Abstract: FR-PO1226
A Rare Case of Cetuximab-Associated Nephrotic-Range Proteinuria and Hypertension in a Kidney Transplant Recipient
Session Information
- Transplantation: Clinical - Rejection, Biomarkers, and Pharmacology
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2002 Transplantation: Clinical
Authors
- Montejo, Carlos, University of Vermont, Burlington, Vermont, United States
- Haq, Kanza, University of Vermont, Burlington, Vermont, United States
- Prikis, Marios, University of Vermont, Burlington, Vermont, United States
Introduction
Cetuximab is an epidermal growth factor receptor inhibitor (EGFR) used for locally advanced, recurrent, and/or metastatic squamous cell carcinoma of the head and neck. Renal toxicity associated with cetuximab is rare, with only few reported cases of glomerulonephritis in non-transplant population. To our knowledge, cetuximab-associated nephrotic-range proteinuria has not been described in kidney transplant recipients.
Case Description
An 81-year-old male with a past medical history of kidney transplant nineteen years prior presented for evaluation of new-onset nephrotic-range proteinuria following initiation of cetuximab for metastatic squamous cell carcinoma of the neck. Maintenance immunosuppressive regimen included tacrolimus and mycophenolate mofetil. Upon diagnosis of metastatic squamous cell carcinoma, mycophenolate mofetil was discontinued and sirolimus was added due to its potential antineoplastic benefit. Proteinuria increased within one month of cetuximab initiation and continued to worsen despite subsequent discontinuation of sirolimus, an also potential cause of proteinuria. Peak proteinuria reached urine albumin to creatinine ratio (UACR) 2650 mg/g and urine protein to creatinine ratio (UPCR) 5.22 g/g (baseline UACR 50-90 mg/g, UPCR 0.17 mg/g). Work up revealed negative donor-specific antibodies, cell free donor derived DNA 0.50%, negative serum protein electrophoresis, normal serum albumin. Urinalysis was without hematuria. The patient also developed worsening hypertension, with systolic blood pressures ranging from 160–185 mmHg, requiring escalation of lisinopril from 5 mg to 15 mg daily. Following cessation of cetuximab, proteinuria trended down steadily, and renal biopsy was deferred.
Discussion
Nephrotic-range proteinuria associated with cetuximab is rare and not well characterized, particularly in kidney transplant patients. Although sirolimus is known to contribute to proteinuria, continued worsening after its discontinuation and subsequent improvement following cessation of cetuximab supports cetuximab as the leading drug causing this worsening proteinuria. This case highlights the importance of close renal monitoring in patients receiving EGFR inhibitors, especially in the transplant population and raises awareness of cetuximab as a potential cause of significant proteinuria.