Autoantibodies neutralizing type I IFNs are present in ~ 4% of uninfected individuals over 70 years old and account for ~ 20% of COVID-19 deaths.

Circulating autoantibodies (auto-Abs) neutralizing high concentrations (10 ng/mL, in plasma diluted 1 to 10) of IFN-α and/or -ω are found in about 10% of patients with critical COVID-19 pneumonia, but not in subjects with asymptomatic infections. We detect auto-Abs neutralizing 100-fold lower, more physiological, concentrations of IFN-α and/or -ω (100 pg/mL, in 1/10 dilutions of plasma) in 13.6% of 3,595 patients with critical COVID-19, including 21% of 374 patients > 80 years, and 6.5% of 522 patients with severe COVID-19. These antibodies are also detected in 18% of the 1,124 deceased patients (aged 20 days-99 years; mean: 70 years). Moreover, another 1.3% of patients with critical COVID-19 and 0.9% of the deceased patients have auto-Abs neutralizing high concentrations of IFN-β. We also show, in a sample of 34,159 uninfected subjects from the general population, that auto-Abs neutralizing high concentrations of IFN-α and/or -ω are present in 0.18% of individuals between 18 and 69 years, 1.1% between 70 and 79 years, and 3.4% >80 years. Moreover, the proportion of subjects carrying auto-Abs neutralizing lower concentrations is greater in a subsample of 10,778 uninfected individuals: 1% of individuals 80 years. By contrast, auto-Abs neutralizing IFN-β do not become more frequent with age. Auto-Abs neutralizing type I IFNs predate SARS-CoV-2 infection and sharply increase in prevalence after the age of 70 years. They account for about 20% of both critical COVID-19 cases in the over-80s, and total fatal COVID-19 cases

CD21 deficiency in two siblings with recurrent respiratory infections and hypogammaglobulinemia

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CD21 deficiency in two siblings with recurrent respiratory infections and hypogammaglobulinemia

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Inherited GATA2 Deficiency Is Dominant by Haploinsufficiency and Displays Incomplete Clinical Penetrance

Marot, Stephane/0000-0003-4438-5793; Jeziorski, Eric/0000-0003-0318-3044; Cobat, Aurelie/0000-0001-7209-6257; Puel, Anne/0000-0003-2603-0323; Boisson-Dupuis, Stephanie/0000-0002-7115-116X; Colobran, Roger/0000-0002-5964-536X; Rosain, Jeremie/0000-0002-2822-161X; Martinez Gallo, Monica/0000-0002-7340-2161; Oleaga-Quintas, Carmen/0000-0002-6057-0959; /0000-0002-9478-8403WOS:000606219800001PubMed: 33417088Purpose Germline heterozygous mutations of GATA2 underlie a variety of hematological and clinical phenotypes. The genetic, immunological, and clinical features of GATA2-deficient patients with mycobacterial diseases in the familial context remain largely unknown. Methods We enrolled 15 GATA2 index cases referred for mycobacterial disease. We describe their genetic and clinical features including their relatives. Results We identified 12 heterozygous GATA2 mutations, two of which had not been reported. Eight of these mutations were loss-of-function, and four were hypomorphic. None was dominant-negative in vitro, and the GATA2 locus was found to be subject to purifying selection, strongly suggesting a mechanism of haploinsufficiency. Three relatives of index cases had mycobacterial disease and were also heterozygous, resulting in 18 patients in total. Mycobacterial infection was the first clinical manifestation in 11 patients, at a mean age of 22.5 years (range: 12 to 42 years). Most patients also suffered from other infections, monocytopenia, or myelodysplasia. Strikingly, the clinical penetrance was incomplete (32.9% by age 40 years), as 16 heterozygous relatives aged between 6 and 78 years, including 4 older than 60 years, were completely asymptomatic. Conclusion Clinical penetrance for mycobacterial disease was found to be similar to other GATA2 deficiency-related manifestations. These observations suggest that other mechanisms contribute to the phenotypic expression of GATA2 deficiency. A diagnosis of autosomal dominant GATA2 deficiency should be considered in patients with mycobacterial infections and/or other GATA2 deficiency-related phenotypes at any age in life. Moreover, all direct relatives should be genotyped at the GATA2 locus.INSERM, University of Paris; Rockefeller University; St. Giles Foundation; National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH)United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute of Allergy & Infectious Diseases (NIAID) [R37AI095983]; French National Research Agency (ANR) under the "Investments for the future" programFrench National Research Agency (ANR) [ANR-10-IAHU-01, ANR13-ISV3-0001-01, ANR-16-CE17-0005-01]; ECOS-NORD [C19S01-63407, SRC2017]; ANRHGDIFDFrench National Research Agency (ANR) [ANR-14-CE15-006-01]; ANR-IFNGPHOX [ANR-13-ISV3-0001-01]; GENMSMD [ANR-16-CE17-0005-01]; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2012/11757-2, 2010/51814-0, 2012/51094-2]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ)National Council for Scientific and Technological Development (CNPq) [303809/2010-8]; Instituto de Salud Carlos IIIInstituto de Salud Carlos IIIEuropean Commission [PI11/01086, PI14/00405]; European Regional Development Fund (ERDF)European Commission; Colombia-France (ECOS-NORD/COLCIENCIAS/MEN/ICETEX) [619-2013]; Diana Garcia de Olarte foundation PID; ColcienciasDepartamento Administrativo de Ciencia, Tecnologia e Innovacion Colciencias [713-2016, 111574455633]; "Poste d'accueil" INSERMInstitut National de la Sante et de la Recherche Medicale (Inserm); Imagine InstituteThe Laboratory of Human Genetics of Infectious Diseases is supported in part by institutional grants from INSERM, University of Paris, The Rockefeller University and the St. Giles Foundation, the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH) (R37AI095983), and grants from the French National Research Agency (ANR) under the "Investments for the future" program (ANR-10-IAHU-01) and IFNGPHOX (ANR13-ISV3-0001-01 for JB and ACN), GENMSMD (ANR-16-CE17-0005-01 for JB) grants, ECOS-NORD (C19S01-63407 for JB and JFR), and SRC2017 (for JB). CO-Q is supported by ANRHGDIFD (ANR-14-CE15-006-01). AG was supported by the ANR-IFNGPHOX (ANR-13-ISV3-0001-01), GENMSMD (ANR-16-CE17-0005-01), and the Imagine Institute. AC-N and EBO-J are supported by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP grants 2012/11757-2, 2010/51814-0, and 2012/51094-2) and Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ grant 303809/2010-8). MMG and RC are supported by Instituto de Salud Carlos III, grants PI11/01086 and PI14/00405, co-financed by the European Regional Development Fund (ERDF). JFR and AAA are supported by Colombia-France (ECOS-NORD/COLCIENCIAS/MEN/ICETEX; 619-2013, Diana Garcia de Olarte foundation PID and Colciencias grant 713-2016 #111574455633). JR was supported by "Poste d'accueil" INSERM and Imagine Institute

