Hyperamylasemia with an abnormal isoamylase distribution in patients with liver diseases

Isoenzymes of amylase were studied in sera from 95 patients with various liver diseases and 82 controls. Twenty-two patients and two controls had hyperamylasemia. Four different zymograms were obtained by isoelectric focusing--normal, pancreatic, salivary/pancreatic, and double pancreatic. The prevalence of these zymograms was similar in controls and in patients with normal values of serum amylase, normal being the prevalent zymogram. Patients with hyperamylasemia had as predominant the salivary/pancreatic zymogram, corresponding to isoenzymes of similar isoelectric point common to both salivary and pancreatic secretions. The inhibitory assay revealed a predominant increase of pancreatic type isoamylase and showed a poor correlation with isoelectric focusing. Our findings indicate that hyperamylasemia occurs frequently in liver diseases and in most cases is associated with an abnormal electrophoretic pattern.