Interrelationships among asthma, atopy, rhinitis and exhaled nitric oxide in a population‐based sample of children

Abstract

SummaryBackground Exhaled nitric oxide (eNO) has attracted increasing interest as a non-invasive marker of airway inflammation in asthma. However, little evidence exists on the influences exerted on eNO by the interrelations among atopic status, asthma and rhinitis. Methods Among the 1156 children who participated in a large-scale epidemiological survey on asthma and allergies (ISAAC II: International Study of Asthma and Allergies in Childhood Phase II) in the city of Clermont-Ferrand, 53 asthmatics without corticosteroid treatment and 96 nonasthmatics were invited to perform eNO and skin prick tests (SPTs) to 12 common allergens. Results Atopic asthmatic children had higher eNO than non-atopic asthmatic children (28.979.1 vs. 17.1713.1 p.p.b.; P 5 0.0004) with a significant increase when one SPT or more are positive (26.577.8 vs. 17.1713.1 p.p.b.; P 5 0.03). Similarly, non-asthmatic, atopic subjects had higher eNO than non-atopic subjects with a significant increase when two SPTs or more are positive (19.479.8 vs. 11.7 76.7 p.p.b.; P 5 0.003). In the case of equal levels of positive SPTs (0, 1, X2), asthmatic children always had higher eNO than non-asthmatic ones. Furthermore, among non-asthmatic children, the eNO level increased only in atopics who had rhinitis (20.7713 vs. 12.576.4 p.p.b. in atopic controls (subjects without rhinitis and asthma) and 12.376.6 p.p.b. in non-atopic controls; P 5 0.001), whereas among asthmatic children, eNO level increased in atopics independently of rhinitis (28.279.5 p.p.b. in those with rhinitis and 30.978.1 p.p.b. in those without) as well as in nonatopics with rhinitis (22.5717.2 p.p.b.). Conclusions Our data suggest that besides atopy and asthma, allergic rhinitis should also be taken into account in the assessment of eNO.

Factors that influence exhaled nitric oxide in Italian schoolchildren

“…[2][3][4] However, other studies did not find a relation between atopy and eNO levels in children. 1,5,15 In particular, Latzin et al 15 failed to demonstrate a relation between atopy and eNO levels in 4-to 18-year-old healthy children. A possible explanation for these conflicting results might be found in the dimension of the studied sample, 5 the different prevalence of atopic children in the study samples, and the different age distributions.…”

“…This result is consistent with previous studies demonstrating the effect of the number of positive skin test results on the level of eNO. 1,2,4,7,22 In particular, Franklin et al 2 found that in healthy children eNO levels were higher in those with a positive skin prick test result and even higher in children with more than 1 positive skin test result, suggesting that allergen sensitization may play a significant role in elevating eNO production in the respiratory tract.…”

“…In fact, some authors did not find any difference in eNO levels between atopic and nonatopic healthy individuals. 1,8 Conversely, other studies demonstrated a linear or dose-response relation between the degree of skin test positivity and eNO levels. 2,4,7 The relative weight of some factors (atopy, clinical disease, number of positive skin test results) remains to be determined.…”

“…Furthermore, the measurement of eNO has been suggested as a valuable tool in adjusting asthma therapy according to inflammation. Increased levels of eNO have been found in asthmatic children 1 and in asymptomatic atopic children. [2][3][4] Consequently, it has been suggested that the relation between asthma and increased eNO levels may be mediated by atopy itself.…”

Óxido nítrico exhalado, asma y atopia: análisis en un panel de niños en Santiago, Chile

“…Esta herramienta se sustenta primariamente en las potenciales diferencias existentes entre población asmática y no asmática; además, recientemente también se han postulado diferencias según nivel de atopia. Diversos estudios han evaluado estas diferencias encontrándose, en general, un aumento en los niveles de ONe en suje-tos asmáticos, aunque también se han encontrado niveles elevados para sujetos atópicos y sobre todo sujetos asmáticos y atópicos [8][9][10][11][12][13][14][15] .…”