Exhaled nitric oxide (NO) at a flow rate of 200mL/s (FeNO200) is a viable method for evaluating NO concentration in chronic obstructive pulmonary disease (COPD), according to a study published in the International Journal of General Medicine.

In this study, researchers assessed 171 subjects (73 healthy controls, 59 patients with stable COPD) and 39 patients with acute exacerbations of COPD (AECOPD). They measured exhaled nitric oxide and clinical variables, including pulmonary function, COPD Assessment Test (CAT), C-reactive protein concentration, and circulating eosinophil count.

According to the results, FeNO200 was notably higher in patients with stable COPD and AECOPD than in healthy controls. Nevertheless, the researchers noted, CaNO (peripheral concentration of NO/alveolar NO) could not differentiate COPD from healthy controls. The study found no link between circulating eosinophil counts or forced expiratory volume in one second and exhaled nitric oxide (FeNO50, FeNO200, CaNO) in patients with COPD.

Furthermore, among patients with AECOPD, the high FeNO50 and FeNO200 groups’ levels were appreciably lower than their baseline levels, and the researchers observed marked significant improvements in CAT in both groups after corticosteroid treatment.

“FeNO200 is a straightforward and feasible method to evaluate the peripheral NO concentration in COPD. FeNO200 can be a type 2 inflammation biomarker and a useful tool for predicting corticosteroid therapy in COPD,” the researchers concluded.

Keywords: biomarker, chronic obstruction pulmonary disease, corticosteroid, exhaled nitric oxide

Link: https://pubmed.ncbi.nlm.nih.gov/33654424/