Why house dust mites cause allergy
The reason why so many people are allergic to house dust mites is coming to light. One of the major mite allergens (Der p2) is a ‘con-artist’ that can mimic a human immune signal for a bacterial infection – even when infection isn’t there! The deception causes the immune system to attack a fake intruder, leading to a reaction against the mite itself.
Mites are ancient animals that evolved about 600 million years ago consequently many of the products that come from mites are completely foreign to man.
When humans are first exposed to house dust mite products their immune system can react in one of three ways: (1) It can ignore the mite as background dust, (2) note it as interesting and tolerate it, or, (3) become concerned and alert to its foreign presence. The last category can turn into an active allergy if the conditions are right. The conditions usually needed for this transformation are genetic influence, age, the amount of exposure, health, and life style. Not all are necessary.
It is now emerging why so many people are sensitive or allergic to dust mites. It appears that one of the major mite allergens, the one that most people are sensitive or allergic to, is a ‘con-artist’. The deceitful mite product or allergen (named Der p2) has the ability to mimic a human immune trigger that signals gram-negative bacterial infections or infections associated with parasites such as an attack from hookworms. Unfortunately it is also an immune signal for allergy.
Not only can Der p2 fool the immune system but also it appears to be able to take other normally harmless proteins along with this deceit.
In house dust mite droppings there are 14 fully indentified proteins that have the potential to become allergens, but first they must enter the body to be noticed. This entrance can be achieved thanks to an active digestive enzyme found in mite droppings. The enzyme, also an allergen, can ‘melt-the-glue’ that binds epithelial cells together causing cell death and a breach in the body’s defences. The breach creates the important entrance for other opportunistic bystanders such as the con-artist Der p2, or other mite products or environmental debris, thus creating a cocktail of mixtures that can confuse and overwhelm an immune system vulnerable to allergy.
The immune system can make mistakes by tagging an ‘innocent’ protein as a allergen.
Similar pages
- A new way to look at house dust mite allergy and avoidance
- Dust mites and human skin – pathways of sensitization explored
- Mites – domestic, storage, and house dust mites. What’s the difference?
- Mites, domestic, storage and house dust
- 2010 – Active allergy to house dust mites makes asthma/COPD worse
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‘Dangerous Allergens: Why Some Allergens are Bad Actors’. Steve N. Georas, Fariba Rezace, Laurie Learner’ Lisa Beck, ‘Curr. Allergy Asthma Rep’. 2010; 10: 92-98
‘CpG Motifs in bacterial DNA trigger direct B-cell activation’. Krieg, A.M. A.K. Yi, S. Matson, T.J. Waldschmidt, G.A. Bishop, R. Teasdale, G.A. Koretzky, and D.M. Klinman. 1995. ‘Nature’ (Lond.). 1995; 374: 546–549
Dogs and cats can become allergic to dust mites. If your pet suffers from atopic dermatitis check out mite exposure as the problem.
