RT Journal Article SR Electronic T1 TH2 specific biomarker profile determines steroid responsiveness in severe asthma JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 393 VO 42 IS Suppl 57 A1 Anna James A1 Maciek Kupczyk A1 Junya Ono A1 Stoichiro Ohta A1 Kenji Izuhara A1 Sven-Erik Dahlén YR 2013 UL http://erj.ersjournals.com/content/42/Suppl_57/393.abstract AB Biomarkers able to determine responsiveness to therapy in severe asthma (SA) are needed. Our goal was to examine the usefulness of periostin, eosinophils and exhaled NO as potential TH2 specific markers of glucocorticoid responsiveness in SA.Following a 4 week treatment optimization period, patients with SA (n=85) and mild-to-moderate asthma (MA) (n=66) underwent a 2 wk double-blind placebo controlled oral prednisolone (0.5 mg/kg BW daily) intervention (OPI). Serum periostin levels were measured by ELISA using 2 rat anti-human periostin mAbs (clones SS18A & SS17B), (Okamoto et al. ERJ 2011;37:1119).The OPI improved lung function in SA (FEV1: 2.28±0.13 L post vs 2.04±0.12 L pre, p<0.05, mean ± SEM) but not in MA. Baseline periostin levels were no different between MA and SA patients (84 vs 84 ng/ml, p=0.711), although higher periostin levels tended to associate with response to OPI (non-responders 82, vs responders 97 ng/ml, p=0.068). Steroid treatment caused a significant reduction in periostin (82 vs 68 ng/ml, p<0.0001). SA patients with the highest exhaled NO, and blood/sputum eosinophils, showed a larger improvement in FEV1% after the OPI compared to those with low levels of studied biomarkers (p<0.05). Dividing patients into high and low periostin groups revealed that patients with high periostin levels also had higher sputum and blood eosinophils (p=0.027, p=0.0002 respectively), lower BMI (p=0.014), higher exhaled NO (p=0.037) and higher total IgE (p=0.020).Our findings confirm associations between serum periostin levels, eosinophilic inflammation and responsiveness to corticosteroid treatment. Furthermore, we demonstrate that levels of serum periostin are sensitive to oral steroid treatment.