From variant of uncertain significance to likely pathogenic in two siblings with atypical RAG2 Deficiency: a case report and review of the literature.

BACKGROUND: Severe combined immunodeficiencies (SCIDs) are hereditary disorders characterized by impaired T and B cell function, resulting in significant immune system dysfunction. Recombination-activating gene (RAG) mutations account for a substantial proportion of SCID cases. Here, we present two sibling cases of SCID caused by a novel RAG2 gene mutation. CASE PRESENTATION: The index case was an 8-year-old boy who had a history of recurring infections. After a comprehensive immunological workup, the initial diagnosis of agammaglobulinemia was revised to combined immunodeficiency (CID). The patient underwent hematopoietic stem cell transplantation (HSCT) but succumbed to cytomegalovirus (CMV) infection. His brother, a 4-month-old boy, presented with CMV chorioretinitis. Leaky SCID was diagnosed based on genetic tests and immunological findings. The patient received appropriate treatment and was considered for HSCT. Both siblings had a homozygous RAG2 gene variant, with the first case classified as a variant of uncertain significance (VUS). The presence of the same mutation in the second brother, and the clinical phenotype, supports considering the mutation as likely pathogenic. CONCLUSIONS: This case report highlights a novel RAG2 gene mutation associated with CID. The classification of a VUS may evolve with accumulating evidence, and additional studies are warranted to establish its pathogenicity. Proper communication between genetic counselors and immunologists, accurate documentation of patient information, increased public awareness, and precise utilization of genetic techniques are essential for optimal patient management.

Clinical heterogeneity in families with multiple cases of inborn errors of immunity.

BACKGROUND: Inborn errors of immunity (IEI) are a diverse range of genetic immune system illnesses affecting the innate and/or adaptive immune systems. Variable expressivity and incomplete penetrance have been reported in IEI patients with similar clinical diagnoses or even the same genetic mutation. METHODS: Among all recorded patients in the national IEI registry, 193 families with multiple cases have been recognized. Clinical, laboratory and genetic variability were compared between 451 patients with different IEI entities. RESULTS: The diagnosis of the first children led to the earlier diagnosis, lower diagnostic delay, timely treatment and improved survival in the second children in the majority of IEI. The highest discordance in familial lymphoproliferation, autoimmunity and malignancy were respectively observed in STK4 deficiency, DNMT3B deficiency and ATM deficiency. Regarding immunological heterogeneity within a unique family with multiple cases of IEI, the highest discordance in CD3+, CD4+, CD19+, IgM and IgA levels was observed in syndromic combined immunodeficiencies (CID), while non-syndromic CID particularly severe combined immunodeficiency (SCID) manifested the highest discordance in IgG levels. Identification of the first ATM-deficient patient can lead to improved care and better survival in the next IEI children from the same family. CONCLUSION: Intrafamilial heterogeneity in immunological and/or clinical features could be observed in families with multiple cases of IEI indicating the indisputable role of appropriate treatment and preventive environmental factors besides specific gene mutations in the variable observed penetrance or expressivity of the disease. This also emphasizes the importance of implementing genetic evaluation in all members of a family with a history of IEI even if there is no suspicion of an underlying IEI as other factors besides the underlying genetic defects might cause a milder phenotype or delay in presentation of clinical features. Thus, affected patients could be timely diagnosed and treated, and their quality of life and survival would improve.

Activated phosphoinositide 3-kinase δ syndrome: Update from the ESID Registry and comparison with other autoimmune-lymphoproliferative inborn errors of immunity.

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.

Assessment of the first presentations of common variable immunodeficiency in a large cohort of patients.

BACKGROUND: Common Variable Immunodeficiency (CVID) is a primary immunodeficiency syndrome resulting in recurrent infections, autoimmunity, and granulomatous manifestations. METHODS AND MATERIALS: This retrospective study was conducted on an Iranian national registry of immunodeficient patients from 2010 to 2021. The frequency of first presentations of CVID and its association with sex, age of onset, and family history of CVID was evaluated. RESULTS: A total of 383 patients entered the study, 164 of whom were female, and the rest were male. The mean age of the patients was 25.3 ± 14.5 years. The most frequent first presentations of CVID were pneumonia (36.8%) and diarrhea (19.1%). Patient sex, age of onset, and family history did not make significant differences in first presentations of this disease. CONCLUSION: pneumonia is the most common first presentation of CVID. Family history of CVID, the age of symptom onset, and sex made no differences in the first presentations of CVID.

