Prospective Study of Aspergillus IgG and Clinical Outcomes in Patients with Bronchiectasis

Introduction: Patients with bronchiectasis frequently exhibit impaired mucociliary clearance and compromised immunity, rendering them more susceptible to Aspergillus-related lung diseases. Positive Aspergillus IgG not only indicates potential aspergillosis but also suggests the possibility of chronic Aspergillus infection or exposure. We aimed to evaluate the implications of positive Aspergillus IgG in bronchiectasis patients without aspergillosis. Methods: A total of 235 patients diagnosed with bronchiectasis were prospectively enrolled from three tertiary care hospitals. Serum samples were obtained for the detection of Aspergillus IgG. The associations between Aspergillus IgG levels and clinical outcomes were subsequently analyzed. Results: Aspergillus IgG was positive in 30% (70/235) of the patients. Those with positive Aspergillus IgG demonstrated significantly higher modified Medical Research Council (mMRC) scores (p = 0.001), poorer lung function (p = 0.027), and more severe disease (p = 0.005). Additionally, this group experienced more exacerbations (p = 0.001) and hospitalizations (p = 0.001) in the preceding year. Although there was no significant difference in mortality between the two groups during the 12-month follow-up, patients with positive Aspergillus IgG had more frequent exacerbations and hospitalizations at both 6-month and 12-month follow-ups post-discharge. Multivariate analysis revealed a significant association between positive Aspergillus IgG and an increased risk of exacerbations in bronchiectasis (HR 1.905, 95% CI 1.179–3.077, p = 0.013). Conclusion: Positive Aspergillus IgG is prevalent among bronchiectasis patients. Furthermore, positive Aspergillus IgG is associated with poorer lung function, increased disease severity and more frequent exacerbations in patients with bronchiectasis.