Alveolar nitric oxide and asthma control in mild untreated asthma.

Background: The role of the peripheral airways in asthma is increasingly being recognized as a potential target for the achievement of optimal control of the disease. We postulated that the inflammatory changes of the small airways are implicated in the lack of asthma control in mild asthma.

Objective: To test this hypothesis, we measured the alveolar fraction of exhaled NO (CalvNO) in patients with mild asthma with different levels of control of symptoms.