For the susceptible human group, they might will be bothered by lots of outdoor allergens, for example, pollen could make them to repel flowers blossoming in Spring, or to shun beautiful sunshine in sunny days. Then could their home be the haven and keep them free of allergic symptoms, such as itching, sneezing and coughing? Unfortunately, the answer is highly possible negative. Depends on if there are pets in the house, or the temperature, humidity as well as food, plants or furniture, every house harbors its own indoor allergens. As a result, asthma, rhinitis, dermatitis and other allergic diseases could be induced. And among the long list of indoor allergens, the name of a cosmopolitan guest, house dust mites (HDM), will always show on the top.
The size of a typical HDM is only less than a millimeter, but the trouble caused by it is big. For example, according to a recent survey, in China only, there are more than 20 million cases of asthma induced by HDM annually. Now, the treatment of HDM is immunotherapy, which means to administrate the gradually increased doses of HDM allergen extracts to patients over a period. So, the availability of high purified and characterized allergen from HDM is the basic requirement. But, so far, most of the allergens used in HDM immunotherapy are still the mixtures of multiple allergens and some other compounds, which directly responsible for the ineffective outcomes and the related side-effects.
Now, either because some minor allergens are present in low concentration in mite extracts, or they only induce allergy to minor population, many mite allergens are still to be indentified. For example, although more than 30 allergens have been estimated in Dermatophagoides farinae, only 14 are reported. Recently, by collaborating with Shenzhen University and the First Affiliated Hospital of Kunming Medical College, Prof. LAI Ren (Kunming Institute of Zoology, the CAS) and his colleagues undertook a study to try to identify the diversity and to complete our knowledge about D. farinae allergens.
In this study, sera from 41 asthmatic patients who had a positive skin reaction to crude D. farinae extract were analyzed. From there, 17 allergens or their isoforms have been identified from the mite extracts of D. farinae by a procedure of proteomics combined with two-dimensional immunoblotting and 8 of them are the first report as mite allergens. More importantly, these newly indentified allergens will be helpful for HDM allergy diagnosis and therapy, especially for patients without response for HDM major allergens.
This current work indicated that many novel D. farinae allergens remain to be investigated and the approach with high resolution is necessary to detect complete repertoire of D. farinae allergens. Get access to full text here: (Molecular and Cellular proteomics: http://www.mcponline.org/content/early/2013/03/12/mcp.M112.027136.full.pdf+html).
(By Su-Qing Liu)
