Periostin is measurable in the airways and increased in patients with severe asthma, especially in those from the type 2 (T2) endotype, a recent study found. Researchers enrolled 40 consecutive patients with severe asthma (T2 endotype: n=25; non-T2 endotype: n=15), 21 patients with mild to moderate asthma, and 15 healthy controls. All participants underwent exhaled breath condensate (EBC) and sputum collection, eosinophil count in blood, fractional exhaled nitric oxide, and IgE measurement. Periostin was assessed by an enzyme-linked immunosorbent assay kit on EBC and induced sputum (IS) supernatant. Among the findings:
- Higher periostin levels were detected in the EBC and in IS of patients with severe asthma compared to those with mild-to-moderate asthma and healthy control subjects, respectively.
- There was an increase of periostin levels in both samples in T2 endotype vs non-T2 endotype and a correlation between periostin levels in EBC and sputum.
- Airways periostin may be a useful marker of severe eosinophilic asthma and may help to phenotype patients that will respond to biologic agents.
Carpagnano GE, Scioscia G, Lacedonia D, et al. Looking for airways periostin in severe asthma. [Published online ahead of print October 15, 2018]. CHEST. doi:10.1016/j.chest.2018.08.1032.