Abstract: TH-PO1115
Fatal Antibody-Mediated Rejection and Immune Checkpoint Inhibitor-Associated Acute Tubular Injury in a Kidney Transplant Recipient: A Cautionary Case
Session Information
- Pathology and Lab Medicine
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pathology and Lab Medicine
- 1700 Pathology and Lab Medicine
Authors
- Parulekar, Jaya S., Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
- Friedewald, John J., Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
- Ellis, Carla L., Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
Introduction
Immune checkpoint inhibitors (ICIs) have transformed the treatment of advanced malignancies, yet their use in kidney transplant recipients is not without risk. These patients face a unique "double jeopardy" of renal injury: ICI-mediated allograft rejection and ICI-associated nephrotoxicity manifesting most commonly as acute tubulointerstitial nephritis (AIN), however; findings at kidney biopsy may vary. Allograft rejection typically occurs early and is predominantly T-cell mediated; however rare cases of antibody mediated rejection (AMR) associated with ICI have been reported. We present the case of a patient who received ICI and had evidence of both ICI-associated acute tubular injury (ATI) and AMR.
Case Description
A 76 y/o female with a deceased donor kidney transplant developed metastatic melanoma 2 years post-transplant. She was started on a PD-1 inhibitor shortly after diagnosis and within 5 weeks, developed a dramatic rise in her serum creatinine (see Table 1 in Figure 1) and reduction in urine output. She also had a rise in donor derived cell free DNA (from 0.23 to 0.89) and Class II DSA (titer 1:8). She was initiated on hemodialysis within 24 hours. Kidney biopsy demonstrated severe acute tubular injury with prominent tubular epithelial cell swelling and diffuse C4d deposition in peritubular capillaries (see Figure 1). Unfortunately, the patient transitioned to comfort care and passed away 3 days later.
Discussion
Despite emerging strategies to mitigate the risks of ICI in transplant recipients, fatal outcomes remain a sobering reality. This case exemplifies the devastating convergence of AMR and ICI-associated ATI in a kidney transplant recipient, highlighting the diagnostic complexity and the variability of histopathologic findings associated with ICI therapy. It also underscores the critical importance of multidisciplinary risk assessment, vigilant renal surveillance (including kidney biopsy), and transparent, shared decision-making when considering ICI therapy in kidney transplant recipients.