Impairment of human lymphocyte function by bile salts

Area of Science:

• Immunology
• Hepatology
• Biochemistry

Background:

• Liver disease is often associated with impaired lymphocyte function.
• Elevated serum bile salt concentrations are observed in various liver conditions.

Purpose of the Study:

• To investigate the in vitro effect of common bile salts on normal peripheral lymphocyte function.
• To compare the immunosuppressive potential of chenodeoxycholate, deoxycholate, and ursodeoxycholate.

Main Methods:

• Peripheral lymphocytes from healthy volunteers were incubated with varying concentrations (75, 100, 250 µmol/L) of three bile salts.
• Lymphocyte blast transformation was measured using tritiated thymidine incorporation after stimulation with phytohemagglutinin or concanavalin A.
• Bile salt concentrations mimicked those found in patients with liver disease.

Main Results:

• All three bile salts significantly suppressed lymphocyte blast transformation at all tested concentrations and with both mitogens.
• Lymphocyte suppression increased in a dose-dependent manner with higher bile salt concentrations.
• Ursodeoxycholate demonstrated significantly less suppression of lymphocyte function compared to chenodeoxycholate and deoxycholate.

Conclusions:

• Elevated serum bile salt levels in liver disease may contribute to the observed immunosuppression.
• Ursodeoxycholate, a therapeutic agent for gallstone dissolution, exhibits a less detrimental effect on lymphocyte function than chenodeoxycholate.
• These findings highlight the immunomodulatory role of bile salts and suggest potential differential effects among them.