Abstract: FR-PO0954
First Successful Treatment of Refractory Granulomatous Acute Interstitial Nephritis with Antithymocyte Globulin in a Pediatric Patient
Session Information
- Pediatric Nephrology: Genetic Diseases, Development, Neonatal Nephrology, Glomerular Diseases, and More
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pediatric Nephrology
- 1800 Pediatric Nephrology
Authors
- Cherkasov, Egor, Charleston Area Medical Center, Charleston, West Virginia, United States
- Young, Kayla, West Virginia University School of Medicine, Morgantown, West Virginia, United States
- Nehus, Edward, Charleston Area Medical Center, Charleston, West Virginia, United States
Introduction
Acute interstitial nephritis (AIN) is an important cause of acute kidney injury in children and is most commonly associated with drug hypersensitivity, autoimmune disease, or infection. Standard treatment includes withdrawal of offending agents and corticosteroids, with additional immunosuppression reserved for refractory disease. Rarely, AIN progresses despite multi-agent therapy.
Case Description
A 13-year-old male with Crohn’s disease, eosinophilic esophagitis, and eczema presented with progressive kidney dysfunction (creatinine 1.9 mg/dL). Kidney biopsy demonstrated severe granulomatous acute interstitial nephritis with marked tubulitis and diffuse interstitial inflammation.
Despite high-dose corticosteroids and withdrawal of potential offending agents, including infliximab and dupilumab, biopsies showed persistent active and chronic tubulointerstitial nephritis. Escalation of immunosuppression with mycophenolate mofetil and tacrolimus failed to produce histologic improvement, with creatinine remaining elevated at 1.7 mg/dL.
Given refractory disease, immunohistochemistry was performed on a repeat biopsy and demonstrated predominance of CD3+ T lymphocytes (~70%) over CD20+ B cells (~30%), supporting a T-cell–mediated process. The patient received five doses of anti-thymocyte globulin (ATG). One month later, repeat biopsy demonstrated resolution of interstitial inflammation and marked improvement in tubulitis. Follow-up biopsy confirmed histologic improvement, and creatinine improved to 1.2 mg/dL at 6-month follow-up.
Discussion
Granulomatous AIN may occur as an extraintestinal manifestation of Crohn’s disease and may be refractory to conventional immunosuppression, even after withdrawal of potential offending agents. This case demonstrates clear histologic and clinical response following T-cell–targeted therapy with ATG, supported by sequential biopsies and T-cell–predominant inflammation on immunohistochemistry. To our knowledge, this represents the first pediatric case of refractory AIN successfully treated with ATG and suggests a role for targeted immunosuppression in refractory cases.