Tacrolimus trough levels higher than 6 ng/mL might not be required after a year in stable kidney transplant recipients.

Jung, Hee-Yeon; Seo, Min Young; Jeon, Yena; Huh, Kyu Ha; Park, Jae Berm; Jung, Cheol Woong; Lee, Sik; Han, Seung-Yeup; Ro, Han; Yang, Jaeseok; Ahn, Curie; Choi, Ji-Young; Cho, Jang-Hee; Park, Sun-Hee; Kim, Yong-Lim; Kim, Chan-Duck

Background: Little is known regarding optimal tacrolimus (TAC) trough levels after 1 year post-transplant in stable kidney transplant recipients (KTRs) who have not experienced renal or cardiovascular outcomes. This study aimed to investigate the effect of 1-year post-transplant TAC trough levels on long-term renal and cardiovascular outcomes and opportunistic infections in stable KTRs. Methods: KTRs receiving TAC with mycophenolate-based immunosuppression who did not experience renal or cardiovascular outcomes within 1 year post-transplant were enrolled from a multicenter observational cohort study. Renal outcome was defined as a composite of biopsy-proven acute rejection, interstitial fibrosis and tubular atrophy, and death-censored graft loss. Cardiovascular outcome was defined as a composite of de novo cardiomegaly, left ventricular hypertrophy, and cardiovascular events. Opportunistic infections were defined as the occurrence of BK virus or cytomegalovirus infections. Results: A total of 603 eligible KTRs were divided into the low-level TAC (LL-TAC) and high-level TAC (HL-TAC) groups based on a median TAC level of 5.9 ng/mL (range 1.3–14.3) at 1 year post-transplant. The HL-TAC group had significantly higher TAC trough levels at 2, 3, 4, and 5 years compared with the levels of the LL-TAC group. During the mean follow-up of 63.7 ± 13.0 months, there were 121 renal outcomes and 224 cardiovascular outcomes. In multivariate Cox regression analysis, LL-TAC and HL-TAC were not independent risk factors for renal and cardiovascular outcomes, respectively. No significant differences in the development of opportunistic infections and de novo donor-specific anti-human leukocyte antigen antibodies and renal allograft function were observed between the two groups. Conclusions: TAC trough levels after 1 year post-transplant remained at a similar level until the fifth year after kidney transplantation and were not directly associated with long-term outcomes in stable Korean KTRs who did not experience renal or cardiovascular outcomes. Therefore, in Asian KTRs with a stable clinical course, TAC trough levels higher than approximately 6 ng/mL might not be required after a year of kidney transplantation.

KIDNEY transplantation; CARDIOVASCULAR diseases risk factors; OPPORTUNISTIC infections; TACROLIMUS; LEFT ventricular hypertrophy

PLoS ONE, 2020, Vol 15, Issue 7, p1

1932-6203

Academic Journal

10.1371/journal.pone.0235418