Korean J Hepatol.
1999 Mar;5(1):50-54.
An Isolated AST Elevation due to Macroenzyme Formation
Abstract
- Serum aspartate aminotransferase (AST) is a common enzyme for the evaluation
of the hepatic, muscular and cardiac diseases and is produced also at kidney, brain,
pancreas, lung, leukocytes, erythrocytes, etc. The elevation of its activity is usually
caused by the necrosis of hepatocytes when there are not muscular injuries or myopathies.
Recently, it is found that AST can exist as a macroenzyme by forming a complex with
an immunoglobulin and this complex is erroneously considered to indicate the presence
of liver disease as a result of elevation of AST activity on routine blood chemistry analysis.
We experienced the patient with isolated AST elevation due to the formation of
AST-mmunoglobulin complex confirmed by AST isoenzyme electrophoresis (EP).