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Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare congenital condition characterized by a selective predisposition to infections caused by weakly virulent mycobacteria and other types of intra-macrophagic pathogens. The 16 genes associated with MSMD display a considerable level of allelic heterogeneity, accounting for 31 distinct disorders with variable clinical presentations and prognosis. Most of MSMD deficiencies are isolated, referred to as selective susceptibility to mycobacterial diseases. However, other deficiencies are syndromic MSMD, defined by the combination of the mycobacterial infection with another, equally common, infectious, specific phenotypes. Herein, we described a series of 32 Iranian MSMD cases identified with seven distinct types of molecular defects, all of which are involved in the interferon gamma (IFNγ) immunity, including interleukin IL-12 receptor-β1 (IL-12Rβ1) deficiency (fifteen cases), IL-12p40 deficiency (ten cases), and IL-23R deficiency (three cases), as well as IFNγ receptor 1 (IFNγR1) deficiency, IFNγ receptor 2 (IFNγR2) deficiency, interferon-stimulated gene 15 (ISG15) deficiency, and tyrosine kinase 2 (TYK2) deficiency each in one case. Since the first report of two MSMD patients in our center, we identified 30 other affected patients with similar clinical manifestations. As the number of reported Iranian cases with MSMD diagnosis has increased in recent years and according to the national vaccination protocol, all Iranian newborns receive BCG vaccination at birth, early diagnosis, and therapeutic intervention which are required for a better outcome and also prevention of similar birth defects. Therefore, we investigated the clinical and molecular features of these 32 patients. The current report also defined novel classes of pathological mutations, further expanding our knowledge of the MSMD molecular basis and associated clinical manifestations.

LPS-responsive beige-like anchor protein (LRBA) deficiency is a monogenic primary immunodeficiency characterized by a heterogeneous spectrum of clinical manifestations associated with immune dysregulation. In this study, we reported clinical, immunologic, and genetic evaluation of two Iranian patients from unrelated families, both suffering from recurrent respiratory tract infections, failure to thrive, interstitial lung disease, autoimmune cytopenia, and hypogammaglobulinemia. Pulmonary abscess in one patient and persistent enteropathy in another were also observed. Further investigations revealed causative mutations in the exon (c.2166_2766del) and intron (c.4730–3 T > G) of the LRBA gene. These results may provide further elucidation of the clinical phenotypes and responsible genetic factors of LRBA deficiency.

Introduction: Inborn errors of immunity (IEIs) are rare inherited disorders with a broad spectrum of manifestations. Here, we aimed to delineate the atopy burden in a cohort of patients with IEIs. Methods: 313 patients with IEIs were enrolled in the study within a 9-years period, and data were collected via a questionnaire. All statistical analyses were performed using SPSS software (v. 25.0, Chicago, IL, USA). The statistical significance level was set at p < 0.05. Results: Overall, 51 out of 313 (16.3%) patients were identified to have atopic manifestations. Food allergy was detected in 34 (10.2%), atopic dermatitis in 21 (6.7%), as well as allergic asthma and allergic rhinitis each in 4 (1.3%) patients. The allergic disorders were reported as initial manifestations among 14 out of 35 (40.0%) atopic patients. Most of these 51 patients fell within the category of combined immunodeficiency (CID) (n = 38, 74.5%), followed by, severe CID (SCID) (n = 5, 9.8%), common variable immunodeficiency (n = 3, 5.9%), chronic granulomatous disease (n = 3, 5.9%), selective IgA deficiency (n = 1, 2.0%), and leukocyte adhesion defect (n = 1, 2.0%). No patient with Mendelian susceptibility to mycobacteria was found to have atopic manifestation. Atopic dermatitis (p = 0.001) and food allergy (p < 0.001) were both significantly higher in patients with CID than in other IEI groups. Among atopic patients with CID and SCID, food allergy and atopic dermatitis were the most prevalent comorbidities. Discussion/Conclusion: Atopic diseases may contribute to the clinical picture of IEIs, particularly in patients with CID. Atopy in association with other warning signs of IEIs increases the possibility of an underlying IEI.

Mendelian susceptibility to mycobacterial disease (MSMD) is a rare group of genetic disorders characterized by infections with weakly virulent environmental mycobacteria (EM) or Mycobacterium bovis bacillus Calmette-Guérin (BCG). Herein, we described the case of a 4.5-yearold boy with protein-losing enteropathy, lymphoproliferation, and candidiasis, who was found to have disseminated Mycobacterium simiae infection. A homozygous mutation in the IL12B gene, c.527_528delCT (p.S176Cfs*12) was identified, responsible for the complete IL-12p40 deficiency. He was resistant to anti-mycobacterial treatment and finally died due to sepsis-related complications.