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Background: Agammaglobulinemia due to variants in IGLL1 has traditionally been considered an exceedingly rare form of severe B-cell deficiency, with only eight documented cases in the literature. Surprisingly, the first agammaglobulinemic patient identified by newborn screening (NBS) through quantification of kappa-deleting recombination excision circles harbored variants in IGLL1., Objective: To provide a comprehensive overview of the clinical and immunological findings of patients with B-cell deficiency attributed to variants in IGLL1., Methods: NBS programs reporting using kappa-deleting recombination excision circle assays, the European Society for Immunodeficiencies Registry, and authors of published reports featuring patients with B-cell deficiency linked to IGLL1 variants were contacted. Only patients with (likely) pathogenic variants, reduced CD19+ counts and no alternative diagnosis were included., Results: The study included 13 patients identified through NBS, two clinically diagnosed patients, and two asymptomatic siblings. All had severely reduced CD19+ B-cells (< 0.1×10 9 /L) on first evaluation, yet subsequent follow-ups indicated residual immunoglobulin production. Specific antibody responses to vaccine antigens varied, with a predominant reduction observed during infancy. Clinical outcomes were favorable with immunoglobulin G substitution. Two patients successfully discontinued substitution without developing susceptibility to infections and maintaining immunoglobulin levels. The pooled incidence of homozygous or compound heterozygous pathogenic IGLL1 variants identified by NBS in Austria, Czechia, and Switzerland was 1.3:100´000, almost double of X-linked agammaglobulinemia., Conclusion: B-cell deficiency resulting from IGLL1 variants appears to be more prevalent than initially believed. Despite markedly low B-cell counts, the clinical course in some patients may be milder than reported in the literature so far., (Copyright © 2024. Published by Elsevier Inc.)

Vaccination rates for mumps, measles, and rubella (MMR) and tetanus, diphtheria, pertussis, and polio (Tdap-IPV) fall short of global targets, highlighting the need for vaccination interventions. This study examines the effectiveness of a city-wide school-based educational vaccination intervention as part of an on-site vaccination program aimed at increasing MMR and Tdap-IPV vaccination rates versus on-site vaccination alone among sociodemographically diverse students from Berlin, Germany. The study was a 1:1 two-arm cluster randomized controlled trial, with schools randomly assigned to either the Educational Class Condition (ECC) or the Low-Intensity Information Condition (LIIC). Both received an on-site vaccination program, while students in the ECC received an additional educational unit. Primary outcomes were MMR and Tdap-IPV vaccination rates. In total, 6512 students from 25 randomly selected urban area secondary schools participated. For students providing their vaccination documents on the day of the intervention (2273, 34.9%), adjusted Poisson mixed models revealed significant between-group differences in favor of the ECC (MMR: logRR = 0.47, 95%CI [0.01,0.92], RR = 1.59; Tdap-IPV: logRR = 0.28, 95%CI [0.10,0.47], RR = 1.32). When adjusting for socioeconomic and migration background, between-group differences became non-significant for MMR but remained significant for Tdap-IPV. Findings suggest that educational, school-based on-site vaccination appears to be a promising strategy for increasing vaccination uptake in adolescents., (© 2024 The Authors. Applied Psychology: Health and Well‐Being published by John Wiley & Sons Ltd on behalf of International Association of Applied Psychology.)

Chronic granulomatous disease (CGD) is caused by an impaired respiratory burst reaction in phagocytes. CGD is an X-linked (XL) (caused by pathogenic variants in CYBB ) or autosomal recessive inborn error of immunity (caused by pathogenic variants in CYBA , NCF1 , NCF2 , or CYBC1 ). Female carriers of XL-CGD and unfavorable lyonization may present with the partial or full picture of CGD. Patients with CGD are at increased risk for invasive bacterial and fungal infections of potentially any organ, but especially the lymph nodes, liver, and lungs. Pathogens most frequently isolated are S. aureus and Aspergillus spp. Autoinflammation is difficult to control with immunosuppression, and patients frequently remain dependent on steroids. To diagnose CGD, reactive oxygen intermediates (O 2 or H - or H 2 O 2 ) generated by the NADPH oxidase in peripheral blood phagocytes are measured upon in vitro activation with either phorbol-12-myristate-13-acetate (PMA) and/or TLR4 ligands ( E. coli or LPS). Conservative treatment requires strict hygienic conduct and adherence to antibiotic prophylaxis against bacteria and fungi, comprising cotrimoxazole and triazoles. The prognosis of patients treated conservatively is impaired: for the majority of patients, recurrent and/or persistent infections, autoinflammation, and failure to thrive remain lifelong challenges. In contrast, cellular therapies (allogeneic stem cell transplantation or gene therapy) can cure CGD. Optimal outcomes in cellular therapies are observed in individuals without ongoing infections or inflammation. Yet cellular therapies are the only curative option for patients with persistent fungal infections or autoinflammation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Staudacher and von Bernuth.)

In patients with severe and recurrent infections, minimal diagnostic workup to test for Inborn Errors of Immunity (IEI) includes a full blood count, IgG, IgA and IgM. Vaccine antibodies against tetanus toxoid are also frequently measured, whereas testing for anti-polysaccharide IgG antibodies and IgG subclasses is not routinely performed by primary care physicians. This basic approach may cause a significant delay in diagnosing monogenic IEI that can present with an impaired IgG response to polysaccharide antigens with or without IgG subclass deficiency at an early stage. Our article reviews genetically defined IEI, that may initially present with an impaired IgG response to polysaccharide antigens, but normal or only slightly decreased IgG levels and normal responses to protein or conjugate vaccine antigens. We summarize clinical, genetic, and immunological findings characteristic for these IEI. This review may help clinicians to identify patients that require extended immunologic and genetic evaluations despite unremarkable basic immunologic findings. We recommend the inclusion of anti-polysaccharide IgG antibodies as part of the initial routine work-up for possible IEI., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (© 2024 Fasshauer, Dinges, Staudacher, Völler, Stittrich, von Bernuth, Wahn and Krüger.)

Heterozygous germline variants in human IKZF1 encoding for IKAROS define an inborn error of immunity with immunodeficiency, immune dysregulation and risk of malignancy with a broad phenotypic spectrum. Growing evidence of underlying pathophysiological genotype-phenotype correlations helps to improve our understanding of IKAROS-associated diseases. We describe 6 patients from 4 kindreds with two novel IKZF1 variants leading to haploinsufficiency from 3 centers in Germany. We also provide an overview of first symptoms to a final diagnosis including data from the literature., Competing Interests: Author AS and HB were employed by the company Labor Berlin Charité-Vivantes GmbH and author MF was employed by the company Hospital St. Georg GGmbH Leipzig. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (© 2024 Strauss, Körholz, Kuehn, Gil Silva, Taube, Trautmann-Grill, Stittrich, Pietzsch, Wiedemuth, Wahn, von Bernuth, Rosenzweig, Fasshauer, Krüger and Schuetz.)

