Racial Differences in Age at Diagnosis and Renal Manifestations of Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis: Insights From a Multi-institutional Electronic Health Record Retrospective Cohort.

BACKGROUND

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare autoimmune disease in which renal involvement is a major determinant of morbidity and mortality. Epidemiologic data suggest lower reported prevalence of AAV among Black populations, but whether differences exist in disease presentation and renal severity at diagnosis remains poorly characterized.

METHODS

We conducted a retrospective cohort study using a large, multi-institutional electronic health record network. Adults diagnosed with AAV between 2015 and 2025 were identified using International Classification of Diseases, Tenth Revision (ICD-10) codes. Demographic characteristics, renal manifestations at presentation, dialysis dependence, and ANCA serologic testing were extracted. Primary analyses compared Black and White patients using descriptive statistics, Welch t-tests, Fisher's exact tests, and odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Among 789 adults with AAV, 84.8% were White and 8.2% were Black. Black patients were diagnosed at a younger mean age than White patients (55 ± 15 vs 64 ± 16 years; p<0.001). Dialysis dependence was more frequent among Black patients (21.5% vs 13.3%; OR: 1.79, CI: 0.88-3.45), as was hematuria (38.5% vs 28.1%; OR: 1.59, CI: 0.9-2.78). Proteinuria occurred at similar rates across groups. ANCA serologic testing was incompletely captured.

CONCLUSIONS

In this multi-institutional cohort, Black patients with AAV presented at a younger age and tended to be more likely to require dialysis and have hematuria. These findings suggest that underrepresentation in rare disease cohorts may coexist with substantial disease burden at presentation, underscoring the importance of examining severity alongside prevalence in population-level studies.