Inhaled formaldehyde exposure: effect on bronchial response to mite allergen in sensitized asthma patients

• Published in: Allergy Vol. 61; no. 11; pp. 1344 - 1350
• Main Authors: Casset, A., Marchand, C., Purohit, A., Le Calve, S., Uring‐Lambert, B., Donnay, C., Meyer, P., De Blay, F.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.11.2006; Blackwell; Wiley
• Subjects: Adult; Air Pollutants - toxicity; Allergic diseases; Animals; Antigens, Dermatophagoides - immunology; Arthropod Proteins; asthma; Asthma - chemically induced; Asthma - etiology; Asthma - immunology; Biological and medical sciences; Bronchi - drug effects; Bronchi - immunology; bronchial responsiveness; Continental interfaces, environment; Cysteine Endopeptidases; Der p 1; Dermatophagoides pteronyssinus; Dermatophagoides pteronyssinus - immunology; Earth Sciences; Eosinophil Cationic Protein - blood; Female; formaldehyde; Formaldehyde - toxicity; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Geochemistry; house dust mite allergen; Humans; Immunopathology; Inhalation Exposure; Male; Medical sciences; Methacholine Chloride - pharmacology; Sciences of the Universe; Sputum - cytology; Allergy; Der p 1; Mite; bronchial responsiveness; Respiratory system; Formaldehyde; Respiratory tract; Immunology; Acari; Bronchus disease; Sensitization; Obstructive pulmonary disease; Human; Immunopathology; Lung disease; Respiratory disease; House dust; Acaridida; Exposure; Dermatophagoides pteronyssinus; Asthma; Inhalation; Acariformes; Arachnida; Arthropoda; Pyroglyphidae; Invertebrata; house dust mite allergen
• ISSN: 0105-4538; 1398-9995; 0108-1675
• DOI: 10.1111/j.1398-9995.2006.01174.x

Background:  Formaldehyde, an indoor air pollutant, is known to be an irritant and an etiologic factor in occupational asthma. An epidemiologic study suggests that it may also increase the risk of childhood asthma for concentrations above 60 μg/m3. Aim:  To evaluate the influence of pre‐exposure to low‐dose formaldehyde (100 μg/m3 in 30 min according to the World Health Organization's recommended maximum value for indoor environments) on bronchial response to Dermatophagoides pteronyssinus. Method:  Nineteen asthmatic subjects were included. Each subject underwent a mite allergen bronchial challenge test immediately after a standardized exposure in a chamber to formaldehyde or air (random order). Induced sputum were collected 24 h before and after mite challenge. Results:  After formaldehyde inhalation, patients developed an immediate bronchial response at a significantly lower dose of mite allergen than after air exposure (the geometric mean PD20 for Der p 1 was 34.3 ng after formaldehyde and 45.4 ng after placebo, P = 0.05). The late‐phase reaction, expressed as the maximum fall in forced expiratory volume in 1 s (FEV1) from baseline, was significantly higher after formaldehyde (15%vs 11%, P = 0.046). Conclusion:  Our study demonstrated that exposure to low levels of formaldehyde significantly enhanced bronchial responsiveness to mite allergen in mite‐sensitized subjects with asthma.