Impairment of human lymphocyte function by bile salts

Since there appears to be an association between depressed lymphocyte function and liver disease, the effect of bile salts on lymphocyte function was determined in vitro. Peripheral lymphocytes from normal volunteers were incubated with varying concentrations of three bile salts (chenodeoxycholate, deoxycholate, or ursodeoxycholate) and stimulated by the mitogens phytohemagglutinin or concanavalin. The three bile salt concentrations used in these experiments were 75, 100, and 250, mumol/L, which are similar to serum levels found in various types of liver disease. Blast transformation, as measured by tritiated thymidine incorporation, was significantly depressed by all three bile salts at all concentrations and with both mitogens. Suppression increased with the higher bile salt concentrations. However, ursodeoxycholate suppressed lymphocyte function significantly less than did either chenodeoxycholate or deoxycholate. These data suggest that elevated serum bile levels associated with liver disease may contribute to immunosuppression and that ursodeoxycholate, an epimer of chenodeoxycholate that is used for gallstone dissolution, depresses lymphocyte function significantly less than does chenodeoxycholate.