Clinical and Genetic Spectrum of a Large Cohort With Total and Sub-total Complement Deficiencies

International audienceThe complement system is crucial for defense against pathogens and the removal of dying cells or immune complexes. Thus, clinical indications for possible complete complement deficiencies include, among others, recurrent mild or serious bacterial infections as well as autoimmune diseases (AID). The diagnostic approach includes functional activity measurements of the classical (CH50) and alternative pathway (AP50) and the determination of the C3 and C4 levels, followed by the quantitative analysis of individual components or regulators. When biochemical analysis reveals the causal abnormality of the complement deficiency (CD), molecular mechanisms remains frequently undetermined. Here, using direct sequencing analysis of the coding region we report the pathogenic variants spectrum that underlie the total or subtotal complement deficiency in 212 patients. We identified 107 different hemizygous, homozygous, or compound heterozygous pathogenic variants in 14 complement genes [C1Qβ (n = 1), C1r (n = 3), C1s (n = 2), C2 (n = 12), C3 (n = 5), C5 (n = 12), C6 (n = 9), C7 (n = 17), C8 β (n = 7), C9 (n = 3), CFH (n = 7), CFI (n = 18), CFP (n = 10), CFD (n = 2)]. Molecular analysis identified 17 recurrent pathogenic variants in 6 genes (C2, CFH, C5, C6, C7, and C8). More than half of the pathogenic variants identified in unrelated patients were also found in healthy controls from the same geographic area. Our study confirms the strong association of meningococcal infections with terminal pathway deficiency and highlights the risk of pneumococcal and auto-immune diseases in the classical and alternative pathways. Results from this large genetic investigation provide evidence of a restricted number of molecular mechanisms leading to complement deficiency and describe the clinical potential adverse events of anti-complement therapy

