Abstract: SA-PO834
Longitudinal Clinical Outcomes with Membranous-Like Nephropathy with Monoclonal Light-Chain Deposition: A Case Series
Session Information
- C3G, TMA, MGRS, Amyloidosis, and More
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Park, Elaine, Medical University of South Carolina, Charleston, South Carolina, United States
- McMahon, Blaithin A., Medical University of South Carolina, Charleston, South Carolina, United States
- Zou, Guangchen, Johns Hopkins Medicine, Baltimore, Maryland, United States
- Atta, Mohamed G., Johns Hopkins Medicine, Baltimore, Maryland, United States
- Teruel, Benjamin R., Medical University of South Carolina, Charleston, South Carolina, United States
Background
Membranous-like nephropathy with monoclonal light chain deposition is a rare entity first described in 2014. This pathological entity is very distinct from primary idiopathic membranous nephropathy, with the prominent feature of masked IgG-kappa deposits on immunofluorescence. The purpose of this small case series is to examine the treatment and long-term outcomes for 6 with patients with this disease.
Methods
This six-patient series was identified at Johns Hopkins Medicine and Medical University of South Carolina. We examined demographics, clinical characteristics at presentation, light microscopic findings, glomerular immunofluorescence staining, and long-term renal outcomes. The median duration of follow-up was 12.5 years.
Results
The patients most commonly presented with edema and had a mean 24 hr urine protein of 3.09 g/day. Only one patient had an identifiable MGUS at presentation. All renal biopsies stained positive for IgG kappa light chain. Half of all patients had electron dense deposits at other sites other than at the sub-epithelial membrane (including sub-endothelial and mesangial site). 5 out of the 6 patients were found to have intramembranous deposits. Treatment included no treatment, RAAS blockade, and immunosuppressants. Of the 6 cases, 4 achieved complete remission and 2 progressed to ESRD.
Conclusion
Although this is a small case series, membranous-like nephropathy with IgG kappa light chain deposition can still contribute to ESRD. None of these patients who progressed to ESRD received cyclophosphamide. Additional observational studies are needed to better understand the response to immunosuppressive therapy.