Increased levels of vascular endothelial growth factor in induced sputum in asthmatic patients.
BACKGROUND
Vascular endothelial growth factor (VEGF) is highly expressed in the airway of asthmatic patients. As VEGF increases airway vascular permeability, consequent thickening of the airway wall mucosa may lead to narrowing of the airway lumen.


OBJECTIVE
We evaluated the relationship between VEGF levels in induced sputum and eosinophilic inflammatory profiles, and the degree of airway vascular permeability in asthmatic patients and we evaluated the effect of inhaled corticosteroids on VEGF levels in induced sputum.


METHODS
Induced sputum specimens were obtained from 28 glucocorticosteroids free asthmatics and 11 healthy control subjects. We examined VEGF levels and airway vascular permeability index in induced sputum. After the initial sputum induction, 21 asthmatics received 8-week inhaled beclomethasone dipropionate (BDP, 800 micro g/day) therapy, then sputum induction was repeated.


RESULTS
The VEGF levels in asthmatics were significantly higher than in healthy control subjects (P < 0.0001). The VEGF levels were negatively correlated with forced expiratory volume of 1 s (FEV1, % predicted, r = - 0.68, P < 0.001), the percentage of eosinophils (r = 0.51, P < 0.01) and ECP levels (r = 0.39, P < 0.05). Moreover, the VEGF levels were significantly correlated with airway vascular permeability index (r = 0.61, P < 0.001). After 8-week inhaled BDP therapy, the VEGF levels were significantly decreased compared to pretreatment levels (P < 0.0001) and the VEGF levels were significantly correlated with airway vascular permeability index even in post-treatment asthmatics (r = 0.62, P < 0.01).


CONCLUSIONS
The VEGF levels in induced sputum were increased in asthmatics and its levels were associated with degree of airway narrowing and airway vascular permeability. These findings provide strong evidence that VEGF may play an important role in the pathogenesis of bronchial asthma.
Asai
K
K
Department of Respiratory Medicine, Graduate School of Medicine, Osaka City University, Abeno-ku, Osaka, Japan. kazuasai@msic.med.osaka-cu.ac.jp
Kanazawa
H
H
Kamoi
H
H
Shiraishi
S
S
Hirata
K
K
Yoshikawa
J
J
D000328:Adult; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D001507:Beclomethasone / Q000627:therapeutic use; D002199:Capillary Permeability / Q000187:drug effects; D016228:Endothelial Growth Factors / Q000378:metabolism*; D004804:Eosinophils / Q000473:pathology; D005260:Female; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D007958:Leukocyte Count; D008222:Lymphokines / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D013183:Sputum / Q000166:cytology / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D018927:Anti-Asthmatic Agents; D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D001507:Beclomethasone