Abstract: FR-PO274
An Unusual Case of Acute Tubulointerstitial Nephritis (ATIN) with CD8-Positive Cytotoxic T Cell Infiltrate
Session Information
- Onconephrology: From AKI to CKD and Everything in Between
November 03, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1700 Onconephrology
Authors
- Triantafyllou, Maria, Memorial Sloan Kettering Cancer Center, New York, New York, United States
- Salvatore, Steven, Weill Cornell Medicine, New York, New York, United States
- Jaffer Sathick, Insara, Memorial Sloan Kettering Cancer Center, New York, New York, United States
Introduction
ATIN is a cause of acute kidney injury (AKI) characterized by tubulointerstitial inflammatory infiltrate, primarily lymphocytic and eosinophilic.We present a case of ATIN with an almost exclusive CD8+ cytotoxic T-cell infiltrate.
Case Description
A 65-year-old man with history of hypertension, nephrolithiasis, prostate cancer treated with brachytherapy, smoldering myeloma, thymoma s/p thymectomy, CD8+ granulomatous lymphadenitis on lymph node biopsy 2 years earlier and family history of autoimmunity presented with AKI amid NSAID use. Exam was normal. Patient discontinued NSAIDs. Work-up revealed proteinuria 378mg/d, serum creatinine 2.6(baseline 1.3)mg/dl, free lambda light chains on UPEP, serum lambda15mg/dl, K/L ratio 0.03 (stable). Urinalysis depicted protein 100mg/dL without abnormal cells or casts. HIV, hepatitis B/C, HTLV-I/II serologies, Parvo, CMV, AAV and EBV PCR were negative. c-ANCA was positive, ANA, dsDNA, PR-3, MPO antibodies negative, complements were normal.
Kidney biopsy showed severe ATIN with CD8+ dominant T cell infiltrate, moderate interstitial fibrosis, no immune complex or amyloid deposition or glomerular crescents. Suspicion for a T-cell lymphoproliferative disorder was entertained. Hematologic workup was negative for thymoma recurrence or myeloma progression including flow cytometry. T-cell receptor studies were polyclonal. Patient was started on prednisone, creatinine improved to 2mg/dl after 2 weeks.
Discussion
This is a case of ATIN with an almost exclusively, atypical CD8+ cytotoxic T-cell infiltrate. Based on prior history, we suspect the underlying cause may be autoimmune dysregulation or T cell disorder. A careful workup to rule out active viral infections and underlying hematologic disorder was performed before starting immunosuppression with close follow up.
Figure 1. Renal biopsy illustrating tubulointerstitial nephritis with CD8 cytotoxic T cell infiltrate,CD8 IHC x20