New Presentation of CD27 Deficiency; Coronary Ectasia and COVID-19.

CD27 is a costimulatory receptor involved in the maturation of the innate and adaptive immunity. CD27, through interaction with CD70, plays a role in the control of Epstein-Barr virus (EBV) infection. CD27 deficiency leads to an immune dysregulation disease characterized by EBV susceptibility. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) might put patients with primary immunodeficiency at risk for adverse outcomes. Chromogenic in situ hybridization (CISH) study was performed to detect EBV in the lymphoma tissue. Genetic analysis of the patient was done with Whole Exome Sequencing and detected variant was confirmed with PCR-Sanger sequencing. Here we report a 20-month-old boy with CD27 deficiency who developed lymphoma and coronary artery ectasia and had been infected with SARS-CoV-2. Clinical and laboratory findings were incompatible with atypical Kawasaki syndrome or multisystem inflammatory syndrome in children (MIS-C). As CD27 deficiency is a rare immune defect, publishing clinical data about the identified patient(s) can shed light on our knowledge about the related phenotype and the spectrum of clinical manifestations associated with CD27 deficiency. Thus, our findings expanded the spectrum of manifestations beyond EBV infection, highlighting this unusual cardiac sequela that could be related to EBV infection, lymphoma, or an underlying disease.

JAGN1 mutation with distinct clinical features; two case reports and literature review.

Jagunal homolog 1 (JAGN1) has been recognized as an essential protein in neutrophil function. The mutated JAGN1 is responsible for immunodeficiency related to innate and humoral defense mechanisms. This deficiency impairs neutrophil development and function, leading to recurrent infections and facial dysmorphism as phenotypic consequences of severe congenital neutropenia (SCN). We report two siblings having the reported JAGN1 mutation with different clinical manifestations. Recurrent abscess formation unresponsive to antibiotic therapy, a history of delayed umbilical separation, frequent bacterial or fungal infection, dysmorphic face, failure to thrive, and other coexisting organ abnormalities should prompt physicians to syndromic immunodeficiencies involving neutrophils. Genetic investigations to elucidate the responsible mutation is critical as clinical management varies. Once the diagnosis is confirmed, a multi-disciplinary team should perform further workups to investigate other coexisting malformations and neurodevelopmental evaluation.

Human PIK3R1 mutations disrupt lymphocyte differentiation to cause activated PI3Kδ syndrome 2.

Heterozygous loss-of-function (LOF) mutations in PIK3R1 (encoding phosphatidylinositol 3-kinase [PI3K] regulatory subunits) cause activated PI3Kδ syndrome 2 (APDS2), which has a similar clinical profile to APDS1, caused by heterozygous gain-of-function (GOF) mutations in PIK3CD (encoding the PI3K p110δ catalytic subunit). While several studies have established how PIK3CD GOF leads to immune dysregulation, less is known about how PIK3R1 LOF mutations alter cellular function. By studying a novel CRISPR/Cas9 mouse model and patients' immune cells, we determined how PIK3R1 LOF alters cellular function. We observed some overlap in cellular defects in APDS1 and APDS2, including decreased intrinsic B cell class switching and defective Tfh cell function. However, we also identified unique APDS2 phenotypes including defective expansion and affinity maturation of Pik3r1 LOF B cells following immunization, and decreased survival of Pik3r1 LOF pups. Further, we observed clear differences in the way Pik3r1 LOF and Pik3cd GOF altered signaling. Together these results demonstrate crucial differences between these two genetic etiologies.

Clinical and Immunologic Characteristics of Non-Hematologic Cancers in Patients with Inborn Errors of Immunity.

