Exhaled nitric oxide, eosinophils and current smoking in COPD patients

High F(ENO) can occur despite low blood eosinophil counts in ex-smokers, while a minority of current smokers have elevated F(ENO) that is not related to eosinophil counts. F(ENO) levels may be related to noneosinophilic mechanisms in a subgroup of COPD. https://bit.ly/3PSWvM2.