles (TRECs), spectratyping, and next-generation sequencing for TRG were analyzed. The mean age of the patients was 7 months and the mean lymphocyte count was slightly lower in patients with DS, whereas thymus TREC results were similar to non-syndromic patients (p = 0.197). The TRG repertoire analysis showed that patients with DS had a significantly larger number of unique TRG sequences, together with decreased clonal expansion. Lastly, the V and J gene usages in the thymus were similar in DS and non-syndromic patients. Patients with DS showed increased TRG repertoire diversity with decreased clonal expansion compared to non-syndromic patients.

Clathrin-mediated endocytosis (CME) is critical for internalisation of molecules across cell membranes. The FCH domain only 1 (FCHO1) protein is key molecule involved in the early stages of CME formation. The consequences of mutations in FCHO1 in humans were unknown. We identify ten unrelated patients with variable T and B cell lymphopenia, who are homozygous for six distinct mutations in FCHO1. We demonstrate that these mutations either lead to mislocalisation of the protein or prevent its interaction with binding partners. Live-cell imaging of cells expressing mutant variants of FCHO1 provide evidence of impaired formation of clathrin coated pits (CCP). Patient T cells are unresponsive to T cell receptor (TCR) triggering. Internalisation of the TCR receptor is severely perturbed in FCHO1-deficient Jurkat T cells but can be rescued by expression of wild-type FCHO1. Thus, we discovered a previously unrecognised critical role of FCHO1 and CME during T-cell development and function in humans. FCH domain only 1 (FCHO1) is a key molecule involved in clathrin-mediated endocytosis (CME). Here, the authors report homozygous FCHO1 mutations in individuals with variable T and B cell lymphopenia, which are associated with loss-of-function of FCHO1 and impaired formation of clathrin-coated pits in T cells.

Avoidance of fasting and regular ingestion of uncooked-cornstarch have long been the mainstay dietary treatment of Glycogen Storage Disease type Ia (GSD-Ia). However, GSD-Ia patients who despite optimal dietary treatment show poor glycemic control and are intolerant to cornstarch, present a complex clinical challenge. We pursued Whole Exome Sequencing (WES) in three such unrelated patients, to both confirm a molecular diagnosis of GSD-Ia, and seek additional variants in other genes (e.g. genes associated with amylase production) which may explain their persistent symptoms. WES confirmed the GSD-Ia diagnosis, with all three probands harboring the homozygous p.R83C variant in G6PC. While no other significant variants were identified for patients A and B, a homozygous p.G276V variant in the SI gene was detected in patient C, establishing the dual-diagnosis of GSD-Ia and Sucrase-Isomaltase Deficiency. To conclude, we suggest that WES should be considered in GSD-Ia patients who show persistent symptoms despite optimal dietary management.

Signal transducer and activator of transcription (STAT)1 heterozygous gain-of-function (GOF) mutations are known to induce immune dysregulation and chronic mucocutaneous candidiasis (CMCC). Previous reports suggest an association between demodicosis and STAT1 GOF. However, immune characterization of these patients is lacking. Here, we present a retrospective analysis of patients with immune dysregulation and STAT1 GOF who presented with facial and ocular demodicosis. In-depth immune phenotyping and functional studies were used to characterize the patients. We identified five patients (three males) from two non-consanguineous Jewish families. The mean age at presentation was 11.11 (range = 0.58–24) years. Clinical presentation included CMCC, chronic demodicosis and immune dysregulation in all patients. Whole-exome and Sanger sequencing revealed a novel heterozygous c.1386C>A; p.S462R STAT1 GOF mutation in four of the five patients. Immunophenotyping demonstrated increased phosphorylated signal transducer and activator of transcription in response to interferon-α stimuli in all patients. The patients also exhibited decreased T cell proliferation capacity and low counts of interleukin-17-producing T cells, as well as low forkhead box protein 3+ regulatory T cells. Specific antibody deficiency was noted in one patient. Treatment for demodicosis included topical ivermectin and metronidazole. Demodicosis may indicate an underlying primary immune deficiency and can be found in patients with STAT1 GOF. Thus, the management of patients with chronic demodicosis should include an immunogenetic evaluation.

Diagnosis of primary complement deficiencies requires a high index of suspicion. Thus, susceptible patients are often underdiagnosed and untreated. Here, we present a multi-center experience with three novel inborn errors of the classical complement system. This is a retrospective multicenter analysis of computerized medical records of children (> 18 years) admitted in the period between 2003 and 2018 at Shaare Zedek Medical Center in Jerusalem and Edmond and Lily Safra Children's Hospital, Tel-Hashomer Medical Center, in Ramat Gan, Israel. Patients were genetically diagnosed by a complimentary immune work-up. We identified 5 patients (3 males) from four different consanguineous families harboring three novel mutations in the complement components C6-C8. Genetic mutations were identified by whole exome sequencing. Clinical manifestations consisted of meningitis with or without meningococcemia. The immune work-up demonstrated nearly absent levels of CH50, compatible with a complement pathway defect. The mean diagnosis delay was 10.56 (0–30) years. Conclusion: Invasive meningococcal infections may be life-threatening and cause severe neurological sequela. Awareness of risk factors for primary complement deficiencies, even at the firs infectious episode, should facilitate prompt immune and genetic investigations, commencing diagnosis and proper treatment.