Inborn errors of immunity (IEI) are a heterogeneous group of inherited disorders, and almost 500 genes associated with these disorders have been identified. Defects in IEI genes lead to diverse clinical manifestations including increased susceptibility to recurrent or prolonged infections, immune dysregulation phenotypes (such as severe atopy, allergy, autoimmunity, and uncontrolled inflammation, lymphoproliferation), as well as predisposition to malignancies. Although the majority of IEI patients present hematologic cancers, the characteristics of other types of cancers are not well described in these groups of patients. By investigating 5384 IEI patients registered in the Iranian national registry the clinical and immunologic phenotypes of patients with non-hematologic cancers were compared with other malignant and non-malignant patients. Solid tumors were reported <20% of malignant IEI patients (n = 27/144 patients) and appeared to be very heterogeneous by type and localization as well as molecular defects (mainly due to DNA repair defect resulted from ATM deficiency). The correlation between the type of malignancy and survival status was remarkable as patients with non-hematologic cancers survive higher than IEI patients with hematologic cancers. Our findings showed that different types of malignancy could be associated with specific entities of IEI. Therefore, the education of physicians about the risk of malignancies in IEI is required for personalized treatment and appropriate management of patients.

CVID-Associated B Cell Activating Factor Receptor Variants Change Receptor Oligomerization, Ligand Binding, and Signaling Responses.

PURPOSE: Binding of the B cell activating factor (BAFF) to its receptor (BAFFR) activates in mature B cells many essential pro-survival functions. Null mutations in the BAFFR gene result in complete BAFFR deficiency and cause a block in B cell development at the transition from immature to mature B cells leading therefore to B lymphopenia and hypogammaglobulinemia. In addition to complete BAFFR deficiency, single nucleotide variants encoding BAFFR missense mutations were found in patients suffering from common variable immunodeficiency (CVID), autoimmunity, or B cell lymphomas. As it remained unclear to which extent such variants disturb the activity of BAFFR, we performed genetic association studies and developed a cellular system that allows the unbiased analysis of BAFFR variants regarding oligomerization, signaling, and ectodomain shedding. METHODS: In addition to genetic association studies, the BAFFR variants P21R, A52T, G64V, DUP92-95, P146S, and H159Y were expressed by lentiviral gene transfer in DG-75 Burkitt's lymphoma cells and analyzed for their impacts on BAFFR function. RESULTS: Binding of BAFF to BAFFR was affected by P21R and A52T. Spontaneous oligomerization of BAFFR was disturbed by P21R, A52T, G64V, and P146S. BAFF-dependent activation of NF-κB2 was reduced by P21R and P146S, while interactions between BAFFR and the B cell antigen receptor component CD79B and AKT phosphorylation were impaired by P21R, A52T, G64V, and DUP92-95. P21R, G64V, and DUP92-95 interfered with phosphorylation of ERK1/2, while BAFF-induced shedding of the BAFFR ectodomain was only impaired by P21R. CONCLUSION: Although all variants change BAFFR function and have the potential to contribute as modifiers to the development of primary antibody deficiencies, autoimmunity, and lymphoma, P21R is the only variant that was found to correlate positively with CVID.

Autoimmunity in monogenic combined immune deficiencies with associated or syndromic features.

Background: Combined immune deficiencies (CIDs) with associated or syndromic features are a highly heterogeneous subgroup of inherited immune disorders. These patients represent specific clinical complications with an increased risk of autoimmune conditions. Methods: We analyzed data of monogenic patients with syndromic CIDs adopted from the Iranian inborn errors of immunity registry up to January 2022. A comprehensive comparison in terms of demographic, clinical, and immunological features was performed between patients with and without autoimmunity and also among four mutation groups with the most registered cases including ATM, STAT3 (AD-LOF), DNMT3B/ZBTB24, and WAS mutations. Results: A total of 137 patients with monogenic syndromic CIDs were included. Most commonly mutated genes were the ATM [80 (58.4%)] and STAT3 (AD-LOF) [19 (13.9%)], followed by DNMT3B [11 (8%)], and WAS [11 (8%)]. More than 18% of all patients with syndromic CIDs, including most DNMT3B/ZBTB24 mutations patients, were clinically diagnosed with antibody deficiencies before genetic evaluation. Patients with ATM and WAS mutations had the latest age of onset and the lowest age of diagnosis, respectively. Autoimmune disorders were diagnosed in 24 patients at a median age of 3.5 (2.6-6.0) years, 70.6% of which were diagnosed prior to the diagnosis of immunodeficiency. Lymphoproliferation, particularly hepatosplenomegaly, was significantly higher in patients with autoimmunity (p=0.004). Syndromic CID patients with autoimmunity had significantly lower IgG levels. Hematologic autoimmunity mainly immune thrombocytopenic purpura was the most frequent autoimmunity among major groups of ATM, STAT3 (AD-LOF), DNMT3B/ZBTB24, and WAS mutations, however ATM-mutated patients present more diversified involved organs including rheumatologic, gastrointestinal and dermatologic autoimmunity. Conclusion: About 18% of patients with monogenic syndromic CIDs developed autoimmunity, mainly in the form of hematological immune diseases. Autoimmunity could be an early-onset involvement with a potential diagnostic impact on suspicious cases of syndromic CIDs.

