Effect of different tacrolimus levels on early outcomes after kidney transplantation

Background: There is a paucity of modern data on the impact of high tacrolimus levels early after kidney transplantation. Material/Methods: This study analyzed the impact of various trough levels of tacrolimus in the first 2 weeks post-transplant on rates of delayed graft function (DGF), length of stay (LoS), hyperkalemia, hyperglycemia, and biopsy-proven acute rejection (BPAR) rates in the first 3 months post-transplant in a retrospective single-center cohort of patients. Patients were divided into 4 groups based on the average of two highest 12-hour trough tacrolimus levels: <10 ng/mL, 10-12 ng/mL, 12-15 ng/mL, >15 ng/mL. Results: The incidence of DGF was noted to be significantly higher in the <10 ng/mL, >15 ng/mL and the 12-15 ng/mL tacrolimus groups as compared to the 10-12 ng/mL group (49%, 25% and 4%, respectively, p£0.0001). Mean LoS was also noted to be significantly higher in the >15 ng/mL tacrolimus group as compared to the 10-12 ng/mL group (7.4 days and 6.1 days respectively, p=0.0007). There was no difference in the rates of hyperkalemia, hyperglycemia or BPAR. Conclusions: This is a modern confirmation of the association between higher tacrolimus levels early after kidney transplantation and increased rate of DGF and increased LoS.