Racial and Clinical Patterns in ANCA-Associated Vasculitis: Insights from a Multi-Institutional Electronic Health Record (EHR) Cohort

Background: The survival of patients with ANCA associated vasculitis (AAV) has improved with early detection and treatment with less toxic immunosuppression. However, mortality and end stage kidney disease remained high in patients with AAV. While clinical experience suggests a lower disease burden among racial minorities, population-level data remains limited. We conducted this study to understand the demographic distribution of AAV and prognosis among different demographic groups. Methods: We used Epic Cosmos to identify adults (≥18 years) with AAV between 1/1/2015 and 4/10/2025 using diagnosis codes for ANCA vasculitis (I77.82), granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Demographics, ANCA serologies (PR3 and MPO via LOINC), renal biopsy (CPT 50200), and co-occurring diagnoses including diabetes, dialysis, and anti-GBM disease were evaluated. Results: Among 789 patients, 84.8% were White, 8.2% Black, and 7.0% others (P-value <0.0001). The cohort was 57.7% female and 42.3% males with a mean age of 63.3 years (SD 16). Black patients were younger on average (55 vs 64 years, P value <0.0001), had higher rates of dialysis dependence (21.5% vs 13.3%, OR 1.83 and p-value of 0.058) and hematuria (38.5% vs 28.1%, p-value 0.082) when compared to white patients. Abnormal serum creatinine was present in 63.1% of White and 53.8% of Black patients (p-value 0.155), while 20% in both groups had documented proteinuria on presentation. Conclusion: This large, multi-site EHR cohort suggests early onset of disease and worse clinical outcomes in blacks compared to whites. These findings could be potentially from under recognition or delayed diagnosis of AAV in Black individuals. Improved diagnostic vigilance and more consistent use of serologic and histologic tools across populations may support earlier and more accurate identification of AAV. We plan to use our registry, Mid Atlantic Glomerulonephritis Network (MAGNET) to better understand gaps, disease patterns and outcomes of patients with AAV in our health system.