A prospective, blind investigation of immunological reactions in chronic inflammatory bowel disease. Suppressor activity and immune capacity.

. In a paired, blind and prospective study including 36 patients with chronic inflammatory bowel disease, i.e. ulcerative colitis (UC) and Crohn's disease (CD), and 36 healthy volunteers, the immune capacity has been examined by three different test systems using peripheral blood mononuclear cells: spontaneous mitotic activity (SMA), concanavalin A (con A) activated lymphoblast transformation test (LTT) and autologous mixed lymphocyte reaction (AMLR). The same patients and controls were examined simultaneously for their suppressor activity by a con A induced suppressor activity (CAISA) test. SMA was similar in UC patients and controls. The lymphoblast transformation (LT) in UC patients was significantly reduced with submaximal concentrations of con A (1 and 2 μg), whereas AMLR was only non-significantly decreased. However, the results registered by these two test systems revealed a significantly positive correlation. CAISA in UC patients was significantly enhanced, but this finding showed no correlation to the reduced LTT and AMLR, indicating a primary defect in the mitotic capacity independent of the observed increment in CAISA. SMA, con A activated LT, AMLR and CAISA were similar in CD patients and controls.