Abstract: PO1926
Resolution of Immune Deposits in the Glomeruli of Patients with Lupus Nephritis (LN)
Session Information
- Glomerular Diseases: Clinical, Outcomes, and Trials - 3
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Malvar, Ana, Hospital Fernandez, Buenos Aires, Argentina
- Alberton, Valeria Gabriela, Hospital Fernandez, Buenos Aires, Argentina
- Fayolle, Karina, Hospital Fernandez, Buenos Aires, Argentina
- Jones, Rocio A., Hospital Fernandez, Buenos Aires, Argentina
- Davila Terreros, Pedro Jose, Hospital Fernandez, Buenos Aires, Argentina
- Lococo, Bruno Jorge, Hospital Fernandez, Buenos Aires, Argentina
- Rovin, Brad H., The Ohio State University, Columbus, Ohio, United States
Background
Patients with proliferative LN have severe glomerular immune injury that resolves over time with treatment. The extent of resolution has been assessed by the NIH activity index (AI) in patients who have had a repeat kidney biopsy during maintenance immunosuppression, and many patients do achieve an AI=0, so-called histologic remission. The fate of glomerular immune complexes in treated LN patients has not yet been characterized. This study examined the immunofluorescence (IF) patterns in biopsies obtained during LN therapy.
Methods
A cohort of Hispanic LN patients (n=89) was studied. All patients had biopsy-proven (Bx1) proliferative (Class III, IV±V) LN, and were treated with corticosteroids plus cyclophosphamide or MMF for 6 months and then switched to MMF for maintenance therapy. After a median of 42 (range 30-52) months patients had a second protocol biopsy (Bx2) to determine if they had achieved histologic remission (AI=0) or had persistent histologic activity (AI≥1). Kidney biopsies were evaluated by standard IF microscopy (IgG, IgA, IgM, C3, C1q), and semi-quantitatively graded on a scale of 0-3 (not present-bright).
Results
cyclophosphamide (48%). These patients had a median serum creatinine of 0.7 mg/dl (0.5-2.2) and proteinuria of 0.2 g/d (0-0.8). The 26 patients who had persistent histologic activity at Bx2 had a median AI of 2 (1-6), serum creatinine of 0.75 mg/dl (0.6-1.1), and proteinuria of 0.2 g/d (0.1-0.9) and about half had been treated with MMF. No residual IF was present in 30% of patients with an AI of 0, but was present in all patients who had an AI≥1. IF for IgG became negative in 46% of patients with an AI=0 between Bx1 and Bx2, but in only 7.7% of patients with AI≥1 (P=0.0005). Similarly, IF for C3 became negative in 84% of patients with AI=0, compared to 31% of patients with AI≥1 (P<0.0001). After a median of 23 months (11-39) 7 patients who had been in histologic remission suffered an LN flare. None of these patients had had complete resolution of IF on Bx2. In contrast, no patient with an AI=0 and an absence of IF on Bx has had an LN flare during a follow-up of 44 months (19-105).
Conclusion
About one third of patients with LN can achieve histologic and immunologic kidney remission. These patients appear to have an outstanding long-term kidney prognosis.
Funding
- Clinical Revenue Support