Progressive Multifocal Leukoencephalopathy in Primary Immunodeficiencies

International audiencePurpose:Progressive multifocal leukoencephalopathy (PML) is a rare but severe demyelinating disease caused by the polyoma-virus JC (JCV) in immunocompromised patients. We report a series of patients with primary immune deficiencies (PIDs) who developed PML. Methods:Retrospective observational study including PID patients with PML. Clinical, immunological, imaging features, and outcome are provided for each patient. Results:Eleven unrelated patients with PIDs developed PML. PIDs were characterized by a wide range of syndromic or genetically defined defects, mostly with combined B and T cell impairment. Genetic diagnosis was made in 7 patients. Before the development of PML, 10 patients had recurrent infections, 7 had autoimmune and/or inflammatory manifestations, and 3 had a history of malignancies. Immunologic investigations showed CD4 + lymphopenia (median 265, range 50-344) in all cases. Six patients received immunosuppressive therapy in the year before PML onset, including prolonged steroid therapy in 3 cases, rituximab in 5 cases, anti-TNF-α therapy, and azathioprine in 1 case each. Despite various treatments, all but 1 patient died after a median of 8 months following PML diagnosis. Conclusion: PML is a rare but fatal complication of PIDs. Many cases are secondary to immunosuppressive therapy warranting careful evaluation before initiation subsequent immunosuppression during PIDs

Mutations in the adaptor-binding domain and associated linker region of p110δ cause Activated PI3K-δ Syndrome 1 (APDS1)

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Successful in utero stem cell transplantation in X-linked severe combined immunodeficiency

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Strains Responsible for Invasive Meningococcal Disease in Patients With Terminal Complement Pathway Deficiencies.

International audienceBackground:Patients with terminal complement pathway deficiency (TPD) are susceptible to recurrent invasive meningococcal disease (IMD). Neisseria meningitidis (Nm) strains infecting these patients are poorly documented in the literature.Methods:We identified patients with TPD and available Nm strains isolated during IMD. We investigated the genetic basis of the different TPDs and the characteristics of the Nm strains.Results:We included 56 patients with C5 (n = 8), C6 (n = 20), C7 (n = 18), C8 (n = 9), or C9 (n = 1) deficiency. Genetic study was performed in 47 patients and 30 pathogenic variants were identified in the genes coding for C5 (n = 4), C6 (n = 5), C7 (n = 12), C8 (n = 7), and C9 (n = 2). We characterized 61 Nm strains responsible for IMD in the 56 patients with TPD. The most frequent strains belonged to groups Y (n = 27 [44%]), B (n = 18 [30%]), and W (n = 8 [13%]). Hyperinvasive clonal complexes (CC11, CC32, CC41/44, and CC269) were responsible for 21% of IMD cases. The CC23 predominates and represented 26% of all invasive isolates. Eleven of the 15 clonal complexes identified fit to 12 different clonal complexes belonging to carriage strains.Conclusions:Unusual meningococcal strains with low level of virulence similar to carriage strains are most frequently responsible for IMD in patients with TPD

PROMIDISα: A T-cell receptor α signature associated with immunodeficiencies caused by V(D)J recombination defects

International audienceBACKGROUND:V(D)J recombination ensures the diversity of the adaptive immune system. Although its complete defect causes severe combined immunodeficiency (ie, T-B- severe combined immunodeficiency), its suboptimal activity is associated with a broad spectrum of immune manifestations, such as late-onset combined immunodeficiency and autoimmunity. The earliest molecular diagnosis of these patients is required to adopt the best therapy strategy, particularly when it involves a myeloablative conditioning regimen for hematopoietic stem cell transplantation.OBJECTIVE:We aimed at developing biomarkers based on analysis of the T-cell receptor (TCR) α repertoire to assist in the diagnosis of patients with primary immunodeficiencies with V(D)J recombination and DNA repair deficiencies.METHODS:We used flow cytometric (fluorescence-activated cell sorting) analysis to quantify TCR-Vα7.2-expressing T lymphocytes in peripheral blood and developed PROMIDISα, a multiplex RT-PCR/next-generation sequencing assay, to evaluate a subset of the TCRα repertoire in T lymphocytes.RESULTS:The combined fluorescence-activated cell sorting and PROMIDISα analyses revealed specific signatures in patients with V(D)J recombination-defective primary immunodeficiencies or ataxia telangiectasia/Nijmegen breakage syndromes.CONCLUSION:Analysis of the TCRα repertoire is particularly appropriate in a prospective way to identify patients with partial immune defects caused by suboptimal V(D)J recombination activity, a DNA repair defect, or both. It also constitutes a valuable tool for the retrospective in vivo functional validation of variants identified through exome or panel sequencing. Its broader implementation might be of interest to assist early diagnosis of patients presenting with hypomorphic DNA repair defects inclined to experience acute toxicity during prehematopoietic stem cell transplantation conditioning