Human leucocyte antigen (HLA) class I and II typing in Belgian multiple sclerosis patients

This is one of the first studies to compare the frequencies of different human leucocyte antigen (HLA) class I and II alleles and haplotype HLA-DRB1*15-DQB1*06 in a cohort of 119 patients with multiple sclerosis (MS) and a cohort of 124 healthy controls in Belgium. An association with MS was found for the HLA-DRB1*15 (odds ratio [OR] 2.60 [95% confidence interval (CI) 1.51-4.50]) and HLA-DQB1*06 (OR 1.97 [95% CI 1.18-3.29]) alleles, and for haplotype DRB1*15-DQB1*06 (OR 2.63 [95% CI 1.52-4.56]). The HLA-B*07 allele also tended to be more frequent in MS patients (OR 1.46 [95% CI 0.80-2.65]) and more frequent among MS patients with than in those without the HLA-DRB1*15 allele (26/54 [48.1%] versus 6/65 [9.2%]; p value <0.0001). Other alleles were underrepresented in MS patients, such as the HLA-DRB1*07 (OR 0.39 [95% CI 0.21-0.73]) and HLA-A*02 (OR 0.56 [95% CI 0.34-0.94]), showing a protective role against the disease. The HLA-B*44 (OR 0.58 [95% CI 0.31-1.09]) and HLA-DRB1*04 (OR 0.75 [95% CI 0.42-1.34]) alleles tended to be less frequent in MS patients. Altogether, the significant results observed in this population are in line with those from other countries and confirm that propensity to MS can be due to a complex presence of various HLA class I and class II alleles.