Abstract: SA-PO753
Monoclonal Gammopathy and Its Associations with Kidney Failure in Patients with ANCA-Associated Vasculitis
Session Information
- ANCA-Associated Vasculitis, Anti-GBM Disease, and Other RPGN
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
- Mekraksakit, Poemlarp, Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Vargas-Brochero, Maria Jose, Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Inácio, António da Silva, Centro Hospitalar de Setubal EPE, Setubal, Portugal
- Radhakrishnan, Yeshwanter, Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Domingues, Patrícia Andreia da Costa, Centro Hospitalar de Setubal EPE, Setubal, Portugal
- Buglioni, Alessia, Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Zand, Ladan, Mayo Clinic Minnesota, Rochester, Minnesota, United States
Background
Up to 30% of patients with ANCA-associated vasculitis (AAV) and kidney involvement progress to end-stage kidney disease (ESKD) despite therapy. The role of monoclonal gammopathy (MG) in disease progression among patients with AAV is not well understood.
Methods
We retrospectively reviewed records of 167 AAV patients with renal involvement tested for MG from January 2000 to December 2023. Patients were divided into monoclonal positive (n=34) and negative (n=133) groups. Multivariate Cox analysis identified predictors of adverse renal outcomes (>40% decline in eGFR or ESKD) and mortality.
Results
The median age of the cohort was 68 years [58.5-74.5], with 85 (50.8%) males. 65.8% tested positive for MPO, and 64.6% received rituximab as induction therapy. Both groups had similar baseline characteristics, but the MG positive group had more moderate/severe Mayo Clinic Chronicity Score (MCCS) (56.7% vs. 33.3%, p=0.01) and less crescentic Berden classification (6.7% vs. 24.8%) on kidney biopsy. Patients in the MG positive group had higher rates of adverse renal outcomes (23.5% vs. 11.3%), ESKD (20.6% vs. 9.8%), death (26.5% vs. 18%), and relapse (35.3% vs. 27.1%) compared to those with no MG. After adjusting for baseline eGFR, hypertension, proteinuria, moderate/severe MCCS, sclerotic Berden class, and induction therapy, MG was associated with adverse renal outcomes (HR 4.64 [95% CI 1.24-17.35]), but not mortality (HR 2.0 [95% CI 0.92-4.3]). Other predictors of adverse renal outcomes were sclerotic Berden classification (HR 12 [2.02-71.9]), proteinuria (HR 1.53 [1.15-2.04] per 1 g/24 hr), and lack of induction therapy (HR 6.3 [1.18-33.5]). Achieving renal remission was associated with lower mortality (HR 0.03 [0.003-0.3]).
Conclusion
AAV patients with renal involvement and MG are at a higher risk of adverse renal outcomes even after adjusting for factors such as eGFR and the degree of chronicity, both of which are known predictors of renal outcomes. The mechanism by which MG worsens outcomes is unclear and requires further research.