ETIOLOGY AND INCIDENCE OF UNCONJUGATED HYPERBILIRUBINEMIA AFTER ORTHOTOPIC LIVER-TRANSPLANTATION

Objectives: Gilbert's syndrome, or slow bilirubin glucuronidation phenotype, is a common cause of benign hyperbilirubinemia in the general population There have been only two previously reported cases of Gilbert's syndrome occurring in patients after liver transplantation. This study was conducted to determine the frequency of Gilbert's syndrome in liver transplant recipients. Methods: The charts of all patients followed by the Mayo Liver Transplant Clinic for 1 yr or more after transplantation, as of June 1992, were reviewed to identify all patients with a consistent pattern of unconjugated hyperbilirubinemia greater than two times the upper limits of normal and with a normal conjugated bilirubin level. These patients were further evaluated to exclude all other causes of hyperbilirubinemia, including biliary obstruction, rejection, viral infection, cholestatic liver disease, and hemolysis. Results: Five of 229 patients (2.2%) had a consistent pattern of unconjugated hyperbilirubinemia. Only three patients (1.3%) had no other identifiable cause of hyperbilirubinemia. Conclusions: This study was performed to determine the incidence of unconjugated hyperbilirubinemia and particularly to determine the incidence of Gilbert's disease in liver transplant recipients. The apparently low frequency of Gilbert's after liver transplantation may reflect the masking of the diagnosis by other transplant-associated pathology or donor selection bias because of unexplained hyperbilirubinemia. Post-transplant patients who fit the Gilbert's syndrome profile of unconjugated hyperbilirubinemia should have a postprandial bilirubin drawn as a First step. The awareness of this syndrome may avoid a costly and invasive evaluation in the fiver transplant recipient.