Background The number of inherited diseases and the spectrum of clinical manifestations of primary immunodeficiency disorders (PIDs) are ever-expanding. Molecular diagnosis using genomic approaches should be performed for all PID patients since it provides a resource to improve the management and to estimate the prognosis of patients with these rare immune disorders. Method The current update of Iranian PID registry (IPIDR) contains the clinical phenotype of newly registered patients during last 5 years (2013-2018) and the result of molecular diagnosis in patients enrolled for targeted and nextgeneration sequencing. Results Considering the newly diagnosed patients (n = 1395), the total number of registered PID patients reached 3056 (1852 male and 1204 female) from 31 medical centers. The predominantly antibody deficiency was the most common subcategory of PID (29.5%). The putative causative genetic defect was identified in 1014 patients (33.1%) and an autosomal recessive pattern was found in 79.3% of these patients. Among the genetically different categories of PID patients, the diagnostic rate was highest in defects in immune dysregulation and lowest in predominantly antibody deficiencies and mutations in the MEFV gene were the most frequent genetic disorder in our cohort.

This study provides proof of principle for the application of targeted next-generation sequencing panels in countries with limited diagnostic resources. The effect of genetic diagnosis on clinical care requires continued improvements in therapeutic resources for these patients.

Background: Selective IgA deficiency (SIgAD) is the most common primary immunodeficiency disorder, which is characterized by significantly decreased serum levels of IgA. Abnormalities of CD4+CD25^highforkhead box P3 (FoxP3)+ regulatory T cells (T_reg) have been shown in association with autoimmune and inflammatory disorders. Methods: In order to evaluate the relationship between autoimmunity and T_reg in SIgAD, we studied 26 IgA-deficient patients (aged 4–17 years) with serum IgA levels <7 mg/dl, 26 age- and sex-matched healthy controls and 26 age- and sex matched idiopathic thrombocytopenic purpura cases with normal immune system. T_reg were determined by flow cytometry using T_reg markers, including CD4, CD25 and FoxP3. Results: The mean percentage of CD4, CD25+FoxP3+ T_reg from all CD4+ cells was 4.08 ± 0.86 in healthy controls, which was significantly higher than in SIgAD patients (2.93 ± 1.3; p = 0.003). We set a cutoff point (2.36%) for T_reg, which was two standard deviations lower than the mean of normal controls. According to this cutoff point and in order to assess the role of T_reg in clinical SIgAD manifestation, we classified patients into two groups: 16 patients in G1 with T_reg <2.36% and 10 patients in G2 with T_reg >2.36%. Autoimmunity was recorded in 9 patients (53.3%) of G1 and only 1 patient of G2, respectively (p = 0.034). Although a defect in class switching recombination was observed in 40% of the patients in G1, none of the G2 patients had such a defect (p = 0.028). Conclusion: This study showed decreased proportions of T_reg in SIgAD patients, particularly in those with signs of chronic inflammation.

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Background/AimsInflammatory bowel disease (IBD) is a chronic disease of the gastrointestinal tract, whose etiologies are still unknown. This study was performed to evaluate the humoral immune response in terms of B cell functions in selected IBD patients.MethodsEighteen pediatric patients with IBD, including 12 cases of ulcerative colitis (UC) and six with Crohn disease (CD), were enrolled in this study. The pneumococcal vaccine was injected in all patients, and the IgG antibody level to the polysaccharide antigen was measured before and 4 weeks after injection. The B cell switch-recombination process was evaluated.ResultsFive patients with IBD (three CD and two UC) had defects in B cell switching, which was significantly higher than in controls (p=0.05). Ten patients had a specific antibody deficiency and exhibited a higher frequency of bacterial infection than the healthy group. The mean increased level of IgG after vaccination was lower in IBD patients (82.9±32.5 µg/mL vs 219.8±59.0 µg/mL; p=0.001). Among the patients who had an insufficient response, no significant difference in the number of switched memory B-cell was observed.ConclusionsA defect in B lymphocyte switching was observed in pediatric IBD patients, and especially in those patients with CD. Owing to an increased risk of bacterial infections in those patients with antibody production defects, pneumococcal vaccination could be recommended. However, not all patients can benefit from the vaccination, and several may require other prophylactic methods.