Exhaled nitric oxide: relation to sensitization and respiratory symptoms.
BACKGROUND
Conflicting data have been presented as to whether nitric oxide (NO) in exhaled air is merely reflecting atopy rather than airway inflammation.


OBJECTIVE
To investigate the relationship between exhaled NO (eNO) and nasal NO (nNO), respiratory symptoms, and atopy, in the context of a cross-sectional study of the respiratory health of bleachery workers.


METHODS
Two hundred and forty-six non-smoking bleachery and paper-mill workers answered a questionnaire and were examined by measurements of eNO and nNO and spirometry, outside the pollen season. Blood samples were collected and analysed for specific IgE against common aeroallergens (birch, timothy, cat and house dust mite). Atopy was defined as a positive Phadiatop trade mark test.


RESULTS
The atopic and the non-atopic subjects without asthma or rhinitis had similar levels of eNO. Subjects reporting asthma or rhinitis who were also sensitized to perennial allergens had higher levels of eNO, whereas those sensitized to only seasonal allergens had similar eNO levels as non-atopic subjects with asthma or rhinitis. In multiple linear regression models adjusted for nNO, eNO was associated with asthma and sensitization to perennial allergens.


CONCLUSIONS
The results indicate that only atopic subjects who have recently been exposed to the relevant allergen have elevated levels of eNO. Atopic subjects who are not being exposed to a relevant allergen or have never experienced symptoms of asthma or rhinitis show normal eNO. These data indicate that eNO relates to airway inflammation in atopic subjects.
Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden. anna-carin.olin@ymk.gu.se
A-C
AC
Olin
K
K
Alving
K
K
Torén
D000328:Adult; D001249:Asthma / Q000276:immunology / Q000378:metabolism*; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests; D002617:Chemical Industry; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007159:Immunologic Tests; D016014:Linear Models; D008137:Longitudinal Studies; D008168:Lung / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D009784:Occupational Diseases / Q000276:immunology / Q000378:metabolism*; D012220:Rhinitis / Q000276:immunology / Q000378:metabolism*
D015415:Biomarkers; D009569:Nitric Oxide