Class II (HLA-DR, HLA-DP, and HLA-DQ) antigens on colonic epithelia in ulcerative colitis: a comparison between uneventful and intractable cases.

Class II antigens on colonic epithelia involved in ulcerative colitis (UC) with uneventful or intractable courses were investigated using an immunoperoxidase method. Twenty normal colonic mucosa served as normal controls. Nineteen specimens from 14 uneventful cases and 23 specimens from 12 intractable cases were studied. Normal colonic epithelia did not express class II antigens. In UC, there were no differences between uneventful cases and intractable cases in the frequencies of class II antigen expression, the distribution of class II antigen expression ratio, or the mutual relationship of the extent of expression of the three class II antigens on colonic epithelia. However, while the extent of expression of HLA-DR and HLA-DP antigens on the epithelia was positively correlated with the degree of inflammation in uneventful cases, there was no such correlation in intractable cases. These observations may suggest that the induction mechanisms of class II antigens on colonic epithelia in UC differ in uneventful and intractable cases.