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 complexed system led mainly by the non-homologous end-joining (NHEJ). Mutations in proteins involved in this process, including the XLF/ Cernunnos gene, cause severe combined immunodeficiency syndrome (SCID) along with neurodevelopmental disease and susseptability to inoizing radiation. Objective: To provide new clinical and immunological insights on XLF/Cernunnos deficiency, arising from a newly diagnosed patient with severe immunodeficiency. Methods: A male infant, born to consanguineous parents, suspected of having primary immunodeficiency underwent immunological and genetic work up. This included a thorough assessment of T cell phenotyping and lymphocyte activation by mitogen stimulation tests, whole exome sequencing (WES), TCR repertoire Vβ repertoire via flow cytometry analysis and TCR and BCR via next generation sequencing (NGS). Results: Clinical findings included microcephaly, recurrent bacterial viral pneumonia and failure to thrive. Immune workup revealed lymphopenia, reduced T cell function and hypogammaglubolinemia. A skewed TCR Vβ repertoire, TCR gamma (TRG) repertoire and BCR repertoire were determined in the patient. Genetic analysis identified a novel autosomal recessive homozygous missense mutation in XLF/Cernunnos c. A580Ins.T; p. M194fs. The patient underwent a successful hematopoietic stem cell transplantation (HSCT). Conclusions: A novel XLF/Cernunnos mutation is reported in a patient presented with SCID phenotype that displayed clonally expanded T and B cells. An adjusted HSCT was safe to ensure full T cell immune reconstitution.

The most recent updated classification of inborn errors of immunity/primary immunodeficiencies, compiled by the International Union of Immunological Societies Expert Committee, was published in January 2020. Within days of completing this report, it was already out of date, evidenced by the frequent publication of genetic variants proposed to cause novel inborn errors of immunity. As the next formal report from the IUIS Expert Committee will not be published until 2022, we felt it important to provide the community with a brief update of recent contributions to the field of inborn errors of immunity. Herein, we highlight studies that have identified 26 additional monogenic gene defects that reach the threshold to represent novel causes of immune defects. ispartof: JOURNAL OF CLINICAL IMMUNOLOGY vol:41 issue:3 pages:666-679 ispartof: location:Netherlands status: published

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.

Background Infantile cortical hyperostosis (ICH)/Caffey disease is an inflammatory collagenopathy of infancy, manifested by subperiosteal bone hyperplasia. Genetically, ICH was linked with heterozygosity for an R836C mutation in the COL1A1 gene. Although an autosomal-recessive trait is also suspected, it has not been proven thus far. Methods A case of an infant male born to consanguineous parents is reported, presenting with classical findings, course, and clinical outcome of ICH. Whole-exome sequencing (WES) was performed in order to identify a possible underlying genetic defect. Results WES analysis revealed a novel homozygous nonsense mutation in lysine 2 of fetuin-A, encoded by the ALPHA-2-HS-GLYCOPROTEIN (AHSG) gene (c.A4T; p.K2X). Fetuin-A is an important regulator of bone remodeling and an inhibitor of ectopic mineralization. By enzyme-linked immunosorbent assay (ELISA), we show a complete deficiency of this protein in the patient’s serum, compared to controls. Conclusion A novel homozygous nonsense mutation in AHSG gene has been found in ICH patient with a typical phenotype, resulting in fetuin-A deficiency. This finding postulates an autosomal-recessive mode of inheritance in ICH, which, unlike the autosomal-dominant inheritance associated with COL1A1, is associated with AHSG and fetuin-A deficiency.

Caspase-8 (CASP8) is a protease that initiates apoptosis and regulates inflammation and immune responses. We identified germline mutations in CASP8 in 3 unrelated patients with infant-onset inflammatory bowel disease: 2 patients were homozygous for the mutation 710A>G, p.Q237R, which resulted in reduced protein expression, and 1 patient carried the mutation 793C>T, p.R265W. We isolated peripheral blood mononuclear cells from our index patient and observed defects in T- and B-cell maturation, proliferation, and/or activation. Macrophages from 1 patient with CASP8 deficiency and monocytic BLaER1 cells with knockout of CASP8 or overexpression of CASP8 with the 710A>G mutation had altered inflammasome activity on stimulation with lipopolysaccharide. Patient-derived intestinal organoids and colon carcinoma cells with knockout of CASP8 had defects in cell death processes that involved loss of TRAIL signaling and increased necroptosis. These findings indicate that CASP8 controls inflammation, innate and adaptive immunity, and intestinal barrier integrity in humans.

