Objective  To compare the clinical efficacy and safety differences between the triple immunosuppressive regimen of mizoribine (MZR) or mycophenolate mofetil (MMF) combined with tacrolimus (Tac) and glucocorticoids of kidney transplant recipients in one year after transplantation.

Methods  A single-center retrospective cohort study design was adopted. The clinical data of 156 patients who underwent the first allogeneic kidney transplantation at the Third Hospital of Peking University from January 2022 to December 2024 were included. The patients were divided into the MZR group (78 cases) and the MMF group (78 cases) based on the initial immunosuppressive regimen after transplantation. The baseline data, medication use in one year after transplantation, blood routine indicators, adverse events and clinical outcomes were compared between the two groups. For the repeated-measurement longitudinal data, repeated-measurement analysis of variance was used to evaluate the main effects of the groups, time and their interaction effects.

Results  At the primary efficacy endpoint, there were no statistically significant differences in the one-year survival rate, graft survival rate and incidence of acute rejection between the two groups (all P > 0.05). In terms of medication patterns and laboratory test indicators, there were significant time main effects and "time × group" interaction effects for Tac dosage (all P < 0.05). The Tac dosage in the MZR group was lower than that in the MMF group from 2 to 3 months after transplantation, and it was higher in the MZR group than in the MMF group from 7 to 12 months and one year after transplantation. White blood cell count in the MZR group was higher at one month after transplantation, and the platelet count was higher one year after transplantation (all P < 0.05). In terms of infection, the incidence of novel coronavirus and Pneumocystis jirovecii pneumonia infections in the MZR group was lower (all P < 0.05). In terms of metabolic indicators, the post-transplantation uric acid level was better in the MZR group than in the MMF group, but the total cholesterol level was higher one year after transplantation (all P < 0.05). In terms of liver function, there was a brief and mild increase in transaminase in the early stage after transplantation in the MZR group.

Conclusions  During the one-year follow-up after transplantation, both the MZR and MMF regimens demonstrate comparable immunosuppressive efficacy and overall safety in Chinese kidney transplant recipients. The MZR regimen shows clear advantages in reducing specific infection risks, alleviating bone marrow suppression and improving uric acid metabolism, but its potential impact on blood lipids needs to be monitored. Therefore, the MZR regimen may be an effective and safe alternative immunosuppressive option for kidney transplant recipients, especially those with high infection risk, poor hematological tolerance, or comorbid hyperuricemia.