Usefulness of periostin as a biomarker of pediatric asthma

Background: There few biomarkers of asthma which can be easily assessed for clinical use, especially in children. Periostin is an extracellular matrix protein and is upregulated by IL-4 and IL-13 stimulation from airway epithelial cells and other structural cells. Serum periostin is expected as a non-invasive biomarker for asthma diagnosis and management. Purpose: To assess the usefulness of serum periostin levels as a clinical biomarker of pediatric asthma. Method: 29 asthmatic children (BA) and 27 non-asthma control children (Cont) were investigated (6-16 years). Bronchial asthma was diagnosed by ISAAC medical questionnaire, and methacholine challenge test was performed for BA. Comorbid diseases including heart disease, renal disease, skeletal disease and atopic dermatitis were excluded. FeNO, lung function, blood eosinophil counts, serum levels of IgE, periostin were assessed. The diagnostic accuracy of these markers to identify asthma was calculated using receiver operating characteristics area under the curve (ROC AUC). Results: Mean PC20 of methacholine was 1.1 mg/ml. Serum periostin levels in BAwas significantly higher than in Cont (mean ± SD: 138.3 ± 34.9 vs 119.2 ± 35.0 ng/ml,p<0.05). FeNO levels and eosinophil counts in BA were also significantly higher than in Cont. ROC AUC for periostin, FeNO, eosinophil counts, PEF, FEV1.0 and MMF were 0.68, 0.72, 0.80, 0.59, 0.60 and 0.67 respectively. Conclusion: Periostin levels in BA were significantly higher in comparison with Cont. ROC AUC for periostin was equivalent to conventional biomarkers, such as FeNO and lung function, suggesting the usefulness of periostin in the diagnosis of asthma in children.