Background: Pulmonary manifestations are the major cause of morbidity and mortality in patients with inborn errors of immunity (IEI). New and more sensitive diagnostic methods can potentially lead to earlier recognition and treatment of IEI lung disease and improve outcome. The aim of this study was to compare multiple-breath washout (MBW) and spirometry in patients with IEI and cystic fibrosis (CF) as well as healthy controls (HC) and to evaluate the sensitivity of lung clearance index (LCI) to assess lung disease in IEI., Methods: IEI patients (n=114) were recruited from our paediatric and adult immunodeficiency outpatient clinics and compared to age-matched CF patients (n=114) and HC (n=114). MBW measurements and spirometry were performed in the study participants, and MBW testing was repeated after 63-707 days in IEI patients (n=70)., Results: The LCI was significantly higher in IEI patients than in HC ( p <0.001) and significantly lower than in CF patients (p<0.001). The forced expiratory volume in 1 s (FEV 1 ) z-score was significantly lower in IEI patients than in HC (p<0.01) and significantly higher than in CF patients (p<0.01). LCI and FEV 1 z-score correlated moderately negatively in the total cohort, the IEI group and the CF group. Nineteen (20.7%) of 92 IEI patients and 35 (33.3%) of 105 CF patients had an elevated LCI but a normal FEV 1 z-score. After a median of 364 days, the median LCI of 70 IEI patients increased significantly by 0.2., Conclusion: MBW is useful to detect lung disease in IEI and is more sensitive than spirometry., Competing Interests: Conflict of interest: S. Thee declares grants to their institution from the German Innovation Fond; payment or honoraria from Chiesi (European Cystic Fibrosis Society meeting 2022) and Vertex (LEAD meeting, adherence forum); and travel expenses from Chiesi to attend the European Cystic Fibrosis Society meeting 2022. Conflict of interest: O. Staudacher declares a Travel Grant for Young Immunologists from Arbeitsgemeinschaft Pädiatrische Immunologie in the 36 months prior to manuscript submission. Conflict of interest: E. Steinke declares grants or contracts from the Clinician Scientist Program of the Berlin Institute of Health (funded by the German Federal Ministry of Education and Research); payment or honoraria for review of educational manuscripts from Vertex Pharmaceuticals Inc.; and a travel grant for conference attendance from the European Cystic Fibrosis Society, all in the 36 months prior to manuscript submission. Conflict of interest: J. Röhmel declares payment or honoraria, and support for attending meetings and/or travel from Vertex Pharmaceuticals in the 36 months prior to manuscript submission (with permission from their institution); and an unpaid role as a work package leader in BEAT-PCD, a European Research Society Clinical Research Collaboration. Conflict of interest: V. Wahn declares payment or honoraria from CSL Behring (related to www.immundefekt.de) and Pharming (related to a manuscript on APDS); and an honorarium and travel expenses from Pharming for attendance at the DGKJ congress, all in the 36 months prior to manuscript submission. Conflict of interest: H. von Bernuth declares consulting fees from Infill Healthcare Communication (2022); payment or honoraria from Deutsche Selbsthilfe Angeborene Immundefekte) (2023) and CSL Behring (2021); and payment for expert testimony from Bundessozialgericht (2023); as well as that they are a member of the Standing Comission on Vaccination at the Robert Koch Insitut, Ständige Impfkommission (STIKO). Conflict of interest: M.A. Mall declares funding to their institution in connection to the present work from the German Ministry for Education and Research (BMBF; Grant #82DZL009B1); and an unpaid role as a Fellow of the European Respiratory Society. Conflict of interest: M. Stahl declares funding to their institution (Heisenberg professorship) from the German Research Foundation (Deutsche Forschungsgemeinschaft) in connection to the present work; as well as unpaid roles as Chairman of the Forschungsgemeinschaft Mukoviszidose; Secretary of the Cystic Fibrosis Group of the European Respiratory Society; and Treasurer of the German Society of Paediatric Pulmonology. Conflict of interest: All other authors declare no competing interests., (Copyright ©The authors 2024.)

We describe humans with rare biallelic loss-of-function PTCRA variants impairing pre-α T cell receptor (pre-TCRα) expression. Low circulating naive αβ T cell counts at birth persisted over time, with normal memory αβ and high γδ T cell counts. Their TCRα repertoire was biased, which suggests that noncanonical thymic differentiation pathways can rescue αβ T cell development. Only a minority of these individuals were sick, with infection, lymphoproliferation, and/or autoimmunity. We also report that 1 in 4000 individuals from the Middle East and South Asia are homozygous for a common hypomorphic PTCRA variant. They had normal circulating naive αβ T cell counts but high γδ T cell counts. Although residual pre-TCRα expression drove the differentiation of more αβ T cells, autoimmune conditions were more frequent in these patients compared with the general population.

Background: Lymphoproliferation and autoimmune cytopenias characterise autoimmune lymphoproliferative syndrome. Other conditions sharing these manifestations have been termed autoimmune lymphoproliferative syndrome-like diseases, although they are frequently more severe. The aim of this study was to define the genetic, clinical, and immunological features of these disorders to improve their diagnostic classification., Methods: In this prospective cohort study, patients were referred to the Center for Chronic Immunodeficiency in Freiburg, Germany, between Jan 1, 2008 and March 5, 2022. We enrolled patients younger than 18 years with lymphoproliferation and autoimmune cytopenia, lymphoproliferation and at least one additional sign of an inborn error of immunity (SoIEI), bilineage autoimmune cytopenia, or autoimmune cytopenia and at least one additional SoIEI. Autoimmune lymphoproliferative syndrome biomarkers were determined in all patients. Sanger sequencing followed by in-depth genetic studies were recommended for patients with biomarkers indicative of autoimmune lymphoproliferative syndrome, while IEI panels, exome sequencing, or genome sequencing were recommended for patients without such biomarkers. Genetic analyses were done as decided by the treating physician. The study was registered on the German Clinical Trials Register, DRKS00011383, and is ongoing., Findings: We recruited 431 children referred for autoimmune lymphoproliferative syndrome evaluation, of whom 236 (55%) were included on the basis of lymphoproliferation and autoimmune cytopenia, 148 (34%) on the basis of lymphoproliferation and another SoIEI, 33 (8%) on the basis of autoimmune bicytopenia, and 14 (3%) on the basis of autoimmune cytopenia and another SoIEI. Median age at diagnostic evaluation was 9·8 years (IQR 5·5-13·8), and the cohort comprised 279 (65%) boys and 152 (35%) girls. After biomarker and genetic assessments, autoimmune lymphoproliferative syndrome was diagnosed in 71 (16%) patients. Among the remaining 360 patients, 54 (15%) had mostly autosomal-dominant autoimmune lymphoproliferative immunodeficiencies (AD-ALPID), most commonly affecting JAK-STAT (26 patients), CTLA4-LRBA (14), PI3K (six), RAS (five), or NFκB (three) signalling. 19 (5%) patients had other IEIs, 17 (5%) had non-IEI diagnoses, 79 (22%) were unresolved despite extended genetics (ALPID-U), and 191 (53%) had insufficient genetic workup for diagnosis. 16 (10%) of 161 patients with a final diagnosis had somatic mutations. Alternative classification of patients fulfilling common variable immunodeficiency or Evans syndrome criteria did not increase the proportion of genetic diagnoses., Interpretation: The ALPID phenotype defined in this study is enriched for patients with genetic diseases treatable with targeted therapies. The term ALPID might be useful to focus diagnostic and therapeutic efforts by triggering extended genetic analysis and consideration of targeted therapies, including in some children currently classified as having common variable immunodeficiency or Evans syndrome., Funding: Deutsche Forschungsgemeinschaft under Germany's Excellence Strategy., Translation: For the German translation of the abstract see Supplementary Materials section., Competing Interests: Declaration of interests SE are members of a data monitoring committee for leniolisib (Pharming). SH and SE received research funding from Pharming. MA and IC are a full-time employees of UCB Pharma and are shareholders of UCB. SE received research support from UCB for this study, including the whole-genome trio analysis of 30 families. All other authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Staphylococcus aureus strains that produce the toxin Panton-Valentine leukocidin (PVL-SA) frequently cause recurrent skin and soft tissue infections. PVL binds to and kills human neutrophils, resulting in the formation of neutrophil extracellular traps (NETs), but the pathomechanism has not been extensively studied. Furthermore, it is unclear why some individuals colonized with PVL-SA experience recurring infections whereas others are asymptomatic. We thus aimed to (1) investigate how PVL exerts its pathogenicity on neutrophils and (2) identify factors that could help to explain the predisposition of patients with recurring infections. We provide genetic and pharmacological evidence that PVL-induced NET formation is independent of NADPH oxidase and reactive oxygen species production. Moreover, through NET proteome analysis we identified that the protein content of PVL-induced NETs is different from NETs induced by mitogen or the microbial toxin nigericin. The abundance of the proteins cathelicidin (CAMP), elastase (NE), and proteinase 3 (PRTN3) was lower on PVL-induced NETs, and as such they were unable to kill S. aureus. Furthermore, we found that neutrophils from affected patients express higher levels of CD45, one of the PVL receptors, and are more susceptible to be killed at a low PVL concentration than control neutrophils. Neutrophils from patients that experience recurring PVL-positive infections may thus be more sensitive to PVL-induced NET formation, which might impair their ability to combat the infection., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2023. Published by Oxford University Press on behalf of Society for Leukocyte Biology.)

