Association of airway wall thickness with serum periostin in steroid-naive asthma

Background: Periostin may be a useful biomarker of T-helper type 2 eosinophilic airway inflammation and has been linked to remodeling in asthma. However, the association between serum periostin and the magnitude of airway wall thickness remains unclear. Objective: We examined the relationship between serum periostin and airway geometry in asthma. Methods: Twenty-six patients with steroid-naive asthma, 30 patients with asthma treated with inhaled corticosteroids, and 46 aged-matched healthy controls were studied. Serum periostin levels, lung function, and inflammatory cell counts in sputum were measured. The following parameters of airway dimension were assessed by computed tomography: lumen area, wall area (WA), WA to total area ratio, and wall thickness. Results: Serum periostin levels were significantly elevated in patients with steroid-naive asthma compared with the controls (p < 0.01) and patients with asthma who were treated with steroids (p < 0.01). In patients who were steroid naive, serum periostin was correlated with air flow limitation (r = -0.62, p < 0.01) and the WA to body surface area (r = 0.71, p < 0.01), and sputum eosinophil percentage (r = 0.60, p < 0.01). Multivariate analysis showed that the percentage of predicted forced expiratory volume in 1 second, WA to body surface area, and sputum eosinophils were independent factors for high serum periostin. Conclusion: Serum periostin may be a candidate for a novel biomarker for not only eosinophilic inflammation but as a marker for airway remodeling in asthma.