[Biliary duct obstruction presenting with laboratory levels indicating liver cell damage].

Some patients with extrahepatic biliary occlusion present high levels of serum aminotransferases indicating parenchymatous liver disease. The levels, usually in the range of 400-500 U/l, may sometimes exceed 1,000 U/l. Most of these patients have stones in the bile ducts, but the causes may occasionally be pancreatic tumours and pancreatitis. Typically the maximum enzyme levels are reached within 1-2 days, followed by a rapid fall--whether the gallstones have passed or not. The alkaline phophatase levels are initially normal or slightly elevated, usually increasing slowly to about twice the upper reference level. The pathogenesis of this rapid elevation of the aminotransferases has yet not been fully elucidated. However, the main mechanisms are probably increased permeability of the hepatocyte membrane caused by elevated pressure in the bile ducts, combined with a direct toxic effect of retinated bile acids. Increased enzyme synthesis may also be a contributory factor. Further knowledge of this not unusual enzyme pattern in acute (and sometimes also chronic) biliary obstruction will help to establish a correct diagnosis at an early stage of the disease, and thus avoid a need for invasive, potentially dangerous investigations.