[Expression of HLA-DR antigens by colonic epithelium in ulcerative colitis]

Expression of HLA-DR antigens by colon epithelium was examined in 35 patients with ulcerative colitis (uc) among whom 21 were in relapse and 14 in remission. Control group consisted of 18 subjects with functional disorders of alimentary tract. Immunohistochemical technique using immunoperoxidase was applied. Colon epithelial cells from all control subjects were HLA-DR negative. Cells of 17 out of 21 patients with ulcerative colitis in relapse and in 4 of 14 patients in remission were HLA-DR positive. No significant correlation was observed between the number of patients with HLA-DR positive epithelium and the insensitive of inflammation estimated clinically, endoscopically and histologically. 6 patients with initially HLA-DR positive epithelium during relapse were studied for the second time and in 4 of them the negative reaction was observed after remission occurred. The aberrant expression of HLA-DR may play an important role in the initiation and/or perpetuation of inflammatory process in ulcerative colitis.