title: HLA-DR expression and disease activity in ulcerative colitis.
abstract: In 12 patients with active ulcerative colitis (UC) the rectal epithelial cells were analyzed for HLA-DR antigens by an immunohistochemical technique. The clinical, rectoscopic, and histologic stages were also determined. The investigations were carried out at the beginning of the study and 2 weeks and 3 months later. The rectal epithelial cells were HLA-DR-positive in all patients at the first two examinations. After 3 months five patients had changed to an HLA-DR-negative stage, whereas the other seven patients remained HLA-DR-positive. Closer analyses showed that expression/nonexpression of HLA-DR antigens on rectal epithelial cells of patients with UC could not be predicted from the clinical, rectoscopic, or histologic findings. HLA-DR expression is normally restricted to immunocompetent cells. The presence of HLA-DR antigens on epithelial cells may be a consequence of immunological reactions. Whether HLA-DR-positive cells have a specific function is unknown.
mesh_terms: D000328:Adult; D000368:Aged; D003093:Colitis, Ulcerative / Q000276:immunology* / Q000473:pathology; D004848:Epithelium / Q000276:immunology; D005260:Female; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D007120:Immunochemistry; D008297:Male; D008875:Middle Aged; D013194:Staining and Labeling
chemical_list: D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II