Role of bronchoscopy for respiratory involvement in eosinophilic granulomatosis with polyangiitis

OBJECTIVES: This study describes data from bronchoscopies performed at the diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA) in Chinese patients. METHODS: We conducted a retrospective study between May 2005 to May 2023 in patients with EGPA who underwent bronchoscopy at the initial diagnosis of the disease. Clinical manifestations and bronchoscopic findings were analysed. RESULTS: 109 patients with EGPA were included, 59 males (54.1%). The most common clinical manifestations were asthma in 104 patients (95.4%), rhinosinusitis in 101 patients (92.7%), and peripheral neuropathy in 70 patients (64.2%). Eosinophilia (>1.0×109/L) was present in 87 patients (79.8%). ANCA positivity was found in 18 patients (16.5%). The most common chest imaging findings were ground-glass opacities in 61 patients (56.0%), bronchial wall thickening and bronchiectasis in 53 patients (48.5%), and consolidation in 52 patients (47.7%). All 109 patients underwent bronchoscopy at diagnosis of the disease. The most common bronchoscopic findings were mucosal oedema and inflammatory changes in 95 patients (87.2%), with specific changes being less common, including tracheobronchial stenosis in 12 patients (11.0%), mucosal nodules and masses in 10 patients (9.2%), and bleeding in 1 patient (0.9%). Transbronchial biopsy (TBB) was performed in 93 patients, with 76 (81.7%) showing pathological support for EGPA, including eosinophilic infiltration in 72 patients (77.4%), vasculitis in 23 patients (24.7%), and granulomas in 7 patients (7.5%). 2 patients underwent transbronchial needle aspiration biopsies of mediastinal lymph nodes, and pathology revealed eosinophilic infiltration and granulomas in both cases. Bronchoalveolar lavage (BAL) was performed in 89 patients, with 67 (75.3%) showing eosinophilia (>1%), and the median percentage of eosinophils was 9 (1, 33%). CONCLUSIONS: Bronchoscopy plays a crucial role in patients with EGPA by detecting endobronchial lesions, providing definitive pathological evidence, and identifying eosinophilic infiltration or infections.