Objective  To investigate the efficacy and safety of programmed cell death protein-1 (PD-1) monoclonal antibody on the treatment of malignant tumor after solid organ transplantation (SOT).

  Methods  The relevant literatures in 7 databases were searched. The data on 54 cases of recipients with malignant tumors treated with PD-1 monoclonal antibody after SOT were collected, and the clinical effects and rejection of SOT recipients treated with PD-1 monoclonal antibody were analyzed.

  Results  Total 32 acceptable articles including 54 SOT recipients were incorporated, including 43 males and 11 females aged 14-79 years old. There are 29 renal transplant recipients, 19 liver transplant recipients and 6 heart transplant recipients. The types of PD-1 monoclonal antibody agent used by SOT recipients included pembrolizumab for 28 patients and nivolumab for 26 patients. The overall remission rate, disease progression rate and fatality rate of PD-1 monoclonal antibody for postoperative malignant tumors of SOT recipients were 32% (17/54), 44% (24/54) and 36% (19/54), respectively. After treatment with PD-1 monoclonal antibody for postoperative malignant tumors of SOT recipients, the incidence of rejection was 39% (21/54), indicating no significant correlation between rejection and type of PD-1 monoclonal antibody (P > 0.05).

  Conclusions  PD-1 monoclonal antibody can effectively treat postoperative malignant tumors of SOT recipients, and may induce rejection during the treatment. But rejection is not the most common cause for death of recipients.