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Mite allergens. Collection, determination, expression of results, and risk levels for sensitization and symptom
1Voksentoppen, Oslo, Norway. stend@usit.liv.uio.no
Abstract:
The presence of mite allergens in dust can be determined by counting mites at different stages of development in dust and by determination of the major allergen content (Der p 1 ) in dust and air, which is crucially important to allergic patients. For comparison of results, similar methods for collection of dust and air must be used. Due to their size, mite bodies and fecal particles are airborne only directly after disturbance. Special filters should be used for dust collection, and upholstered surfaces should be vacuumed for 2 min/m2 (minimum 4 m2) and hard surfaces for 1 min/m2 (minimum 8 m2). Heavy contaminations should be removed. Preferably, the method given in the ISAAC study should be followed. Samples should be deep-frozen for at least some days to kill the mites. ELISA techniques, preferably using polyclonal antibodies and antigen with all isoforms present, should be used for determination of allergens. The allergen load has been given in ng/g of dust, but allergen/m2 or per sample area should be preferred. Allergen in the air should be given in pg/m3. A tentative limit of 2000 ng/g was proposed for sensitization and asthma. This limit is still valid on a population basis, but recent data indicate that highly susceptible young children become sensitized at concentrations 10-100 times lower and that ng levels of cat allergen/m3, as found in schools, induce chronic asthma.
Insights
Accurate measurement of mite allergens (Der p 1) in dust and air is vital for allergic patients. Standardized methods for dust collection and analysis, like ELISA, are essential for reliable results and managing asthma risks.
Area of Science:
- Environmental Science
- Allergy and Immunology
- Analytical Chemistry
Background:
- Mite allergens in dust are significant triggers for allergic diseases.
- Accurate quantification of mite allergens is crucial for patient management and risk assessment.
Purpose of the Study:
- To outline standardized methods for collecting and analyzing mite allergens in dust and air.
- To provide guidance on preferred units and reference values for allergen quantification.
Main Methods:
- Dust and air sampling using specialized filters and vacuuming protocols (e.g., ISAAC study methods).
- Deep-freezing samples to kill mites.
- Enzyme-Linked Immunosorbent Assay (ELISA) with polyclonal antibodies for allergen determination.
Main Results:
- Standardized collection methods are necessary for comparable results.
- Preferred units for allergen load are ng/m2 or per sample area, and pg/m3 for airborne allergens.
- A tentative limit of 2000 ng/g for sensitization and asthma is noted, with lower thresholds for susceptible children.
Conclusions:
- Standardized protocols for mite allergen assessment are critical for clinical relevance.
- Revised reporting units and consideration of lower sensitization thresholds are important for public health.
- Accurate allergen measurement aids in understanding and mitigating asthma triggers.