PT  - JOURNAL ARTICLE
AU  - Guus Westerhof
AU  - Daniel Korevaar
AU  - Marijke Amelink
AU  - Selma De Nijs
AU  - Christa de Groot
AU  - Els Weersink
AU  - Anneke ten Brinke
AU  - Patrick Bossuyt
AU  - Elisabeth Bel
TI  - Biomarkers for sputum eosinophilia in mild-moderate and severe adult-onset asthma patients
DP  - 2014 Sep 01
TA  - European Respiratory Journal
PG  - P2053
VI  - 44
IP  - Suppl 58
4099  - http://erj.ersjournals.com/content/44/Suppl_58/P2053.short
4100  - http://erj.ersjournals.com/content/44/Suppl_58/P2053.full
SO  - Eur Respir J2014 Sep 01; 44
AB  - Introduction Eosinophilic airway inflammation is an important pathological characteristic of severe asthma. Treatment guided by sputum eosinophils reduces asthma exacerbations, but differential sputum cell counts are not widely available.Aim We aimed to estimate the diagnostic accuracy of non-invasive biomarkers for sputum eosinophilia in adult-onset asthma patients.Methods Three observational clinical trials enrolled patients with adult-onset asthma from pulmonary outpatient clinics. Blood and sputum eosinophils, exhaled nitric oxide (FeNO) and total IgE were assessed in 1-2 days, in 336 patients. In retrospective analyses, area under the receiver operating characteristics curve (AUC) was used to express the accuracy of blood eosinophils, FeNO and IgE in detecting sputum eosinophilia (threshold ≥3%).Results Sputum eosinophilia was present in 116 patients (35 %). The AUC for blood eosinophils was 0.83 (95%CI 0.78-0.87), vs 0.82 for FENO (95%CI 0.77-0.87) and 0.69 (95%CI 0.63-0.75) for total IgE. AUC's in patients with mild-moderate asthma and severe asthma were, respectively, 0.82 and 0.81 (p=.92) for FeNO, 0.78 and 0.87 (p=.08) for blood eosinophils and 0.66 and 0.68 (p=.67) for IgE.Conclusion Both blood eosinophils and FeNO have reasonable accuracy as markers of airway eosinophilia in adult-onset asthma patients; there is no difference in accuracy between mild-moderate and severe asthma patients.