Kidney Week

Abstract: SA-PO0766

Renal-Limited Histiocytic Glomerulopathy Presenting as Nephrotic Syndrome and AKI

Session Information

• Glomerular Diseases: Lupus Nephritis, Monoclonal Gammopathy-Related Disease, and Transplantation
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Sosa, Piera A., University of California San Francisco, San Francisco, California, United States

Piera A. Sosa, MD

• Vaidya, Neha Vijay, University of California San Francisco, San Francisco, California, United States

Neha Vijay Vaidya, MD

• Urisman, Anatoly, University of California San Francisco, San Francisco, California, United States

Anatoly Urisman, MD, PhD

• Lee, Jerry, University of California San Francisco, San Francisco, California, United States

Jerry Lee, MD, MS, MPhil

• Varanasi, Laalasa, University of California San Francisco, San Francisco, California, United States

Laalasa Varanasi, MD

• Muiru, Anthony N., University of California San Francisco, San Francisco, California, United States

Anthony N. Muiru, MD, MPH

Introduction

Histiocytic glomerulopathy is a rare pattern of glomerular injury characterized by prominent histiocytic glomerular infiltration. Most cases are associated with systemic inflammatory or infectious conditions, and few cases limited to the kidneys have been reported.

Case Description

A 71 year old male with diabetes, hypertension, monoclonal gammopathy of undetermined significance, and CKD, presented with worsening anasarca. Labs were notable for proteinuria (peak UPCR of 26.8 g/g), and AKI (serum creatinine of 2.8 mg/dL from baseline of 1.1 mg/dL). Serologic evaluation for membranous, monoclonal gammopathy, and infection-associated nephropathy was negative. Renal biopsy showed endocapillary hypercellularity with macrophage infiltration superimposed on diabetic glomerulosclerosis. Immunofluorescence and electron microscopy showed no immune complex or monoclonal immunoglobulin deposition.
The patient did not have systemic features of hemophagocytic lymphohistiocytosis and work up including whole body PET CT was negative. He was treated with various immunomodulatory therapies, including high dose corticosteroids and cyclosporine without response, eventually progressing to renal failure requiring hemodialysis.
Notably, he was found to have elevated CXCL9 levels, consistent with interferon-γ–mediated hyperinflammation. Ultimately, he was initiated on Emapalumab, resulting in lowering of CXCL9 levels and renal recovery. His 24hr creatinine clearance improved from 6 mL/min to 21 mL/min where dialysis was weaned to twice weekly. Repeat renal biopsy depicted no evidence of histiocytic glomerulopathy.

Discussion

This case highlights renally limited histiocytic glomerulopathy driven by interferon-γ–driven inflammation, progressing to nephrotic syndrome and renal failure requiring dialysis. Targeted cytokine inhibition with Emapalumab was associated with clinical improvement, suggesting a potential therapeutic role. This case underscores the diagnostic and therapeutic challenges of histiocytic glomerulopathy.