Safety of Tacrolimus Monotherapy within 12 Months after Liver Transplantation in the Era of Reduced Tacrolimus and Mycophenolate Mofetil: National Registry Study

Tacrolimus monotherapy is accepted as a feasible option during early post-liver transplantation as per current international consensus guidelines. However, its effects in the recent era of reduced tacrolimus (TAC) and mycophenolate mofetil (MMF) remain unclear. Liver recipients who either received TAC monotherapy from the treatment onset or switched from TAC/MMF to TAC-mono within 12 months (TAC-mono group; n = 991) were chronologically matched to patients who continued to receive TAC/MMF (TAC/MMF group; n = 991) at the corresponding time points on time-conditional propensity scores. Outcomes within 12 months after matched time points were compared. Biopsy-proven rejection (TAC/MMF: 3.5% vs. TAC-mono: 2.6%; p = 0.381) and graft failure (0.2% vs. 0.7%; p = 0.082) were similar in both groups. However, the decline in eGFR was 3.1 mL/min/1.73 m(2) (95% CI: 0.8-5.3) greater at six months (p = 0.008) and 2.4 mL/min/1.73 m(2) (95% CI: -0.05-4.9) greater at 12 months (p = 0.048) after the matched time points in TAC-mono group than that in TAC/MMF group. TAC trough levels were also higher in the TAC-mono group throughout the study period. TAC-mono within 12 months after liver transplantation is immunologically safe. However, it can increase the required TAC dose and the decline in renal function than that in TAC/MMF combination therapy.