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.

Genomic testing identifies monogenic causes in patients with very early-onset inflammatory bowel disease: a multicenter survey in an Iranian cohort.

Patients with very early-onset inflammatory bowel disease (VEO-IBD) may present because of underlying monogenic inborn errors of immunity (IEI). Strong differences have been observed in the causes of monogenic IBD among ethnic populations. This multicenter study was carried out on 16 Iranian patients with VEO-IBD. We reviewed clinical and basic immunologic evaluation including flow cytometry and immunoglobulin levels. All patients underwent clinical whole exome sequencing (WES). Sixteen patients (8 females and 8 males) with a median age of 43.5 months were enrolled. The median age at the onset of symptoms was 4 months. Most patients (12, 75%) had consanguineous parents. Chronic non-bloody diarrhea (13, 81.3%) and perianal diseases including perianal abscess (6, 37.5%), anal fissure (6, 37.5%), or anal fistula (2, 12.5%) were the most common manifestations. WES identified a spectrum of genetic variants in 13 patients (81.3%): IL10RB (6, 37.5%), MVK (3, 18.8%), and CASP8, SLC35C1, G6PC3, and IKBKB in 1 patient, respectively. In 3 patients (18.7%), no variant was identified. Flow cytometry identified a spectrum of abnormalities that helped to assess the evidence of genetic diagnosis. At the end of the survey, 3 (18.8%) patients were deceased. This high rate of monogenic defects with a broad spectrum of genes reiterates the importance of investigating IEI in patients with infantile-onset IBD.

Clinical and immunological characteristics of 69 leukocyte adhesion deficiency-I patients.

BACKGROUND: In order to support the comprehensive classification of Leukocyte Adhesion Deficiency-I (LAD-I) severity by simultaneous screening of CD11a/CD18, this study assessed clinical, laboratory, and genetic findings along with outcomes of 69 LAD-I patients during the last 15 years. METHODS: Sixty-nine patients (40 females and 29 males) with a clinical phenotype suspected of LAD-I were referred to Immunology, Asthma, and Allergy research institute, Tehran, Iran between 2007 and 2022 for further advanced immunological screening and genetic evaluations as well as treatment, were enrolled in this study. RESULTS: The diagnosis median age of the patients was 6 months. Delayed umbilical cord separation was found in 25 patients (36.2%). The median diagnostic delay time was 4 months (min-max: 0-82 months). Forty-six patients (66.7%) were categorized as severe (CD18 and/or CD11a: below 2%); while 23 children (33.3%) were in moderate category (CD18 and/or CD11a: 2%-30%). During the follow-ups, 55.1% of children were alive with a mortality rate of 44.9%. Skin ulcers (75.4%), omphalitis (65.2%), and gingivitis (37.7%) were the most frequent complaints. Genetic analysis of the patients revealed 14 previously reported and three novel pathogenic mutations in the ITGB2 gene. The overall survival of patients with and without hematopoietic stem cell transplantation was 79.3% and 55.6%, respectively. CONCLUSION: Physicians' awareness of LAD-I considering delayed separation of umbilical cord marked neutrophilic leukocytosis, and variability in CD11 and CD18 expression levels, and genetic analysis leads to early diagnosis and defining disease severity. Moreover, the prenatal diagnosis would benefit families with a history of LAD-I.

The First Iranian Cohort of Pediatric Patients with Activated Phosphoinositide 3-Kinase-δ (PI3Kδ) Syndrome (APDS).

BACKGROUND: Activated phosphoinositide 3-kinase δ syndrome (APDS) is a recently defined combined primary immunodeficiency disease (PID) characterized by recurrent respiratory tract infections, lymphoproliferation, autoimmunity and lymphoma. Gain-of-function mutations in PIK3CD and loss-of-function of PIK3R1 genes lead to APDS1 and APDS2, respectively. METHODS: Demographic, clinical, immunological and genetic data were collected from medical records of 15 pediatric patients, who were genetically identified using the whole-exome sequencing method. RESULTS: Fifteen patients (6 APDS1 and 9 APDS2) were enrolled in this study. Recurrent respiratory tract infections followed by lymphoproliferation and autoimmunity were the most common manifestations (86.7%, 53.3% and 26.7%, respectively). Five patients (33.3%) had a Hyper-IgM-syndrome-like immunoglobulin profile. In the APDS1 group, splice site and missense mutations were found in half of the patients and the C-lobe domain of PIK3CD was the most affected region (50%). In the APDS2 group, splice site mutation was the most frequent mutation (77.8%) and the inter-SH2 domain was the most affected region of PIK3R1 (66.7%). Mortality rate was significantly higher in APDS2 group (P = .02) mainly due to chronic lung infections. CONCLUSION: Respiratory tract infections and humoral immunodeficiency are commonly the most important complication in pediatric APDS patients, and they can be fatal by ultimately causing catastrophic damage to the structure of lungs. Hence, physicians should be aware of its significance and further work-up of patients with recurrent respiratory tract infections especially in patients with lymphoproliferation. Moreover, delineation of genotype-phenotype associations with disease severity could be helpful in the timely application of appropriate management and patients' survival.

