Effect of treatment with inhaled corticosteroid on serum periostin levels in asthma

BACKGROUND AND OBJECTIVE: Periostin is a biomarker of eosinophilic airway inflammation and may contribute to airway remodeling in asthma. The anti-inflammatory activity of inhaled corticosteroids (ICS) for asthma control is widely recognized. The aim of this study was to assess the effects of ICS on serum periostin levels and its relationships to inflammation and airway geometry. METHODS: Forty-two healthy controls and 20 patients with steroid-naïve asthma before and after treatment with fluticasone propionate (800 μg/day for 16 weeks) were examined. Serum periostin, lung function and inflammatory cell counts in sputum were measured. Airway dimensions were determined by quantitative computed tomography (total area of the airway (Ao), wall area (WA), wall thickness (T) and percentage wall area (WA%) ). RESULTS: Serum periostin concentrations were significantly higher in patients with asthma than in controls. Periostin levels were correlated with airway wall thickness and sputum eosinophilia and inversely correlated with airflow limitation in asthma. ICS significantly decreased serum periostin (P < 0.01), decreased WA corrected for body surface area (WA/BSA, P < 0.05), T/√BSA (P < 0.01) and WA% (P < 0.01), reduced the percentage of sputum eosinophils (P < 0.01) and improved airflow limitation. The decrease in serum periostin levels was associated with an increased per cent predicted forced expiratory volume in 1 s (r = -0.64, P < 0.01), decreased WA/BSA (r = 0.46, P < 0.05) and decreased sputum eosinophils (r = 0.71, P < 0.01). CONCLUSION: Serum periostin levels respond partially to ICS and may reflect a reduction in airway inflammation and wall thickening in asthma.