Laboratory detection of macro-aspartate aminotransferase: Case report and evaluation of the PEG-precipitation method

Abstract Background Chronic elevated AST without other signs of liver disease, cardiac or skeletal abnormalities, is suggestive for macro-AST. Laboratory detection can be performed by gel filtration chromatography, ultrafiltration or precipitation with polyethylene glycol (PEG). Patient and methods A healthy 27 year-old female was referred because of chronic elevated AST (116–704 U/L) without other abnormalities. Macro-AST positivity was suspected since AST was no longer measurable in the supernatant of a serum sample ( Conclusion Early recognition of macro-AST, proven by simple PEG precipitation, can avoid time-consuming and invasive investigations.