Eosinophilic Bronchiectasis: Prevalence, Severity, and Associated Features-A Cohort Study.

Area of Science:

• Pulmonology
• Respiratory Medicine
• Clinical Science

Background:

• Bronchiectasis (BE) traditionally involves neutrophilic inflammation.
• Eosinophilic bronchiectasis (EB) is an emerging endotype requiring further characterization.
• Limited data exist on EB prevalence, clinical features, and disease severity.

Purpose of the Study:

• Assess EB prevalence and compare clinical features with non-EB patients.
• Evaluate the Type-2 (T2) high endotype in BE (T2-high EB) versus non-T2-high EB.
• Identify predictors for EB development.

Main Methods:

• Prospective study of 153 BE patients.
• Data collection included clinical, radiological, and microbiological findings.
• EB defined as blood eosinophil count (BEC) ≥ 300 cells/μL; T2-high EB as BEC ≥ 300 cells/μL and fractional exhaled nitric oxide (FeNO) ≥ 25 ppb.
• Disease severity assessed using BSI, FACED, E-FACED, and BACI scores.

Main Results:

• EB prevalence was 27%, and T2-high EB prevalence was 20%.
• EB patients showed poorer lung function, more severe radiologic features, and higher severity scores (BSI, FACED, E-FACED, BACI) compared to non-EB patients.
• EB was associated with higher exacerbation rates and positively correlated with disease severity scores (BSI, FACED, mMRC) and inversely with pulmonary function.

Conclusions:

• EB represents a distinct endotype of bronchiectasis.
• Dyspnea (mMRC ≥ 1), exacerbations (≥ 1/year), and chronic Pseudomonas aeruginosa colonization are significant predictors of EB.
• Blood eosinophil count (BEC) can serve as a valuable biomarker for assessing EB severity and guiding diagnosis.