Serum transforming growth factor-beta1 in asthmatic children

Abstract

Background: Transforming growth factor-beta1 is a multifunctional cytokine which has been linked to the pathogenesis of subepithelial fibrosis and airway wall remodeling in bronchial asthma. Objective: To outline the changes in serum TGF-beta1 in children with bronchial asthma in relation to severity of asthma and different treatment modalities. Methods: Twenty-three children with bronchial asthma recruited from the Pediatric Allergy and Immunology Clinic of Ain Shams University Children’s Hospital were enrolled in the study as well as 29 healthy controls. Asthmatic children were classified according to severity into two groups; the mild asthma group which included 12 children, 4 with mild intermittent and 8 with mild persistent asthma (none received steroid therapy), and the severe persistent asthma group which included 11 children (all were on steroid therapy). All patients were subjected to clinical evaluation and laboratory investigations including absolute eosinophilic count (AEC), total serum IgE% and biologically active serum TGF-beta1 by ELISA technique. All patients were studied during acute asthma exacerbations. Reevaluation during steady state asthma was carried out for 8 patients with mild persistent asthma and 9 with severe persistent asthma. Results: During acute asthma exacerbations, the mean serum TGF-beta1 was significantly elevated in mild asthma (77.04 ± 57.04 ng/ml) compared to controls (21.81 ± 22.09 ng/ml). However for severe persistent asthma , the mean serum TGF-beta1 was significantly lower (4.23 ± 0.85 ng/ml) than in controls. Comparison of paired observations of serum TGF-beta1 revealed a significant drop, during steady state, in patients with mild asthma, whereas in severe asthma, a significant rise was observed. The levels of both asthma groups during steady state were comparable to the control values. A positive correlation, of borderline significance, between serum TGF-beta1 and total serum IgE% was observed among mild asthamtics during acute exacerbations (r = 0.55). Conclusion: The behavior of serum TGF-beta1 in acute asthma exacerbations depends on asthma severity and is perhaps related to steroid inhalation therapy. The tendency towards normality of serum TGF-beta1 in steady state asthma is possibly a good prognostic sign.

Keywords: TGF-beta1, bronchial asthma, children, remodeling

Egypt J Pediatr Allergy Immunol 2004; 2(1): 46-51