Background: Newborn screening (NBS) programs for severe combined immunodeficiency facilitate early diagnosis of severe combined immunodeficiency and promote early treatment with hematopoietic stem cell transplantation, resulting in improved clinical outcomes. Infants with congenital athymia are also identified through NBS because of severe T-cell lymphopenia. With the expanding introduction of NBS programs, referrals of athymic patients for treatment with thymus transplantation have recently increased at Great Ormond Street Hospital (GOSH) (London, United Kingdom)., Objective: We studied the impact of NBS on timely diagnosis and treatment of athymic infants with thymus transplantation at GOSH., Methods: We compared age at referral and complications between athymic infants diagnosed after clinical presentation (n = 25) and infants identified through NBS (n = 19) who were referred for thymus transplantation at GOSH between October 2019 and February 2023. We assessed whether age at time of treatment influences thymic output at 6 and 12 months after transplantation., Results: The infants referred after identification through NBS were significantly younger and had fewer complications, in particular fewer infections. All deaths occurred in the group of those who did not undergo NBS, including 6 patients before and 2 after thymus transplantation because of preexisting infections. In the absence of significant comorbidities or diagnostic uncertainties, timely treatment was achieved more frequently after NBS. Treatment when younger than age 4 months was associated with higher thymic output at 6 and 12 months after transplantation., Conclusion: NBS contributes to earlier recognition of congenital athymia, promoting referral of athymic patients for thymus transplantation before they acquire infections or other complications and facilitating treatment at a younger age, thus playing an important role in improving their outcomes., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

The peptide toxin candidalysin, secreted by Candida albicans hyphae, promotes stimulation of neutrophil extracellular traps (NETs). However, candidalysin alone triggers a distinct mechanism for NET-like structures (NLS), which are more compact and less fibrous than canonical NETs. Candidalysin activates NADPH oxidase and calcium influx, with both processes contributing to morphological changes in neutrophils resulting in NLS formation. NLS are induced by leucotoxic hypercitrullination, which is governed by calcium-induced protein arginine deaminase 4 activation and initiation of intracellular signalling events in a dose- and time-dependent manner. However, activation of signalling by candidalysin does not suffice to trigger downstream events essential for NET formation, as demonstrated by lack of lamin A/C phosphorylation, an event required for activation of cyclin-dependent kinases that are crucial for NET release. Candidalysin-triggered NLS demonstrate anti-Candida activity, which is resistant to nuclease treatment and dependent on the deprivation of Zn 2+ . This study reveals that C. albicans hyphae releasing candidalysin concurrently trigger canonical NETs and NLS, which together form a fibrous sticky network that entangles C. albicans hyphae and efficiently inhibits their growth., (© 2023 The Authors. Published under the terms of the CC BY 4.0 license.)

X-linked chronic granulomatous disease (XL-CGD) is an inherited disorder of superoxide production, causing failure to generate the oxidative burst in phagocytes. It is characterized by invasive bacterial and fungal infections, inflammation, and chronic autoimmune disease. While XL-CGD carriers were previously assumed to be healthy, a range of clinical manifestations with significant morbidity have recently been described in a subgroup of carriers with impaired neutrophil oxidative burst due to skewed lyonization. Allogeneic hematopoietic stem cell transplantation (HSCT) is the standard curative treatment for CGD but has rarely been reported in individual symptomatic carriers to date. We undertook a retrospective international survey of outcome of HSCT for symptomatic XL-CGD carriers. Seven symptomatic female XL-CGD carriers aged 1-56 years underwent HSCT in four centers, indicated for severe and recurrent infection, colitis, and autoimmunity. Two patients died from transplant-related complications, following donor engraftment and restoration of oxidative burst. All surviving patients demonstrated resolution of their neutrophil oxidative burst defect with concordant reduction in infection and inflammatory symptoms and freedom from further immunosuppressive therapy. In conclusion, allogeneic HSCT may cure the phagocyte defect in symptomatic XL-CGD carriers and improve their recurrent and disabling infective and inflammatory symptoms but risks transplant-related complications., (© 2023. The Author(s).)

Background: Activated phosphoinositide-3-kinase δ syndrome (APDS) is an inborn error of immunity (IEI) with infection susceptibility and immune dysregulation, clinically overlapping with other conditions. Management depends on disease evolution, but predictors of severe disease are lacking., Objectives: This study sought to report the extended spectrum of disease manifestations in APDS1 versus APDS2; compare these to CTLA4 deficiency, NFKB1 deficiency, and STAT3 gain-of-function (GOF) disease; and identify predictors of severity in APDS., Methods: Data was collected from the ESID (European Society for Immunodeficiencies)-APDS registry and was compared with published cohorts of the other IEIs., Results: The analysis of 170 patients with APDS outlines high penetrance and early onset of APDS compared to the other IEIs. The large clinical heterogeneity even in individuals with the same PIK3CD variant E1021K illustrates how poorly the genotype predicts the disease phenotype and course. The high clinical overlap between APDS and the other investigated IEIs suggests relevant pathophysiological convergence of the affected pathways. Preferentially affected organ systems indicate specific pathophysiology: bronchiectasis is typical of APDS1; interstitial lung disease and enteropathy are more common in STAT3 GOF and CTLA4 deficiency. Endocrinopathies are most frequent in STAT3 GOF, but growth impairment is also common, particularly in APDS2. Early clinical presentation is a risk factor for severe disease in APDS., Conclusions: APDS illustrates how a single genetic variant can result in a diverse autoimmune-lymphoproliferative phenotype. Overlap with other IEIs is substantial. Some specific features distinguish APDS1 from APDS2. Early onset is a risk factor for severe disease course calling for specific treatment studies in younger patients., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. All rights reserved.)

Background: Assessment of T-cell receptor excision circles (TRECs) in dried blood spots of newborns allows the detection of severe combined immunodeficiency (SCID) (T cells <300/μL at birth) with a presumed sensitivity of 100%. TREC screening also identifies patients with selected combined immunodeficiency (CID) (T cells >300/μL, yet <1500/μL at birth). Nevertheless, relevant CIDs that would benefit from early recognition and curative treatment pass undetected., Objective: We hypothesized that TREC screening at birth cannot identify CIDs that develop with age., Methods: We analyzed the number of TRECs in dried blood spots in archived Guthrie cards of 22 children who had been born in the Berlin-Brandenburg area between January 2006 and November 2018 and who had undergone hematopoietic stem-cell transplantation (HSCT) for inborn errors of immunity., Results: All patients with SCID would have been identified by TREC screening, but only 4 of 6 with CID. One of these patients had immunodeficiency, centromeric instability, and facial anomalies syndrome type 2 (ICF2). Two of 3 patients with ICF whom we have been following up at our institution had TREC numbers above the cutoff value suggestive of SCID at birth. Yet all patients with ICF had a severe clinical course that would have justified earlier HSCT., Conclusions: In ICF, naïve T cells may be present at birth, yet they decline with age. Therefore, TREC screening cannot identify these patients. Early recognition is nevertheless crucial, as patients with ICF benefit from HSCT early in life., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Patient registries are a very important and essential tool for investigating rare diseases, as most physicians only see a limited number of cases during their career. Diseases of multi-organ autoimmunity and autoinflammation are especially challenging, as they are characterized by diverse clinical phenotypes and highly variable expressivity. The GAIN consortium (German multi-organ Auto Immunity Network) developed a dataset addressing these challenges. ICD-11, HPO, and ATC codes were incorporated to document various clinical manifestations and medications with a defined terminology. The GAIN dataset comprises detailed information on genetics, phenotypes, medication, and laboratory values. Between November 2019 and July 2022, twelve centers from Europe have registered 419 patients with multi-organ autoimmunity or autoinflammation. The median age at onset of symptoms was 13 years (IQR 3-28) and the median delay from onset to diagnosis was 5 years (IQR 1-14). Of 354 (84.5%) patients who were genetically tested, 248 (59.2%) had a defined monogenetic cause. For 87 (20.8%) patients, no mutation was found and for 19 (4.5%), the result was pending. The most common gene affected was NFkB1 (48, 11.5%), and the second common was CTLA4 (40, 9.5%), both genetic patient groups being fostered by specific research projects within GAIN. The GAIN registry may serve as a valuable resource for research in the inborn error of immunity community by providing a platform for etiological and diagnostic research projects, as well as observational trials on treatment options., (© 2023. The Author(s).)

