Doing a bronchoscopy in patients with severe uncontrolled asthma may help to more accurately identify candidates for biologic therapy, suggests a study recently reported in the journal Chest.¹

Researchers from Spain enrolled 100 patients with severe uncontrolled asthma from specialized asthma clinics at five hospitals. They aimed to study the usefulness and safety of bronchoscopy in evaluating patients before initiating treatment with a biologic. Bronchoscopy was done in all patients as part of the routine assessment.  Clinically, 28% patients were categorized as T2-allergic, 64% as T2-eosinophilic and 8% as non-T2 based on blood eosinophil count, fractional exhaled nitric oxide (FeNO) and immunoglobulin (Ig) E. Bronchial aspirates and biopsies were collected during bronchoscopy and compared between the different patient groups.

Twenty-one percent of patients were found to have GERD on bronchoscopy, 5% had vocal cord dysfunction, while 3% patients had tracheal abnormalities. 91% of the bronchial biopsies collected from 68% of patients showed the presence of eosinophils.

Results also showed that nearly 8% of patients who were earlier categorized as T2-phenotype did not have eosinophils in the bronchial biopsy, while biopsies of three patients in the non-T2 group showed eosinophils. Nearly 89% of patients in the T2-allergic group were found to be T2-eosinophilic based on the presence of submucosal eosinophils in biopsy specimens.

On culture of the bronchial aspirate, bacteria (most commonly Pseudomonas aeruginosa and Staphylococcus aureus) were isolated in 27% of patients. In 14% of patients, fungi (Aspergillus spp. most commonly) were isolated.

Given that biologics are only effective in eosinophilic or allergic asthma, these findings demonstrating “poor correlation between blood and tissue eosinophils” make the case for adoption of bronchoscopy in routine evaluation of patients with severe uncontrolled asthma. They also highlight the limitations of using blood eosinophil count and FeNO as biomarkers of T2 inflammation. In this age of personalized or precision medicine, routine bronchoscopy can be safely done in individual patients “to better phenotype and personalize asthma management” with optimal patient outcomes. Moreover, bronchoscopy can detect underlying treatable medical conditions that could be contributing to poor asthma control, such as GERD and infections as shown in this study thus precluding the use of biologics.

Reference

1. Cosio BG, et al. Redefining the role of bronchoscopy in the work-up of severe uncontrolled asthma in the era of biologics: a prospective study. Chest. 2023 Mar 13;S0012-3692(23)00354-9. doi: 10.1016/j.chest.2023.03.012.