Interstitial Lung Disease with Myeloperoxidase-antineutrophil Cytoplasmic Antibody-associated Vasculitis in Elderly Patients

Anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) occurs in elderly people, and patients with anti-myeloperoxidase autoantibodies (MPO-ANCA)-positive AAV are often complicated with interstitial lung disease (ILD). This study aimed to evaluate the age-related clinical features of elderly patients with MPO-ANCA-positive AAV-ILD. This study retrospectively investigated 63 patients with MPO-ANCA-positive AAV-ILD, all of whom were 65 years or older at diagnosis. Clinical characteristics, causes of death and survival rates among three groups stratified by age (65-74 years, n = 29; 75-79 years, n = 18; over 80 years, n = 16) were compared. This study also examined the association with severe infections in these patients. Among the three age groups, there were significant differences in sex (P = 0.032), serum Krebs von den Lungen-6 (P < 0.01), and total ground-glass opacity score (P = 0.011). The causes of death were mainly severe infections and complications of ILD. Kaplan-Meier curve analysis showed a significantly lower 5-year survival rate in the oldest group (P < 0.01). Regarding severe infections in these patients, the 5-year cumulative incidence of severe infections was higher in the patients receiving steroid pulse therapy (P = 0.034). The clinical characteristics of MPO-ANCA-positive AAV-ILD differ with age in elderly patients, with age being an important poor prognostic factor in these patients. The administration of steroid pulse therapy is a significant risk factor of severe infection in MPO-ANCA-positive elderly patients with AAV-ILD.