Role of prostaglandins on lymphocyte transformation in Crohn's disease.

We analyzed the response to phytohemagglutinin (PHA) of peripheral blood (PBL), intraepithelial (IEL) and lamina propia (LPL) lymphocytes in eight patients with Crohn's disease (CD). We also studied the effect of indomethacin, a prostaglandin synthetase inhibitor, and monocyte depletion on mitogen-induced stimulation of these cells. The blastic stimulation index was significantly lower in PBL and intestinal mucosa lymphocytes of CD than in controls (p less than 0.001). This index increased after addition of indomethacin in PBL and LPL and after monocyte depletion in PBL. The suppressor index on blastic stimulation, obtained when indomethacin had been added to the cultures was higher in PBL and intestinal mucosa lymphocytes of patients with CD than in controls. After monocyte depletion, this suppressor index decreased significantly in PBL and did not change in controls. These data suggest that prostaglandins could be one of the responsible factors for hyporesponsiveness of lymphocytes in CD.