title: Macroamylase: prevalence, distribution of age, sex, amylase activity, and electrophoretic mobility.
abstract: The contribution made by macroamylase to the occurrence of hyperamylasemia of unknown origin has not been previously quantitated nor has the distribution of age and sex been identified in a large sample. Knowing the pattern of this enzyme complex when analyzed by an electrophoretic isoenzyme procedure would be of importance in recognizing its presence. During a three-year period we have studied a population of 2 900 patients with elevated serum amylase from whom specimens were sent to our laboratory with a request for amylase isoenzyme analysis. It was assumed that the primary reason for requesting these analyses was to clarify the presentation of hyperamylasemia. Macroamylase occurred in 9.6% of these patients. The total activity of the macroamylase specimens was typically 1 to 4 times normal but ranged to 20 times normal. Comparing these patients with a macroamylase-negative group, the distribution of age and sex was found to be no different. Macroamylase had a characteristically unusual electrophoretic pattern with bands faster than normal pancreatic amylase in 10% of cases, bands between pancreatic and salivary in 30% of cases, and the remaining 60% with atypical anodal bands.
mesh_terms: D000328:Adult; D000375:Aging; D000681:Amylases / Q000097:blood* / Q000302:isolation & purification / Q000502:physiology; D002850:Chromatography, Gel; D003430:Cross-Sectional Studies; D004586:Electrophoresis; D006801:Humans; D007527:Isoenzymes / Q000097:blood* / Q000502:physiology; D012737:Sex Factors
chemical_list: D007527:Isoenzymes; D000681:Amylases; C001663:macroamylase