Macro-aspartate aminotransferase in a healthy woman

An increase in serum aspartate aminotransferase (AST) may be related to different conditions, including viral hepatitis, alcoholic liver disease, cirrhosis, cholestatic syndromes, acute myocardial infarction, or skeletal muscle trauma [1]. Chronic and isolated elevation of AST in patients with no related clinical signs or symptoms is suggestive for the presence of macro-aspartate aminotransferase (macroAST) [2]. MacroAST is a macroenzyme that circulates in the bloodstream as a high molecular weight complex, either by self-polymerisation or by association with serum proteins such as immunoglobulins (Ig) [1]. The formation of this complex, particularly with Ig, may lead to increased activity and/or reduced inactivation, clearance or excretion [1,3]. Below is a case report of a healthy woman with elevated AST levels due to the presence of macroAST.