The possibility that the HLA-Dw2, BfS disequilibrium has resulted from a selective advantage conferred on the general community but at the expense of increasing susceptibility to MS should be considered.
Normal or only slightly elevated frequencies of B7 and Dw2 were found in MS patients without oligoclonal CSF IgG (35 and 29%), normal CSF-IgG index (43 and 39%), and the most benign course (42 and 37%).
The conclusions were: 1) There were no significantly higher occurrences of HLA-A3, B7, Dw2 or DRw2 in Japanese MS. 2) Japanese MS might nevertheless be associated with the human major histocompatibility complex, because HLA-B40 was significantly less frequent in MS and two anti HLA-DRw sera, 7w008 and 034, reacted positively more often against lymphocytes from MS patients.
Results on serotyping for "B-cell DW2" antigen are suggestive of an increased frequency of this antigen in chronic progressive MS patients (RR = 2.9, P = 0.01).
Linkage of a hypothesized multiple sclerosis susceptibility gene with certain haplotypes of HLA-A3, HLA-B7 HLA-DW2, and the new B group 4 can be inferred.