Chronic kidney disease in patients with ANCA‑associated vasculitis: a bidirectional cohort study. Nephrology and Dialysis

Abstract

Objective: to assess the prevalence of chronic kidney disease (CKD) stages and to identify factors associated with progression to advanced CKD stages in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Materials and Methods: this bidirectional cohort study enrolled adult patients with AAV who were hospitalized at least once between 2010 and 2025 and were subsequently followed on an inpatient and/or outpatient basis. Kidney involvement associated with AAV was confirmed by kidney biopsy or, if unavailable, by the presence of manifestations within the renal domain of the Birmingham Vasculitis Activity Score (BVAS v.3). The primary endpoint was CKD stage at the end of follow-up, defined according to the KDIGO 2024 guidelines. Risk stratification for adverse CKD outcomes also followed the KDIGO 2024 guidelines. Multivariable ordinal logistic regression was conducted to identify factors associated with advanced CKD stages, with results reported as odds ratios (ORs) and 95% confidence intervals (CIs). Results: a total of 706 patients were included. Kidney involvement was identified at any time during follow-up in 58.6% (95% CI 54.9-62.3%). The median (interquartile range, IQR) age at AAV diagnosis was 50 (36-60) years, and the median follow-up duration was 54 (15-101) months. CKD staging was performed in 673 patients. Among 395 patients with AAV and kidney involvement, advanced CKD stages (G4–G5) were diagnosed in 29.9% (95% CI 25.4-34.7%), and 60% (95% CI 55.0-64.9%) were stratified into high or very high risk for adverse outcomes. Among 278 patients who did not develop AAV-related kidney involvement at any time during follow-up, CKD developed in 24.8% (95% CI 19.9-30.3%), including CKD G4 in 0.7% (95% CI 0.1-2.6%), and 3.2% (95% CI 1.5-6.1%) were stratified into high or very high risk. Multivariable ordinal logistic regression identified dialysis dependence at diagnosis (OR 2.54, 95% CI 1.22-5.33), isolated renal involvement in AAV (OR 2.04, 95% CI 1.03-4.06), and arterial hypertension (OR 3.70, 95% CI 2.17-6.31) as factors associated with advanced CKD. A preserved eGFR at diagnosis (OR 0.66, 95% CI 0.61-0.72 per 10 mL/min increment) and achievement of renal remission within four months (OR 0.13, 95% CI 0.07-0.24) were associated with a lower probability of advanced CKD. Conclusion: reduced baseline eGFR, dialysis dependence at diagnosis, arterial hypertension, and failure to achieve renal remission are the primary factors independently associated with progression to advanced CKD stages in patients with AAV.