HLA antigens and ulcerative colitis in Japan.

The HLA antigens in 44 cases of ulcerative colitis and 271 control individuals in Japan were studied. The NIH tissue typing method was used according to the new leukocyte nomenclature adapted by the WHO Committee. In normal Japanese populations, the HLA antigens, which were of high frequency, were HLA A2(37.3%), A9(60.9%) and B5 (40.6%). On the contrary, the significantly high frequency of HLA B5 was demonstrated in ulcerative colitis, compared with that in control. Moreover, HLA B5 in cases with ulcerative colitis excluding those with proctitis only, was found with higher frequency than that in total cases. Although the most frequent haplotype was HLA A9-B5 in control, so frequent haplotype was not found in ulcerative colitis. A family study revealed no significant diathesis on the hapolytpe of HLA in ulcerative colitis. The relationship between MLC locus and ulcerative colitis was not yet clarified from the study of one family whose two members suffered from ulcerative colitis.