Comparison of Common Monogenic Defects in a Large Predominantly Antibody Deficiency Cohort.

BACKGROUND: Predominantly antibody deficiencies (PADs) are the most common primary immunodeficiencies, characterized by hypogammaglobulinemia and inability to generate effective antibody responses. OBJECTIVE: We intended to report most common monogenic PADs and to investigate how patients with PAD who were primarily diagnosed as suffering from agammaglobulinemia, hyper-IgM (HIgM) syndrome, and common variable immunodeficiency (CVID) have different clinical and immunological findings. METHODS: Stepwise next-generation sequencing and Sanger sequencing were performed for confirmation of the mutations in the patients clinically diagnosed as suffering from agammaglobulinemia, HIgM syndrome, and CVID. RESULTS: Among 550 registered patients, the predominant genetic defects associated with agammaglobulinemia (48 Bruton's tyrosine kinase [BTK] and 6 µ heavy chain deficiencies), HIgM syndrome (21 CD40 ligand and 7 activation-induced cytidine deaminase deficiencies), and CVID (17 lipopolysaccharides-responsive beige-like anchor deficiency and 12 atypical Immunodeficiency, Centromeric instability, and Facial dysmorphism syndromes) were identified. Clinical disease severity was significantly higher in patients with µ heavy chain and CD40 ligand mutations compared with patients with BTK (P = .003) and activation-induced cytidine deaminase (P = .009) mutations. Paralysis following live polio vaccination was considerably higher in patients with µ heavy chain deficiency compared with BTK deficiency (P < .001). We found a genotype-phenotype correlation among patients with BTK mutations regarding clinical manifestation of meningitis and chronic diarrhea. Surprisingly, we noticed that first presentations in most patients with Immunodeficiency, Centromeric instability, and Facial dysmorphism were respiratory complications (P = .008), whereas first presentations in patients with lipopolysaccharides-responsive beige-like anchor deficiency were nonrespiratory complications (P = .008). CONCLUSIONS: This study highlights similarities and differences in the clinical and genetic spectrum of the most common PAD-associated gene defects. This comprehensive comparison will facilitate clinical decision making, and improve prognosis and targeted treatment.

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 ITGB2 gene in 12 new cases of leukocyte adhesion deficiency-type I revealed four novel mutations from Iran.

BACKGROUND: Leukocyte adhesion deficiency type I (LAD-I) is a rare, autosomal recessive inherited immunodeficiency disease. LAD-I is caused by mutations in the ITGB2 gene and characterized by recurrent severe bacterial infections, as well as impaired wound healing with lack of pus formation. METHODS: In this study, we investigated ITGB2 gene mutations in 12 patients and their parents. Genomic DNA was extracted from whole blood samples. All coding regions of the ITGB2 gene were amplified using PCR and followed by direct sequencing. RESULTS: Genetic analysis revealed 12 different homozygous mutations, including six missense (c.382G>A, c.2146G>C, c.715G>A, c.691G>C, c.1777C and new c.1686C>A), two new nonsense (c.1336G>T and c.1821C>A), three-frame shift (c.1143delc, c.1907delA and new c.474dupC) and a splice site (c.1877+2T>C). Flow cytometry analysis of CD11/CD18 expression on neutrophils revealed defect in CD18 in all twelve cases (1.4% to 42%), CD11a in ten cases (0.1% to 26.7%), CD11b in nine cases (1.2% to 58.8%), and CD11c in all cases (0 % to 18.1%). The patients' parents were both heterozygous carriers. CONCLUSION: Our findings showed four new mutations in the ITGB2 gene. These results can be used for decisive genetic diagnosis, genetic counseling, as well as  prenatal diagnosis for all patients who are suspended to LADI.

Health-related quality of life in primary antibody deficiency.

Patients with primary antibody deficiencies (PAD) are susceptible to recurrent and chronic infections and a variety of complications. This study was performed to assess quality of life (QoL) of PAD patients who were under long term treatment and regular follow-up.Thirty six adults with proved diagnosis of PAD, who had received regular intravenous immunoglobulin replacement therapy, were enrolled in this study. The QoL of selected PAD patients was measured by Medical Outcomes Study 36-item Short-Form (SF-36) Health Survey questionnaire.The patients with PAD showed significantly reduced scores in physical component in comparison with healthy age-sex matched control subjects (60.2±20.1 vs. 85.5±4.7, P<0.001). Mental component score was also significantly decreased in the patient's group (59.8±19.5 vs. 72.3±3.4, P=0.002). There was a reverse association between SF-36 scores and number of infections episodes (r=-0.73 P=0.003). The patients with long delay diagnosis showed significantly lower SF-36 scores (r=-0.62, P=0.003).The patients with PAD who were diagnosed timely and managed appropriately seem to have lower complications and better QoL. However, the patients with severe phenotypes and long delay in diagnosis showed lower QoL, even in medical management.