Analysis of peripheral lymphocyte subsets and lymphocytophilic antibodies in ulcerative colitis defined by monoclonal antibody

T cell subsets of peripheral blood lymphocytes were assessed in 27 patients with ulcerative colitis by a fluorescence activated cell sorter, using monoclonal antibodies to the surface antigens of suppressor/cytotoxic (Anti-Leu-2a) and helper/inducer (Anti-Leu-3a) T cells. The population of suppressor T cells was decreased in the the lymphocyte from patients with active ulcerative colitis (8.2±3.6%,p<0.01), compared with those from normal controls (24.6±3.6%). Furthermore, the binding capacity of each lymphocytes from patients with ulcerative colitis to Anti-Leu-2a was decreased. The relationship between lymphocytophilic antibodies found in patients with ulcerative colitis and T cell subsets was examined by cell sorting on a fluorescence activated cell sorter. The lymphocytophilic antibodies were demonstrated to be mainly reactive with suppressor T cells, but also reactive with non-suppressor, non-helper T cell subsets and some populations of helper T cells. These results suggest that some other factors except lymphocytophilic antibodies may influence the decrease in suppressor T cells in patients with ulcerative colitis.