Aumento aislado y sostenido de aspartato aminotransferasa por presencia de macroenzimas: caso clínico / Persistent elevation of aspartate aminotransferase (AST) due to the presence of macro-AST: report of one case

We report an asymptomatic 23-year-old woman with an isolated and persistent increase in serum levels of aspartate aminotransferase (AST). An extensive work up including laboratory and image testing revealed no abnormalities thus suggesting the presence of macro-AST. A polyethylene glycol (PEG) precipitation assay was performed and confirmed the presence of macro-AST.