Impact of SARS-CoV-2 Pandemic on Patients with Primary Immunodeficiency.

Although it is estimated that COVID-19 life-threatening conditions may be diagnosed in less than 1:1000 infected individuals below the age of 50, but the real impact of this pandemic on pediatric patients with different types of primary immunodeficiency (PID) is not elucidated. The current prospective study on a national registry of PID patients showed that with only 1.23 folds higher incidence of infections, these patients present a 10-folds higher mortality rate compared to population mainly in patients with combined immunodeficiency and immune dysregulation. Therefore, further management modalities against COVID-19 should be considered to improve the survival rate in these two PID entities using hematopoietic stem cell transplantation and immunomodulatory agents.

Autoimmune manifestations among 461 patients with monogenic inborn errors of immunity.

BACKGROUND: The inborn errors of immunity (IEIs) are a group of heterogeneous disorders mainly characterized by severe and recurrent infections besides other complications including autoimmune and inflammatory diseases. In this study, we aim to evaluate clinical, immunologic, and molecular data of monogenic IEI patients with and without autoimmune manifestations. METHODS: We have retrospectively screened cases of monogenic IEI in the Iranian PID registry for the occurrence of autoimmunity and immune dysregulation. A questionnaire was filled for all qualified patients with monogenic defects to evaluate demographic, laboratory, clinical, and molecular data. RESULTS: A total of 461 monogenic IEI patients (290 male and 171 female) with a median (IQR) age of 11.0 (6.0-20.0) years were enrolled in this study. Overall, 331 patients (72.1%) were born to consanguineous parents. At the time of the study, 330 individuals (75.7%) were alive and 106 (24.3%) were deceased. Autoimmunity was reported in 92 (20.0%) patients with a median (IQR) age at autoimmune diagnosis of 4.0 (2.0-7.0) years. Sixteen patients (3.5%) showed autoimmune complications (mostly autoimmune cytopenia) as the first presentation of the disease. Most of the patients with autoimmunity were diagnosed clinically with common variable immunodeficiency (42.4%). The frequency of sinusitis and splenomegaly was significantly higher in patients with autoimmunity than patients without autoimmunity. In patients with autoimmunity, the most common pathogenic variants were identified in LRBA (in 21 patients, 23.0%), ATM (in 13 patients, 14.0%), and BTK (in 9 patients, 10.0%) genes. In the evaluation of autoimmunity by different genes, 4 of 4 IL10RB (100%), 3 of 3 AIRE (100%), and 21 of 30 LRBA (70.0%) mutated genes had the highest prevalence of autoimmunity. CONCLUSIONS: Autoimmune phenomena are common features among patients with monogenic IEI and are associated with a more complicated course of the disease. Therefore, when encountering autoimmune disorders, especially in the setting of dysgammaglobulinemia, it would be appropriate to conduct next-generation sequencing to discover responsible genes for the immune dysregulation at an early stage of the disease.

Identification of Cytochrome b-245, beta-chain gene mutations, and clinical presentations in Iranian patients with X-linked chronic granulomatous disease.

BACKGROUND: X-linked chronic granulomatous disease (X-CGD) is an immunodeficiency disorder caused by defects in the gp91phox subunit that leads to life-threatening infections. We aimed to identify CYBB gene mutations and study clinical phenotypes in Iranian patients with probable X-CGD. METHODS: We studied four unrelated Iranian patients with probable X-CGD and their families recruited in several years. We isolated genomic DNA from whole blood and performed Sanger sequencing in the CYBB gene's coding and flanking regions. We also performed pathogenicity predictions using in silico tools. RESULTS: We detected four different mutations, including a novel insertion mutation in exon 5 (p.Ile117AsnfsX6), in the patient. Bioinformatics analysis confirmed the pathogenic effect of this mutation. We predicted protein modeling and demonstrated lost functional domains. The patient with the insertion mutation presented pneumonia and acute sinusitis during his life. We also detected three other known nonsense mutations (p.Arg157Ter, p.Arg226Ter, and p.Trp424Ter) in the CYBB gene. The patient with p.Arg157Ter developed lymphadenitis and pneumonia. Moreover, the patient with inflammatory bowel disease showed p.Arg226Ter and the patient with tuberculosis presented p.Trp424Ter. We detected different clinical features in the patients compared to other Iranian patients with the same mutations. CONCLUSION: Our results expand the genetic database of patients with X-CGD from Iran and make it much easier and faster to identify patients with X-CGD. Our results also help to detect carriers and enable prenatal diagnosis in high-risk families as a cost-effective strategy.

