Clinical significance of increased vascular endothelial growth factor, transforming growth factor-beta1, and YKL-40 in the serum of children with asthma

ABSTRACT

PURPOSE: Vascular endothelial growth factor (VEGF), transforming growth factor beta1 (TGF-beta1), and platelet derived growth factor (PDGF) are known to be involved in the pathogenesis of inflammation and remodeling in asthmatic airways. YKL-40, a chitinase-like protein, and clusterin have been reported to be biomarkers for severe asthma. We examined the serum levels of growth factors, YKL-40, and clusterin in children with acute asthma or stable asthma, and investigated their correlation with clinical findings and lung function parameters. METHODS: Forty-one children (> or =6 years of age) with asthma were enrolled, and 2 groups were defined 23 patients admitted with acute asthma (acute asthma group) and 18 patients with stable asthma (stable asthma group). The serum levels of VEGF, TGF-beta1, PDGF-BB, YKL-40, and clusterin were measured using enzyme-linked immunosorbent assay and assessed in relation to clinical manifestations and spirometric parameters. Fifteen age-matched controls were also studied. RESULTS: The serum levels of VEGF, TGF-beta1, and YKL-40 were significantly elevated in children with acute asthma compared to controls. The serum levels of VEGF and YKL-40 were higher in the stable asthma group than in controls. The serum levels of VEGF, TGF-beta1, and YKL-40 were not different between the acute asthma and stable asthma groups. The serum VEGF levels in the acute asthma group correlated significantly with asthma severity. The serum TGF-beta1 levels in stable asthma group showed a significant inverse correlation with (FEV1) forced expiratory volume in one second and FEF(25%-75%) (forced expiratory flow between 25 and 75 percent of expired vital capacity). Serum YKL-40 had no significant relationship with clinical manifestations and spirometric parameters. CONCLUSION: Our study suggests that increased serum levels of VEGF and YKL-40 might affect asthmatic airways not only during acute exacerbation but also in stable state and that serum TGF-beta1 might be a biomarker for airway obstruction in children with asthma.