The Efficacy of Tacrolimus Versus Microemulsified Cyclosporin in Prevention of Early Acute Cellular Rejection Following Liver Transplantation: a Histopathological Assessment; on Behalf of the UK and Republic of Ireland Liver Transplant Study Group

Background: A large multicentre liver transplantation trial comparing the efficacy of tacrolimus (T) with microemulsified cyclosporin (MC) and the same concomitant immunosuppressive therapy has been performed. Methods: To date 272 first protocol liver biopsies have been reviewed blindly by two independent pathologists with a prior training period, at a single centre. Strict criteria for adequacy of biopsies were applied. Acute cellular rejection was scored according to the Banff criteria. Additional features including steatosis, cholestasis and lobular inflammation were assessed. Biopsies in which the pathologists differed were re-assessed jointly and a consensus reached. Results: Overall none/borderline rejection showed a significant difference between the groups (T 16% v MC 10%, p = 0.04); no significant difference was found in the other grades mild rejection (T 21% v MC 20%), moderate/severe rejection (T 15% v MC 19%). The average Banff Grade for both treatment arms showed no significant difference (T = 4.1 v MC -4.8). Scores for additional histological features were comparable. Cundusious: Monotherapy with tacrolimus or microemulsified cyclosporin in the early transplant period shows no difference in the histopathological grading of acute cellular rejection. The trend towards less rejection in the Tacrolimus group is to be confirmed with the full database.