Predictors of survival and renal replacement therapy in anca-associated vasculitis with renal involvement: An 11-year real-world cohort from North Macedonia.

BACKGROUND

Antineutrophil Cytoplasmic Antibody (ANCA) - Associated Vasculitis (AAV) is a rare systemic small-vessel vasculitis in which renal involvement is a major determinant of morbidity and survival. Despite therapeutic advances, many patients still present with advanced kidney disease. Data from Southeast Europe remain limited.

METHODS

We conducted an 11-year retrospective observational study of adult patients with AAV and renal involvement treated at national nephrology center in North Macedonia. Demographic, clinical, laboratory, treatment, and outcome data were analyzed. Predictors of mortality were evaluated using Cox proportional hazards models, while renal outcomes were assessed using Fine-Gray competing risk regression with death treated as a competing event.

RESULTS

Forty-two patients were included (57.1% male; mean age 56.5 ± 14.9 years). Renal involvement was severe at presentation, with a mean eGFR of 26.2 ± 16.4 mL/min/1.73 m2 corresponding to CKD stage G4. Pulmonary involvement was observed in 71.4%, whereas 21.4% had renal-limited disease. During follow-up, 27 patients (64.3%) progressed to RRT and 17 (40.5%) died. Median overall survival was 84.0-months (95% CI 57.4-110.6). In multivariable Cox regression, older age independently predicted mortality (HR = 1.05, 95% CI 1.01-1.10). In multivariable Fine-Gray competing risk analysis, lower baseline eGFR independently predicted progression to ESRD (sHR 0.96 per/mL/min/1.73 m2 increase, 95% CI 0.93-0.99), whereas pulmonary involvement was not independently associated with either outcome.

CONCLUSION

This first national cohort from North Macedonia confirms that AAV with renal involvement presents with advanced kidney dysfunction, a compressed time to RRT, and substantial early mortality. Baseline renal function remains the dominant determinant of renal outcome, underscoring the need for earlier diagnosis and structured referral pathways.