Measurement of bronchial and alveolar nitric oxide production in normal children and children with asthma.
BACKGROUND
Airway inflammation is characteristic of asthma. Distal inflammation may be particularly important.


OBJECTIVE
To calculate alveolar nitric oxide (NO) concentration (C(alv)) and bronchial flux NO (J(NO)) in children.


METHODS
We measured C(alv) and J(NO) from the fractional exhaled NO (FeNO(50)) measured at multiple exhalation flow rates in 132 children (aged 4-18 yr) with known atopic status, medication, and asthma control.


RESULTS
Of participants, 85% (112/132) completed all measurements. In 20 of 112, the result did not fit the linear model. Thus, J(NO) and C(alv) 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: FeNO(50): 28.1 (4.3-190), 10.35 (3.3-29), 21.8 (8.7-69) ppb, respectively; J(NO): 1,230 (204-9,236), 480 (196-1,913), 1,225 (486-4,119) pl/s, respectively; C(alv): 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 children gave intraclass correlation coefficients (single measures) of 0.99 (J(NO)) and 0.81 (C(alv)). J(NO) and C(alv) were higher in children with asthma than normal children (p = 0.0004 and p = 0.0002, respectively). Children with poorly controlled asthma (n = 27) had higher FeNO(50) measurements than children with good symptom control (n = 25): C(alv): mean (+/- SD), 3.17 +/- 1.62 versus 2.26 +/- 1.30 ppb, p = 0.03; J(NO): mean (+/- SD), 2,634 +/- 2,255 versus 1,193 +/- 1,294 pl/s, p = 0.007, respectively.


CONCLUSIONS
Measurement of J(NO) and C(alv) is feasible in 70% of school-age children. FeNO(50) and J(NO) give the same information (r = 0.97, p < 0.0001), C(alv) is higher in asthmatic children than in normal children and is affected by asthma control, but not by atopy. C(alv) may possibly reflect alveolar inflammation in asthma.
Paraskakis
Emmanouil
E
Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK. paraskakis@edu.med.uoc.gr.
Brindicci
Caterina
C
Fleming
Louise
L
Krol
Renata
R
Kharitonov
Sergei A
SA
Wilson
Nicola M
NM
Barnes
Peter J
PJ
Bush
Andrew
A
D000293:Adolescent; D001249:Asthma / Q000378:metabolism*; D001944:Breath Tests; D001980:Bronchi / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D005240:Feasibility Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007249:Inflammation / Q000378:metabolism* / Q000473:pathology; D016014:Linear Models; D008297:Male; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000378:metabolism*; D015203:Reproducibility of Results
D009569:Nitric Oxide