Patients with common variable immunodeficiency (CVID) generally bear a higher risk of non Hodgkin B-cell lymphomas and solid tumors, in particular gastric adenocarcinoma.Here we report a case of a 58-year-old male CVID patient who developed both malignancies within a very short period, as documented by two subsequent esophagogastroduodenoscopies performed within 4 months. While the first upper gastrointestinal endoscopy for routine surveillance purposes was uneventful, the second one after developing unexplained weight loss revealed two new neoplastic lesions in the stomach. The histological evaluation revealed a poorly differentiated adenocarcinoma infiltrating the muscularis propria forcing gastrectomy as well as a high-grade B-non-Hodgkin-lymphoma with detection of a MYC- and BCL6-translocation, necessitating chemotherapy with R-CHOP.This case emphasizes the necessity of high awareness for gastric neoplasia in patients with CVID and highlights the need of a standardized yet not established endoscopic surveillance protocol for this vulnerable group., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Background: We previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15-20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in ~ 80% of cases., Methods: We report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded., Results: No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5-528.7, P = 1.1 × 10 -4 ) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR = 3.70[95%CI 1.3-8.2], P = 2.1 × 10 -4 ). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR = 19.65[95%CI 2.1-2635.4], P = 3.4 × 10 -3 ), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR = 4.40[9%CI 2.3-8.4], P = 7.7 × 10 -8 ). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD] = 43.3 [20.3] years) than the other patients (56.0 [17.3] years; P = 1.68 × 10 -5 )., Conclusions: Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old., (© 2023. The Author(s).)

Purpose: Besides their developmental and neurological phenotype, most patients with MECP2/IRAK1 duplication syndrome present with recurrent and severe infections, accompanied by strong inflammation. Respiratory infections are the most common cause of death. Standardized pneumological diagnostics, targeted anti-infectious treatment, and knowledge of the underlying pathomechanism that triggers strong inflammation are unmet clinical needs. We investigated the influence of IRAK1 overexpression on the canonical NF-κB signaling as a possible cause for excessive inflammation in these patients., Methods: NF-κB signaling was examined by measuring the production of proinflammatory cytokines and evaluating the IRAK1 phosphorylation and degradation as well as the IκBα degradation upon stimulation with IL-1β and TLR agonists in SV40-immortalized fibroblasts, PBMCs, and whole blood of 9 patients with MECP2/IRAK1 duplication syndrome, respectively., Results: Both, MECP2/IRAK1-duplicated patients and healthy controls, showed similar production of IL-6 and IL-8 upon activation with IL-1β and TLR2/6 agonists in immortalized fibroblasts. In PBMCs and whole blood, both patients and controls had a similar response of cytokine production after stimulation with IL-1β and TLR4/2/6 agonists. Patients and controls had equivalent patterns of IRAK1 phosphorylation and degradation as well as IκBα degradation upon stimulation with IL-1β., Conclusion: Patients with MECP2/IRAK1 duplication syndrome do not show increased canonical NF-κB signaling in immortalized fibroblasts, PBMCs, and whole blood. Therefore, we assume that these patients do not benefit from a therapeutic suppression of this pathway., (© 2022. The Author(s).)

Human papillomaviruses (HPV) 6 and 11 cause 90% of recurrent laryngeal papillomatosis (RLP). It is unclear whether recurrences are caused by new infections or the spread of infected cells. Symptomatic and sometimes curative treatment is laser surgery or conventional microsurgical removal. RLP surgery aims to relieve shortness of breath and improve the voice. Patients (especially children) are affected by voice problems, repetitive surgeries, pulmonary manifestations, and psychological trauma. Vaccination with Gardasil 9 (Merck & Co., Rahway, NJ, USA) prevents new infections with HPV 6, 11, 16, 18, 31, 33, 45, 52, and 58 and induces vaccine antigen-specific antibodies and CD4+ T helper cells. According to current studies, RLP can be avoided with prophylactic vaccination. The treatment is associated with a general vaccination risk (European Medicines Agency approval: girls and boys from 9 years). Studies also show that the vaccine after removal of HPV-associated neoplasia/papilloma prevents recurrences. Extension of the vaccination recommendation to prevent recurrences of HPV-associated diseases in men may promote applicability and herd immunity. For rare and treatment-refractory cases with laryngotracheal involvement, systemic therapy with bevacizumab (e.g. Avastin; Genentech, San Francisco, CA, USA), a VEGF antibody, is a promising adjuvant treatment option., (© 2022. The Author(s).)

Background: Non-pharmaceutical interventions (NPI) during the COVID-19 pandemic aimed at prevention of SARS-CoV-2 transmission also influenced transmission of viruses other than SARS-CoV-2. The aim of this study was to describe and compare the burden of common viral respiratory and gastrointestinal infections in children admitted to Berlin University Children's Hospital (BCH) before and during the COVID-19 pandemic at different levels of public NPI measures., Methods: In this retrospective study, we analyzed the frequency of detection of common human respiratory and gastrointestinal viruses from January 2016 through January 2022 in all patients admitted to BCH. We compared virus detection before and during the COVID-19 pandemic at different levels of public NPI measures., Results: The frequency of detection of seasonal enveloped and non-enveloped viruses [Boca-, Corona-, Influenza-, Metapneumo-, Parainfluenza-, Rota-, and Respiratory Syncytial Viruses (RSV)] was diminished during the COVID-19 pandemic, whereas detection rates of non-seasonal viruses (Rhino-/Entero-, and Adenoviruses) were stable during the pandemic. After withdrawal of major NPI measures, we observed an out of season surge of the detection rates of Boca-, Corona-, Parainfluenzaviruses, and RSV. In contrast, no increased detection frequency was observed for Influenza-, Metapneumo-, and Rotaviruses as of January 2022., Conclusion: Corona-, Boca-, Parainfluenzaviruses, and RSV returned as frequently detected pathogens after withdrawal of major NPI measures. The out of season rise might be attributed to an "immune-debt" due to missing contact to viral antigens resulting in waning of population immunity during the COVID-19 pandemic., Competing Interests: Authors NU, AE, AK, and HB were employed by Labor Berlin GmbH, a joint subsidiary of the public hospitals Charité Universitätsmedizin Berlin and Vivantes — Netzwerk für Gesundheit GmbH. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Terliesner, Unterwalder, Edelmann, Corman, Knaust, Rosenfeld, Gratopp, Ringe, Martin, von Bernuth, Mall and Kallinich.)

Purpose: Six to 19% of critically ill COVID-19 patients display circulating auto-antibodies against type I interferons (IFN-AABs). Here, we establish a clinically applicable strategy for early identification of IFN-AAB-positive patients for potential subsequent clinical interventions., Methods: We analyzed sera of 430 COVID-19 patients from four hospitals for presence of IFN-AABs by ELISA. Binding specificity and neutralizing activity were evaluated via competition assay and virus-infection-based neutralization assay. We defined clinical parameters associated with IFN-AAB positivity. In a subgroup of critically ill patients, we analyzed effects of therapeutic plasma exchange (TPE) on the levels of IFN-AABs, SARS-CoV-2 antibodies and clinical outcome., Results: The prevalence of neutralizing AABs to IFN-α and IFN-ω in COVID-19 patients from all cohorts was 4.2% (18/430), while being undetectable in an uninfected control cohort. Neutralizing IFN-AABs were detectable exclusively in critically affected (max. WHO score 6-8), predominantly male (83%) patients (7.6%, 18/237 for IFN-α-AABs and 4.6%, 11/237 for IFN-ω-AABs in 237 patients with critical COVID-19). IFN-AABs were present early post-symptom onset and at the peak of disease. Fever and oxygen requirement at hospital admission co-presented with neutralizing IFN-AAB positivity. IFN-AABs were associated with lower probability of survival (7.7% versus 80.9% in patients without IFN-AABs). TPE reduced levels of IFN-AABs in three of five patients and may increase survival of IFN-AAB-positive patients compared to those not undergoing TPE., Conclusion: IFN-AABs may serve as early biomarker for the development of severe COVID-19. We propose to implement routine screening of hospitalized COVID-19 patients for rapid identification of patients with IFN-AABs who most likely benefit from specific therapies., (© 2022. The Author(s).)