Diversity of malignancies in patients with different types of inborn errors of immunity.

Genetic defects in the development, maturation, and/or function of the immune cells can lead to Inborn errors of immunity (IEI) which may predispose patients to malignancies. The overall risk for cancer in children with IEI ranges from 4 to 25% and the type of malignancy is highly dependent on the specific mutant gene underlying IEI. We investigated 3056 IEI patients registered in the Iranian national registry between the years 1999 and 2020 in this retrospective cohort study. The frequency of malignancy and its association with the type of IEI in these patients were evaluated. A total of 82 IEI patients with malignancy were enrolled in this study. Among them, predominantly lymphoma was the most common type of malignancy (67.1%), followed by leukemia (11%), and cancers of the head and neck (7.3%). Among identified lymphoma cancers, non-Hodgkin's lymphomas were the most frequent type (43.9%) followed by different subtypes of Hodgkin's lymphoma (23.2%). Solid tumors (18.3%) appeared to be very heterogeneous by type and localization. The correlation between the type of malignancy and survival status and the association between the type of malignancy and IEI entities were unremarkable. The awareness of the association between the presence of IEI and cancer highlights the importance of a synergistic effort by oncologists and immunologists in the early diagnosis of malignancy and personalized therapeutic strategies in IEI patients.

Detrimental NFKB1 missense variants affecting the Rel-homology domain of p105/p50.

Most of the currently known heterozygous pathogenic NFKB1 (Nuclear factor kappa B subunit 1) variants comprise deleterious defects such as severe truncations, internal deletions, and frameshift variants. Collectively, these represent the most frequent monogenic cause of common variable immunodeficiency (CVID) identified so far. NFKB1 encodes the transcription factor precursor p105 which undergoes limited proteasomal processing of its C-terminal half to generate the mature NF-κB subunit p50. Whereas p105/p50 haploinsufficiency due to devastating genetic damages and protein loss is a well-known disease mechanism, the pathogenic significance of numerous NFKB1 missense variants still remains uncertain and/or unexplored, due to the unavailability of accurate test procedures to confirm causality. In this study we functionally characterized 47 distinct missense variants residing within the N-terminal domains, thus affecting both proteins, the p105 precursor and the processed p50. Following transient overexpression of EGFP-fused mutant p105 and p50 in HEK293T cells, we used fluorescence microscopy, Western blotting, electrophoretic mobility shift assays (EMSA), and reporter assays to analyze their effects on subcellular localization, protein stability and precursor processing, DNA binding, and on the RelA-dependent target promoter activation, respectively. We found nine missense variants to cause harmful damage with intensified protein decay, while two variants left protein stability unaffected but caused a loss of the DNA-binding activity. Seven of the analyzed single amino acid changes caused ambiguous protein defects and four variants were associated with only minor adverse effects. For 25 variants, test results were indistinguishable from those of the wildtype controls, hence, their pathogenic impact remained elusive. In summary, we show that pathogenic missense variants affecting the Rel-homology domain may cause protein-decaying defects, thus resembling the disease-mechanisms of p105/p50 haploinsufficiency or may cause DNA-binding deficiency. However, rare variants (with a population frequency of less than 0.01%) with minor abnormalities or with neutral tests should still be considered as potentially pathogenic, until suitable tests have approved them being benign.

Transcriptional regulation of B cell class-switch recombination: the role in development of noninfectious complications.

