Abstract

BACKGROUND: We investigated whether a low fixed Tac starting dose regimen could lead to a better achievement of Tac target concentrations, as well as an effective immunosuppressive treatment, in Chinese kidney transplant recipients (KTRs).

MATERIAL AND METHODS: We collected whole-blood and serum samples from 189 KTRs and the Tac starting dose was 2, 2.5, or 3 mg/day. Information on Tac C0, dose, body weight, body mass index (BMI), Scr, eGFR, and CYP3A5 genotypes were collected from a routine therapeutic drug monitoring database. The correlation between Tac C0 and body weight (or BMI) was investigated by calculating the goodness of fit. Multivariable logistic regression was performed to estimate the independent associated factors.

RESULTS: The patients with 3 mg per day of Tac had higher C0 at day 7 compared to those with 2 or 2.5 mg. For patients receiving the same Tac starting dose, no significant difference was found in Tac C0 at day 7 among different body weight or BMI groups. There was no significant difference in Scr or eGFR at 1 year after transplant, nor was there a significant difference in the rates of DGF or AR at post-transplant day 30 among different Tac starting dose groups or among the 3 Tac C0 range groups. CYP3A5 genotype and Tac initial dose were independently associated with Tac C0.

CONCLUSIONS: CYP3A5 genotype and Tac initial dose were independently associated with Tac C0 in renal transplant recipients. Our results suggest that a low Tac target C0 range (5–8 ng/ml) with a low fixed starting dose (3 mg/day) would be safe and effective among Chinese KTRs.

Keywords: Body Mass Index, Body Weight, Kidney Transplantation, Tacrolimus