Knowing an individual‘s natural exposure to HDM is still a challenging task. The approach to solve this issue was to validate the suitability of the personal particle sampler, originally designed to sample pollen and fungal spores, to collect HDM material in its natural appearance and quantify the aeroallergen material.
The personal particle sampler is a wearable device sampling ambient air and guiding the air to an adhesive stripe, where particles deposit. The stripe is contained in an exchangeable cartridge. After exposure, the stripe can be removed and analyzed microscopically or biochemically.
Two properties of the personal particle sampler were examined: The correlation of sampled HDM allergen to concentration of allergen in the ambient air, and the maximum particle size of HDM material, which could be sampled. To analyze the correlation, several particle samplers were placed in an exposure chamber, which is able to generate a definable and constant HDM particle concentration over a dedicated period of time using grinded HDM material (less than 5um). The sampled material was then analyzed using a standard antigen test (Der p1 and Der f1).
To analyze the maximum detectable particle size, different grain sizes where used in trickle tests, using full HDM bodies as the reasonable limit. The particles adhering to the stripe were verified microscopically.
In the environmental chamber test, a proportional relation between ambient HDM material concentration and allergen content sampled was proven. The proportional relation was significant considering the variance of the allergen concentration due to the dispersal system as well as the accuracy of the allergen analysis itself.
In the maximum particle size test, even whole HDM bodies could be sampled, thus stuck on the stripe.
The personal particle sampler is suitable for determining an individual’s exposure to HDM material. However, it still has to be proven, that the concentration measured by the personal particle sampler correlates with an allergenic person’s recognized symptoms in real life.