Kabuki syndrome (KS) is a genetic disorder caused mainly by de novo pathogenic variants in KMT2D or KDM6A, characterized by recognizable facial features, intellectual disability, and multi-systemic involvement, including short stature, microcephaly, hearing loss, cardiac defects, and additional congenital anomalies. While congenital anomalies of the kidneys and urinary tract (CAKUT) are known manifestations of this disorder, studies focused solely on kidney involvement are scarce, and its prevalence is most likely underestimated. This study aimed to describe the prevalence and nature of CAKUT and other renal manifestations, in a cohort of KS patients followed at a single tertiary center.All patients who were evaluated at the Sheba Medical Center and received a clinical and/or molecular diagnosis of KS, over a 16-year period (2004-2020), were included. Digital medical records, including ultrasound studies, were reviewed by a team of pediatric nephrologists.Thirteen patients were included in the study, at ages ranging from the neonatal period to 20 years. In eight patients, a pathogenic variant in KMT2D was established. CAKUT were detected in 8/13 (61.5%) of patients and varied from hypospadias, hydronephrosis, or double collecting systems to pelvic kidney, kidney asymmetry, horseshoe kidney, or kidney agenesis. One patient experienced kidney failure necessitating transplantation at 20 years of age.Our findings underscore the high prevalence of CAKUT and genitourinary involvement in patients with KS and suggest that assessment by pediatric nephrology specialists is warranted as part of the routine multidisciplinary evaluation of newly diagnosed patients. A higher resolution version of the Graphical abstract is available as Supplementary information.

Immunoglobulin replacement therapy is a mainstay therapy for patients with primary immunodeficiency (PID). The content of these preparations was studied extensively. Nevertheless, data regarding the effective specific antibodies content (especially in the nadir period), and, in different groups of PID patients is limited. We studied trough IgG concentrations as well as anti-Pneumococcus, anti-Haemophilus influenzae b, anti-Tetanus, and anti-Measles antibody concentrations in 17 PID patients receiving intravenous immunoglobulin (IVIg) compared with healthy controls matched for age and ethnicity. We also analyzed these results according to the specific PID diagnosis: X-linked agammaglobulinemia (XLA), combined immunodeficiency (CID), and ataxia telangiectasia (AT). We recorded a higher concentration of anti-pneumococcal polysaccharide antibodies in healthy controls compared to the entire group of PID patients. We also found significantly higher anti-tetanus toxoid antibody concentrations in the XLA patients, compared to CID patients. Anti-Haemophilus Influenzae b antibody titers were overall similar between all the groups. Interestingly, there were overall low titers of anti-Measles antibodies below protective cutoff antibody concentrations in most patients as well as in healthy controls. We conclude that relying on total IgG trough levels is not necessarily a reflection of effective specific antibodies in the patient’s serum. This is especially relevant to CID patients who may have production of nonspecific antibodies. In such patients, a higher target trough IgG concentration should be considered. Another aspect worth considering is that the use of plasma from adult donors with a waning immunity for certain pathogens probably affects the concentrations of specific antibodies in IVIg preparations.

Kabuki syndrome (KS) is a genetic disorder caused by pathogenic variants in KMT2D or KDM6A, and manifesting with multi-systemic involvement, including recognizable facial features, developmental delay and multiple congenital anomalies. Ophthalmological involvement has been described in varying rates in several studies. We aimed to evaluate the prevalence and nature of ophthalmological findings in a cohort of KS patients in Israel. Medical records of all patients diagnosed with KS in our tertiary center between 2004 and 2020 were retrospectively reviewed. Data collected included physical examination findings, molecular analysis as well as comprehensive ophthalmic characteristics including visual acuity, ocular alignment and motility, ocular adnexa, anterior segments and dilated fundus exams. Finally, an updated systematic review of the literature was performed. Thirteen unrelated patients were included in the study, diagnosed at an age raging from the first months of life to 20 years. Of these, three (23%) showed significant ophthalmological abnormalities, beyond the characteristic structural findings of long palpebral fissures and lower eyelid eversion. These included bilateral posterior colobomata in the first patient; bilateral ptosis, hypermetropia, esotropia, blue sclera and anisocoria in the second; and bilateral congenital cataracts in the third. To conclude, our findings underscore the importance of a comprehensive ophthalmological evaluation as part of the routine multidisciplinary assessment of children suspected/diagnosed with KS.

