Relationships between Airway Remodeling and Clinical Characteristics in COPD Patients

Abstract

Background: Airway remodeling is a cardinal feature of chronic obstructive pulmonary disease (COPD) pathology. However, inconsistent findings have been reported regarding the nature of proximal airway remodeling in COPD. This is likely due to the heterogeneity of COPD. This study investigated the histopathological features of airway remodeling in bronchial biopsies of COPD patients compared to smoking controls (S). We tested the hypothesis that histopathological features in bronchial biopsies relate to clinical characteristics in COPD patients, focusing on smoking status, symptom burden, lung function, exacerbation risk and inhaled corticosteroid (ICS) use. Methods: We recruited 24 COPD patients and 10 S. We focused on reticular basement membrane thickness (RBM), surface immunoglobulin A (IgA) expression, goblet cell numbers (periodic acid-Schiff [PAS]+), sub-mucosal remodeling markers including collagen 4, 6 and laminin expression, and inflammatory cell counts (CD45+). Results: RBM thickness was increased in frequent exacerbators, IgA expression was reduced in COPD patients with worse lung function, and goblet cell numbers were increased in COPD patients compared to S but with no difference between the COPD subgroups. Collagen 4 expression was associated with higher symptom burden and worse quality of life. Sub-mucosal inflammatory cell counts were increased in COPD non-inhaled corticosteroid (ICS) users compared to ICS users and S. Conclusion: We observed relationships between the histopathological features of airway remodeling and clinical characteristics in COPD patients. Our data highlight the influence of clinical heterogeneity on diverse patterns of airway remodeling in COPD patients.

Polymerized cyclodextrin microparticles for sustained antibiotic delivery in lung infections

“…The H&E staining was utilized to determine the inflammatory response to the microparticles. The PAS stain detects carbohydrates and polysaccharides to determine the presence of lung damage and the presence of perfuse mucin infiltrate 27,28 . The lung histology suggests the absence of lung damage, consistent with minimal inflammation (designated by the arrows that highlight epithelium and interstitial tissue in Figure 7B,C).…”

“…The PAS stain detects carbohydrates and polysaccharides to determine the presence of lung damage and the presence of perfuse mucin infiltrate. 27,28 The lung histology suggests the absence of lung damage, consistent with minimal inflammation (designated by the arrows that highlight epithelium and interstitial tissue in Figure 7B,C). Mucin accumulation was minimal, with no pink carbohydrate and phospholipid materials accumulated in the airway spaces (designated by black arrows, Figure 7D,E).…”

“…Fixed lung sections were stained with either hematoxylin and eosin (H&E) or periodic acid Schiff (PAS) to define the lung response to the infection with and without microparticle delivery. H&E facilitates documentation of the inflammatory cell recruitment into the tissue whereas accumulation of mucin based carbohydrates and polysaccharides was visualized with PAS 27,28 …”

“…H&E facilitates documentation of the inflammatory cell recruitment into the tissue whereas accumulation of mucin based carbohydrates and polysaccharides was visualized with PAS. 27,28…”