Clinical value of routine isoamylase analysis of hyperamylasemia

To study incidence and cause of hyperamylasemia in various diseases, serum amylase was determined in 1371 consecutive patients and subsequent isoamylase analysis was carried out in 91 hyperamylasemic sera. Hyperamylasemia was observed in various diseases: acute pancreatitis (5/5), chronic pancreatitis (0/3), mumps (3/3), cerebrovascular diseases (2/39), respiratory diseases (6/69), heart diseases (5/89), liver diseases (16/101), cholelithiasis (0/13), diabetes mellitus (2/66), peptic ulcer (0/46), other digestive diseases (0/33), malignant tumor (9/249), renal failure (21/25), intraabdominal surgery (9/35), extraabdominal surgery (2/20), trauma (1/23), and miscellaneous (10/552). Salivary type hyperamylasemia due to dominant increase of salivary type isoamylase occurred in over half of the hyperamylasemic patients. Knowledge of hyperamylasemia in various diseases and routine isoamylase analysis of hyperamylasemic sera would enhance diagnostic accuracy and exclude unnecessary treatment of pancreatitis solely because of the presence of hyperamylasemia.