Changes in serum salivary isoamylases in Sjögren's Syndrome

Quantitative polyacrylamide disk gel electrophoresis of sera from 27 patients with Sjögren's syndrome (SS) and 12 comparable normal subjects revealed that serum amylase activity in patients with SS varies due to changes in the salivary isoenzyme, while pancreatic isoamylase remains normal. The SS group can be divided into those patients with markedly increased salivary isoamylase and those with normal or low salivary isoamylase. At this time we cannot be certain whether this reflects different stages in a progressive disorder, or differences in the underlying pathologic processes. Analysis of amylase isoenzymes in serum previously has been shown to be of value in pancreatic disorders, and we have now demonstrated that changes in the salivary glands may also be relected in serum amylase isoenzymes. Study of patients with other salivary and pancreatic disorders will be needed to define the clinical utility of amylase isoenzyme analysis.