macroenzyme

macroenzyme

(1) Obsolete for aspartate aminotransferase (AST).
(2) A normal enzyme or isoenzyme complexed to an immunoglobulin resulting in persistent false elevation, which may trigger an aggressive and/or invasive workup to identify a nonexistent condition.
 
Examples
Macro-amylase, macro-AST, macro-CK, macro-LD; most common in those > age 60; identified by serum electrophoresis.