Abstract: FR-PO1259
Proliferative Glomerulonephritis with Monoclonal Immunoglobulin Deposits (PGNMID): A Case Series
Session Information
- Onconephrology: Diagnostic Dilemmas, Therapy-Related Toxicities, and Clinical Cases
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1600 Onconephrology
Authors
- Nadayil, Jasmine, University of South Florida, Tampa, Florida, United States
- Trinh, Anhthu, University of South Florida, Tampa, Florida, United States
- Jayakumar, Vaishnavi, University of South Florida, Tampa, Florida, United States
- Bassil, Claude, University of South Florida, Tampa, Florida, United States
- Audi, Akram, University of South Florida, Tampa, Florida, United States
Background
PGNMID is a rare and heterogeneous renal disorder within the spectrum of monoclonal gammopathy of renal significance (MGRS). It is characterized by deposition of monotypic immunoglobulins within the glomeruli, often in the absence of a detectable circulating clone, posing diagnostic and therapeutic challenges.
Methods
We conducted a case series of biopsy-proven PGNMID at a tertiary cancer center, analyzing pathologic features, treatment strategies, and renal outcomes.
Results
6 patients (ages 28–80) demonstrated clinical and biologic heterogeneity. Presentations ranged from indolent subnephrotic proteinuria to nephrotic syndrome and acute kidney injury. Biopsies showed PGNMID, specifically IgG depositis. IgG1 was more common than IgG3. 2/6 patients had detectable circulating monoclonal proteins, and one had a defined clonal B-cell disorder.
Rituximab-based regimens induced complete remission in 50% of treated patients, while bortezomib-based therapy achieved partial response. Clinical outcomes spanned complete remission (4/6), partial response (1/6), and stable disease (1/6). Notably, one young patient achieved stability with renin–angiotensin system blockade alone. One patient demonstrated treatment-refractory disease requiring plasma cell–directed therapy.
Conclusion
This series highlights PGNMID as a heterogeneous entity with variability in treatment response. It supports a paradigm in which a subset of PGNMID may be driven by oligoclonal/low-level immunoglobulin production rather than a true pathologic clone. Rituximab was associated with favorable renal responses, raising the hypothesis that it may have therapeutic effects through immune and inflammatory pathways. Minimal residual disease testing may confer benefit in disease monitoring. Further studies are needed to define the role of B-cell targeted therapies in patients and establish standardized treatments. Overall, these findings challenge uniform classification as MGRS and emphasize the need for risk-stratified, individualized management.
| Case | Age, Gender | Ig subtype | Treatment | Outcome |
| 1 | 68F | IgG1λ | RTX | CR |
| 2 | 58F | IgG1κ | RTX | CR |
| 3 | 61M | IgG3κ | CyBorD | PR |
| 4 | 58M | IgG3κ | RTX | CR |
| 5 | 28M | IgG1κ | ACEi | Stable |
| 6 | 80M | IgG1λ | RTX, DVCd | CR |
CR, complete remission; PR, partial remission