HLA class II alleles and multiple sclerosis in Tunisian patients.

The aim of our study was to investigate the association of HLA-DRB1 and -DQB1 alleles with multiple sclerosis (MS) in a Tunisian population and their effect on age at onset and disease severity. 58 MS patients and 105 healthy controls were genotyped for HLA class II alleles by PCR-SSP technique. An association of MS with HLA-DRB1*15 was found (14.7% vs 3.8%, OR (95% CI)=4.34 (1.69-11.39), p(c)=2.5×10(-3)) after Bonferroni's correction. Moreover, the DRB1*15-DQB1*06 (13.8% vs 2.8%, OR (95% CI)=5.44 (1.92-17.41), p(c)=1.1×10(-3)) and DRB1*04-DQB1*04 (8.6% vs 1.9%, OR (95% CI)=4.86 (1.36-21.62), p(c)=0.028) haplotypes were found to confer a susceptibility to multiple sclerosis. To our knowledge, this is the first study performed to analyze the association of HLA-DRB1/DQB1 alleles on MS susceptibility in Tunisia. The modern Tunisian gene pool shows some degree of heterogeneity and reflects a significant gene flow from Mediterranean regions.