Is blood eosinophil count better predictor of COPD exacerbation compared to exacerbation history?

A new study published in BMC Respiratory Research suggests that among patients with COPD, blood eosinophil count does not predict future exacerbations  in the same way that exacerbation history does.

The ability of blood eosinophils to predict the effects of inhaled corticosteroids (ICS) on chronic obstructive lung disease (COPD) is of interest. The majority of the data come from interventional clinical research; however, information from randomly chosen real-world populations may aid to improve treatment choices. 

DACCORD is a real-world, non-interventional research. Heinrich Worth and team conducted this study where patients with COPD who had been receiving triple treatment for less than six months were enrolled in Cohort 3. Patients were followed for a year after switching to a long-acting muscarinic antagonist/long-acting beta2-agonist (LABA/LAMA) or continuing triple therapy. Patients were separated into four groups for these post-hoc analyses based on their history of exacerbations and baseline blood eosinophil count (100 vs. > 300 cells/L). Exacerbation rates were determined for both treatments individually and as a whole.

The key findings of this study were:

The main groups of the 430 individuals included in the current analysis had modest exacerbation histories with high (44.2%) or low (36.7%) eosinophil counts. 

The majority of patients (68.8% overall; 83.2% and 63.7% with LABA/LAMA and triple treatment) did not worsen throughout follow-up. 

The greatest exacerbation rates were in groups with a high history of exacerbations, which substantially differed from groups with a low history of exacerbations (matched by eosinophil count) in the overall analysis. 

Rates did not change when groups were made based on eosinophil count (matched by exacerbation history).

In conclusion, according to this study findings, although eosinophil count may serve to guide the start of inhaled corticosteroids (ICS) in COPD patients, it is less of a factor when switching from triple treatment to a LABA/LAMA.

Reference: 

Worth, H., Buhl, R., Criée, C.-P., Kardos, P., Gückel, E., & Vogelmeier, C. F. (2023). In ‘real world’ patients with COPD, exacerbation history, and not blood eosinophils, is the most reliable predictor of future exacerbations. In Respiratory Research (Vol. 24, Issue 1). Springer Science and Business Media LLC. https://doi.org/10.1186/s12931-023-02311-x