S146 Aspergillus in bronchiectasis: data from the EMBARC registry

Introduction Aspergillus fumigatus causes airway disorders including Allergic bronchopulmonary aspergillosis (ABPA), Aspergillus sensitisation (AS) and Aspergillus bronchitis (AB). The clinical significance of Aspergillus lung diseases in bronchiectasis is not well understood, partially due to no universally-accepted diagnostic criteria for ABPA. Objective Investigate the clinical significance of Aspergillus disease in bronchiectasis while comparing existing and modified ABPA diagnostic criteria. Methods Bronchiectasis patients enrolled into the EMBARC registry from 2015–2022 with serological testing for Aspergillus disease (total IgE, Aspergillus-specific IgE or Aspergillus skin test, Aspergillus-specific IgG and blood eosinophil counts) were included. ABPA was defined using Modified-ISHAM criteria (2021) with sensitivity analysis performed using ISHAM-ABPA criteria (2013). Elevated Aspergillus-specific IgE/positive Aspergillus skin test without ABPA was deemed ‘AS’. Those with elevated Aspergillus-specific IgG without ABPA acted as surrogate for AB. Patients not meeting these criteria formed the control group. Exacerbations during annual follow-up were analysed using negative binomial modelling and survival analysis was performed using Cox proportional hazards regression with adjustment for relevant confounders. Results 9953 patients were included. Using Modified-ISHAM criteria (2021), 608 (6.1%) had ABPA, 570 (5.7%) showed AS, 806 (8.1%) had raised Aspergillus-specific IgG, 184 (1.8%) had both AS and raised Aspergillus-specific IgG and 619 (6.2%) had elevated eosinophil counts without Aspergillus disease. 78 ABPA diagnoses were missed using the original ISHAM-ABPA criteria (2013) (31 previously AS, 47 previously AS with raised Aspergillus-specific IgG). All patients with Aspergillus disease had more severe bronchiectasis and worse lung function at baseline. Long-term follow-up revealed patients with raised Aspergillus-specific IgG experience more exacerbations (RR1.19 95%CI 1.05–1.35, p=0.008) and more frequent hospitalisations (RR1.66 95%CI 1.37–1.99, p<0.001), while a trend towards increased mortality was observed in those with ABPA (HR 1.40 95%CI 0.99–1.99, p=0.057). Inhaled corticosteroids modified hospitalisation risk associated with AS (RR0.70 95%CI 0.54–0.90, p=0.006 vs RR0.91 95%CI 0.54–1.52, p=0.71) and raised Aspergillus-specific IgG (RR1.32 95%CI 1.04–1.68, p=0.02 vs RR2.26 95%CI 1.68–3.02, p<0.001). Conclusion Aspergillus disease is common in bronchiectasis and associates with worsened disease severity and outcomes which can be modified by ICS. The Modified-ISHAM criteria (2021) captured ABPA diagnoses that would have been missed using existing ISHAM-ABPA criteria (2013). Please refer to page A288 for declarations of interest related to this abstract.