Objectives: Post-measles increased susceptibility to subsequent infections seems particularly relevant in low-resource settings. We tested the hypothesis that measles causes a specifically increased rate of infections in children, also in a high-resource setting., Methods: We conducted a retrospective cohort study on a large measles outbreak in Berlin, Germany. All children with measles who presented to hospitals in Berlin were included as cases, children with non-infectious and children with non-measles infectious diseases as controls. Repeat visits within 3 years after the outbreak were recorded., Results: We included 250 cases, 502 non-infectious, and 498 infectious disease controls. The relative risk for cases for the diagnosis of an infectious disease upon a repeat visit was 1.6 (95% CI 1.4-2.0, p < 0.001) vs. non-infectious and 1.3 (95% CI 1.1-1.6, p = 0.002) vs. infectious disease controls. 33 cases (27%), 35 non-infectious (12%) and 57 (18%) infectious disease controls presented more than three times due to an infectious disease ( p = 0.01, and p = 0.02, respectively). This results in a relative risk of more than three repeat visits due to an infection for measles cases of 1.8 (95% CI 1.3-2.4, p = 0.01), and 1.4 (95% CI 1.0-1.9, p = 0.04), respectively., Conclusion: Our study demonstrates for the first time in a high-resource setting, that increased post-measles susceptibility to subsequent infections in children is measles-specific-even compared to controls with previous non-measles infections., Competing Interests: HB is an associated member of the standing committee on vaccination against measles at the Robert Koch Institute. DM-K is a member of the standing committee on vaccination against measles at the Robert Koch Institute. AMa and SS are consulting members of the standing committee on vaccination at the Robert Koch Institute. UH is a member of the standing committee on vaccination at the Robert Koch Institute. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Bühl, Staudacher, Santibanez, Rossi, Girschick, Stephan, Schmidt, Hundsdoerfer, von Moers, Lange, Barker, Mall, Heininger, Matysiak-Klose, Mankertz and von Bernuth.)

The rate of SARS-CoV-2 infections in children remains unclear due to many asymptomatic cases. We present a study of cross-sectional seroprevalence surveys of anti-SARS-CoV-2 IgG in 10,358 children recruited in paediatric hospitals across Germany from June 2020 to May 2021. Seropositivity increased from 2.0% (95% CI 1.6, 2.5) to 10.8% (95% CI 8.7, 12.9) in March 2021 with little change up to May 2021. Rates increased by migrant background (2.8%, 4.4% and 7.8% for no, one and two parents born outside Germany). Children under three were initially 3.6 (95% CI 2.3, 5.7) times more likely to be seropositive with levels equalising later. The ratio of seropositive cases per recalled infection decreased from 8.6 to 2.8. Since seropositivity exceeds the rate of recalled infections considerably, serologic testing may provide a more valid estimate of infections, which is required to assess both the spread and the risk for severe outcomes of SARS-CoV-2 infections., (© 2022. The Author(s).)

Graft-versus-host disease (GvHD) is still the major non-relapse, life-limiting complication after hematopoietic stem cell transplantation. Modern pharmacologic immunosuppression is often insufficient and associated with significant side effects. Novel treatment strategies now include adoptive transfer of ex vivo expanded regulatory T cells (Tregs), but their efficacy in chronic GvHD is unknown. We treated three children suffering from severe, therapy-refractory GvHD with polyclonally expanded Tregs generated from the original stem cell donor. Third-line maintenance immunosuppression was tapered to cyclosporin A and low-dose steroids shortly before cell transfer. Regular follow-up included an assessment of the subjective and objective clinical development, safety parameters, and in-depth immune monitoring. All patients showed marked clinical improvement with substantially decreased GvHD activity. Laboratory follow-up showed a significant enhancement of the immunologic engraftment, including lymphocytes and dendritic cells. Monitoring the fate of Tregs by next-generation sequencing demonstrated clonal expansion. In summary, adoptive transfer of Tregs was well tolerated and able to modulate an established undesired T cell mediated allo-response. Although no signs of overimmunosuppression were detectable, the treatment of patients with invasive opportunistic infections should be undertaken with caution. Further controlled studies are necessary to confirm these encouraging effects and eventually pave the way for adoptive Treg therapy in chronic GvHD., Competing Interests: Declaration of interests Authors declare that they have no competing interests., (Copyright © 2022. Published by Elsevier Inc.)

In childhood, a multitude of causes lead to pulmonary alveolar proteinosis (PAP), an excessive surfactant accumulation in the alveolar space, limiting gas exchange. Autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF) causing autoimmune PAP, the principal aetiology in adults, are rare. In this first case series on autoimmune PAP, we detail the presentation and management issues of four children. Whereas three children presented insidiously with progressive dyspnoea, one was acutely sick with suspected pneumonia. During management, one patient was hospitalised with coronavirus disease 2019, noninvasively ventilated, and recovered. All treatment modalities known from adults including whole-lung lavage, augmentation of GM-CSF by inhaled GM-CSF, removal of neutralising antibody by plasmapheresis and interruption of antibody production using rituximab were considered; however, not all options were available at all sites. Inhaled GM-CSF appeared to be a noninvasive and comfortable therapeutic approach. The management with best benefit-to-harm ratio in autoimmune PAP is unknown and specialised physicians must select the least invasive and most effective treatment. To collect this cohort in a rare condition became feasible as patients were submitted to an appropriate registry. To accelerate the authorisation of novel treatments for autoimmune PAP, competent authorities should grant an inclusion of adolescents into trials in adults., Competing Interests: Conflict of interest: M. Griese reports grants or contracts received from Böhringer Ingelheim paid to their institution; participation on a Data Safety Monitoring Board or Advisory Board for Böhringer Ingelheim, personal fees received. Unpaid Head chILD-EU; all disclosures made outside the submitted work. Conflict of interest: P. Panagiotou has nothing to disclose. Conflict of interest: E.D. Manali reports receiving grants or contracts, paid to their institution, from Hoffmann La Roche, Boehringer Ingelheim and Savara; personal payments for lectures, presentations, speakers' bureaus, manuscript writing or educational events received from Hoffmann La Roche and Boehringer Ingelheim; support for attending meetings and/or travel paid to the institution received from Hoffmann La Roche and Boehringer Ingelheim; all disclosures made outside the submitted work. Conflict of interest: M. Stahl has nothing to disclose. Conflict of interest: N. Schwerk has nothing to disclose. Conflict of interest: V. Costa has nothing to disclose. Conflict of interest: K. Douros has nothing to disclose. Conflict of interest: M. Kallieri has nothing to disclose. Conflict of interest: R.M. Urbantat has nothing to disclose. Conflict of interest: H. von Bernuth reports receiving payment or honoraria for lectures, presentations, speakers’ bureaus, manuscript writing or educational events from CSL Behring and Octapharma; participation on an advisory board for Takeda; and is an associate member of the Standing committee on vaccinations. All disclosures made outside the submitted work. Conflict of interest: L. Kolilekas has nothing to disclose. Conflict of interest: L. Morais has nothing to disclose. Conflict of interest: A. Ramos has nothing to disclose. Conflict of interest: K. Landwehr has nothing to disclose. Conflict of interest: K. Knoflach has nothing to disclose. Conflict of interest: F. Gothe has nothing to disclose. Conflict of interest: K. Reiter has nothing to disclose. Conflict of interest: V. Papaevangelou has nothing to disclose. Conflict of interest: A.G. Kaditis has nothing to disclose. Conflict of interest: C. Kanaka-Gantenbein has nothing to disclose. Conflict of interest: S.A. Papiris reports receiving grants or contracts paid to their institution from Hoffmann La Roche, Boehringer Ingelheim and Savara; personal payments received from Hoffmann La Roche and Boehringer Ingelheim for attending meetings and/or travel; all disclosures made outside the submitted work., (Copyright ©The authors 2022.)

Rubella virus (RuV) has recently been found in association with granulomatous inflammation of the skin and several internal organs in patients with inborn errors of immunity (IEI). The cellular tropism and molecular mechanisms of RuV persistence and pathogenesis in select immunocompromised hosts are not clear. We provide clinical, immunological, virological, and histological data on a cohort of 28 patients with a broad spectrum of IEI and RuV-associated granulomas in skin and nine extracutaneous tissues to further delineate this relationship. Combined immunodeficiency was the most frequent diagnosis (67.8%) among patients. Patients with previously undocumented conditions, i.e., humoral immunodeficiencies, a secondary immunodeficiency, and a defect of innate immunity were identified as being susceptible to RuV-associated granulomas. Hematopoietic cell transplantation was the most successful treatment in this case series resulting in granuloma resolution; steroids, and TNF-α and IL-1R inhibitors were moderately effective. In addition to M2 macrophages, neutrophils were identified by immunohistochemical analysis as a novel cell type infected with RuV. Four patterns of RuV-associated granulomatous inflammation were classified based on the structural organization of granulomas and identity and location of cell types harboring RuV antigen. Identification of conditions that increase susceptibility to RuV-associated granulomas combined with structural characterization of the granulomas may lead to a better understanding of the pathogenesis of RuV-associated granulomas and discover new targets for therapeutic interventions., Competing Interests: MA is employed by Sidra Medicine and Hamad Medical Corporation, Qatar. HB is employed by Labor Berlin GmbH, Germany. JH received grants from Immune Deficiency Foundation, the US immunodeficiency network, Chao-physician Scientist award, the Texas Medical Center Digestive Diseases Center and the Jeffrey Modell Foundation. JH received honorarium, consultation fees from Horizon, Pharming, Baxalta, CSL Behring, the National guard, and Al-Faisal University Hospital. TPA received consultation fees from Horizon, Pharming, CSL Behring. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Perelygina, Faisthalab, Abernathy, Chen, Hao, Bercovitch, Bayer, Noroski, Lam, Cicalese, Al-Herz, Nanda, Hajjar, Vanden Driessche, Schroven, Leysen, Rosenbach, Peters, Raedler, Albert, Abraham, Rangarjan, Buchbinder, Kobrynski, Pham-Huy, Dhossche, Cunningham Rundles, Meyer, Theos, Atkinson, Musiek, Adeli, Derichs, Walz, Krüger, von Bernuth, Klein, Icenogle, Hauck and Sullivan.)

