Human leukocyte antigen (HLA) polymorphism and type 1 diabetes in the Moroccan population

Abstract

Insulin-dependent diabetes mellitus or type 1 diabetes is an autoimmune multifactorial disease which has a great socio-economic impact. In Morocco, less is known about the contribution of Human leukocyte antigen (HLA) alleles to type 1 diabetes susceptibility. Our study focused on evaluating the distribution of class II HLA genes among Moroccan patients presenting type 1 diabetes coming from different regions of the country. A total of 76 patients diagnosed with type I diabetes were compared to a group of 248 healthy controls matched by age, sex, and ethnic origin. The HLA class II (DR and DQ) typing of patients and controls was performed using polymerase chain reaction sequence-specific primers (PCR-SSP). Ambiguous typings were reanalyzed by Luminex technology. We found a significant association between HLA-DRB1*03 (p = 0.0001), DRB1*04 (p = 0.0001), DQB1*02 (p = 0.0001, OR = 4.4) and DQB1*03 (p = 0.002) alleles frequencies and the susceptibility to diabetes. The HLA-DQB1*06 allele was significantly decreased in patients (p = 0.008). DRB1*03-DQB1*02, DRB1*04-DQB1*03 and DRB1*04-DQB1*02 haplotypes induce susceptibility to type 1 diabetes while DRB1*13-DQB1*06 and DRB1*15-DQB1*06 haplotypes seems to confer a protective effect in our population. These data highlights that Moroccans diabetic patients do share a series of traits with diabetics of other origins but also have specific characteristics.

Key words: Type 1 diabetes, susceptibility, human leukocyte antigen (HLA), Moroccan population.