Macro-Aspartate Aminotransferase: A Benign Cause of Abnormal Laboratory Findings.

Isolated, persistent elevations of aspartate aminotransferase (AST) without plausible explanation may lead to diagnostic confusion. Macro-enzyme aspartate aminotransferase (macro-AST) is an uncommon and benign cause of persistently elevated AST levels in the absence of other diseases. We present a case of macro-AST in an otherwise healthy adult male which was confirmed by polyethylene glycol (PEG) precipitation.