Silica and asbestos exposure in ANCA-associated vasculitis with pulmonary involvement.

Silica and asbestos exposure are thought to belong to the triggering factors of antineutrophil cytoplasm antibodies (ANCA)-associated vasculitis. We carried out a study to find out whether patients with pulmonary involvement attributable to ANCA-associated vasculitis (AAV) have been exposed to silicon-containing materials. Thirty-one patients (12 women, 19 men, median age 51 years) were interviewed using a structured questionnaire. Occupational exposure to silicon-containing chemicals was reported by 22.6% of the patients (12.9% to SiO2, 9.7% to asbestos), compared with 0% of control subjects (p<0.05). Our findings support the pathophysiologic role of silica in AAV.