INTRODUCTION: The process of immunoglobulin class switch recombination (CSR) occurs in secondary lymphoid organs. This highly regulated process is essential for the development of different antibody isotype maturation and long-life memory/plasma cell generation. Patients with impaired CSR present heterogeneous noninfectious complications. AREAS COVERED: We provide an overview of recent advancements in the tight regulation of B cells before and during the CSR at different levels of cytokine stimulations, intracellular signaling, transcription-factor activation, gene transcription, and epigenetic controls. EXPERT OPINION: Besides recurrent infections which result from the lack of production of class-switched immunoglobulins, intrinsic B cell signaling pathways and regulatory component defects have distinct roles in other immune-related clinical manifestations including autoimmunity, atopy, lymphoproliferation, and cancer.

Updates of cancer hallmarks in patients with inborn errors of immunity.

PURPOSE OF REVIEW: The development of cancer in patients with genetically determined inborn errors of immunity (IEI) is much higher than in the general population. The hallmarks of cancer are a conceptualization tool that can refine the complexities of cancer development and pathophysiology. Each genetic defect may impose a different pathological tumor predisposition, which needs to be identified and linked with known hallmarks of cancer. RECENT FINDINGS: Four new hallmarks of cancer have been suggested, recently, including unlocking phenotypic plasticity, senescent cells, nonmutational epigenetic reprogramming, and polymorphic microbiomes. Moreover, more than 50 new IEI genes have been discovered during the last 2 years from which 15 monogenic defects perturb tumor immune surveillance in patients. SUMMARY: This review provides a more comprehensive and updated overview of all 14 cancer hallmarks in IEI patients and covers aspects of cancer predisposition in novel genes in the ever-increasing field of IEI.

Disease Progression of WHIM Syndrome in an International Cohort of 66 Pediatric and Adult Patients.

Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome (WS) is a combined immunodeficiency caused by gain-of-function mutations in the C-X-C chemokine receptor type 4 (CXCR4) gene. We characterize a unique international cohort of 66 patients, including 57 (86%) cases previously unreported, with variable clinical phenotypes. Of 17 distinct CXCR4 genetic variants within our cohort, 11 were novel pathogenic variants affecting 15 individuals (23%). All variants affect the same CXCR4 region and impair CXCR4 internalization resulting in hyperactive signaling. The median age of diagnosis in our cohort (5.5 years) indicates WHIM syndrome can commonly present in childhood, although some patients are not diagnosed until adulthood. The prevalence and mean age of recognition and/or onset of clinical manifestations within our cohort were infections 88%/1.6 years, neutropenia 98%/3.8 years, lymphopenia 88%/5.0 years, and warts 40%/12.1 years. However, we report greater prevalence and variety of autoimmune complications of WHIM syndrome (21.2%) than reported previously. Patients with versus without family history of WHIM syndrome were diagnosed earlier (22%, average age 1.3 years versus 78%, average age 5 years, respectively). Patients with a family history of WHIM syndrome also received earlier treatment, experienced less hospitalization, and had less end-organ damage. This observation reinforces previous reports that early treatment for WHIM syndrome improves outcomes. Only one patient died; death was attributed to complications of hematopoietic stem cell transplantation. The variable expressivity of WHIM syndrome in pediatric patients delays their diagnosis and therapy. Early-onset bacterial infections with severe neutropenia and/or lymphopenia should prompt genetic testing for WHIM syndrome, even in the absence of warts.

Genomic characterization of lymphomas in patients with inborn errors of immunity.

Patients with inborn errors of immunity (IEI) have a higher risk of developing cancer, especially lymphoma. However, the molecular basis for IEI-related lymphoma is complex and remains elusive. Here, we perform an in-depth analysis of lymphoma genomes derived from 23 IEI patients. We identified and validated disease-causing or -associated germline mutations in 14 of 23 patients involving ATM, BACH2, BLM, CD70, G6PD, NBN, PIK3CD, PTEN, and TNFRSF13B. Furthermore, we profiled somatic mutations in the lymphoma genome and identified 8 genes that were mutated at a significantly higher level in IEI-associated diffuse large B-cell lymphomas (DLBCLs) than in non-IEI DLBCLs, such as BRCA2, NCOR1, KLF2, FAS, CCND3, and BRWD3. The latter, BRWD3, is furthermore preferentially mutated in tumors of a subgroup of activated phosphoinositide 3-kinase δ syndrome patients. We also identified 5 genomic mutational signatures, including 2 DNA repair deficiency-related signatures, in IEI-associated lymphomas and a strikingly high number of inter- and intrachromosomal structural variants in the tumor genome of a Bloom syndrome patient. In summary, our comprehensive genomic characterization of lymphomas derived from patients with rare genetic disorders expands our understanding of lymphomagenesis and provides new insights for targeted therapy.

