A cause of hyperamylasemia associated with chronic liver disease.

The cause of hyperamylasemia associated with chronic liver disease is unclear. In an attempt to identify the tissue of origin of hyperamylasemia in 3 patients with chornic active hepatitis their serum was isoelectrically focused. The isoamylase patterns obtained were compared to those of pancreatic and salivary amylase. The apparent salivary gland origin of the excessive blood amylase in the patients studied was substantiated by radiological demonstration of parotid sialoectasia in one patient and histological evidence of sialoadenitis in another. Further evidence was the coincident isoelectric points of the predominant isoamylase in the sera of the liver disease patients and of patients with parotid inflammatory disease. Hyperamylasemia associated with chronic liver disease may be of salivary gland origin and as such forms part of the spectrum of extrahepatic manifestations of chronic active hepatitis.