ASTHMA

Exhaled nitric oxide rather than lung function distinguishes preschool children with probable asthma

L P Malmberg, A S Pelkonen, T Haahtela, M Turpeinen

Division of Allergy, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland

Correspondence to:
Correspondence to:
Dr L P Malmberg, Division of Allergy, Department of Medicine, Helsinki University Central Hospital, P O Box 160, 00029 Helsinki, Finland;
pekka.malmberg{at}hus.fi

Background: Respiratory function and airway inflammation can be evaluated in preschool children with special techniques, but their relative power in identifying young children with asthma has not been studied. This study was undertaken to compare the value of exhaled nitric oxide (FE_NO), baseline lung function, and bronchodilator responsiveness in identifying children with newly detected probable asthma.

Methods: Ninety six preschool children (age 3.8–7.5 years) with asthmatic symptoms or history and 62 age matched healthy non-atopic controls were studied. FE_NO was measured with the standard online single exhalation technique, and baseline lung function and bronchodilator responsiveness were measured using impulse oscillometry (IOS).

Results: Children with probable asthma (n=21), characterised by recent recurrent wheeze, had a significantly higher mean (SE) concentration of FE_NO than controls (22.1 (3.4) ppb v 5.3 (0.4) ppb; mean difference 16.8 ppb, 95% CI 12.0 to 21.5) and also had higher baseline respiratory resistance, lower reactance, and larger bronchodilator responses expressed as the change in resistance after inhalation of salbutamol. Children with chronic cough only (n=46) also had significantly raised mean FE_NO (9.2 (1.5) ppb; mean difference 3.9 ppb, 95% CI 0.8 to 7.0) but their lung function was not significantly reduced. Children on inhaled steroids due to previously diagnosed asthma (n=29) differed from the controls only in their baseline lung function. The analysis of receiver operating characteristics (ROC) showed that FE_NO provided the best power for discriminating between children with probable asthma and healthy controls, with a sensitivity of 86% and specificity of 92% at the cut off level of 1.5 SD above predicted.

Conclusions: FE_NO is superior to baseline respiratory function and bronchodilator responsiveness in identifying preschool children with probable asthma. The results emphasise the presence of airway inflammation in the early stages of asthma, even in young children.

Keywords: asthma; preschool children; lung function tests; nitric oxide

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

Relevant Article

Airwaves

Wisia Wedzicha
Thorax 2003 58: 463. [Extract] [Full Text] [PDF]

This article has been cited by other articles:

• Mattila, P S, Hammaren-Malmi, S, Pelkonen, A S, Malmberg, L P, Makela, M J, Saxen, H, Tarkkanen, J (2009). Effect of adenoidectomy on respiratory function: a randomised prospective study. Arch. Dis. Child. 94: 366-370 [Abstract] [Full Text]  
• Rodway, G., Choi, J, Hoffman, L., Sethi, J. (2009). Exhaled nitric oxide in the diagnosis and management of asthma: clinical implications. Chronic Respiratory Disease 6: 19-29 [Abstract]  
• Russell, G. (2008). Wheeze in preschool children. BMJ 336: 1387-1388 [Full Text]  
• Lim, K. G., Mottram, C. (2008). The Use of Fraction of Exhaled Nitric Oxide in Pulmonary Practice. Chest 133: 1232-1242 [Abstract] [Full Text]  
• Kullowatz, A., Rosenfield, D., Dahme, B., Magnussen, H., Kanniess, F., Ritz, T. (2008). Stress Effects on Lung Function in Asthma are Mediated by Changes in Airway Inflammation. Psychosom. Med. 70: 468-475 [Abstract] [Full Text]  
• Kostikas, K., Papaioannou, A. I., Tanou, K., Koutsokera, A., Papala, M., Gourgoulianis, K. I. (2008). Portable Exhaled Nitric Oxide as a Screening Tool for Asthma in Young Adults During Pollen Season. Chest 133: 906-913 [Abstract] [Full Text]  
• Miedinger, D., Chhajed, P. N., Tamm, M., Stolz, D., Surber, C., Leuppi, J. D. (2007). Diagnostic Tests for Asthma in Firefighters. Chest 131: 1760-1767 [Abstract] [Full Text]  
• Taylor, D R, Pijnenburg, M W, Smith, A D, Jongste, J C D (2006). Exhaled nitric oxide measurements: clinical application and interpretation. Thorax 61: 817-827 [Abstract] [Full Text]  
• Brussee, J. E., Smit, H. A., Kerkhof, M., Koopman, L. P., Wijga, A. H., Postma, D. S., Gerritsen, J., Grobbee, D. E., Brunekreef, B., de Jongste, J. C. (2005). Exhaled nitric oxide in 4-year-old children: relationship with asthma and atopy. Eur Respir J 25: 455-461 [Abstract] [Full Text]  
• Deykin, A, Malmberg, L P (2004). FENO as a diagnostic tool in paediatric asthma * Author's reply. Thorax 59: 271-271 [Full Text]  
• Smith, A. D., Cowan, J. O., Filsell, S., McLachlan, C., Monti-Sheehan, G., Jackson, P., Taylor, D. R. (2004). Diagnosing Asthma: Comparisons between Exhaled Nitric Oxide Measurements and Conventional Tests. Am. J. Respir. Crit. Care Med. 169: 473-478 [Abstract] [Full Text]