Acute Allograft Rejection in Kidney Transplant Recipients Treated With Immune Checkpoint Inhibitors: An Educational Case Report.

Rationale: Kidney transplant (KT) recipients have an increased risk of malignancy due to chronic immunosuppression. The emerging use of immune checkpoint inhibitors (ICIs) has been a promising development for the treatment of malignancy, but their use adds to the complexity of immunosuppression management for KT recipients. This case report describes 2 cases of acute rejection in KT recipients following ICI initiation and discusses the balance of malignancy treatment with adequate immunosuppression. Presenting Concerns of Patients: The first patient is a 44-year-old male KT recipient with a diagnosis of metastatic renal cell carcinoma presenting with acute kidney injury 6 days following initiation of an ICI. The second patient is a 73-year-old male KT recipient with a diagnosis of squamous cell carcinoma presenting with acute kidney injury 2 weeks following initiation of an ICI. Diagnoses: Both patients were diagnosed with acute rejection in the setting of reduced immunosuppression and initiation of an ICI. Interventions: Both cases received an increased dose of steroid without improvement of graft function. The first patient subsequently underwent a delayed graft nephrectomy due to complications of acute rejection, whereas the second patient did not undergo nephrectomy. Outcomes: The first patient experienced complications including perioperative bleeding requiring multiple operations, but ultimately stabilized on hemodialysis and showed a durable response to ICI. The second patient remained dialysis-dependent post-ICI treatment and was readmitted with allograft complications leading to his eventual death. Teaching Points: This study underscores the complexity of managing KT recipients diagnosed with malignancy and receiving ICIs. The balance between immunosuppression reduction to treat malignancy and preventing allograft rejection presents a significant challenge. Key considerations include the risk of acute allograft rejection and patient-centered decision-making. These cases highlight the need for further research to develop evidence-based guidelines for managing this patient population. In addition, the patient perspective in this study highlights the importance of careful risk-benefit analysis and the impact of treatment decisions on patient-focused outcomes.