Patients with ataxia-telangiectasia (A-T) suffer from progressive cerebellar ataxia, immunodeficiency, respiratory failure, and cancer susceptibility. From a clinical point of view, A-T patients with IgA deficiency show more symptoms and may have a poorer prognosis. In this study, we analyzed mortality and immunity data of 659 A-T patients with regard to IgA deficiency collected from the European Society for Immunodeficiencies (ESID) registry and from 66 patients with classical A-T who attended at the Frankfurt Goethe-University between 2012 and 2018. We studied peripheral B- and T-cell subsets and T-cell repertoire of the Frankfurt cohort and survival rates of all A-T patients in the ESID registry. Patients with A-T have significant alterations in their lymphocyte phenotypes. All subsets (CD3, CD4, CD8, CD19, CD4/CD45RA, and CD8/CD45RA) were significantly diminished compared to standard values. Patients with IgA deficiency (n = 35) had significantly lower lymphocyte counts compared to A-T patients without IgA deficiency (n = 31) due to a further decrease of naïve CD4 T-cells, central memory CD4 cells, and regulatory T-cells. Although both patient groups showed affected TCR-ß repertoires compared to controls, no differences could be detected between patients with and without IgA deficiency. Overall survival of patients with IgA deficiency was significantly diminished. For the first time, our data show that patients with IgA deficiency have significantly lower lymphocyte counts and subsets, which are accompanied with reduced survival, compared to A-T patients without IgA deficiency. IgA, a simple surrogate marker, is indicating the poorest prognosis for classical A-T patients. Both non-interventional clinical trials were registered at clinicaltrials.gov 2012 (Susceptibility to infections in ataxia-telangiectasia; NCT02345135) and 2017 (Susceptibility to Infections, tumor risk and liver disease in patients with ataxia-telangiectasia; NCT03357978)., (© 2021. The Author(s).)

Hyper-IgE syndromes and chronic mucocutaneous candidiasis constitute rare primary immunodeficiency syndromes with an overlapping clinical phenotype. In recent years, a growing number of underlying genetic defects have been identified. To characterize the underlying genetic defects in a large international cohort of 275 patients, of whom 211 had been clinically diagnosed with hyper-IgE syndrome and 64 with chronic mucocutaneous candidiasis, targeted panel sequencing was performed, relying on Agilent HaloPlex and Illumina MiSeq technologies. The targeted panel sequencing approach allowed us to identify 87 (32 novel and 55 previously described) mutations in 78 patients, which generated a diagnostic success rate of 28.4%. Specifically, mutations in DOCK8 (26 patients), STAT3 (21), STAT1 (15), CARD9 (6), AIRE (3), IL17RA (2), SPINK5 (3), ZNF341 (2), CARMIL2/RLTPR (1), IL12RB1 (1), and WAS (1) have been detected. The most common clinical findings in this cohort were elevated IgE (81.5%), eczema (71.7%), and eosinophilia (62.9%). Regarding infections, 54.7% of patients had a history of radiologically proven pneumonia, and 28.3% have had other serious infections. History of fungal infection was noted in 53% of cases and skin abscesses in 52.9%. Skeletal or dental abnormalities were observed in 46.2% of patients with a characteristic face being the most commonly reported feature (23.1%), followed by retained primary teeth in 18.9% of patients. Targeted panel sequencing provides a cost-effective first-line genetic screening method which allows for the identification of mutations also in patients with atypical clinical presentations and should be routinely implemented in referral centers., (© 2021. The Author(s).)

Accumulation of human CD21 low B cells in peripheral blood is a hallmark of chronic activation of the adaptive immune system in certain infections and autoimmune disorders. The molecular pathways underpinning the development, function, and fate of these CD21 low B cells remain incompletely characterized. Here, combined transcriptomic and chromatin accessibility analyses supported a prominent role for the transcription factor T-bet in the transcriptional regulation of these T-bet high CD21 low B cells. Investigating essential signals for generating these cells in vitro established that B cell receptor (BCR)/interferon-γ receptor (IFNγR) costimulation induced the highest levels of T-bet expression and enabled their differentiation during cell cultures with Toll-like receptor (TLR) ligand or CD40L/interleukin-21 (IL-21) stimulation. Low proportions of CD21 low B cells in peripheral blood from patients with defined inborn errors of immunity (IEI), because of mutations affecting canonical NF-κB, CD40, and IL-21 receptor or IL-12/IFNγ/IFNγ receptor/signal transducer and activator of transcription 1 (STAT1) signaling, substantiated the essential roles of BCR- and certain T cell–derived signals in the in vivo expansion of T-bet high CD21 low B cells. Disturbed TLR signaling due to MyD88 or IRAK4 deficiency was not associated with reduced CD21 low B cell proportions. The expansion of human T-bet high CD21 low B cells correlated with an expansion of circulating T follicular helper 1 (cTfh1) and T peripheral helper (Tph) cells, identifying potential sources of CD40L, IL-21, and IFNγ signals. Thus, we identified important pathways to target autoreactive T-bet high CD21 low B cells in human autoimmune conditions, where these cells are linked to pathogenesis and disease progression.

Background: In Germany, so far the COVID-19 pandemic evolved in two distinct waves, the first beginning in February and the second in July, 2020. The Berlin University Children's Hospital at Charité (BCH) had to ensure treatment for children not infected and infected with SARS-CoV-2. Prevention of nosocomial SARS-CoV-2 infection of patients and staff was a paramount goal. Pediatric hospitals worldwide discontinued elective treatments and established a centralized admission process. Methods: The response of BCH to the pandemic adapted to emerging evidence. This resulted in centralized admission via one ward exclusively dedicated to children with unclear SARS-CoV-2 status and discontinuation of elective treatment during the first wave, but maintenance of elective care and decentralized admissions during the second wave. We report numbers of patients treated and of nosocomial SARS-CoV-2 infections during the two waves of the pandemic. Results: During the first wave, weekly numbers of inpatient and outpatient cases declined by 37% ( p < 0.001) and 29% ( p = 0.003), respectively. During the second wave, however, inpatient case numbers were 7% higher ( p = 0.06) and outpatient case numbers only 6% lower ( p = 0.25), compared to the previous year. Only a minority of inpatients were tested positive for SARS-CoV-2 by RT-PCR (0.47% during the first, 0.63% during the second wave). No nosocomial infection of pediatric patients by SARS-CoV-2 occurred. Conclusion: In contrast to centralized admission via a ward exclusively dedicated to children with unclear SARS-CoV-2 status and discontinuation of elective treatments, maintenance of elective care and decentralized admission allowed the almost normal use of hospital resources, yet without increased risk of nosocomial infections with SARS-CoV-2. By this approach unwanted sequelae of withheld specialized pediatric non-emergency treatment to child and adolescent health may be avoided., Competing Interests: HB was employed by Labor Berlin GmbH, a joint subsidiary of the public hospitals Charité Universitätsmedizin Berlin and Vivantes—Netzwerk für Gesundheit GmbH. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Terliesner, Rosen, Kaindl, Reuter, Lippold, Mall, Bernuth and Gratopp.)