The clinical, molecular, and therapeutic features of patients with IL10/IL10R deficiency: a systematic review.

Interleukin10 (IL10) and IL10 receptor (IL10R) deficiencies are monogenic inborn errors of immunity (IEI) causing early-onset inflammatory bowel diseases (IBD). In this report, we systematically reviewed articles that included related keywords using PubMed, Web of Science, and Scopus databases. The articles were screened for eligibility criteria before data extraction. We assessed 286 patients (44.5% female) with IL10 and/or IL10R deficiencies who were predominantly from China (40.7%), Italy (13.9%), and South Korea (8.5%). The median age of onset was 1.0 (0.3-4.0) months with a median age of genetic diagnosis at 16.0 (7.4-81.0) months. Consanguinity was reported in all evaluable patients with IL10 deficiency and in 38.2% of patients with IL10R deficiency (22.9% of patients with IL10RA, and 79.4% of patients with IL10RB deficiency). The most prevalent mutations in IL10RA were c.301C>T (p.R101W) and c.537G>A (p.T179T), those in IL10RB were c.139A>G (p.K47E) and c.611G>A (p.W204X). Auto-inflammation and enteropathy were present in all cases. The first presentation of both groups was protracted diarrhea (45.7%), bloody diarrhea (17.8%), and colitis (15.5%). Patients with IL10R deficiency had a high frequency of dermatologic manifestations (50.5%) and failure to thrive (60.5%), while IL10-deficient patients lacked those complications. In the majority of patients, the basic immunologic parameters were in normal ranges. Of the entire publications, 30.7% underwent hemopoietic stem cell transplantation, 57.5% surgery, and 86.6% immunosuppressive treatment. The 10-year survival rate was higher in patients with IL10 deficiency than in patients with IL10R deficiency. In conclusion, IL10/IL10R deficiency predominantly presents with treatment-resistant, early-onset IBD within the first months of life. We detected no clear correlation between the phenotype of patients carrying the same variant. The high prevalence of distinct clinical manifestations reported in IL10RA- and IL10RB-deficient patients might be attributable to the interactions between the target tissue and cytokines other than IL10 capable of binding to IL10RB. These results gain translational significance by contributing to earlier diagnosis, adequate therapy, and avoiding delay in the diagnosis and unfavorable outcomes.

Immunophenotypic and functional analysis of lymphocyte subsets in common variable immunodeficiency patients without monogenic defects.

Common variable immunodeficiency (CVID) is accompanied by various lymphocyte abnormalities believed to be mostly responsible for disease features in patients with no diagnosed monogenic defects. Here, we evaluated the association of B and T lymphocyte abnormalities with the incidence of CVID. Twenty-six genetically unsolved CVID patients were examined for B and T lymphocyte subsets by flow cytometry and CD4+ T-cell proliferation by carboxyfluorescein succinimidyl ester (CFSE) test. We detected a reduction in total, naive, memory B cells and plasmablasts, and also total, naive, central memory and regulatory CD4+ T cells, besides naive CD8+ T cells. There was an increase in CD21low and transitional B cells, effector memory (EM) and terminally differentiated effector memory (TEMRA ) CD4+ T-cell subsets as well as total, EM, TEMRA , activated and cytotoxic CD8+ T cells among non-monogenic CVID patients. CD4+ T-cell proliferation response was reduced regarding both division index and percent divided. In conclusion, regarding the similarity of lymphocyte abnormalities between patients without genetic defects and those with monogenic defects, genetic mutations are not responsible for these specific lymphocyte changes. However, the novel correlations observed between lymphocyte alterations among genetically unsolved CVID patients may serve as a guide to predict the potential of future CVID development for hypogammaglobulinemia children.

Expanding the Clinical and Immunological Phenotypes and Natural History of MALT1 Deficiency.

