D1.85 - Baseline lung function and clinical outcomes in Allergic Bronchopulmonary Mycosis: A real-world cohort from a Severe Asthma Multidisciplinary Unit

Allergic bronchopulmonary mycosis (ABPM) is a hypersensitivity reaction to fungal airway colonization, most commonly due to Aspergillus (allergic bronchopulmonary aspergillosis; ABPA), characterized by eosinophilia, elevated IgE, and radiologic abnormalities including bronchiectasis. Although FEV1 predicts exacerbation risk and lung function decline, its prognostic role in ABPM has not been well defined.

We conducted a retrospective study of ABPM patients followed in a Severe Asthma Multidisciplinary Unit between 2024-2025. Staging was based on revised ISHAM criteria (remission defined as sustained clinico-radiological improvement and total IgE stability). We searched for association between FEV1% at diagnosis and asthma control (Asthma Control Test; ACT≥20) and ABPM remission at last follow-up. We also characterized changes in eosinophil count, total IgE, and radiologic findings.

Nineteen patients with ABPM and severe asthma were included (median age 67 years [IQR:48-79]; 47.4% female). Mean time since diagnosis was 10.9 years (range:1-31y). Seventeen had ABPA and two non-Aspergillus ABPM (Candida spp). At diagnosis, 11/19 (57,9%) had positive A.fumigatus specific IgE; precipitating IgG antibodies were positive in 9/19 (47.4%). Mean eosinophil count decreased 86.4%. Mean total IgE reduced 2.5%. At follow-up, 12 (63.2%) patients were in ABPM remission, 3 (15.8%) in exacerbation, 3 (15.8%) had advanced fibrotic disease despite asthma control, and 1 (5.3%) had acute ABPA. Fourteen patients had bronchiectasis. FEV1% at diagnosis was significantly higher in patients achieving asthma control at follow-up (82.3% in controlled vs. 56.8% in non-controlled, p=0.045), but was not different between patients with or without ABPM remission (p=0.588). Sixteen patients were treated with biologics (mepolizumab=10; benralizumab=3; tezepelumab=2; dupilumab=1), with 11 (68.8%) achieving asthma control. Two patients were in remission and controlled without biologics, while one patient was undergoing treatment for acute ABPA.

In this real-world ABPM cohort, higher FEV1% at diagnosis was associated with ACT≥20 at follow-up, but not with ABPM remission. Total IgE showed minimal reduction, suggesting limited utility of this measurement in this cohort. Eosinophils decreased considerably due to anti-IL5/IL-5Rα therapy. Larger prospective studies are needed to confirm these findings.