Abstract: SA-PO201
A Case of Proliferative Glomerulonephritis with Monoclonal Immunoglobulin Deposits Presenting as Hypertensive Emergency
Session Information
- Onconephrology: Immunological Cross-Talk
November 04, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1700 Onconephrology
Authors
- Saum, Keith Louis, University of Michigan Michigan Medicine, Ann Arbor, Michigan, United States
- Farkash, Evan A., University of Michigan Michigan Medicine, Ann Arbor, Michigan, United States
- Bitzer, Markus, University of Michigan Michigan Medicine, Ann Arbor, Michigan, United States
Introduction
Proliferative Glomerulonephritis with Monoclonal Immunoglobulin Deposits (PGNMID) is a subtype of monoclonal gammopathy of renal significance (MGRS), resulting from deposition of intact monoclonal IgG in glomeruli. Herein, we present the case of a 65-year-old who presented for new headaches and hypertensive emergency and was subsequently found to have PGNMID.
Case Description
A 65-year-old female with no significant past medical history developed new headaches and was treated with ibuprofen 800 mg TID for 5-months. Subsequently, she was found to have new hypertension with BP of 190/90 mmHg, serum creatinine of 1.0 mg/dl and nephrotic-range proteinuria of 5.4 g/g creatinine. Urinalysis was positive for protein and blood with no dysmorphic RBCs or casts on urine sediment. Labs also revealed new anemia and thrombocytopenia with elevated LDH, undetectable haptoglobin, and normal peripheral blood smear. Further serologic evaluation for C3, C4, ANA, cryoglobulin, ANCA, HIV, HBV, HCV, Anti-PLA2R, DAT, and ADAMSTS13 activity were normal/negative. Paraproteinemia evaluation with SPEP and UPEP were without evidence of M-protein, aside from a marginal free Kappa/lambda light chain ratio (1.8). Despite cessation of NSAIDS and adequate blood pressure control with amlodipine and losartan, proteinuria persisted with rising creatinine. Therefore, kidney biopsy was pursued which showed neutrophilic glomerulitis with a membranoproliferative pattern and rare fibrocellular crescents. Immunofluorescence showed only mesangial and capillary C3 and C1q deposits; however, pronase treated paraffin tissue unmasked IgG-kappa restricted subendothelial and mesangial deposits, diagnostic of PGNMID. She was treated with six cycles of cyclophosphamide, bortezomib, and dexamethasone (CyBorD) resulting in initial improvement in proteinuria and serum creatinine. Repeat bone marrow was without residual plasma cells on flow cytometry.
Discussion
PGNMID is a MGRS that does not meet criteria for multiple myeloma or lymphoma, and a monoclonal immunoglobulin or abnormal bone marrow B cell clone is detected in only 30% of cases. Pronase treatment of paraffin tissue to reveal masked immunoglobulin deposits can provide insightful guidance in glomerular deposition diseases when routine immunofluorescence is not diagnostic.