[HLA-DR antigen expression on colonic epithelium of ulcerative colitis in comparison with infectious colitis and ischemic colitis].

We examined HLA-DR antigen expression on endoscopically biopsied colonic epithelium of ulcerative colitis (UC), infectious colitis and ischemic colitis. Since this monoclonal antibody (LN-3 ICN Immunobiological, USA) is available for usual formalin fixated materials, if the fixation is limited within 36 hours. 886 samples from 55 UC cases, 91 samples from 19 infectious colitis cases, 63 samples from 15 ischemic colitis cases and 63 samples from normal cases were enough statistically, compared to DR antigen expression. UC expressed clearly statistical high positive DR staining rate than infections colitis and ischemic colitis. Further, samples from UC and infectious colitis were compared in the histopathologically each with the same grade of inflammation, UC expressed higher positive rates of DR antigen than infectious colitis, and both UC and infectious colitis showed increased positive rates of DR antigen with advance of histopathological grades of inflammation.