Thai Patients With Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: Outcomes and Risk Factors for Mortality

Patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV) have an increased risk of premature death. Different subtypes, predictors, and ethnicities may affect the overall survival. However, the overall survival of Thai AAV patients has not been reported. We examined the mortality and prognosis of these patients.

This medical record review study included adult AAV patients, admitted to Songklanagarind Hospital from 2007 to 2017. Antineutrophil cytoplasmic antibody-associated vasculitis was diagnosed according to the 1990 American College of Rheumatology criteria or 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. Follow-up data were collected until June 2018. Prognostic factors and overall survival were analyzed.

Among 57 AAV patients, mean (SD) age was 49.3 (16.1) years. Microscopic polyangiitis was the predominant diagnosis (42%). Kidneys (67%) and lungs (65%) were the 2 most affected organs. Initial Birmingham Vasculitis Activity Score (BVAS) greater than 20 was found in 61% of patients. Corticosteroids were the main drugs, and 58% received cyclophosphamide during the induction phase. Overall mean survival time was 38.8 (42.2) months. Patient survival was 91% and 82% at 1 and 6 months, respectively. One-year and 5-year survival rates were 78% and 63%, respectively. Univariate analysis showed that initial BVAS of greater than 20, neutrophil-to-lymphocyte ratio greater than 5.8, and need for invasive ventilator were significant predictors of mortality. Initial BVAS of greater than 20 was the only predictor of death in multivariate analyses (odds ratio, 4.22; 95% confidence interval, 1.01-17.63; p = 0.048).

The mortality rate of Thai AAV patients is high and strongly related to high disease activity. An early recognition and referral system are warranted to improve outcomes.