الفهرس 
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Abstract
Background: Domestic mites are a combination of household-living storage mites and house-dust mites, belonging to the Acari subclass. Indoor domestic mites are a primary source of allergens all over the world. Identifying mites to species level can help to improve the management of mites-related allergies as they produce species-specific allergens. The impact of the diversity and changing ecological conditions indoors are useful in developing strategies to avoid the development and growth of large populations of domestic allergic mites. Mites’ extracts are important for diagnosing and treating domestic mites’ allergy. The effective cultivation processes play a critical role in the final yield of mites’ allergen extract. Genes encoding interleukin 12B and interleukin 17A, which determine the course of T cell-mediated immune response, are prime candidates for susceptibility to allergy.
Objective: This work aimed to identify species of domestic mites in various Egyptian governorates and to produce large amounts of mites’ antigens. It also aimed to evaluate whether a single nucleotide polymorphism of IL-12B (+1188A/C, rs3212227) and IL17-A (-197G/A, rs2275913) genes confer susceptibility to domestic mites’ allergic diseases.
Subjects and methods: Dust samples were collected from the houses of allergic patients. Mites were isolated from the collected dust and identified, concerning seasonal variations in population. Dermatophagiodes, Blomia, and Tyrophagus domestic mites genera were cultivated on a fine-ground mixture of dust and sawdust (2:1). Dry yeast, wheat germ, and cornflour at a ratio of 2:1:1 were used as food. A cement base was used on the bottom of the rearing containers. The population growth rates were determined.
This case-control study enrolled 120 subjects; 60 domestic mites’ allergic patients and 60 healthy non-allergic controls. Total immunoglobulin (Ig) E level, absolute eosinophilic count, serum IL-4, IL-10, IL-12B, and IL-17A levels for the studied subjects were measured.
Then, genotyping of single nucleotide polymorphisms at (+1188A/C) for IL-12B and (-197G/A) for IL-17A gene were conducted using restriction fragment length polymorphisms.
Results: Within 120 dust samples, seven species were identified: Dermatophagoides farinae (69.4%), Dermatophagoides pteronyssinus (55.5%), Tyrophagus species (38.8%), Blomia tropicalis (30.5%), Cheyletus species (13.8%). Euroglyphus species (5.5%) and Tarsonemus species (5.5%). The highest positive domestic mites’ samples were in Qalyubia (73.7%) and the lowest positive samples were in Cairo (33.3%). The highest numbers of domestic mites populations were during spring and autumn. The chosen method for mites cultivation that utilized high protein and carbohydrate foods, an average temperature of (25±2) °C, and relative humidity of (80±5) was successful. During the observation period to the mites culture for 14 weeks, the peak in number was obtained after eight weeks of the culture in Tyrophagus, ten weeks in Dermatophagiodes, and 12 weeks in Blomia; thereafter the number decreased.