Contribution of vascular endothelial growth factor to pathophysiology of bronchial asthma Mohamed El-Ghazali, Asser Kamar, Hoda El-Attar.

Abstract EN

Vascular endothelial growth factor, a regulator of angiogenesis and vascular permeability, is highly expressed in asthmatic airways.

So this work was undertaken to evaluate the relationship between serum levels of VEGF and both pulmonary function data in chronic stable asthma and bronchia hyper responsiveness in exercise-induced bronchospasm (EIB) Fifteen normal subjects (6 females and 9 males) and fifteen asthmatics with EIB (7 females and 8 males) were subjected to pulmonary function tests and exercise challenge.

Serum VEGF was assessed at rest and at post-exercise maximal bronchoconstriction.

All pulmonary function data in asthmatics were significantly lower than the corresponding values in controls.

The concentration of serum VEGF in asthmatics were higher than in controls (130.33 ± 49.7 ng/ml versus 11.75 ± 2.6 ng/ml, p < 0.001) and correlated significantly with severity of asthma assessed by FEV/FVC% (r = -0.9243, p < 0.001) and Spiro metric parameters of small airways including FEE25%( r=- 0.8052, p < 0.001) and FEF50% (r =-0.7796, 0.001 and EFE75% (r = -0.7224, p< 0.001).

After exercise, VEGF increased significantly to be 1680.33±49.7 ng /ml in asthmatics (p < 0.001) and the degree of post-exercise change in VEGF was significantly correlated with the degree of bronchial hyper responsiveness toexercise (r= 0.8368, p < 0.001).

Also, post-exercise recovery time was correlated significantly with the basal serum level of VEGF (r = 0.8878, p < 0.001).

In conclusion, increased VEGF expression may be involved in pathophysiology of bronchial asthma most probably either through increased angiogenesis and micro vascular remodeling in stable chronic asthma or via increased vascular permeability and hyperemia in exercise–induced bronchoconstriction.

This concept may represent a new target for asthma therapy.