The risk factors of anti-neutrophil cytoplasmic antibody-associated vasculitis-associated interstitial lung disease: a systematic review and meta-analysis

BACKGROUND: Anti-neutrophil cytoplasmic Antibody-Associated Vasculitis (AAV) is an immune-mediated disease characterized by Anti-Neutrophil Cytoplasmic Antibody (ANCA) positivity. Patients with AAV are known to be at high risk for the occurrence of Interstitial Lung Disease (ILD). The authors aimed to explore the risk factors in patients with AAV-ILD to enhance awareness among the public and healthcare providers, and to facilitate the timely adoption of effective strategies for prevention and management. METHODS: The authors searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure Database (CNKI), the WanFang Database, Chinese biomedical literature service system (SinoMed), and China Science and Technology Journal Database (VIP) for studies that focused on the risk factors in patients with AAV-ILD from database inception to 21 September 2024. Methodological quality was assessed using the Newcastle-Ottawa Scale (NOS). The authors used a random-effects model or a fixed-effects model to evaluate the underlying risk factors of AAV-ILD. RESULTS: A total of 25 studies were included, including 13 case-control studies, 5 cohort studies, and 7 cross-sectional studies, respectively. The authors identified preliminary risk factors for AAV-ILD, including age, male, smoking history, KL-6, ESR, MPO-ANCA, cough, dyspnea, and HRCT findings such as honeycombing, interlobular septal thickening, and lattice shadows, Ear, nose & throat involvement, Hb, alb, BVAS, and fever. The study design type, follow-up (time), Country, sample, type of AAV, quality score, and were initially considered not to be sources of heterogeneity. CONCLUSIONS: This study has preliminarily identified multiple risk factors associated with ILD in AAV patients, encompassing sociodemographic, lifestyle, and clinical factors. While these findings may serve as a reference for further investigation, large-scale prospective cohort studies or longitudinal research remain necessary for validation. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, identifier CRD42024592874.