Immune Checkpoint Inhibitors and Allograft Rejection Risk: Emerging Evidence Regarding Their Use in Kidney Transplant Recipients.

The indications for immune checkpoint inhibitor (ICI) use in cancer treatment continue to expand. This is attributable to their proven anticancer activity in addition to their tolerability and favorable toxicity profile as compared to conventional chemotherapeutic agents. ICIs work by blocking the inhibitory signals between tumor cells and T-cells, thereby enhancing the T-cell cytotoxic activity to inhibit tumor growth. Because of their immune-stimulating effect, ICIs are linked to adverse renal outcomes in both native and transplanted kidneys. The risk of kidney allograft rejection in the setting of ICI use has been reported to be around 40%, leading to an increased risk of graft loss. In this report, we review the literature examining outcomes in kidney transplant recipients receiving ICIs for various oncologic indications.