Increased expression of Vascular Endothelial Growth Factor-A in seasonal allergic rhinitis

Increased vascular dilatation and permeability characterize allergic rhinitis. In this study oligonucleotide microarrays (Affymetrix HuGe95A) were used to identify differentially expressed vasoactive genes in nasal biopsies from 23 patients with symptomatic seasonal allergic rhinitis (SAR) and 12 healthy controls. RNA was extracted from the biopsies and pooled in three patient and three control pools. Out of 12,626 analysed transcripts, 39 were higher and 81 lower in the patients. Of these transcripts two have vasoactive effects: Vascular Endothelial Growth Factor-A (VEGF-A) and the Beta-1-Adrenergic Receptor. Both were higher in patients than in controls. The mean +/- SEM expression levels in arbitrary units of VEGF-A were 130 +/- 123 in the patients and 59 +/- 53 in the controls. The fold ratio in expression levels between patients/controls was 2.2. The corresponding values for the beta-1-adrenergic receptor were 129 +/- 123 in the patients and 40 +/- 31 in the controls. The fold ratio between patient/controls was 3.2. The role of VEGF-A was assessed by determining VEGF-A concentrations in nasal fluids from another 30 patients with SAR before and after allergen provocation. VEGF-A increased from 124.3 +/- 30.2 to 163.2 +/- 37.8 pg/ml after challenge, P < 0.05. In summary, oligonucleotide microarray analysis of nasal biopsies and protein analyses of nasal fluids indicate that VEGF-A may be an important mediator in SAR.