Histological patterns of rejection using oral microemulsified cyclosporineand tacrolimus (FK506) as monotherapy induction after orthotopic liver transplantation

Background/Aims: We describe the histological patterns of rejection in live r transplant recipients using induction therapies with cyclosporine and tac rolimus monotherapy compared with standard triple therapy as historical con trol. Methods: Patients formed part of the initial cohort in an open-labell ed, randomised pilot study and were selected consecutively if they had hist ological rejection and no other confounding diagnoses. There were 13 patien ts in the cyclosporine monotherapy group (CsA), II in the tacrolimus monoth erapy group and 13 in the triple therapy group (CAP). The histology of live r biopsies was reassessed blindly and the severity of rejection was recorde d. Results: The total Royal Free Hospital (RFH) rejection scores as well as other histological features (zone 3 haemorrhage, apoptosis in zones I and 3, steatosis, cholestasis, nuclear vacuolation, lymphoblasts and ballooning ) were comparable in the three groups. There was no difference in individua l components of the histological features comprising the diagnosis of rejec tion, except that the portal inflammation score was significantly lower in the tacrolimus group when compared with the CsA group (p=0.04). There was n o significant difference in the number of patients with moderate/severe rej ection between the three groups. Overall, there was no significant increase in histological severity of rejection in the monotherapy groups. Conclusio ns: The results suggest that the monotherapy may be as effective as the tri ple therapy in the initial post-transplant phase and that no particular gra ft histological changes were associated with the type of treatment.