Phenotype of asthma related with high serum periostin levels

Background: Asthma is a heterogeneous disease composed of various phenotypes. Periostin, a molecule inducible with interleukin (IL)-4 or IL-13 in bronchial epithelial cells, is a biomarker of “TH2-high” asthma. The objective of this study is to examine whether the serum periostin concentrations are correlated with the severity, specific phenotype(s), or comorbidity of asthma. Methods: Serum concentrations of periostin were measured in 190 Japanese asthmatic patients and 11 healthy controls. The protocol was registered under UMIN 000002980 in the clinical trial registry. Results: The serum concentrations of periostin were significantly higher (P = 0.014) in asthmatics [70.0 (54.0–93.5) ng/ml] than in healthy subjects [57.0 (39.0–63.0) ng/ml], though we found no correlation between serum periostin concentrations and treatment steps required to control asthma. To characterize “high-periostin” phenotype(s), the patients with asthma were divided among tertiles based on the serum concentrations of periostin. The high-periostin group was older at onset of asthma (P = 0.04), had a higher prevalence of aspirin intolerance (P = 0.04) or concomitant nasal disorders (P = 0.03–0.001), higher peripheral eosinophil counts (P