Korean J Transplant.  2021 Oct;35(Supple 1):S17. 10.4285/ATW2021.OP-1045.

Low early post-transplant tacrolimus level within 1 month is associated with poor renal allograft survival in kidney transplant patients

• Ryu J
• Jeon HJ
• Koo TY
• Yang J

• KMID: 2521189
• DOI: http://doi.org/10.4285/ATW2021.OP-1045

Abstract

Background
Low-dose tacrolimus therapy with trough level between 3 to 7 ng/mL has been suggested as safe and better for allograft survival in previous studies. Here, we investigated the association of sequential tacrolimus trough-level from at discharge until 1 year after kidney transplantation and graft survival rate.
Methods
This retrospective observation study included patients older than 18 years who underwent kidney transplantation under tacrolimus-based regimens in the Seoul University Hospital between April 30, 1997, and April 30, 2020. Kaplan-Meier survival analysis and multivariate Cox regression analysis were performed according to tacrolimus trough-levels from within 1 month to 1 year after kidney transplantation.
Results
A total of 1,759 kidney transplant patients were included and 72 grafts failed during the study period. Tacrolimus level <7 ng/mL within 1 month after transplantation was associated with worse death-censored graft survival (P=0.000). However, mean tacrolimus level <5–7 ng/mL within 1 year was not associated with all-cause mortality or graft survival. In multivariate analysis, tacrolimus <7 ng/mL was an independent risk factor for poor graft survival (hazard ratio, 0.225; 95% confidence interval, 0.115–0.521; P=0.001). Furthermore, tacrolimus level <7 ng/mL within 1 month was associated with worse overall patient survival (P=0.017). In respect to post-transplant complications including malignancy, infection, post-transplant diabetes mellitus (PTDM), cardiovascular disease and fracture, PTDM-free survival rate was higher in tacrolimus >12 ng/mL within 2 months after transplantation was significantly lower (P=0.001). Infection rate was increased over 10 ng/mL of tacrolimus within 2 months (P=0.034).
Conclusions
Keeping sufficient tacrolimus level (≥7 ng/mL) within 1 month after transplantation is beneficial for good long-term allograft survival.