Frequency of HLA Class I and Class II Alleles in Patients with CVID from Turkey

Background: Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency. Certain gene loci are pointed out in several studies in CVID patients. Until now, monogenic defects have been identified in only 2-10% of CVID patients; therefore, association of the disease with HLA alleles may be important for elucidating immunological and genetic mechanisms behind CVID. The aim of this study is to investigate the relationship between CVID and HLA alleles. Methods: HLA class I/II alleles were analyzed in 65 patients with CVID and alleles that may be related to disease susceptibility were determined by comparing with 300 healthy controls. We also evaluated HLA allele frequencies in CVID patients with gastrointestial system (GIS) involvement and autoimmune manifestations. Results: When compared with controls, frequencies of B*27, B*35, C*04, and DRB1*04 alleles were significantly different in patients with CVID (p < .05). Frequencies of C*12, DRB1*13, and DRB1*15 alleles were more frequent in controls, indicating protective alleles (p < .05). There was a statistically significant difference for DQ2 and DQ8 haplotypes between patients with GIS involvement and controls. Conclusion: In comparison with literature, distinctive HLA alleles found in our study may originate from the diversity in gene pool between the populations. These data may provide clues for disease susceptibility.