Concept on the pathogenesis and treatment of primary biliary cirrhosis

Abstract

Primary biliary cirrhosis (PBC) is an organ-specific autoimmune disease that predominantly affects women and is characterized by chronic, progressive destruction of small intrahepatic bile ducts with portal inflammation and ultimately fibrosis, leading to liver failure in the absence of treatment. Little is known about the etiology of PBC. PBC is characterized by anti-mitochondrial antibodies and destruction of intra-hepatic bile ducts. The serologic hallmark of PBC is the presence of auto-antibodies to mitochondria, especially to the E2 component of the pyruvate dehydrogenase complex (PDC). Current theories on the pathogenesis of PBC favor the hypothesis that the disease develops as a result of an inappropriate immune response following stimulation by an environmental or infectious agent. Some reports suggest that xenobiotics and viral infections may induce PBC. The pathogenetic mechanism is believed to be caused by a defect in immunologic tolerance, resulting in the activation and expansion of self-antigen specific T and B lymphocyte clones and the production of circulating autoantibodies in addition to a myriad of cytokines and other inflammatory mediators. This leads to ductulopenia and persistent cholestasis, by developing end-stage hepatic-cell failure. In this review are given our own and literary data about mechanisms of development of intrahepatic cholestasis and possible ways of its correction.

Figure 1

Hepatocytic ultrastructure. Digitonin-treated biopsy specimen. The specimen is contrasted with aqueous uranyl acetate and lead citrate. Deposits of cholesterol-digitonin complexes (the view of “tender spoondrift clouds”) are seen in the cytoplasm close to the mitochondria. The mitochondrial membrane forms pseudopodia here and there (indicated by arrow).

Figure 2

Hepatocytic ultrastructure in PBC. Biopsy specimen. The specimen is contras-ted with aqueous uranyl acetate and lead citrate. Arrows indicate myelin-like and multilamellar structures with increased osmiophi-lia.

Figure 3

The scheme of liver biopsy specimen homogenization for quantitative adhesiometric study.

Figure 4

The scheme of mechanisms responsible for triggering and developing the major signs of PBC.

Figure 5

Ursodeoxycholic acid.

Figure 6

S-adenosyl-L-methionine.