Bronchial vascular remodelling in COPD patients and its relationship with inhaled steroid treatment

Abstract

Background: Up to now, only few studies have evaluated microvascular changes and proangiogenetic mediators in the bronchial mucosa of COPD patients and the results provided were discordant. Furthermore, in this regard, the role of ICS has been scarcely investigated in COPD.

Objective: This study was designed to evaluate vascular remodelling, its relationship with inflammatory cells and treatment effects in bronchial mucosa of COPD patients.

Methods: The study included 10 non-treated COPD patients (COPD), 10 COPD patients treated (COPD/ICS) with nebulized BDP 1600-2400 mcg daily (equivalent to 800-1200 mcg via MDI) and 8 control subjects (CS). Bronchial biopsies were evaluated for number and size of vessels and vascular area. Specimens were also examined for VEGF, bFGF and TGF-β] expression. Moreover, inflammatory cell counts were performed.

Results: Vascular area and vessel size were significantly increased in COPD as compared to COPD/ICS and CS (p<0.05), VEGF+ cells, bFGF+ cells and TGF-β]+ cells were significantly increased in COPD as compared to COPD/ICS and CS (p<0.05). In addition, bFGF+ cells were significantly increased in COPD/ICS as compared to CS. CD8+ and CD68+ cells were significantly increased in COPD as compared to COPD/ICS and CS (p<0.05).

In COPD, VEGF+ cells correlated with number of vessels (p<0.05), vascular area (p<0.01) and vessel size (p<0.05). Moreover, TGF-β]+ cells significantly correlated with vascular area (p<0.05).

Conclusion: Bronchial vascular remodelling in COPD patients is mainly related to morphological changes of the mucosal microvessels rather than to new vessel formation, and may be reduced in patients under steroid treatment.