Validation and further insight into the International Severe Asthma Registry (ISAR) eosinophil gradient algorithm in the Wessex AsThma CoHort of difficult asthma (WATCH) using historical blood eosinophil counts and induced sputum (original) (raw)

CHI3L1/YKL-40 in serum of patients with normal sputum eosinophil levels, 9 and CHI3L1/YKL-40 was also identified in our previous severe asthma cohort as a sub-phenotype in severe asthma. 1 Thus, monitoring a broad spectrum of airway inflammatory markers in asthma should be an important future consideration in addition to the use of classifications like the ISAR algorithm. In conclusion, though the term "non-eosinophilic asthma" is used to describe severe asthma patients without current evidence of raised eosinophils while on high dose steroids. It is imprecise: many of these patients will have an underlying eosinophilic phenotype. Nevertheless, though, they may underestimate the presence of an eosinophilic phenotype. It is important to reiterate that contemporaneous blood and sputum measurements are proven theragnostic biomarkers, predicting response to anti IL-5 and steroid treatment for reducing asthma exacerbations.