Background: Exposure and sensitization to pet allergens are associated with allergic asthma in children. Conflicting data have emerged regarding the potential benefit of air cleaners with respect to a reduction of indoor pet allergens and bronchial hyperresponsiveness (BHR). Methods: In a randomized controlled trial 36 asthmatic children with sensitization to cat and/or dog and significant exposure to cat and/or dog allergen (Fel d 1 and/or Can f 1 >500 ng/g of carpet dust) were included in order to study the effect of high-efficiency particulate arresting (HEPA) air cleaners placed in the living room and bedroom compared with the effect of sham air cleaners. Patients were allocated to two groups: group 1 exposed to active filters and group 2 exposed to sham filters. At month 0, after 6 months and after 12 months, pulmonary function testing and cold air challenge were performed, serum eosinophil cationic protein (ECP) and specific IgE to seven aeroallergens were determined, and carpet dust samples and filters were collected. Major pet allergen concentrations (Fel d 1, Can f 1) were determined in filters and bulk dust samples. Results: Thirty patients completed the study. After 6 and 12 months, there was no significant change in delta FEV1 after cold air challenge, or in the use of medication and serum ECP levels. However, there was a trend in the active group towards an improvement of bronchial hyperresponsiveness, whereas the sham filter group showed a deterioration of BHR. Conclusion: Although HEPA air cleaners retained airborne pet allergens, no effect on disease activity or allergen concentrations in bulk dust samples was observed in this study.

Keywords:
Cat allergen, Dog allergen, Asthma, Air cleaners, Pet allergen reduction, Bronchial hyperresponsiveness
1.
Wahn U, Lau S, Bergmann R, Kulig M, Forster J, Bergmann K, Bauer CP, Guggenmoos-Holzmann I: Indoor allergen exposure is a risk factor for sensitization during the first three years of life. J Allergy Clin Immunol 1997;99:763–769.
2.
Lau S, Illi S, Sommerfeld C, Niggemann B, Bergmann R, von Mutius E, Wahn U: Early exposure to house-dust mite and cat allergens and the development of childhood asthma: a cohort study. Lancet 2000;356:1392–1397.
3.
Arshad SH, Tariq SM, Matthews S, Hakim E: Sensitization to common allergens and its association with allergic disorders at age 4 years: a whole population birth cohort study. Pediatrics 2001;108:E33.
4.
Almqvist C, Egmar AC, Hedlin G, Lundqvist M, Nordvall SL, Pershagen G, Svartengren M, van Hage-Hamsten M, Wickman M: Direct and indirect exposure to pets – risk of sensitization and asthma at 4 years in a birth cohort. Clin Exp Allergy 2003;33:1190–1197.
5.
Illi S, von Mutius E, Lau S, Niggemann B, Gruber C, Wahn U, Multicentre Allergy Study (MAS) group: Perennial allergen sensitisation early in life and chronic asthma in children: a birth cohort study. Lancet 2006;368:763–770.
6.
Ehnert B, Lau-Schadendorf S, Weber A, Buettner P, Wahn U: Reducing domestic exposure of dust mite allergen reduces bronchial hyperreactivity in sensitive asthmatic children. J Allergy Clin Immunol 1992;90:135–138.
7.
Instanes C, Hetland G, Berntsen S, Lovik M, Nafstad P: Allergens and endotoxin in settled dust from day-care centres and schools in Oslo, Norway. Indoor Air 2005;15:356–362.
8.
Chan-Yueng M, McClean PA, Sandell PR, Slutsky AS, Zamel N: Sensitization to cat without direct exposure to cats. Clin Exp Allergy 1999;29:762–765.
9.
Avner DB, Perzanowski MS, Platts-Mills TA, Woodfolk JA: Evaluation of different techniques for washing cats: quantitation of allergen removed from the cat and the effect on airborne Fel d 1. J Allergy Clin Immunol 1997;100:307–312.
10.
Hodson T, Custovic A, Simpson A, Chapman MD, Woodcock A, Green R: Washing the dog reduces dog allergen levels, but the dog needs to be washed twice a week. J Allergy Clin Immunol 1999;103:581–585.
