Kidney Week

Abstract: FR-PO1260

A Case of Dense Deposit Disease with Nivolumab and Ipilimumab Therapy in a Patient with Malignant Pleural Mesothelioma

Session Information

• Onconephrology: Diagnostic Dilemmas, Therapy-Related Toxicities, and Clinical Cases
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Onconephrology

• 1600 Onconephrology

Authors

• Terada, Shohei, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Shohei Terada, MD

• Yamamura, Ryosuke, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Ryosuke Yamamura, MD, PhD

• Nagayoshi, Yu, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Yu Nagayoshi, MD, PhD

• Fujimoto, Daisuke, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Daisuke Fujimoto, MD, PhD

• Kanki, Tomoko, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Tomoko Kanki, MD

• Nakagawa, Terumasa, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Terumasa Nakagawa, MD

• Miyasato, Yoshikazu, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Yoshikazu Miyasato, MD, PhD, MPH

• Mizumoto, Teruhiko, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Teruhiko Mizumoto, MD, PhD

• Kakizoe, Yutaka, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Yutaka Kakizoe, MD, PhD

• Adachi, Masataka, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Masataka Adachi, MD, PhD

• Izumi, Yuichiro, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Yuichiro Izumi, MD, PhD

• Kuwabara, Takashige, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Takashige Kuwabara, MD, PhD

• Koda, Yukimasa, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Yukimasa Koda

• Yokoi, Hideki, Department of Nephrology, Kumamoto University Hospital, Kumamoto, Japan

Hideki Yokoi, MD, PhD

Introduction

Immune checkpoint inhibitors (ICIs) can cause immune-related adverse events (irAEs), including renal toxicities. Acute interstitial nephritis is the most common renal irAE, whereas only a few cases of C3 glomerulopathy (C3G) as renal irAE have been reported. However, the clinicopathological features of C3G under ICIs remain unclear. Here, we report a case of dense deposit disease (DDD) developing after nivolumab and ipilimumab therapy in a patient with malignant pleural mesothelioma.

Case Description

A 67-year-old man with biphasic malignant pleural mesothelioma (cT1N1M0, clinical Stage II) had received nivolumab and ipilimumab therapy for one year. After eight cycles of the therapy, blood and urine tests showed hematuria, proteinuria, and renal dysfunction during the routine checkup. In the results of renal biopsy, PAS staining showed diffuse endocapillary hypercellularity, PAM staining demonstrated double contour formation of the glomerular basement membrane, and Azan staining highlighted subepithelial and subendothelial deposits. Immunofluorescence showed dominant C3 deposition with weak IgM staining. We also observed continuous intramembranous sausage-like dense deposits on electron microscopy. From these results, we diagnosed the patient with DDD caused by ICIs.

Discussion

Following the diagnosis, the patient was treated with methylprednisolone pulse therapy, resulting in rapid improvement in urinary abnormalities and kidney function. No recurrence was observed during steroid tapering.
This case highlights a rare presentation of DDD associated with ICI therapy. Given the temporal association with nivolumab/ipilimumab administration and the absence of other identifiable triggers, the clinical course was considered consistent with an irAE. However, pathological examination revealed several hump-like deposits, which are atypical for DDD. Electron microscopy was therefore essential for the detailed evaluation of ICI-induced membranoproliferative glomerulonephritis. Complement-mediated glomerular disease should be considered in patients who develop urinary abnormalities and renal dysfunction during ICI therapy.