Effect of formaldehyde on asthmatic response to inhaled allergen challenge.
BACKGROUND
Exposure to formaldehyde may lead to exacerbation of asthma.


OBJECTIVE
Our aim in this study was to investigate whether exposure to a low level (500 microg/m(3)) of formaldehyde enhances inhaled allergen responses.


METHODS
Twelve subjects with intermittent asthma and allergy to pollen were exposed, at rest, in a double-blind crossover study to either formaldehyde or purified air for 60 min. The order of exposure to formaldehyde and air-only was randomized, and exposures were separated by 2 weeks. We also performed an allergen inhalation challenge after each exposure. Airway responsiveness to methacholine and lower airway inflammation (induced sputum) were assessed 8 hr after allergen challenge.


RESULTS
The median dose of allergen producing a 15% decrease in forced expiratory volume in 1 sec (PD(15)FEV(1)) was 0.80 IR (index of reactivity) after formaldehyde exposure compared with 0.25 IR after air-only exposure (p = 0.06). Formaldehyde exposure did not affect allergen-induced increase in responsiveness to methacholine (p = 0.42). We found no formaldehyde-associated effect on the airway inflammatory response, in particular the eosinophilic inflammatory response, induced by the allergen challenge 8 hr before.


CONCLUSIONS
In this study, exposure to 500 microg/m(3) formaldehyde had no significant deleterious effect on airway allergen responsiveness of patients with intermittent asthma; we found a trend toward a protective effect.
Ezratty
Véronique
V
Service des Etudes Médicales d'EDF et de Gaz de France, Paris, France. veronique.ezratty@edfgdf.fr
Bonay
Marcel
M
Neukirch
Catherine
C
Orset-Guillossou
Gaëlle
G
Dehoux
Monique
M
Koscielny
Serge
S
Cabanes
Pierre-André
PA
Lambrozo
Jacques
J
Aubier
Michel
M
D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000633:toxicity*; D000485:Allergens / Q000276:immunology; D001249:Asthma / Q000175:diagnosis / Q000209:etiology* / Q000276:immunology; D005260:Female; D005557:Formaldehyde / Q000633:toxicity*; D006801:Humans; D019570:Inhalation Exposure; D008297:Male; D012129:Respiratory Function Tests; D013183:Sputum / Q000737:chemistry
D000393:Air Pollutants; D000485:Allergens; D005557:Formaldehyde