Environmental factors and primary biliary cirrhosis

Abstract

The complex interplay between immune factors and genetic susceptibility plays an essential role in autoimmune diseases. This is especially true for primary biliary cirrhosis (PBC). PBC is an autoimmune cholestatic liver disease characterized by the destruction of the small intrahepatic bile ducts and the presence of high-titer antimitochondrial antibodies (AMA). Among the currently known risk factors, genetic predisposition remains to be the dominant one. However, it is insufficient to explain the different geographic distributions of PBC and the incomplete concordance in identical twins. This suggests an association between specific environmental factors and the development of PBC. Nevertheless, a clear and rational association of environmental factors with primary biliary cirrhosis has not yet been fully elucidated. Our current understanding of the environmental triggers of PBC is limited to numerous suspected factors involved in its development, such as xenobiotics, electrophilic drugs, infection, and other physical, chemical, and even biological factors. Although the factors leading to the breakdown of immune tolerance in PBC are still largely unknown, related geoepidemiological studies may help us better understand the impact of the environment. In addition, a better understanding of the interplay between environmental factors and PBC is the critical step toward improving our management and control of PBC and autoimmunity in general.