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Purpose: Major histocompatibility complex class II (MHC-II) deficiency is a rare inborn error of immunity (IEI). Impaired antigen presentation to CD4+ T-cells results in combined immunodeficiency. Patients typically present with severe respiratory and gastrointestinal tract infections at early ages. Hematopoietic stem cell transplantation (HSCT) is the only curative therapy. Methods: We describe the clinical, immunologic, and genetic features of eighteen unrelated Iranian patients with MHC-II deficiency. Results: Consanguinity was present in all affected families. The median age at the initial presentation was 5.5 months (range seven days to 18 years). The main symptoms included failure to thrive, persistent diarrhea, and pneumonia. Autoimmune and neurologic features were documented in 30% of the patients, respectively. Thirteen patients carried RFXANK gene mutations, two carried RFX5 gene mutations, and three carried a RFXAP gene mutation. Six patients shared the same RFXANK founder mutation (c.162delG); limited to the Iranian population and dated to approximately 1,296 years ago. Four of the patients underwent HSCT; three of them are alive. On the other hand, nine of the fourteen patients who did not undergo HSCT had a poor prognosis and died. Conclusion: MHC-II deficiency is not rare in Iran, with a high rate of consanguinity. It should be considered in the differential diagnosis of combined immunodeficiency (CID) at any age. With the limited access to HSCT and its variable results in MHC-II deficiency, implementing genetic counseling and family planning for the affected families are mandatory. We better determined the c.162delG RFXANKheterozygous mutation frequency in the Iranian population.

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.

Cernunnos deficiency is a rare radiosensitive form of severe combined immunodeficiency (SCID). Herein, we report a patient with recurrent infections, birdlike face, microcephaly, Failure to thrive (FTT), and hypogammaglobinemia accompanied by considerable and rare features of sensorineural hearing loss and hypothyroidism with a mutation in splicing site of the third intron of non-homologous end joining 1 (NHEJ1) gene. The mutation was associated with T-B-NK + in flowcytometry. Distinct clinical manifestation along with a rarely reported genetic site mutation was noticeable in the reported case. The clinicians should be sensitive enough to suspect SCID in any patient with recurrent infections, microcephaly, FTT, and hypogammaglobinemia. Also, it is highlightable that every case of SCID with microcephaly should prompt us to the SCIDs with genetic mutations sensitive to radiation and further investigations are mandatory in highly suspicious patients.

Background: Inborn errors of immunity (IEIs) are a group of congenital diseases caused by genetic defects in the development and function of the immune system. The involvement of the respiratory tract is one of the most common presentations in IEIs. Methods: Overall, 117 patients with diagnosed IEIs were followed-up within 8 years at the National Research Institute of Tuberculosis and Lung Diseases (NRITLD). Demographic, clinical, and laboratory data were collected in a questionnaire. Pulmonary function test (PFT), chest X-ray (CXR), and high-resolution computed tomography (HRCT) scans were obtained where applicable. Results: Our study population consisted of 48 (41%) patients with predominantly antibody deficiencies (PADs), 39 (32%) patients with congenital defects of phagocytes, 14 (11.9%) patients with combined immunodeficiency (CID), and 16 (14%) patients with Mendelian susceptibility to mycobacterial diseases (MSMD).. Recurrent pneumonia was the most common manifestation, while productive cough appeared to be the most common symptom in almost all diseases. PFT showed an obstructive pattern in patients with PAD, a restrictive pattern in patients with CID, and a mixed pattern in patients with CGD. HRCT findings were consistent with bronchiectasis in most PAD patients, whereas consolidation and mediastinal lesions were more common in the other groups. Conclusions: Pulmonary manifestations vary among different groups of IEIs. The screening for lung complications should be performed regularly to reveal respiratory pathologies in early stages and follow-up on already existing abnormalities. (C) 2022 Codon Publications. Published by Codon Publications.

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.