Bronchial and alveolar components of exhaled nitric oxide and their relationship

Association between peripheral airway function and neutrophilic inflammation in asthma

“…One previous study reported slight improvement, but not normalization, in Sacin when ICS treatment was changed to ultra‐fine ICS aerosol especially in patients with abnormal acinar airway function at baseline . The lack of an association between Sacin and eosinophil% in this study is also consistent with a previous report highlighting normal alveolar F E NO values in the majority of asthma patients treated with ICS …”

Irreversible acinar airway abnormality in well controlled asthma

“…In particular, the values for bronchial NO production and alveolar NO concentration obtained here fall within the ranges of normal obtained in a recent compilation [5] while the FENO 50 values are well below the cut-off reported for identifying patients with eosinophilic airway inflammation [15].…”

“…Since no inflammatory markers were obtained in that study, it was impossible to know whether this residual small airway dysfunction was inflammatory in origin. Other studies using alveolar nitric oxide as an outcome parameter, have observed decreases in alveolar nitric oxide following small particle steroid formulations in relatively mild asthma or with systemic treatment in mild-to-moderate refractory asthma [5]. Alveolar nitric oxide has also been shown to be weakly associated with acinar ventilation heterogeneity, at least in asthma patients on a maintenance treatment exceeding 500 mg BDP equivalent per day [6].…”

Estimation of Parameters in the Two-Compartment Model for Exhaled Nitric Oxide

“…The sensitivity of C A NO estimates to the estimation method raises important concerns about the validity of comparing C A NO estimates from studies that used different estimation methods. The large number of negative C A NO estimates from the Condorelli method (and, to a lesser extent, the Kerckx method) suggest that the existing implementations of these methods may not be appropriate for the CHS study population or may over-correct for back-diffusion, mirroring concerns raised elsewhere [51].…”