Diagnostic considerations for cholestatic liver disease.

Cholestatic liver disease results from insufficient bile synthesis, secretion and/or flow through the biliary tract. Common presenting features include fatigue, pruritus, and cholestatic liver enzyme abnormalities wherein elevations of serum alkaline phosphatase and gamma-glutamyltransferases levels exceed those of alanine and aspartate aminotransferases. With prolonged cholestasis, fat soluble vitamin deficiencies, fibrosis, cirrhosis, and, on occasion, carcinoma of the biliary tract or liver can occur. Once mechanical obstruction to bile flow has been ruled out, the majority of causes can be classified as immune-mediated, infectious, or miscellaneous. Because specific therapeutic options are increasing for many causes of cholestasis, an accurate diagnosis is an important first step towards treatment. Thus, this review focuses on the diagnostic features of non-mechanical causes of cholestasis.