Higher tacrolimus trough levels on days 2–5 post-renal transplant are associated with reduced rates of acute rejection

Abstract:  We analyzed the association between whole-blood trough tacrolimus (TAC) levels in the first days post-kidney transplant and acute cellular rejection (ACR) rates. Four hundred and sixty-four consecutive, deceased-donor kidney transplant recipients were included. All were treated with a combination of TAC, mycophenolate mofetil and prednisolone. Patients were analyzed in four groups based on quartiles of the mean TAC on days 2 and 5 post-transplant: Group 1: median TAC 11 ng/mL (n = 122, range 2–13.5 ng/mL), Group 2: median 17 ng/mL (n = 123, range 14–20 ng/mL), Group 3: median 24 ng/mL (n = 108, range 20.5–27 ng/mL) and Group 4: median 33.5 ng/mL (n = 116, range 27.5–77.5 ng/mL). A graded reduction in the rates of ACR was observed for each incremental days 2–5 TAC. The one-yr ACR rate was 24.03% (95% CI 17.26–32.88), 22.20% (95% CI 15.78–30.70), 13.41% (95% CI 8.15–21.63) and 8.69% (95% CI 4.77–15.55) for Groups 1–4, respectively (p = 0.003). This study suggests that higher early TACs are associated with reduced rates of ACR at one yr.