Azathioprine hepatitis in kidney transplant recipients. A predisposing role of chronic viral hepatitis.

Influence of viral liver diseases on the occurrence of azathioprine hepatitis was evaluated in 21 kidney transplant recipients. Diagnosis of azathioprine hepatitis was always based on jaundice, which disappeared after azathioprine withdrawal in 18 patients and after azathioprine dose reduction in 3 patients. Histopathological diagnosis of azathioprine toxicity was ascertained in 14 patients. Rechallenge with azathioprine performed in 4 patients, within 2-4 months after the first jaundice episode, resulted in relapse of jaundice in all cases. Viral hepatitis B virus and hepatitis C markers were present in all 20 tested patients (serum hepatitis B surface antigen in 6 patients and anti-HCV antibodies in 17 patients). Biopsy-proven chronic hepatitis was observed in 18 patients, including 14 chronic active hepatitis, 3 chronic persistent hepatitis and cirrhosis in 1. In kidney transplant recipients, azathioprine hepatitis seems to be facilitated or induced by hepatitis B virus or hepatitis C virus chronic hepatitis. Azathioprine reduction or withdrawal should therefore be combined with the diagnostic evaluation and the treatment of viral liver diseases.