Introduction

Two  eosinophil sub-types have been recently described in murine model, a.) inflammatory  (iEos) and b.) resident or physiological (rEos). Different proportions of those sub-types may help explain variance in clinical expression between asthma and COPD. This study compared subtypes of eosinophils in bronchial tissue of asthmatic and COPD patients.

Methods

Two stable cohorts were studied: COPD and asthma patients. Bronchial biopsies and peripheral blood from the same patients were studied by flow cytometry for surface protein profiles for eosinophilic differentiation (rEos: Siglec-8+CD62L+IL-3Rlo and iEos: Siglec-8+CD62LloIL-3Rhi). The IL-5 receptor and CD11b were also measured.

Results 

Ten COPD patients and ten asthma patients were recruited. The proportion of inflammatory eosinophils is different in asthma patients in bronchial tissue and blood  (Table 1).  IL5 receptors have decreased in bronchial tissue of asthma patients (Figure 1). Other CD markers such as CD11b and IL3 receptors were not significantly different between asthmatics  and COPD in bronchial tissue. 

Conclusión

This study shows differences in the eosinophils between COPD and asthma patients in bronchial tissue. There are more inflammatory eosinophils in asthma patients compared to COPD in bronchial tissue and blood. Differentiating subtypes of eosinophils could help to direct the target for biological therapies in both COPD and asthma.