RT Journal Article
SR Electronic
T1 Exhaled nitric oxide and bronchial responsiveness in healthy subjects exposed to organic dust
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 426
OP 431
DO 10.1183/09031936.02.00257402
VO 20
IS 2
A1 B-;M. Sundblad
A1 B-;M. Larsson
A1 L. Palmberg
A1 K. Larsson
YR 2002
UL http://erj.ersjournals.com/content/20/2/426.abstract
AB Inhalation of organic dust from swine houses causes an intense inflammatory reaction in the respiratory tract, and increased bronchial responsiveness to methacholine in healthy subjects. The aims of the present study were to investigate whether exhaled nitric oxide (NO) is a marker of the inflammation caused by exposure to organic dust (swine dust), whether there is a relationship between an increase in exhaled NO and bronchial responsiveness, and also whether wearing a half-mask influences the airway reaction (assessed by exhaled NO) and the increased bronchial responsiveness. Thirty-three healthy nonatopic, nonsmoking subjects were exposed during 3 h of light work in a swine confinement building. Eleven of the subjects were wearing a half-mask and 22 were unprotected. Lung function, bronchial responsiveness and exhaled NO were measured before and after exposure. The provocative concentration causing a 20% fall in forced expiratory volume in one second fell by 2.7 (2.1–4.1) (median (25th–75th percentiles)) doubling concentration steps in subjects without a half-mask and by 1.5 (0.9–2.9) doubling concentration steps in subject wearing a mask. Exhaled NO increased from 7.5 (5.7–13.7) parts per billion (ppb) before to 13.4 (10.5–17.5) ppb after exposure in the unprotected group and was unaltered (8.3 (6.1–14.1) to 8.6 (6.6–14.6) ppb) in the group wearing a half-mask. There was no correlation between NO increase and provocative dose causing a 20% fall in the forced expiratory volume in one second decrease. In conclusion, bronchial responsiveness and exhaled nitric oxide increased after exposure to a swine confinement facility. Half-mask abolished the increase in exhaled nitric oxide levels, but influenced the increase in bronchial responsiveness to a minor extent. These results indicate that these two outcome measures reflect different aspects of airway inflammation induced by exposure to a farming environment. This study was supported by The Swedish Heart-Lung Foundation.