Eosinophilic COPD phenotyping: a cluster analysis approach

<bold>Introduction:</bold> The inflammatory pattern in COPD can vary, and in some patients, eosinophils may cause inflammation, that promotes airway obstruction. GOLD guidelines recommend adding inhaled corticosteroids (ICS) to long-acting bronchodilators only in patients with at least one moderate exacerbation per year and peripheral blood eosinophils ≥100 cells/uL. However, the ICS response could be uneven in these patients, suggesting the presence of other features that could impact the response to treatment. <bold>Aims and Objectives:</bold> To identify different clusters of patients with eosinophilic COPD. <bold>Methods:</bold> We enrolled 173 patients with a diagnosis of COPD and peripheral blood eosinophils ≥100 cells/uL. We performed a cluster analysis, considering several anamnestic, clinical, functional and radiological features. <bold>Results:</bold> The analysis showed the presence of two clusters. Patients belonging to the first one were younger (p= 0.02), had a less frequent familiarity for COPD (p = 0.01) and for work exposure to toxic agents (p = 0.04), had fewer comorbidities (p = 0.01) and fewer COPD-related symptoms (p < 0.0001). The second cluster of patients, on the other hand, showed more severe symptoms and exacerbations despite a lower blood eosinophilic count (p <0.0001). <bold>Conclusions:</bold> Patients with a higher blood eosinophilic count tend to show a milder COPD phenotype, while those with a lower eosinophilic trait are more prone to develop exacerbations and COPD-related symptoms. Finding additional biomarkers is necessary to pinpoint more specific treatable traits and to develop more individualized therapies