Association of Human Leukocyte Antigen (HLA) class II ( and ) alleles and haplotypes with Rheumatoid Arthritis in Sudanese patients.

The aim of this study was to determine the Human Leukocyte Antigen (HLA) class II ( and ) alleles and haplotype frequency in Rheumatoid Arthritis RA) in the Sudanese population. The frequency of and - alleles and haplotypes were determined in 122 RA patients and 100 controls. HLA alleles were genotyped by the polymerase chain reaction-sequence specific primers (PCR-SSP) method. In RA patients, alleles were high in frequency (9.6% vs 14.2%, = 0.038 and = 0.042, respectively), and dependently on anti-citrullinated protein antibodies (ACPAs) seropositivity ( = 0.044 and = 0.027, respectively). In contrast, the frequency of the allele was significantly low in patients than in controls (11.7% vs 5.0%, = 0.010). Moreover, the allele was strongly associated with RA risk (42.2%, = 2.2x10), whereas, and showed protective effects against RA (23.1% and 42.2%, = 0.024 and = 2.2x10, respectively). Five different HLA haplotypes, ( = 0.00003), ( = 0.00014) ( = 0.027) ( = 0.004), and ( = 3.79x10) were significantly associated with RA risk, while 3 protective haplotypes ( = 0.008), ( = 0.004) ( = 0.02) were identified. This is the first study determining the association between HLA class II alleles and haplotypes and RA risk in our population.