Serum periostin levels correlate with airway hyper-responsiveness to methacholine and mannitol in children with asthma.

Periostin is a matricellular protein, and its synthesis in airway epithelial cells and lung fibroblasts is induced by interleukin (IL)-4 and IL-13. The significance of periostin as a biomarker of TH 2-induced airway inflammation, and (importantly) as a measure of the response to TH 2-targeted therapy, has recently been emphasized. We explored the relationship between periostin and airway hyperresponsiveness (AHR) in asthmatic children. The study included 83 children aged 6-15 years in an asthmatic group (n = 54) and healthy controls (n = 29). We measured the periostin levels in serum and performed methacholine and mannitol provocation challenges. The responses to mannitol were expressed as the provocative dose causing a 15% fall in the FEV1 (the PD15 dose). Of the 54 subjects with asthma, all had positive methacholine bronchial provocation test (BPT) results and 38 had positive mannitol BPT results. Children with asthma had significantly higher periostin levels than controls [76.0 (65.0-91.8) vs 71.0 (57.5-80.0) ng/mL; P = 0.017]. Periostin levels were significantly correlated with both the methacholine PC20 and mannitol PD15 values. Serum levels of periostin, a new biomarker induced by IL-13, were higher in asthmatic children, and were associated with AHR to methacholine and mannitol.