Liver graft rejection following immune checkpoint inhibitors treatment: a review

Immune checkpoint inhibitors (ICIs) have demonstrated remarkable efficacy in a variety of solid tumors; nonetheless, they have not been well investigated and are still recognized as a relative contraindication for patients with a liver transplantation (LT) history, since ICIs treatment might potentially lead to graft rejection. The program death-1 (PD-1) and the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) pathways are implicated in the tolerance of transplanted organ, as well as blockade of the pathways, which contribute to eliminating tumors and may inadvertently lead to peripheral transplant rejection. Currently, no guidelines are available regarding the treatment for ICIs patients with a prior LT history. Therefore, this study was carried out to review the recent studies, attempting to introduce the ICIs-related graft rejection after LT from various aspects. We believed that ICIs could be given for the well-informed patients receiving LT and developed recurrence in a controlled setting. Typically, these patients should be treated according to a clinical care path or a prospective clinical trial, so as obtain a persistent anti-tumor immune response in the meantime of avoiding graft rejection, adjust the immunosuppression, reduce the possibility of graft loss following rejection, and have the opportunity to develop biomarkers for tumor response and transplant rejection.