Register for Exposure To Cats Can Induce Tolerance
AsthmaMarch 26, 2001
2001 MAR 26 - (NewsRx.com & NewsRx.net) -- Children exposed to cat allergens at home can produce an immune response without developing asthma, report authors of a study in the March 10, 2001, issue of the Lancet.
However, in some children, exposure to cat allergens remains the highest single risk factor for asthma.
Although asthma is strongly associated with immediate hypersensitivity to indoor allergens, several previous epidemiological studies have suggested that a cat in the household can decrease the risk of asthma. Thomas Platts-Mills and colleagues from the University of Virginia, Charlottesville, investigated the immune response to cat and mite allergens, and asthma among children with a wide range of allergen exposure.
The investigators measured the presence of antibodies to cat and mite allergens in 226 children (aged 12-14 years) and compared the data with evidence of asthma and the allergen concentrations in house dust. Exposure to high quantities of cat allergen can produce an immunoglobulin G (IgG) and IgG4 antibody response without IgE antibodies, skin sensitization, or risk of asthma.
Platts-Mills et al. conclude that this modified Th2 response should be regarded as a form of tolerance and may be the correct objective of immunotherapy. They comment that the findings support the role of an immune response distinct from the Th1-type response, which has previously been proposed as the alternative response to allergens.
Platts-Mills comments: "The fact that this tolerant response to cat allergens can occur has important implications for the advice we give patients. It also provides a new insight into the relevance of the home environment to the increase in asthma."
Dr. Thomas Platts-Mills can be contacted at the UVA Asthma and Allergic Diseases Center, University of Virginia Health System, PO Box 801355, Charlottesville, VA 22908, USA. Tel: 1-804-924-5917; fax: 1-804-924-5779; e-mail: tap2z@virginia.edu.
This article was prepared by Health & Medicine Week editors from staff and other reports.
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