A study on P-glycoprotein in primary biliary cirrhosis

Histological studies of primary biliary cirrhosis (PBC) have revealed the c haracteristic development of chronic non-suppurative destructive cholangiti s. Biochemical studies confirm the release of autoantibodies to the pyruvat e dehydrogenase complex. We have studied the pathology of PBC in terms of a n exocrine gland secretion disorder. We focused on P-glycoprotein (P-gp). w hich is encoded in the multidrug-resistance gene (mdr-1) related to the exo crine function of the liver, and to the pumping function of the cell membra ne. We performed an immunohistological study of hepatic tissues from four p atients with PBC (Scheuer classification, stages I-IV). Fixed hepatic tissu es were cut into sections, then reacted with JBS-1, a monoclonal antibody t o P-gp. P-gp showed less staining in the specimens of broken cholangiole at all four stages of Scheuer classification than that in normal hepatic tiss ue. Proliferated false bile ducts and bile capillary tissues extracted from the alcoholic and viral cirrhosis patients were highly positive for P-gp. Reduction or absence of P-gp was observed in the interlobular bile duct tis sue of livers affected by PBC. It is suggested that at least one of the pat hogeneses of PBC of PBC is closely related to exocrine function disorder as a membrane transport protein abnormality. Med Sci Res 27:731-734 (C) 1999 Lippincott Williams & Wilkins.