Abstract: FR-PO0716
Membranous-Like Glomerulopathy with Masked IgG Kappa Deposits in a 70-Year-Old Woman: Expanding the Age Spectrum of a Rare Entity
Session Information
- Glomerular Diseases: Membranous Nephropathy, FSGS, and Podocytopathies
October 23, 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
- Nouman, Muhammad Khuram, University of Louisville, Louisville, Kentucky, United States
- Caster, Dawn J., University of Louisville, Louisville, Kentucky, United States
Introduction
Membranous-like glomerulopathy with masked IgG kappa deposits (MGMID) is a rare immune complex glomerular disease typically described in younger women with autoimmune features. Diagnosis requires paraffin immunofluorescence(IF) after protease digestion. We report MGMID in a 70 YO woman, expanding the recognized age spectrum and highlighting a possible drug-associated trigger.
Case Description
A 70 YO AA woman with HTN, prediabetes and CKD was referred for proteinuria. Creatinine was 1.02 mg/dL with UPCR 1.7 g/g. SPEP was negative, and kappa/lambda ratio was normal. Autoimmune workup showed positive ANA and elevated anti-dsDNA (95 IU/mL), with negative anti-Smith, RNP, and Sm/RNP antibodies. Anti-chromatin antibody was positive. The patient had been on hydralazine, which was discontinued due to concern for drug-induced autoimmunity.
Kidney biopsy showed findings consistent with MGMID. Routine IF demonstrated C3 and trace IgM only. Paraffin IF after protease digestion revealed granular mesangial and capillary wall staining for IgG, C3, and kappa light chain with negative lambda. Serum amyloid P staining was positive within glomerular deposits. Electron microscopy showed segmental subepithelial hump-like and mesangial electron-dense deposits with podocyte foot process effacement.
The patient was managed with RAS blockade for antiproteinuric effect, with consideration of SGLT2 inhibitor therapy and rituximab if proteinuria persists.
Discussion
MGMID may be misdiagnosed as membranous nephropathy, infection-related glomerulopathy, or monoclonal gammopathy-associated kidney disease when specialized staining is not performed. This case is notable for presentation at age 70 years, extending the known age range. Concomitant hydralazine exposure and positive anti-chromatin antibody raise the possibility of a drug-induced autoimmune mechanism contributing to disease pathogenesis. Recognition of this association is important, as drug withdrawal may influence clinical course and management.
Acknowledgment
Special thanks to Arkana labs for providing pathology slides.