Effects of rapamycin in liver transplantation

Rapamycin is a potent new immunosuppressant with a mechanism of action that is distinct from that of calcineurin inhibitors, but few clinical data on rapamycin in liver transplantation are available. Hence it is necessary to evaluate the efficacy and side-effects of rapamycin-based immunosuppression in liver transplant patients.

We retrospectively analysed 39 liver transplantation patients who took rapamycin as an immunosuppressant. This series consisted of 28 patients with hepatocellular carcinoma, 9 patients with chronic fulminant hepatitis, and 2 patients with end-stage liver cirrhosis. Eight patients used rapamycin for monotherapy, and 31 used rapamycin-based immunosuppression. In the 31 patients, 7 patients used rapamycin instead of mycophenolate mofetil to treat acute rejection.

In the 28 patients with hepatocellular carcinoma, the one-year survival rate was 67% without any tumor recurrence. The acute rejection in 7 patients was relieved in 1-2 weeks after the administration of rapamycin. All the 8 patients who received rapamycin monotherapy survived for at least 6 months and liver function tests and biopsy showed nothing abnormal. Jaundice in 8 patients with chronic rejection was reduced sharply after use of rapamycin.

Rapamycin given alone or in conjunction with calcineurin inhibitors appears to be an effective primary immunosuppressant regimen for orthotopic liver transplantation patients. Further studies are warranted to evaluate the efficacy and side-effect profile of rapamycin in liver transplant patients.