D1.50 - Allergic Bronchopulmonary Aspergillosis in a Tertiary Allergy Center: Clinical Characteristics, Radiologic Subtypes, and Biologic Use

Allergic bronchopulmonary aspergillosis (ABPA) is hypersensitivity reaction to Aspergillus fumigatus. Recognizing its clinical impact, the recent ISHAM guideline recommends assessing A. fumigatus sensitization in all newly diagnosed adult asthma patients in tertiary care settings. We aimed to characterize the clinical features of ABPA in patients managed at a single tertiary allergy center.

We retrospectively reviewed patients who were diagnosed with ABPA between 2004 and 2025 at the Allergy-Asthma Center, Severance Hospital. ABPA was adjudicated according to the 2024 revised ISHAM-ABPA criteria. A. fumigatus sensitization was defined as specific IgE ≥0.35 kUA/L. Diagnostic cut-offs were total IgE ≥500 IU/mL, A. fumigatus-specific IgG ≥27 mgA/L, and blood eosinophils ≥500 cells/µL. Chest computed tomography (CT) was performed in all 31 patients, and radiologic subtypes were classified as ABPA-S, ABPA-B, ABPA-MP, ABPA-HAM, or ABPA-CPF.

31 patients were included (61% female; mean age at diagnosis, 57.9 ± 13.7 years). Median (IQR) values were: A. fumigatus-specific IgE 1.9 (0.6–7.7) kUA/L; total IgE 1217 (656–2167) IU/mL; A. fumigatus-specific IgG 43.0 (29.8–65.5) mgA/L; blood eosinophil count 1370 (660–2420) cells/µL; and induced sputum eosinophils 28 (8–48.5)%. The mean spirometric values with standard deviations were FVC 56.1 ± 22.0%prediceted and and FEV1 72.2 ± 14.6 %prediceted.

Seven patients received oral corticosteroids (OCS) for over 2weeks, while 15 patients were prescribed short-course OCS (1-2 weeks) as rescue medication at follow-up visits. Itraconazole was administered in 14 patients. Nine patients received biologic therapy for severe asthma; among them, seven received reslizumab, one omalizumab, and one dupilumab. Radiologic subtypes on chest CT were ABPA-S (n=11), ABPA-B (n=7), ABPA-MP (n=8), ABPA-HAM (n=2), and ABPA-CPF (n=3).

In this tertiary allergy center cohort, ABPA was characterized by a high type 2 inflammatory burden with frequent use of antifungal therapy and biologics, underscoring the need for systematic A. fumigatus sensitization screening and phenotype-guided management in asthma patients referred to specialty care.