Impact of Trough Levels of Tacrolimus on Kidney Function and Graft Survival in Short and Longer Periods After Renal Transplantation.

Background: Optimizing immunosuppressive treatment in the early posttransplant period is important for achieving long-term graft function and survival.

Material And Methods: There were 205 renal transplant recipients involved in this study. Patients were divided into groups according to the induction therapy (no induction vs basiliximab/daclizumab vs rabbit antithymocyte globulin), maintenance therapy at the time of transplantation (tacrolimus [TAC] vs cyclosporine), the average trough TAC levels in months 4 to 6 after TO and serum creatinine 5 years after renal transplantation.

Results: The incidence of acute rejection was significantly higher in cyclosporine than in TAC group of patients (P = .0364). The average TAC levels on elapsed time after transplantation significantly decreased (P < .0001). Five years after renal transplantation, there were higher TAC levels (5.6 ± 0.7 ng/mL) in the group with "zero" low levels than in the group with "zero" high levels (4.6 ± 1.1 ng/mL), which was statistically significant (P < .0001). We did not find any difference in graft and patient survival in posttransplant years 2 to 5 according to TAC levels or the induction treatment.

Conclusions: In our study, we have confirmed that better graft function 5 years after transplantation was connected with higher trough tacrolimus levels on elapsed time after renal transplantation.