Abstract: SA-PO0919
Membranous-Like Glomerulopathy with IgG Kappa Deposits (MGMID): A Management Challenge
Session Information
- Glomerular Case Reports: ANCA, IgA, IgG, and More
November 08, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Shettigar, Shruti Kishor, University of Florida, Gainesville, Florida, United States
- Jadvani, Rutvikkumar B, Government Medical College Surat, Surat, GJ, India
- Pramod, Sheena, University of Florida, Gainesville, Florida, United States
Introduction
MGMID is a pattern of immune complex deposition characterized by masked deposits that show IgG kappa restriction and are subepithelial and mesangial located. C3 staining by immunofluorescence microscopy (IF) may cause misdiagnosis as C3 glomerulonephritis (GN) or atypical infection associated GN. We discuss its diagnostic and management challenges.
Case Description
29-year-old female with morbid obesity and HTN for 5 years on Losartan was seen for CKD stage 2. Her serum creatinine was 1.2 (baseline 1mg/dl 3 years ago) 1+ blood and 3+ protein on urinalysis and 24hour albuminuria of 3,717mg, proteinuria of 6,102mg with serum albumin of 3.6g/dl. GN and autoimmune panel, PLA2R antibody except weakly positive ANA at 1:180, were negative. Kappa/Lambda ratio was 1.2 with normal serum electrophoresis. On kidney biopsy, light microscopy showed increase in mesangial cellularity and matrix, thick glomerular capillary loops. IF showed diffuse granular staining for IgG (1+), IgM (1-2+), C3 (1+), kappa light chain (2+) & diffuse, pseudolinear staining along glomerular capillary for albumin (1+). EM showed sub-epithelial, intra-membranous and large subepithelial immune deposits with hump-like appearance and mesangial /subendothelial deposits with diffuse podocyte effacement and atrophic tubules suggesting acute post-infectious glomerulonephritis. Stain for IgG4 and phospholipase A2 receptor were negative. ASO titer was negative with no occult infections. Additional testing revealed diffuse positive staining for serum amyloid protein (SAP).
Discussion
MGMID is a distinct entity seen mostly in young females < 40 years with vague history of autoimmune disease and positive autoimmune serology in 55% cases. Pronase digestion to unmask the kappa IgG and staining for SAP that colocalizes with IgG in glomerular immune deposits has high sensitivity to help diagnose this rare entity. Treatments reported vary from RAAS blockade or SGLT-2 inhibitors to corticosteroids, Rituximab, cyclophosphamide, mycophenolate mofetil, calcineurin inhibitor (tacrolimus). Approximately 50 % of cases responded with either conservative or immunosuppressive therapy. We decided to treat with RAAS blockade, SGLT2I and GLP1 over 6 months prior to considering immunosuppressive therapy. A central MGMID registry would be crucial to study better treatment options.