β‐hexosaminidase in bile and plasma from patients with cholestasis

Abstract

beta-Hexosaminidase (Hex) activity was determined in bile from 18 patients with cholestasis, six patients without cholestasis and in ten normal liver biopsies. The difference in the mean activities in bile from patients with and without cholestasis was not significant. Only about 0.5 promille of total liver Hex activity was lost per day via the bile flow. Gel chromatography showed that enzyme forms present in bile had higher molecular weights than the forms present in liver tissue, indicating that the biliary enzyme was not routed through the lysosomes before release into the bile. In 32 patients with cholestasis, plasma Hex was increased compared to controls, and correlated to bilirubin. The activity was significantly higher in patients with severe cholestasis than in patients with less severe forms of cholestasis, but no significant difference in Hex activity was observed between patients with benign or malignant biliary obstruction. No significant difference was noted between patients with cholestasis for less than 1 week compared to those whose illness had lasted more than 1.5 weeks. The impact of biliary obstruction on plasma Hex is further illustrated by the observation that decompression lowered plasma Hex as well as bilirubin and alkaline phosphatase.