Effect of Formaldehyde on Asthmatic Response to Inhaled Allergen Challenge

Abstract

BackgroundExposure to formaldehyde may lead to exacerbation of asthma.ObjectivesOur aim in this study was to investigate whether exposure to a low level (500 μg/m3) of formaldehyde enhances inhaled allergen responses.MethodsTwelve 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.ResultsThe median dose of allergen producing a 15% decrease in forced expiratory volume in 1 sec (PD15FEV1) 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.ConclusionIn this study, exposure to 500 μg/m3 formaldehyde had no significant deleterious effect on airway allergen responsiveness of patients with intermittent asthma; we found a trend toward a protective effect.

The Health Risk of Formaldehyde to Human Beings

“…Mucociliary clearance in the nasal cavity has been found to be reduced following exposure to 0.25 ppm formaldehyde in volunteers. In healthy volunteers as well as asthma patients, there was no clinical effect on lung function after exposure to formaldehyde up to 3.0ppm for up to 3 h [24,47] .…”

Zur Frage eines Asthma auslösenden bzw. verschlechternden Potenzials von Formaldehyd in der Innenraumluft bei Kindern

“…Harving et al [53] Ezratty et al [56] exponierten in einer verblindeten Cross-over-Studie 12 Pollenallergiker mit intermitierendem Asthma über eine Stunde mit jeweils 0,5 mg Formaldehyd/m³. Es ergaben sich keine signifikanten Effekte auf die Lungenfunktion und keine Entzündungszeichen (z.…”

The Ontogeny, Distribution, and Regulation of Alcohol Dehydrogenase 3: Implications for Pulmonary Physiology

“…To date, controlled human studies have not examined whether formaldehyde alters ADH3 or nitrosothiol homeostasis. However, two recent studies have examined the influence of formaldehyde on response to allergens, with one study reporting that formaldehyde potentiates bronchoresponsiveness and the other indicating that formaldehyde mitigates bronchoconstriction (Casset et al, 2006;Ezratty et al, 2007). Given that pulmonary responses are probably influenced by underlying conditions that influence nitrosothiol status as well as exposure-induced changes in nitrosothiol homeostasis, the effects of formaldehyde on pulmonary endpoints may be highly labile and thus sensitive to dose, duration, and timing of measurements.…”