Lymphocyte subpopulations in Crohn's disease and chronic ulcerative colitis.

Lymphocyte subpopulations in peripheral blood were studied by the sheep red blood cell rosette technique for the identification of T-lymphocytes, and immunofluorescence staining with rabbit anti-human immunoglobulin sera for the identification of B-lymphocytes. In Crohn's disease, the total number of lymphocytes was found to be reduced and an almost equal reduction in all the lymphocyte subpopulations studied was found. In ulcerative colitis neither the number of T-lymphocytes nor of B-lymphocytes were found to differ significantly from normal values and the same was true of all B-lymphocyte subpopulations. However, the number of lymphocytes carrying neither surface immunoglobulin nor sheep red blood cell receptors was found to be significantly increased. The results were correlated to clinical data.