Objective: Evidence for the duration of perioperative antibiotic prophylaxis (PAP) after the correction of craniosynostosis in children is scarce. We evaluated the necessary duration of PAP to ensure a minimal rate of postoperative wound infections. Methods: In this monocentric, retrospective, and prospective pilot study, two PAP protocols were compared. From August 2017 to May 2018, treatment group 1 (TG 1) was treated using the standard PAP protocol with at least three doses of antibiotics. Between May 2018 and March 2019, a shortened PAP with a single-shot administration was given to treatment group 2 (TG 2a and b). Endpoints of this study were wound infection rate, colonization rate of wound drains, and the course of treatment reflected by clinical and laboratory data. Results: A cohort of 187 children underwent craniosynostosis correction: 167 were treated according to protocols--95 patients with at least three doses (TG 1) and 72 patients with a single-shot of cefuroxime (TG 2a). Baseline characteristics were similar for both groups. We could not detect significant differences, neither for wound infection rates (TG 1: 1.1%, TG 2a: 0.0%, p = 0.38) nor for colonization rates of wound drains (TG 1: 4.8%, TG 2a: 10.5%, p = 0.27). Conclusions: Single-shot PAP had no adverse effects on the wound infection rate or the colonization rate of the wound drains compared with prolonged perioperative antibiotic prophylaxis. As a result, single-shot preoperative PAP is now applied to the majority craniosynostosis patients undergoing surgical correction in our unit., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Holle, Finger, Lugonja, Schmidt, Schaumann, Gratopp, Thomale, von Bernuth and Schulz.)

Coronavirus disease 2019 (COVID-19) is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Type I interferons are important in the defense of viral infections. Recently, neutralizing IgG auto-antibodies against type I interferons were found in patients with severe COVID-19 infection. Here, we analyzed expression of CD169/SIGLEC1, a well described downstream molecule in interferon signaling, and found increased monocytic CD169/SIGLEC1 expression levels in patients with mild, acute COVID-19, compared to patients with severe disease. We recommend further clinical studies to evaluate the value of CD169/SIGLEC1 expression in patients with COVID-19 with or without auto-antibodies against type I interferons., (© 2021. The Author(s).)

Autoantibodies against IFN-α and IFN-ω (type I IFNs) were recently reported as causative for severe COVID-19 in the general population. Autoantibodies against IFN-α and IFN-ω are present in almost all patients with autoimmune polyendocrine syndrome type 1 (APS-1) caused by biallelic deleterious or heterozygous dominant mutations in AIRE. We therefore hypothesized that autoantibodies against type I IFNs also predispose patients with APS-1 to severe COVID-19. We prospectively studied 6 patients with APS-1 between April 1, 2020 and April 1, 2021. Biobanked pre-COVID-19 sera of APS-1 subjects were tested for neutralizing autoantibodies against IFN-α and IFN-ω. The ability of the patients' sera to block recombinant human IFN-α and IFN-ω was assessed by assays quantifying phosphorylation of signal transducer and activator of transcription 1 (STAT1) as well as infection-based IFN-neutralization assays. We describe 4 patients with APS-1 and preexisting high titers of neutralizing autoantibodies against IFN-α and IFN-ω who contracted SARS-CoV-2, yet developed only mild symptoms of COVID-19. None of the patients developed dyspnea, oxygen requirement, or high temperature. All infected patients with APS-1 were females and younger than 26 years of age. Clinical penetrance of neutralizing autoantibodies against type I IFNs for severe COVID-19 is not complete.

Background: Pulmonary invasive aspergillosis is a frequent and life-threatening complication for patients with chronic granulomatous disease (CGD). Despite combined treatment with several groups of antifungal agents, conservative treatment of invasive aspergillosis often remains refractory. Pulmonary invasive aspergillosis is often treated by surgical resection of consolidated lobes or segments, donor granulocyte transfusions and allogeneic hematopoietic stem cell transplantation (HSCT). These options are not mutually exclusive and often combined., Methods and Results: We here describe the treatment of 3 patients with CGD who received HSCT upon active pulmonary invasive aspergillosis: Two of them received HSCT as salvage therapy for refractory aspergillosis, and 1 patient received elective HSCT in infancy but developed pulmonary aspergillosis during secondary graft failure. Based on our experience and available literature, we discuss indication as well as timing of HSCT, granulocyte transfusions and surgery in patients with CGD and pulmonary invasive aspergillosis., Conclusions: Upon diagnosis with invasive aspergillosis in CGD, we propose to start antifungal treatment and preparation for HSCT at the same time. Remission of pulmonary invasive aspergillosis before HSCT remains preferable but is not mandatory. When pulmonary aspergillosis in patients with CGD remains refractory for longer than 3 months on conservative treatment, HSCT without prior surgery or accompanying granulocyte transfusions is a feasible option., Competing Interests: S.L-.K. was supported by a personal “Clinical Scientist” grant (Charité, BSRT/BCRT) and the Rahel-Hirsch-Habilitation Grant (Charité). H.v.B. has received honoraria from CSL-Behring, Takeda and Swedish Orphan Biovitrum GmbH. The other authors have no conflicts of interest to disclose., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

In common variable immunodeficiency (CVID), heterozygous damaging NFKB1 variants represent the most frequent monogenic cause. NFKB1 encodes the precursor p105, which undergoes proteasomal processing to generate the mature NF-κB transcription factor subunit p50. The majority of NFKB1 sequence changes comprises missense variants of uncertain significance (VUS), each requiring functional evaluation to assess causality, particularly in families with multiple affected members presenting with different phenotypes. In four affected members of a German family, all diagnosed with CVID, we identified a previously uncharacterized heterozygous NFKB1 missense variant (c.1049A>G; p.Tyr350Cys). The clinical phenotypes varied markedly regarding onset, frequency and severity of infections. Consistent immunologic findings were hypogammaglobulinemia with normal specific antibody response to protein- and polysaccharide-based vaccinations, reduced switched memory B cells and decreased lymphocyte proliferation upon stimulation with the B cell mitogen SAC. To assess the pathogenicity of the NFKB1 missense variant, we employed immunophenotyping and functional analyses in a routine in vitro cell culture model. Following site-directed mutagenesis to introduce the variant into overexpression vectors encoding EGFP-fused p105 or p50, we analyzed transiently transfected HEK293T cells by confocal imaging and Western blotting. The cytoplasmic p105-Tyr350Cys precursor gained only weak expression levels indicating accelerated decay. The missense change disabled processing of the precursor to prevent the generation of mutant p50. Unlike the wildtype p50, the overexpressed mutant p50-Tyr350Cys was also not sustainable and showed a conspicuous subnuclear mislocalization with accumulation in dense aggregates instead of a homogenous distribution. Electrophoretic mobility shift assays, fluorescence-based reporter gene analyses and co-transfection experiments however demonstrated, that the DNA-binding activity of p50-Tyr350Cys and the interaction with RelA(p65), IκBα and wildtype p50 were preserved. Mutation carriers had reduced p105 and p50 levels, indicating insufficient protein amounts as the most likely primary defect. In conclusion, the missense variant c.1049A>G caused a detrimental defect, preventing the persistent expression of both, the p105-Tyr350Cys precursor and the mature p50-Tyr350Cys. The variable clinical phenotypes among affected family members sharing an identical pathogenic NFKB1 variant support a disease mechanism provoked by a p105/p50 (haplo)insufficient condition., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Fliegauf, Krüger, Steiner, Hanitsch, Büchel, Wahn, von Bernuth and Grimbacher.)

