Dust mite allergens and asthma—A worldwide problem

Abstract

After the discovery ofhouse dust mites in 1964 their association with asthma has been reported from many different parts of the world including the developing countries. Two sets of major allergens from mites of the genus Dermatophagoides are now well recognized. The Group I allergens are glycoproteins of relative molecular mass (Mr) 25 000, which show both structural homology and cross-reactivity. The allergen Der p I has been cloned and sequenced confirming the M, and establishing its nature as a protease. The Group II allergens (Mr 15 000) show even closer homology and cross-reactivity.Specific immunoassays for Group I and Group II allergens, using monospecific antisera and monoclonal antibodies, have been standardized and are suitable for measuring allergen levels in different parts of the world.Measures for reducing the levels of mite allergens in houses include the covering of mattresses, hot washing of bedding, and removal of carpets from bedrooms as well as humidity control, vacuum cleaning, and the use ofacaricides in the rest ofthe house. There is already evidence that these procedures can cause a major improvement in the symptoms of asthma. While provisional standards for both sensitization to mites and also mite allergen exposure can now be recommended, there is an urgent needfor controlled studies using protocols demonstrated to reduce mite allergen levels by at least tenfold and for further international collaboration.

What's in this issue?

“…A recent narrative review [5] of 30 clinical trials involving bedding encasement for treating asthma found that only four of these trials reported significant reduction in dust-mite allergen exposure with concomitant reduction in bronchial hyperresponsiveness (BHR). As in many other studies [6], the review found reduction in exposure to mite allergen in ten of the studies, but BHR was not significantly reduced in asthmatic patients as compared to controls. The authors concluded that ''although bedding encasement might be an effective asthma treatment under some conditions, when implemented in clinical trials by asthma patients, its effectiveness is inconsistent and appears to be, at best, modest''.…”

Seasonal Variation of Skin Reactivity and Specific IgE Antibody to House Dust Mite

“…1 IgE antibody responses to house dust mite allergen have been considered to play an important role in the development of bronchial asthma. 2 Although, traditionally, house dust mite has been considered a perennial allergen, aggravation of clinical symptoms related to house dust mite sensitivity in association with seasonal increase in mite numbers has been frequently observed by practitioners.…”

Residential exposure to plasticizers and its possible role in the pathogenesis of asthma.

“…It is therefore a possibility that indoor pollutants might be of greater importance in the development of asthma than outdoor pollutants. Several studies have shown significant associations between health outcomes and exposure to indoor components like environmental tobacco smoke (12)(13)(14)(15), NO2 (16), mite allergens (17)(18)(19), and mold or dampness (20)(21)(22)(23)(24).…”