Diagnostic bronchoscopy for allergic bronchopulmonary aspergillosis/mycosis

<bold>Background and aim:</bold> Diagnostic bronchoscopy is often performed in the patients with allergic bronchopulmonary aspergillosis/mycosis (ABPA/ABPM) to obtain samples for mycological and pathological examination of fungi in the bronchi. We investigated the clinical significance of bronchoscopy for the diagnosis of ABPA/ABPM that has not been validated yet. <bold>Methods:</bold> ABPA/ABPM cases in a Japanese nationwide survey of ABPA/ABPM conducted in 2020 were retrospectively reviewed. ABPA/ABPM was diagnosed based on Asano’s criteria. <bold>Results:</bold> Bronchoscopy had been performed in 317 (73%) cases among 423 patients diagnosed with definite/probable ABPA/ABPM. Patients without asthma (n = 74) were more likely to receive bronchoscopic examination (95%) than asthmatic subjects (68%). Fungal culture in bronchial lavage fluid/mucus plugs (n = 288) was positive in 127 (44%) cases with <italic>Aspergillus</italic> spp., <italic>Schizophyllum commune</italic>, and other fungi, whose positivity was higher than in sputum (34%). Pathological examination of mucus plugs (n = 227) identified fungal hyphae in 113 (42%) cases. In the patients who received bronchoscopic examination, the diagnostic score of Asano’s criteria increased from 6.4 ± 1.2 to 7.0 ± 1.3 (p < 0.001), resulting in the higher rate of definite diagnosis of ABPA/ABPM fulfilling six or more components (77% vs. 87%, p < 0.001). <bold>Conclusions:</bold> Diagnostic bronchoscopy with detailed mycological and pathological evaluation contributes to the more accurate diagnosis of ABPA/ABPM. Supported by Research Grant on Allergic Disease and Immunology from the Japan Agency for Medical Research and Development (23ek0410097)