International audience; Inborn errors of TLR3-dependent IFN-α/β– and IFN-λ–mediated immunity in the CNS can underlie herpes simplex virus 1 (HSV-1) encephalitis (HSE). The respective contributions of IFN-α/β and IFN-λ are unknown. We report a child homozygous for a genomic deletion of the entire coding sequence and part of the 3′-UTR of the last exon of IFNAR1, who died of HSE at the age of 2 years. An older cousin died following vaccination against measles, mumps, and rubella at 12 months of age, and another 17-year-old cousin homozygous for the same variant has had other, less severe, viral illnesses. The encoded IFNAR1 protein is expressed on the cell surface but is truncated and cannot interact with the tyrosine kinase TYK2. The patient’s fibroblasts and EBV-B cells did not respond to IFN-α2b or IFN-β, in terms of STAT1, STAT2, and STAT3 phosphorylation or the genome-wide induction of IFN-stimulated genes. The patient’s fibroblasts were susceptible to viruses, including HSV-1, even in the presence of exogenous IFN-α2b or IFN-β. HSE is therefore a consequence of inherited complete IFNAR1 deficiency. This viral disease occurred in natural conditions, unlike those previously reported in other patients with IFNAR1 or IFNAR2 deficiency. This experiment of nature indicates that IFN-α/β are essential for anti–HSV-1 immunity in the CNS

Pediatric research is a diverse field that is constantly growing. Current machine learning advancements have prompted a technique termed text-mining. In text-mining, information is extracted from texts using algorithms. This technique can be applied to analyze trends and to investigate the dynamics in a research field. We aimed to use text-mining to provide a high-level analysis of pediatric literature over the past two decades.We retrieved all available MEDLINE/PubMed annual data sets until December 31, 2018. Included studies were categorized into topics using text-mining.Two hundred and twenty-five journals were categorized as Pediatrics, Perinatology, and Child Health based on Scimago ranking for medicine journals. We included 201,141 pediatric papers published between 1999 and 2018. The most frequently cited publications were clinical guidelines and meta-analyses. We found that there is a shift in the trend of topics. Epidemiological studies are gaining more publications while other topics are relatively decreasing.The topics in pediatric literature have shifted in the past two decades, reflecting changing trends in the field. Text-mining enables analysis of trends in publications and can serve as a high-level academic tool.Text-mining enables analysis of trends in publications and can serve as a high-level academic tool. This is the first study using text-mining techniques to analyze pediatric publications. Our findings indicate that text-mining techniques enable better understanding of trends in publications and should be implemented when analyzing research.

SLP76 is a key molecule involved in the T cell signaling pathway; therefore, SLP76 deficiency can lead to a severe type of immunodeficiency. By reporting on a patient with germline mutation in SLP76, deficiency in this gene is linked, for the first time, to a human disease., 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.

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.

Background: More than 50 different monogenic disorders have been identified as directly causing inflammatory bowel diseases, typically manifesting in the first years of life. We present the clinical course and immunological work-up of an adult patient who presented in adolescent years with an atypical gastrointestinal phenotype and was diagnosed more than two decades later with a monogenic disorder with important therapeutic implications. Methods: Whole exome sequencing was performed in a 37-years-old patient with a history of diarrhea since adolescence. Sanger sequencing was used to validate the suspected variant. Mass cytometry (CyTOF) and flow cytometry were conducted on peripheral blood mononuclear cells for deep immunophenotyping. Next-generation sequencing of the TCRB and IgH was performed for global immune repertoire analysis of circulating lymphocytes. Results: We identified a novel deleterious c.1455C>A (p.Y485X) mutation in LRBA. CyTOF studies demonstrated significant changes in immune landscape in the LRBA-deficient patient, including an increase in myeloid derived suppressor cells and double-negative T cells, decreased B cells, low ratio of naive:memory T cells, and reduced capacity of T cells to secrete various cytokines following stimulation, including tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). In addition, this patient exhibited low frequency of regulatory T cells, with a reduction in their CTLA4 expression and interleukin (IL)-10 secretion. Finally, we show marked oligoclonal expansion of specific B- and T-cell clones in the peripheral blood of the LRBA-deficient patient. Conclusions: LRBA deficiency is characterized by marked immunological changes in innate and adaptive immune cells. This case highlights the importance of advanced genetic studies in patients with a unique phenotype, regardless of their age at presentation.

The recent outbreak of COVID-19 which began in Wuhan, China in December 2019 and rapidly spread worldwide evolving into a pandemic, poses a global health emergency. As of mid-April over 2 million people have been infected with over 145 thousand casualties. The disease is more severe in the older population, whereas in children lower infection rates and milder symptoms are more common. Severe symptoms in the pediatric population, although uncommon, have been reported mainly in infants younger than 1 year of age. Perinatal transmission is infrequent and associated with a relatively mild illness in the newborn.

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.