Association between HLA-D region epitopes and multiple sclerosis in Arabs.

We have studied the HLA associations of MS patients in Arab patients from two regions. Those patients from the Mediterranean area showed an association of MS with HLA-DR2 (p less than 0.001) and -DQw1 (p less than 0.05), whilst in those from the Gulf there was an association with -DRw53 (p less than 0.02). In the Mediterranean patients -DRw52 was negatively associated with MS (p less than 0.05). In the control populations from the two regions there was a considerable variation in the incidence of HLA antigens. Thus, Gulf Arabs had an increased incidence of -DR1 (p less than 0.05), -DR2 (p less than 0.02), -DR6 (p less than 0.05) and decreased incidence of -DR5 (p less than 0.05), -DRw52 (p less than 0.02) and -DQw3 (p less than 0.01) compared to the Mediterranean control population. These findings are discussed in relation to the aetiology of the disease.