Stability of eosinophilic inflammation in COPD bronchial biopsies

In their recent research letter, Higham et al. [1], provide valuable data analysing in detail the sources of variability in eosinophil counts in the lamina propria of large airway biopsies from COPD patients, described as "inflammation". The population of COPD they studied seems somewhat atypical from the average COPD patient in having a high median blood eosinophil count of 400 per μL and median bronchodilator reversibility of 15%, potentially consistent with an atopy/asthma-overlap phenotype. Even so, there is arguably no evidence for an inflammatory process being present in the airway sub-epithelial tissue layer. Indeed, interestingly the eosinophil count in the airway tissue was quite closely related to that in the blood, suggesting perhaps that it more reflected movement of cells between these two compartments rather than any local concentration.
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: Original Articles: Correspondence Source Type: research