Primary biliary cirrhosis

Abstract

Primary biliary cirrhosis (PBC) is an immune-mediated chronic cholestatic liver disease with a slowly progressive course. Without treatment, most patients eventually develop fibrosis and cirrhosis of the liver and may need liver transplantation in the late stage of disease. PBC primarily affects women (female preponderance 9-10:1) with a prevalence of up to 1 in 1,000 women over 40 years of age. Common symptoms of the disease are fatigue and pruritus, but most patients are asymptomatic at first presentation. The diagnosis is based on sustained elevation of serum markers of cholestasis, i.e., alkaline phosphatase and gamma-glutamyl transferase, and the presence of serum antimitochondrial antibodies directed against the E2 subunit of the pyruvate dehydrogenase complex. Histologically, PBC is characterized by florid bile duct lesions with damage to biliary epithelial cells, an often dense portal inflammatory infiltrate and progressive loss of small intrahepatic bile ducts. Although the insight into pathogenetic aspects of PBC has grown enormously during the recent decade and numerous genetic, environmental, and infectious factors have been disclosed which may contribute to the development of PBC, the precise pathogenesis remains enigmatic. Ursodeoxycholic acid (UDCA) is currently the only FDA-approved medical treatment for PBC. When administered at adequate doses of 13-15 mg/kg/day, up to two out of three patients with PBC may have a normal life expectancy without additional therapeutic measures. The mode of action of UDCA is still under discussion, but stimulation of impaired hepatocellular and cholangiocellular secretion, detoxification of bile, and antiapoptotic effects may represent key mechanisms. One out of three patients does not adequately respond to UDCA therapy and may need additional medical therapy and/or liver transplantation. This review summarizes current knowledge on the clinical, diagnostic, pathogenetic, and therapeutic aspects of PBC.

Fig. 1

Summary of standard therapy and promising future therapeutic options in PBC with respect to their action in the pathophysiologic chain of PBC. UDCA in a dose of 13–15 mg per kg body weight per day, administered in either one dose or divided into two administrations per day, is the only FDA-approved drug and the cornerstone in PBC therapy. Liver transplantation (LTx) is performed for liver failure in end-stage disease. The most advanced database for future therapeutic consideration is available for budesonide. Though speculative, current preliminary data suggest a future role for agonists to certain nuclear receptors: peroxisome proliferator activated receptor alpha (PPARα), farnesoid x receptor (FXR), vitamin D receptor (VDR), pregnane x receptor (PXR), and constitutive androstane receptor (CAR)