Kidney ANCA-Associated Vasculitides (AAV) Manifestations and Outcomes in a Diverse Pediatric Cohort: A Single-Center Experience

Background: Renal involvement and long-term outcomes in childhood ANCA-associated vasculitides (AAV) has been understudied in various racial and ethnic minority groups. Methods: This is a retrospective analysis of pediatric patients with renal AAV diagnosed between 2011 and 2023, followed at Texas Children’s Hospital. We report the clinical features, histopathology, renal outcomes, and prognostic factors in a diverse pediatric patient cohort. Results: A total 37 cases of pediatric renal AAV were identified. 17 (46%) patients presented with rapidly progressive glomerulonephritis (RPGN). At diagnosis, 3 (8%) patients had normal kidney function, 25 (68%) had an AKI, and 8 (22%) patients had an AKI that required acute renal replacement therapy (RRT). 24 (65%) patients received induction immunosuppression with cyclophosphamide and rituximab. 10 patients had therapeutic plasma exchange for RPGN. 8 of these patients were dialysis-dependent from diagnosis. As creatinine increases, the odds of dialysis dependency increases (OR=2.23, 95%CI [1.41, 3.5], p=0.001). Presentation with AKI not requiring RRT is associated with less dialysis dependency (OR=0.04, 95%CI [0.01, 0.29], p=0.001), while presentation with an AKI requiring RRT is associated with dialysis dependency (OR=60.67, 95%CI [5.26, 699.82], p=0.001). Kidney biopsies were scored using the renal ANCA renal risk score (ARRS) by Brix et al. The AUC for Brix score predicting dialysis dependency is 0.944 (95% CI=0.876-1.00) with a sensitivity of 88.89% and specificity of 88.46% for a score of >=9. Conclusion: In a racially and ethnically diverse pediatric cohort, approximately a third of patients developed ESKD. As Brix score increases, the odds of dialysis-dependency increases.