Vascular endothelial growth factor up‐regulation and bronchial wall remodelling in asthma

Abstract

Background There is increasing in vitro evidence to support a role for vascular endothelial growth factor (VEGF), a major regulator of angiogenesis, as a mediator of fibrosis associated with neovascularization. Objective We tested the hypothesis that VEGF is involved both in increased airway mucosal vascularity and in the subepithelial fibrosis of asthmatic patients. Methods Bronchial biopsies were performed in 24 asthmatic patients and eight healthy controls. Immunostaining, using computerized image analysis, was performed using monoclonal antibodies against VEGF⁺ cells, type IV collagen, to outline the basement membrane thickness, and tryptase and EG2, to identify mast cells and eosinophils, respectively. Results The counts of VEGF⁺ cells (P+ cells (both PP+ cells was significantly related to the number of vessels (PPP+ cells (PPPP<0.05) in a subgroup of asthmatic patients. Conclusions This study shows that VEGF, in addition to being involved in the vascular component of airway remodelling, may play a role in the thickening of the basement membrane in asthma.