Abstract
BACKGROUND: Elevated Aspergillus fumigatus (A. fumigatus)-specific Immunoglobulin E (IgE) is recognized as an essential diagnostic criterion for allergic bronchopulmonary aspergillosis (ABPA). However, it remains unknown whether initial A. fumigatus-specific IgE at acute stage has a role beyond diagnostic purposes. METHOD: This two-center retrospective study enrolled 149 acute ABPA patients. Risk factors for one-year exacerbation were analyzed using univariate and multivariate logistic regression. Participants were then divided into a discovery cohort (n = 93) to determine the optimal initial A. fumigatus-specific IgE cut-off value via receiver operating characteristic (ROC) curve, and a validation cohort (n = 56) to confirm exacerbation differences based on this cut-off value. RESULT: Multivariate logistic regression analysis revealed that female sex (odds ratio (OR) 2.44, 95% confidence interval (CI) 1.15-5.16, P = 0.020), A. fumigatus-specific IgE (OR 1.05, 95% CI 1.02-1.08, P = 0.002), and bronchiectasis (OR 3.61, 95% CI 1.07-12.21, P = 0.039) were independent risk factors for ABPA exacerbation. In the discovery cohort, the optimal initial cut-off value for A. fumigatus-specific IgE was calculated to be 9.88 kUA/L. And, the validation cohort confirmed that patients with A. fumigatus-specific IgE > 9.88 kUA/L were at higher risk of exacerbation (P = 0.005). CONCLUSION: This study highlighted the prognostic utility of initial A. fumigatus-specific IgE at acute stage and found that elevated levels, especially those exceeding 9.88 kUA/L, were associated with increased risks of exacerbation in ABPA patients.