MHC class II deficiency: Clinical, immunological, and genetic insights in a large multicenter cohort.

BACKGROUND: Major Histocompatibility Complex Class II (MHC-II) deficiency, a combined immunodeficiency, results from loss of Human Leukocyte Antigen class II expression on antigen-presenting cells. Currently, hematopoietic stem cell transplantation (HSCT) stands as the sole curative approach, though factors influencing patient outcomes remain insufficiently explored. OBJECTIVE: Our aim was to elucidate the clinical, immunological, and genetic profiles associated with MHC-II deficiency and identify prognostic indicators that affect survival rates. METHODS: In this multicenter retrospective analysis, we gathered data from 35 patients diagnosed with MHC-II deficiency across 12 centers in Turkey. We recorded infection histories, gene mutations, immune cell subsets, and surface MHC-II expression on blood cells. We conducted survival analyses to evaluate the impact of various factors on patient outcomes. RESULTS: Predominant symptoms observed were pneumonia (n=29, 82.9%), persistent diarrhea (n=26, 74.3%), and severe infections (n=26, 74.3%). The RFXANK gene mutation (n=9) was the most frequent, followed by mutations in RFX5 (n=8), CIITA (n=4), and RFXAP (n=2) genes. Patients with RFXANK mutations presented with later onset and diagnosis compared to those with RFX5 mutations (p=0.0008 and p=0.0006, respectively), alongside a more significant diagnostic delay (p=0.020). A notable founder effect was observed in 5 patients with a specific RFX5 mutation (c.616G>C). The overall survival rate for patients was 28.6% (n=10), showing a significantly higher proportion in individuals with HSCT (n=8, 80%). Early demise (p=0.006) and higher CD8+ T-cell counts were observed in patients with the RFX5 mutations compared to RFXANK-mutant patients (p=0.006 and p=0.009, respectively). CONCLUSION: The study delineates the genetic and clinical panorama of MHC-II deficiency, emphasizing the prevalence of specific gene mutations such as RFXANK and RFX5. These insights facilitate early diagnosis and prognosis refinement, significantly contributing to the management of MHC-II deficiency.

Therapeutic modalities and clinical outcomes in a large cohort with LRBA deficiency and CTLA4 insufficiency.

BACKGROUND: LPS-responsive beige-like anchor (LRBA) deficiency (LRBA-/-) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA4) insufficiency (CTLA4+/-) are mechanistically overlapped diseases presenting with recurrent infections and autoimmunity. The effectiveness of different treatment regimens remains unknown. OBJECTIVE: Our aim was to determine the comparative efficacy and long-term outcome of therapy with immunosuppressants, CTLA4-immunoglobulin (abatacept), and hematopoietic stem cell transplantation (HSCT) in a single-country multicenter cohort of 98 patients with a 5-year median follow-up. METHODS: The 98 patients (63 LRBA-/- and 35 CTLA4+/-) were followed and evaluated at baseline and every 6 months for clinical manifestations and response to the respective therapies. RESULTS: The LRBA-/- patients exhibited a more severe disease course than did the CTLA4+/- patients, requiring more immunosuppressants, abatacept, and HSCT to control their symptoms. Among the 58 patients who received abatacept as either a primary or rescue therapy, sustained complete control was achieved in 46 (79.3%) without severe side effects. In contrast, most patients who received immunosuppressants as primary therapy (n = 61) showed either partial or no disease control (72.1%), necessitating additional immunosuppressants, abatacept, or transplantation. Patients with partial or no response to abatacept (n = 12) had longer disease activity before abatacept therapy, with higher organ involvement and poorer disease outcomes than those with a complete response. HSCT was performed in 14 LRBA-/- patients; 9 patients (64.2%) showed complete remission, and 3 (21.3%) continued to receive immunosuppressants after transplantation. HSCT and abatacept therapy gave rise to similar probabilities of survival. CONCLUSIONS: Abatacept is superior to immunosuppressants in controlling disease manifestations over the long term, especially when started early, and it may provide a safe and effective therapeutic alternative to transplantation.

Endoscopic findings in patients with familial Mediterranean fever and dyspeptic symptoms.

AIM: The aim of the study was to evaluate the clinical, endoscopic, histopathological, laboratory, and imaging findings of patients with familial Mediterranean fever (FMF) presenting with dyspeptic symptoms. MATERIAL AND METHODS: Endoscopy was performed in 28 patients with FMF undergoing colchicine therapy, who presented to our hospital between 2012 and 2014 with abdominal pain, diarrhoea, and dyspeptic complaints. Upper gastrointestinal system endoscopy was performed in all patients; 16 of these underwent colonoscopy. Demographic characteristics, clinical and laboratory data, genetic analysis, imaging data, and endoscopy and colonoscopy findings were evaluated in all patients. RESULTS: Histopathological analysis of biopsy specimens revealed gastrointestinal pathology in 21 (75%) patients. Upper endoscopy analysis revealed that 14 (50%) patients had antral gastritis (8 Helicobacter pylori (-) antral gastritis and 6 H. pylori (+) chronic active gastritis) and 2 (7%) cases had giardiasis. Four antral gastritis cases had concomitant esophagitis, and 2 patients had widespread ulcers in the terminal ileum. The rest had a normal colonic appearance; however, three patients with normal colonoscopic findings were found to have chronic active colitis on histopathological examination. CONCLUSIONS: In this study, most patients with FMF presenting with dyspeptic complaints had gastrointestinal pathology. Furthermore, there was higher inflammatory bowel disease incidence in these patients.

Nitric oxide synthase gene polymorphisms in children with minimal change nephrotic syndrome.

AIMS: Nitric oxide (NO) attenuates many functions within the kidney, and all NO synthase (NOS) isoforms are constitutively expressed in the kidney. But the exact role of NO in renal diseases is still debatable. The aim of the present study was to investigate endothelial (eNOS), and neuronal (nNOS) NOS gene polymorphisms in children with minimal change nephrotic syndrome (MCNS). MATERIALS AND METHODS: Eighty-six Turkish children with clinical MCNS, ranging in age from 2 to 10 years, were compared with 114 healthy age- and sex-matched controls. The glu 298 Asp (G/T) polymorphism of the eNOS, and C276T (C/T) polymorphism of nNOS genes were genotyped using polymerase chain reaction. RESULTS: The distribution of GG, TG, and TT genotypes for eNOS was 52%, 33% and 15% in MCNS compared with 61%, 26% and 13% in the controls (P > 0.05). The distribution of CC, TC, and TT genotypes for nNOS was 16%, 66% and 18% in MCNS compared with 10%, 43% and 47% in the controls. TT genotype distribution of nNOS was found to be lower in patients (P = 0.003). The eNOS and nNOS gene polymorphisms were not associated with gender, positive family history, frequency of relapses, or response to steroid. CONCLUSIONS: The present study is the first to investigate eNOS and nNOS gene polymorphisms in children with MCNS. The nNOS gene polymorphism may be associated with MCNS in children, but further studies in a larger population with different glomerular diseases are needed to confirm the results.