11.
de Blay F, Chapman MD, Platts-Mills TA: Airborne cat allergen (Fel d I). Environmental control with the cat in situ. Am Rev Respir Dis 1991;143:1334–1339.
12.
Custovic A, Fletcher A, Pickering CA, Francis HC, Green R, Smith A, Chapman MD, Woodcock A: Domestic allergens in public places III: house dust mite, cat, dog and cockroach allergens in British hospitals. Clin Exp Allergy 1998;28:53–59.
13.
Wickman M, Egmar A, Emenius G, Almquist C, Berglind N, Larsson P, Van Hage-Hamsten M: Fel d 1and Can f 1 in settled dust and airborne Fel d 1 in allergen avoidance day-care centres for atopic children in relation to number of pet-owners, ventilation and general cleaning. Clin Exp Allergy 1999;29:626–632.
14.
Custovic A, Green R, Fletcher A, Smith A, Pickering CA, Chapman MD, Woodcock A: Aerodynamic properties of the major dog allergen Can f 1: distribution in homes, concentration, and particle size of allergen in the air. Am J Respir Crit Care Med 1997;155:94–98.
15.
Luczynska CM, Li Y, Chapman MD, Platts-Mills TA: Airborne concentrations and particle size distribution of allergen derived from domestic cats (Felix domesticus). Am Rev Respir Dis 1990;141:361–367.
16.
van der Heide S, van Aalderen WM, Kauffman HF, Dubois AE, de Monchy JG: Clinical effects of air cleaners in homes of asthmatic children sensitised to pet allergens. J Allergy Clin Immunol 1999;104:447–451.
17.
Wood RA, Johnson EF, van Natta ML, Chen PH, Eggelston PA: A placebo-controlled trial of a Hepa air cleaner in the treatment of cat allergy. Am J Respir Crit Care Med 1998;158:115–120.
18.
Francis H, Fletcher G, Anthony C, Pickering C, Oldham L, Hadley E, Custovic A, Niven R: Clinical effects of air filters in homes of asthmatic adults sensitised and exposed to pet allergens. Clin Exp Allergy 2003;33:101–105.
19.
Mata Fernandez C, Fernandez-Benito M, Perez Miranda M, Guillen Grima F: Validation of the Spanish version of phase III ISAAC questionnaire on asthma. J Investig Allergol Clin Immunol 2005;15:201–210.
20.
Juniper EF, Guyatt GH, Feeny DH, Ferrie PJ, Griffith LE, Townsend M: Measuring quality of life in children with asthma. Qual Life Res 1996;5:35–46.
21.
Global Initiative for Asthma (GINA): Pocket Guide for Asthma Management and Prevention in Children, 2006.
22.
Arbes SJ, Sever M, Metha J, Collette N, Thomas B, Zeldin DC: Exposure to indoor allergens in day-care facilities: results from 2 North Carolina counties. J Allergy Clin Immunol 2005;116:133–139.
23.
Pereira FL, Silva DA, Sopolete MC, Sung SS, Taketomi EA: Mite and cat allergen exposure in Brazilian public transport vehicles. Ann Allergy Asthma Immunol 2004;93:179–184.
24.
van der Heide S, Kauffmann HF, Dubois AE, de Monchy JG: Allergen reduction measures in houses of allergic asthmatic patients: effects of air-cleaners and allergen-impermeable mattress covers. Eur Respir J 1997;10:1217–1223.
25.
Gore RB, Bishop S, Durrell B, Curbishly L, Woodcock A, Custovic A: Air filtration units in homes with cats: can they reduce personal exposure to cat allergen? Clin Exp Allergy 2003;33:765–769.
26.
Custovic A, Simpson A, Pahdi H, Green RM, Chapman MD, Woodcock A: Distribution, aerodynamic characteristics, and removal of the major cat allergen Fel d 1 in British homes. Thorax 1998;53:33–38.
27.
Wood RA, Laheri AN, Eggleston PA: The aerodynamic characteristics of cat allergen. Clin Exp Allergy 1993;23:733–739.
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2008
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