A study on 41 cases of macroamylasemia detected in a period of 15 months

Abstract

A search for macroamylasemia has been routinely carried out on the serum samples ordered to perform amylase isozyme analysis (“the ordered samples”) and the out-patients' specimens with hyperamylasemia (≥200S.U./dl). Of 41 macroamylasemia which were picked up over a period of 15 months, 38 cases were determined to be due to amylase-binding immunoglobulins and types of the immunoglobulins were identified. Incidence of amylase anomaly in the hyperamylasemic sera from out-patients was much higher than that in “the ordered samples”. No significant relations were found between the macro to total ratio of amylase activity and the level of total amylase activity. As for the heavy chain of the amylase-binding immunoglobulin, α-chain (IgA) occupied 74% (28 cases), and κ-type was dominant in its light chain. Amylase bound to IgG and IgA were frequently positioned in their electrophoretic mobilities at post-P and fast-S, respectively. As for the feature of the patients with macroamylasemia, males from 50 through 70 years of age were predominant, and malignancy, gout and diabetes mellitus were frequently found.