Abstract: FR-PO0472
A Rare Case of IgG4-Related Disease (IgG4-RD)
Session Information
- AKI: Case Reports - TMA, Vasculitis, Immune-Mediated Injury, and Systemic Disease
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 102 AKI: Clinical, Outcomes, and Trials
Authors
- Pervaze, Shohan, University of Cincinnati, Cincinnati, Ohio, United States
- Muralidharan, Suchitra, University of Cincinnati, Cincinnati, Ohio, United States
- Andrews, Trisha, University of Cincinnati, Cincinnati, Ohio, United States
- Sircy, Aaron N., University of Cincinnati, Cincinnati, Ohio, United States
Introduction
IgG4-related disease is a systemic fibroinflammatory disorder characterized by immune-mediated inflammation and fibrosis that can involve multiple organs. Population-based studies from Japan estimate a prevalence of approximately 2–10 cases per 100,000 individuals. IgG4-related nephropathy, occurs in approximately 10–30% of patients with systemic IgG4-RD. Most commonly presents as tubulointerstitial nephritis, although glomerular manifestations have also been reported. Among renal manifestations, IgG4-TIN represents the predominant histopathologic pattern, whereas glomerular disease is less frequent. Prostatic involvement in IgG4-RD is exceptionally rare and likely underrecognized, with only limited case reports and small case series described in the literature. We present a rare case of IgG4-related nephropathy in a patient with a prior history of biopsy-proven IgG4 prostatitis.
Case Description
A 67-year-old male pilot presented with incidentally discovered subacute acute kidney injury, with serum creatinine increasing from approximately 1.0 to 2.31 mg/dL in the absence of nephrotoxic exposure or urinary symptoms. Urinalysis demonstrated mild proteinuria (protein-creatinine ratio 0.37 g/g) and trace glucosuria, suggesting a predominantly tubulointerstitial rather than primary glomerular process. Kidney biopsy revealed plasma cell–rich interstitial inflammation, lymphocytic tubulitis, and interstitial fibrosis. Immunostaining demonstrated greater than 10 IgG4-positive plasma cells per high-power field with an IgG4+/IgG+ plasma cell ratio of 50–60%, consistent with IgG4-related nephropathy. Review of prior pathology from prostate tissue demonstrated IgG4-rich prostatitis, establishing multi-organ IgG4-Related Disease.
Discussion
Treatment option were steriod driven initially, which induced improvement of UPCR and sCr. However, due to replase, B- cell directed therapy was introduced, such as inebilizumab in this case.
Ideally we should have low threshold for renal biopsy in patient with unknown cause of proteinuria. Treament based on finiding provides us direction and ultimately best outcome for patients.
Cr trend