Background: Hematopoietic stem cell transplantation (HSCT) can cure chronic granulomatous disease (CGD), but it remains debated whether all conventionally treated CGD patients benefit from HSCT., Methods: We retrospectively analyzed 104 conventionally treated CGD patients, of whom 50 patients underwent HSCT., Results: On conventional treatment, seven patients (13%) died after a median time of 16.2 years (interquartile range [IQR] 7.0-18.0). Survival without severe complications was 10 ± 3% (mean ± SD) at the age of 20 years; 85% of patients developed at least one infection, 76% one non-infectious inflammation. After HSCT, 44 patients (88%) were alive at a median follow-up of 2.3 years (IQR 0.8-4.9): Six patients (12%) died from infections. Survival after HSCT was significantly better for patients transplanted ≤8 years (96 ± 4%) or for patients without active complications at HSCT (100%). Eight patients suffered from graft failure (16%); six (12%) developed acute graft-vs-host disease requiring systemic treatment. Conventionally treated patients developed events that required medical attention at a median frequency of 1.7 (IQR 0.8-3.2) events per year vs 0 (IQR 0.0-0.5) in patients beyond the first year post-HSCT. While most conventionally treated CGD patients failed to thrive, catch-up growth after HSCT in surviving patients reached the individual percentiles at the age of diagnosis of CGD., Conclusion: Chronic granulomatous disease patients undergoing HSCT until 8 years of age show excellent survival, but young children need more intense conditioning to avoid graft rejection. Risks and benefits of HSCT for adolescents and adults must still be weighed carefully., (© 2020 The Authors. Pediatric Allergy and Immunology published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Background: Phlegmonous and gangrenous appendicitis represent independent pathophysiological entities with different clinical courses ranging from spontaneous resolution to septic disease. However, reliable predictive methods for these clinical phenotypes have not yet been established. In an attempt to provide pathophysiological insights into the matter, a genomewide gene expression analysis was undertaken in patients with acute appendicitis., Methods: Peripheral blood mononuclear cells were isolated and, after histological confirmation of PA or GA, analysed for genomewide gene expression profiling using RNA microarray technology and subsequent pathway analysis., Results: Samples from 29 patients aged 7-17 years were included. Genomewide gene expression analysis was performed on 13 samples of phlegmonous and 16 of gangrenous appendicitis. From a total of 56 666 genes, 3594 were significantly differently expressed. Distinct interaction between T and B cells in the phlegmonous appendicitis group was suggested by overexpression of T cell receptor α and β subunits, CD2, CD3, MHC II, CD40L, and the B cell markers CD72 and CD79, indicating an antiviral mechanism. In the gangrenous appendicitis group, expression of genes delineating antibacterial mechanisms was found., Conclusion: These results provide evidence for different and independent gene expression in phlegmonous and gangrenous appendicitis in general, but also suggest distinct immunological patterns for the respective entities. In particular, the findings are compatible with previous evidence of spontaneous resolution in phlegmonous and progressive disease in gangrenous appendicitis., (© The Author(s) 2021. Published by Oxford University Press on behalf of BJS Society Ltd.)

Introduction: Primary immunodeficiencies (PIDs) are a heterogeneous group of rare diseases characterized by increased susceptibility to infections and a reduced quality of life (QoL). The influence of a patient empowerment programme for PID (PID-PEP) on general and health-related QoL was assessed in the present study., Material and Methods: PID-PEP is provided by a multidisciplinary team for patients with PID and immunoglobulin G (IgG) replacement therapy during a weekend course to improve patient self-management regarding chronic disease and long-term therapy. Twenty-six adult patients with PID undergoing PID-PEP were recruited. Short Form-36 (SF-36) and the Life Quality Index (LQI) were assessed as generic and disease-specific QoL instruments before as well as 6 months after the programme., Results: Median visual analogue scale (VAS) values of present health status significantly increased from 68 at baseline to 76 after PID-PEP (p = 0.002). Furthermore, the SF-36 mental component summary (MCS) significantly improved from 36 to 43 following the programme (p = 0.042). Of the eight SF-36 dimensions, vitality (VT) significantly improved (p = 0.025). Median LQI index significantly increased from 77 at baseline to 86 after PID-PEP (p = 0.008). Furthermore, the LQI domains treatment interference (I) and therapy-related problems (II) significantly improved., Conclusions: Our PID-PEP significantly improved general and health-related QoL. It needs to be evaluated in future studies whether the beneficial effects of PID-PEP are sustained over longer periods of time and whether repeated PID-PEP sessions further improve QoL outcome., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Termedia.)

Biallelic mutations in the genes encoding CD27 or its ligand CD70 underlie inborn errors of immunity (IEIs) characterized predominantly by Epstein-Barr virus (EBV)-associated immune dysregulation, such as chronic viremia, severe infectious mononucleosis, hemophagocytic lymphohistiocytosis (HLH), lymphoproliferation, and malignancy. A comprehensive understanding of the natural history, immune characteristics, and transplant outcomes has remained elusive. Here, in a multi-institutional global collaboration, we collected the clinical information of 49 patients from 29 families (CD27, n = 33; CD70, n = 16), including 24 previously unreported individuals and identified a total of 16 distinct mutations in CD27, and 8 in CD70, respectively. The majority of patients (90%) were EBV+ at diagnosis, but only ∼30% presented with infectious mononucleosis. Lymphoproliferation and lymphoma were the main clinical manifestations (70% and 43%, respectively), and 9 of the CD27-deficient patients developed HLH. Twenty-one patients (43%) developed autoinflammatory features including uveitis, arthritis, and periodic fever. Detailed immunological characterization revealed aberrant generation of memory B and T cells, including a paucity of EBV-specific T cells, and impaired effector function of CD8+ T cells, thereby providing mechanistic insight into cellular defects underpinning the clinical features of disrupted CD27/CD70 signaling. Nineteen patients underwent allogeneic hematopoietic stem cell transplantation (HSCT) prior to adulthood predominantly because of lymphoma, with 95% survival without disease recurrence. Our data highlight the marked predisposition to lymphoma of both CD27- and CD70-deficient patients. The excellent outcome after HSCT supports the timely implementation of this treatment modality particularly in patients presenting with malignant transformation to lymphoma.

In 2017, in the Polish-German transborder area of West Pomerania, Mecklenburg-Western Pomerania, and Brandenburg, in collaboration with two centers in Warsaw, a partnership in the field of newborn screening (NBS) for severe primary immunodeficiency diseases (PID), mainly severe combined immunodeficiency (SCID), was initiated. SCID, but also some other severe PID, is a group of disorders characterized by the absence of T and/or B and NK cells. Affected infants are susceptible to life-threatening infections, but early detection gives a chance for effective treatment. The prevalence of SCID in the Polish and German populations is unknown but can be comparable to other countries (1:50,000-100,000). SCID NBS tests are based on real-time polymerase chain reaction (qPCR) and the measurement of a number of T cell receptor excision circles (TREC), kappa-deleting recombination excision circles (KREC), and beta-actin (ACTB) as a quality marker of DNA. This method can also be effective in NBS for other severe PID with T- and/or B-cell lymphopenia, including combined immunodeficiency (CID) or agammaglobulinemia. During the 14 months of collaboration, 44,287 newborns were screened according to the ImmunoIVD protocol. Within 65 positive samples, seven were classified to immediate recall and 58 requested a second sample. Examination of the 58 second samples resulted in recalling one newborn. Confirmatory tests included immunophenotyping of lymphocyte subsets with extension to TCR repertoire, lymphoproliferation tests, radiosensitivity tests, maternal engraftment assays, and molecular tests. Final diagnosis included: one case of T-B low NK+ SCID, one case of atypical T low B low NK+ CID, one case of autosomal recessive agammaglobulinemia, and one case of Nijmegen breakage syndrome. Among four other positive results, three infants presented with T- and/or B-cell lymphopenia due to either the mother's immunosuppression, prematurity, or unknown reasons, which resolved or almost normalized in the first months of life. One newborn was classified as truly false positive. The overall positive predictive value (PPV) for the diagnosis of severe PID was 50.0%. This is the first population screening study that allowed identification of newborns with T and/or B immunodeficiency in Central and Eastern Europe., (Copyright © 2020 Giżewska, Durda, Winter, Ostrowska, Ołtarzewski, Klein, Blankenstein, Romanowska, Krzywińska-Zdeb, Patalan, Bartkowiak, Szczerba, Seiberling, Birkenfeld, Nauck, von Bernuth, Meisel, Bernatowska, Walczak and Pac.)

This evidence-based clinical guideline provides consensus-recommendations for the treatment and care of patients with primary antibody deficiencies (PADs). The guideline group comprised 20 clinical and scientific expert associations of the German, Swiss, and Austrian healthcare system and representatives of patients. Recommendations were based on results of a systematic literature search, data extraction, and evaluation of methodology and study quality in combination with the clinical expertise of the respective representatives. Consensus-based recommendations were determined via nominal group technique. PADs are the largest clinically relevant group of primary immunodeficiencies. Most patients with PADs present with increased susceptibility to infections, however immune dysregulation, autoimmunity, and cancer affect a significant number of patients and may precede infections. This guideline therefore covers interdisciplinary clinical and therapeutic aspects of infectious (e.g., antibiotic prophylaxis, management of bronchiectasis) and non-infectious manifestations (e.g., management of granulomatous disease, immune cytopenia). PADs are grouped into disease entities with definitive, probable, possible, or unlikely benefit of IgG-replacement therapy. Summary and consensus-recommendations are provided for treatment indication, dosing, routes of administration, and adverse events of IgG-replacement therapy. Special aspects of concomitant impaired T-cell function are highlighted as well as clinical data on selected monogenetic inborn errors of immunity formerly classified into PADs (APDS, CTLA-4-, and LRBA-deficiency)., (© 2020 The Authors. European Journal of Immunology published by Wiley-VCH GmbH.)