Estimation of hepatic bilirubin UDP-glucuronyl transferase in patients with noncirrhotic portal fibrosis and liver disease: Significance and limitations.

Using a micromethod, hepatic bilirubin UDP-glucuronyl transferase has been assayed in percutaneous needle biopsy samples obtained from patients with infectious hepatitis, postnecrotic cirrhosis, Gilbert's disease, noncirrhotic portal fibrosis (NCPF), granuloma of the liver, and extrahepatic portal vein obstruction. The results were compared with those obtained from 10 control subjects. Patients with cirrhosis and infectious hepatitis revealed normal bilirubin transferase levels, whereas those with Gilbert's disease showed significantly low enzyme levels. Many patients with NCPF, some with extrahepatic portal vein obstruction, and patients with granulomatous involvement of the liver demonstrated significantly low levels. This low hepatitic-enzyme activity was not associated with hyperbilirubinemia. The mechanism of such low values in NCPF and other disorders is not known. It is postulated that low heaptic-enzyme activity in noncirrhotic portal fibrosis is due to sparse smooth endoplasmic reticulum. This study also emphasizes that serum bilirubin may remain normal with very low hepatic-enzyme activity. Although induction of the microsomal enzyme bilirubin transferase was observed following phenobarbitone administration in noncirrhotic portal fibrosis, this was not apparent in patients with cirrhosis, possibly due to maximal enzyme induction having been achieved by endogenous substrate.