[Analysis of subsets of colonic mucosal lymphocyte in ulcerative colitis by two color flow cytometry]

To assess how the immunological events occur in the colonic mucosa in patients with ulcerative colitis, it is thought to be important to evaluate the subpopulations and/or subsets of mucosal lymphocytes. In this point of view, we assayed those by lymphocyte isolation techniques and two color flow cytometry. Although our results showed no disease-specific abnormalities of the percentages of CD3, CD4, CD8, CD20, and HLA-DR (+) cells in PBL (peripheral blood lymphocyte) nor CML (colonic mucosal lymphocyte), these subsets of CML appeared to be altered according to the grade of severity of inflammation. In our cases, the HLA-DR (+) cell and CD4 population were larger in severely inflamed mucosa. Furthermore, fluorescence intensities of HLA-DR antigen of CD20 population in CML were greater than those in PBL. These results suggest that the B cell-mediated mechanisms may play an important role in maintaining the severe inflammation, and the clinical significance of these studies are discussed.