Katoh S, et al. - Researchers performed this study on 60 asthmatics, including 30 with atopic-asthma and 30 with non-atopic asthma, and 30 chronic obstructive pulmonary disease (COPD) patients, to assess biomarkers to distinguish between asthma and COPD. The participants were examined with respect to blood eosinophil counts and fractional exhaled nitric oxide (FeNO) levels and were compared in terms of serum periostin, interleukin-25 (IL-25), and immunoglobulin E (IgE) concentrations. Patients with asthma vs patients with COPD had significantly higher peripheral blood eosinophil counts, FeNO levels, and total serum IgE concentrations, but not serum periostin or serum IL-25 concentrations. Patients with atopic-asthma vs those with non-atopic asthma and COPD had increased serum periostin and IgE concentrations. The utility of FeNO levels and peripheral blood eosinophil counts was suggested as biomarkers for distinguishing between patients with asthma and COPD. Serum periostin and IgE concentrations could be biomarkers for atopic asthma.