Monogenic Primary Immunodeficiency Disorder Associated with Common Variable Immunodeficiency and Autoimmunity.

BACKGROUND: Common variable immunodeficiency (CVID) is the most frequent primary immunodeficiency disorder mainly characterized by recurrent bacterial infections besides other immunological defects including loss of or dysfunction of B cells and decreased immunoglobulin levels. In this study, our aim is to evaluate clinical, immunological, and molecular data of patients with a primary clinical diagnosis of CVID and autoimmune phenotype with a confirmed genetic diagnosis. METHODS: Among 297 patients with CVID, who were registered in the Iranian Primary Immunodeficiency Registry at Children's Medical Center Hospital in Iran, 83 patients have been genetically examined and 27 patients with autoimmunity and confirmed genetic mutations were selected for analysis. Whole-exome sequencing and confirmatory Sanger sequencing methods were used for the study population. A questionnaire was retrospectively filled for all patients to evaluate demographic, laboratory, clinical, and genetic data. RESULTS: In the 27 studied patients, 11 different genetic defects were identified, and the most common mutated gene was LRBA, reported in 17 (63.0%) patients. Two patients (7.7%) showed autoimmune complications as the first presentation of immunodeficiency. Eleven patients (40.7%) developed one type of autoimmunity, and 16 patients (59.3%) progressed to poly-autoimmunity. Most of the patients with mono-autoimmunity (n = 9, 90.0%) primarily developed infectious complications, while in patients with poly-autoimmunity, the most common first presentation was enteropathy (n = 6, 37.6%). In 13 patients (61.9%), the diagnosis of autoimmune disorders preceded the diagnosis of primary immunodeficiency. The most frequent autoimmune manifestations were hematologic (40.7%), gastrointestinal (48.1%), rheumatologic (25.9%), and dermatologic (22.2%) disorders. Patients with poly-autoimmunity had lower regulatory T cells than patients with mono-autoimmunity. CONCLUSION: In our cohort, the diagnosis of autoimmune disorders preceded the diagnosis of primary immunodeficiency in most patients. This association highlights the fact that patients referring with autoimmune manifestations should be evaluated for humoral immunity.

Fourth Update on the Iranian National Registry of Primary Immunodeficiencies: Integration of Molecular Diagnosis.

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 next-generation 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. CONCLUSIONS: During a 20-year registration of Iranian PID patients, significant changes have been observed by increasing the awareness of the medical community, national PID network establishment, improving therapeutic facilities, and recently by inclusion of the molecular diagnosis. The current collective study of PID phenotypes and genotypes provides a major source for ethnic surveillance, newborn screening, and genetic consultation for prenatal and preimplantation genetic diagnosis.

Investigation of Fc Receptor-Like 3 (FCRL-3) Gene Polymorphism (rs7528684) with Susceptibility to Allergic Asthma in Iranian North-Western Azeri Population.

BACKGROUND: Asthma is a clinical setting in which multiple cellular and molecular mechanisms are involved. Additionally, increasing genetic studies have provided evidence that single nucleotide polymorphisms (SNPs) in asthma relevant genes confer susceptibility to the disease. Fc receptor-like (FCRL) 3, a transmembrane molecule basically involved in B-cell signaling, mediates immune-disorders including allergy. Aim of study was to investigate the possible association of rs7528684 SNP in FCRL3 gene with a predisposition to allergic asthma in Iranian North-western Azeri population. METHODS: The frequency of genotypes and alleles of rs7528684 SNP in the FCRL3 gene was determined using the TaqMan genotyping method in 191 asthmatic patients and 186 healthy controls. RESULTS: The most frequent genotype in patients and control groups were CT (n = 81, 42.4%) and TT (n = 76, 40.9%), respectively. Statistical analysis showed no significant difference in genotype frequency (p = 0.81) and also in frequency of C and T alleles (p = 0.52) between two groups. CONCLUSIONS: Our results revealed no association between the rs7528684 SNP with susceptibility to allergic asthma in the included population. More studies in different ethnic groups will result in more valid conclusions.