LUNG FUNCTION OF PATIENTS WITH AN EOSINOPHILIC PHENOTYPE: AN ANALYSIS OF THE US BRONCHIECTASIS AND NTM RESEARCH REGISTRY

SESSION TITLE: Late-Breaking Developments in the Management of Obstructive Lung Disease SESSION TYPE: Original Investigations PRESENTED ON: 10/10/2023 10:30 am - 11:30 am PURPOSE: Eosinophilic bronchiectasis is an emerging phenotype that has been associated with worse clinical outcomes compared to those without this feature. The objective of this study was to evaluate the lung function and the other clinical characteristics of patients with an eosinophilic bronchiectasis phenotype in the US Bronchiectasis and NTM Research Registry (BRR). METHODS: Patients with non–cystic fibrosis bronchiectasis and a baseline blood eosinophil count in the BRR database were included in this study. The eosinophilic phenotype was defined as a blood eosinophil count ≥ 150 cells/mcL. Baseline clinical characteristics, including demographics, comorbidities, lung function, symptoms, history of exacerbations, and positive Pseudomonas aeruginosa cultures were evaluated in the overall cohort and stratified by eosinophil count (<150 and ≥ 150 cells/mcL). Categorical variables were compared using chi-square tests, and continuous variables were compared using t-tests. Log-binomial regression models were fit to estimate unadjusted risk ratios and 95% CI to model the probability of clinically important variables in patients with an eosinophilic phenotype. A multivariable analysis adjusting for covariates of interest (gender, age, asthma, COPD, dyspnea, fatigue, corticosteroid use, exacerbation history, type of cultures) was performed. RESULTS: 872 patients were included in the study (mean age 67.5±12.4 years, 79.4% women) and 400 (46%) were considered to have an eosinophilic phenotype. Gender, baseline diagnosis of asthma or COPD, prior 2-year history of exacerbations, positive cultures for Pseudomonas aeruginosa, and non-tuberculous mycobacteria were comparable between groups. Compared to patients with no eosinophilic phenotype, those with the eosinophilic phenotype had worse lung function (FEV1 70.9±22.9 vs 77.8±22.7 % predicted, p<0.001) and more frequently self-reported fatigue (57 vs 48%, p=0.011). Univariate analyses revealed that the risk of pre-bronchodilator FEV1 less than 80% predicted among patients with an eosinophilic phenotype was 28% higher than among patients without an eosinophilic phenotype (RR 1.28; 95% CI: 1.13, 1.45, p<0.001). There was a 21% increased risk of decreased lung function (i.e., FEV1 < 80%) for patients with an eosinophilic phenotype compared to a non-eosinophilic phenotype, after controlling for all other factors (RR 1.21, 95% CI: 1.01,1.46, p= 0.044). CONCLUSIONS: The eosinophilic bronchiectasis phenotype was associated with significantly worse lung function compared to those without this phenotype. Further, longitudinal studies are needed to evaluate lung function decline in this subgroup of patients over time. CLINICAL IMPLICATIONS: These results further support that patients with eosinophilic bronchiectasis may have distinct characteristics and clinical course. These patients may require different therapeutic strategies, including those that target eosinophilphilic inflammation. DISCLOSURES: PI for a clinical trial; relationship with AN2 Please note: 2021 to present Added 11/13/2022 by Doreen Addrizzo-Harris PI of research trial relationship with Boehringer Please note: 2022-2023 Added 04/01/2023 by Doreen Addrizzo-Harris to my institution PI for research grant relationship with Zambone Please note: 2018-2021 by Doreen Addrizzo-Harristo my institution PI for research trial relationship with Hill-Rom Please note: 2019-2023 Added 04/01/2023 by Doreen Addrizzo-Harris to my institution Clinical Trial, I am PI relationship with Insmed Please note: 2017-2023 Added 04/01/2023 by Doreen Addrizzo-Harris to my institution No relevant relationships by Timothy Aksamit Consultant relationship with Physio-Assist Please note: 2021 Added 11/04/2022 by Ashwin Basavaraj Advisory Board, PI in clinical study relationship with Hill-Rom Please note: 2019-present Added 11/04/2022 by Ashwin Basavaraj Advisory Board relationship with Insmed Please note: 2018-present Added 11/04/2022 by Ashwin Basavaraj Advisory Committee Member relationship with Zambon Please note: 2021 Added 10/24/2022 by Ashwin Basavaraj Principal investigator in clinical trial relationship with Baxter Please note: 2020-present Added 10/24/2022 by Ashwin Basavaraj Consultant relationship with Insmed Please note: 2018-present Added 10/24/2022 by Ashwin Basavaraj Consultant relationship with Dymedso Please note: 2021 Added 11/04/2022 by Ashwin Basavaraj Consultant relationship with Zambon Please note: 2021 Added 11/04/2022 by Ashwin Basavaraj No relevant relationships by Amanda Brunton No relevant relationships by Radmila Choate No relevant relationships by Alejandro Diaz Consultant relationship with AstraZeneca Please note: $5001 - $20000 by Diego Maselli Caceres, Consultant relationship with Amgen Please note: 10/1/2021 by Diego Maselli Caceres, Speaker/Speaker's Bureau relationship with Sanofi/Regeneron Please note: 1 year by Diego Maselli Caceres, value=Honoraria Speaker/Speaker's Bureau relationship with AstraZeneca Please note: 1 year by Diego Maselli Caceres, value=Honoraria Speaker/Speaker's Bureau relationship with GSK Please note: 1 year by Diego Maselli Caceres, Consultant relationship with Sanofi/Regeneron Please note: $5001 - $20000 by Diego Maselli Caceres, Consultant relationship with GSK Please note: $5001 - $20000 by Diego Maselli Caceres, Speaker/Speaker's Bureau relationship with Insmed Please note: recused October 2022 Added 06/01/2023 by Pamela McShane, value=Honoraria Advisory Committee Member relationship with Insmed Please note: 2021-ongoing Added 04/06/2023 by Mark Metersky Advisory Committee Member relationship with Boehringer-Ingelheim Please note: 2022 Added 04/06/2023 by Mark Metersky No relevant relationships by Bruce Miller No relevant relationships by Marcos Restrepo No disclosure on file for George Solomon No disclosure on file for Meilinh Thi