Measurement of Bronchial and Alveolar Nitric Oxide Production in Normal Children and Children with Asthma

Rationale: Airway inflammation is characteristic of asthma. Distal inflammation may be particularly important.Objective: To calculate alveolar nitric oxide (NO) concentration (Calv) and bronchial flux NO (JNO) in children.Methods: We measured Calv and JNO from the fractional exhaled NO (FeNO50) measured at multiple exhalation flow rates in 132 children (aged 4–18 yr) with known atopic status, medication, and asthma control.Measurements and Main Results: Of participants, 85% (112/132) completed all measurements. In 20 of 112, the result did not fit the linear model. Thus, JNO and Calv were assessed in 92 (70%) subjects. The median (range) values of asthmatic (n = 52), normal (n = 20), and nonasthmatic atopic (n = 20) children were as follows: FeNO50: 28.1 (4.3–190), 10.35 (3.3–29), 21.8 (8.7–69) ppb, respectively; JNO: 1,230 (204–9,236), 480 (196–1,913), 1,225 (486–4,119) pl/s, respectively; Calv: 2.22 (0.44–6.63), 1.63 (0.44–3), 1.21 (0.03–2.85) ppb, respectively. A reproducibility study in 18 other child...