Kidney Pathology and Outcomes in Anca-Associated Vasculitis: Retrospective Analysis of 85 Patients

This is the authors' abstract. We don't add key points for this paper.

ANCA-associated vasculitis (AAV) pose a significant risk of kidney failure, kidney biopsy remains a key prognostic tool. Pathology classification of the AAV glomerulonephritis (GN) developed by Berden et al showed correlation between GN classes and kidney outcomes; ANCA Renal Risk Score (ARRS) included tubular atrophy and interstitial fibrosis (TA/IF) as an additional parameter for risk assessment. We aimed to evaluate kidney survival across AAV GN classes and ARRS groups. A single-center retrospective study included 85 adult patients with biopsy-proven AAV kidney disease followed in 2000-2020. Primary outcome was kidney survival at the end of 18 [5; 66] months follow-up, kidney death considered as CKD stage 5. We found significant difference in the kidney survival for sclerotic, mixed, crescentic and focal AAV GN classes: 19%, 76.2%, 91.7% and 100% respectively (p=0.009). Kidney survival was 0%, 75.6% and 100% for the high, median and low risk ARRS groups respectively (p<0.001); TA/IF analysis showed kidney survival 49.6% vs 87.7% for widespread and mild TA/IF respectively (р=0.003). Kidney survival was significantly lower in anti-MPO-ANCA versus anti-PR3-ANCA carriers (50.3% and 78.1% respectively, р=0.045). We conclude that unfavorable AAV kidney outcomes associated with sclerotic GN class by Berden’s classification, ARRS high risk group, and anti-MPO-ANCA subtype.