A 26-year-old male with renal allograft, who received immunosuppressive treatment with azathioprine, presented marked elevations of serum biliary tract enzymes, such as gamma-glutamyl transpeptidase (5,609 units/l) and alkaline phosphatase (60.5 Bessey-Lowry units), 14 months after transplantation. Two months later the patient became icteric; he died of respiratory failure 19 months after the renal allograft. Postmortem examination revealed intrahepatic cholestasis with minimal inflammatory cell infiltration, indicating drug hepatotoxicity.</p
