Blood eosinophil count and treatment patterns of chronic obstructive pulmonary disease patients in South Korea using...

Chronic obstructive pulmonary disease (COPD) management guidelines have increasingly emphasised the importance of exacerbation prevention, and the role of blood eosinophil count (BEC) as a biomarker for inhaled corticosteroids (ICS) response. This study aimed to describe the distribution and stability of BEC and understand real-world treatment patterns among COPD patients in South Korea.

This was a retrospective database analysis using data obtained from the KOrea COPD Subgroup Study (KOCOSS) registry between January 2012 and August 2018. KOCOSS is an ongoing, longitudinal, prospective, multi-centre, non-interventional study investigating early COPD amongst South Korean patients. BEC stability was assessed by calculating the intra-class correlation (ICC) coefficient. "Exacerbators" were patients who had a record of ≥ 1 exacerbation in the 12 months prior to the visit.

The study included 2,661 patients with a mean age of 68.6 years. Most patients were male (92.0%). Mean BEC was significantly higher in exacerbators compared to non-exacerbators. Patients with ≥ 2 exacerbations at baseline had a less stable BEC over time (ICC = 0.44) compared to non-exacerbators (ICC = 0.57). Patients with BEC ≥ 300 cells/μL at baseline predominantly received triple therapy (43.8%).

This study may further develop current understanding on BEC profiles amongst COPD patients in South Korea. BEC measurements are stable and reproducible among COPD patients, which supports its use as a potential biomarker.