Multiple sclerosis in the Orkney and Shetland Islands. III: Histocompatibility determinants.

Histocompatibility testing was performed in 48 multiple sclerosis patients and two carefully matched control groups in Orkney Islands, an area of high multiple sclerosis prevalence. The frequency of HLA-A3, HLA-B7, and DW2 was comparable in patients and controls. However, HLA-B7 was significantly more common in female patients compared with male patients. A B-cell alloantigen (B-cell 4) was also as frequent in patients as among controls. Strong linkage between HLA-B7, DW2 and B-cell 4 occurred in controls, but not patients; the linkage was particularly striking in female controls. These data are not consistent with theories that relate certain of the histocompatibility antigens to the aetiology of multiple sclerosis.