PURPOSE: MALT1 deficiency is a combined immune deficiency characterized by recurrent infections, eczema, chronic diarrhea, and failure to thrive. Clinical and immunological characterizations of the disease have not been previously reported in large cohorts. We sought to determine the clinical, immunological, genetic features, and the natural history of MALT-1 deficiency. METHODS: The clinical findings and treatment outcomes were evaluated in nine new MALT1-deficient patients. Peripheral lymphocyte subset analyses, cytokine secretion, and proliferation assays were performed. We also analyzed ten previously reported patients to comprehensively evaluate genotype/phenotype correlation. RESULTS: The mean age of patients and disease onset were 33 ± 17 and 1.6 ± 0.7 months, respectively. The main clinical findings of the disease were recurrent infections (100%), skin involvement (100%), failure to thrive (100%), oral lesions (67%), chronic diarrhea (56%), and autoimmunity (44%). Eosinophilia and high IgE were observed in six (67%) and two (22%) patients, respectively. The majority of patients had normal T and NK cells, while eight (89%) exhibited reduced B cells. Immunoglobulin replacement and antibiotics prophylaxis were mostly ineffective in reducing the frequency of infections and other complications. One patient received hematopoietic stem cell transplantation (HSCT) and five patients died as a complication of life-threatening infections. Analyzing this cohort with reported patients revealed overall survival in 58% (11/19), which was higher in patients who underwent HSCT (P = 0.03). CONCLUSION: This cohort provides the largest analysis for clinical and immunological features of MALT1 deficiency. HSCT should be offered as a curative therapeutic option for all patients at the early stage of life.

Care of patients with inborn errors of immunity in thirty J Project countries between 2004 and 2021.

Introduction: The J Project (JP) physician education and clinical research collaboration program was started in 2004 and includes by now 32 countries mostly in Eastern and Central Europe (ECE). Until the end of 2021, 344 inborn errors of immunity (IEI)-focused meetings were organized by the JP to raise awareness and facilitate the diagnosis and treatment of patients with IEI. Results: In this study, meeting profiles and major diagnostic and treatment parameters were studied. JP center leaders reported patients' data from 30 countries representing a total population of 506 567 565. Two countries reported patients from JP centers (Konya, Turkey and Cairo University, Egypt). Diagnostic criteria were based on the 2020 update of classification by the IUIS Expert Committee on IEI. The number of JP meetings increased from 6 per year in 2004 and 2005 to 44 and 63 in 2020 and 2021, respectively. The cumulative number of meetings per country varied from 1 to 59 in various countries reflecting partly but not entirely the population of the respective countries. Altogether, 24,879 patients were reported giving an average prevalence of 4.9. Most of the patients had predominantly antibody deficiency (46,32%) followed by patients with combined immunodeficiencies (14.3%). The percentages of patients with bone marrow failure and phenocopies of IEI were less than 1 each. The number of patients was remarkably higher that those reported to the ESID Registry in 13 countries. Immunoglobulin (IgG) substitution was provided to 7,572 patients (5,693 intravenously) and 1,480 patients received hematopoietic stem cell therapy (HSCT). Searching for basic diagnostic parameters revealed the availability of immunochemistry and flow cytometry in 27 and 28 countries, respectively, and targeted gene sequencing and new generation sequencing was available in 21 and 18 countries. The number of IEI centers and experts in the field were 260 and 690, respectively. We found high correlation between the number of IEI centers and patients treated with intravenous IgG (IVIG) (correlation coefficient, cc, 0,916) and with those who were treated with HSCT (cc, 0,905). Similar correlation was found when the number of experts was compared with those treated with HSCT. However, the number of patients treated with subcutaneous Ig (SCIG) only slightly correlated with the number of experts (cc, 0,489) and no correlation was found between the number of centers and patients on SCIG (cc, 0,174). Conclusions: 1) this is the first study describing major diagnostic and treatment parameters of IEI care in countries of the JP; 2) the data suggest that the JP had tremendous impact on the development of IEI care in ECE; 3) our data help to define major future targets of JP activity in various countries; 4) we suggest that the number of IEI centers and IEI experts closely correlate to the most important treatment parameters; 5) we propose that specialist education among medical professionals plays pivotal role in increasing levels of diagnostics and adequate care of this vulnerable and still highly neglected patient population; 6) this study also provides the basis for further analysis of more specific aspects of IEI care including genetic diagnostics, disease specific prevalence, newborn screening and professional collaboration in JP countries.