Abundance of domestic mites in dwellings of children and adolescents with asthma in relation to environmental factors and allergy symptoms

Exposure to house dust allergens, mainly from domestic mites, is an important cause of allergic reactions in sensitized asthmatic patients. A total of 63 dust samples were collected from 16 flats in Bytom (south Poland); in each flat a person (age 4–17 years) suffering from bronchial asthma lived with his/her family. Mite density was calculated as the number of specimens per g of dust. The results were compared with household features and the data were statistically analyzed. In total 566 mite specimens were isolated, including 526 members of the family Pyroglyphidae (93%). The dominant species were Dermatophagoides pteronyssinus (60% of the total count) and Dermatophagoides farinae (32%). Pyroglyphids were found in all mite positive samples (68%) of which 35% also contained non-pyroglyphids, including glycyphagids, cheyletids and gamasids. The results suggest associations between the density of some mite taxa (per g of dust) and the following indoor environmental factors: presence of pets, number of inhabitants, coal-stoves as a type of heating, cleaning frequency, higher relative humidity, presence of flowers and PVC windows. The severity of asthma seems to be associated with the numbers of D. farinae, total domestic mites and live mites per g of dust.

Population dynamics of some domestic mites in laboratory culture

Background Domestic mites are a primary source of allergens indoors all over the world. Extracts of mite allergens are important for diagnosing and treating mites allergy. The effective cultivation processes play a critical role in the final composition of mites' allergen extracts. In order to produce large amounts of antigens of domestic mites, culture techniques of domestic mites were studied. Domestic mites were isolated from collected dust samples and cultured on a fine-ground mixture of dust and sawdust (2:1). While dry yeast, wheat germ, and cornflour were used at a ratio of 2:1:1 for nutrition. Food was placed over a few centimeters of cement base that had been placed on the bottom of the rearing containers. The population growth rates were determined. Results Successful methods for mite cultures utilize high protein and carbohydrate foods, an average temperature of (25 ± 2) °C and relative humidity (80 ± 5) %. During a 14-week observation period of mites' culture, the peak in number was obtained after 8 weeks of the culture in Tyrophagus, 10 weeks in Dermatophagoides, and 12 weeks in Blomia; thereafter, the number decreased. Significant differences were found in the growth rates of Dermatophagoides (P = 0.02) and Blomia (P = 0.03) in between pure and mixed cultures. Conclusions The modifications made to the mixture of diet used for cultivation showed a high yield of domestic mites. Also, the cement layer also is an excellent way to make space for egg laying and prevent mites from escaping.

Assessment of serum levels of allergen-specific immunoglobulin E in different seasons and breeds in healthy horses

The present study was designed to asses specific IgE towards environment allergens in 42 healthy horses. Determination of this immunoglobulin in serum serve as diagnostic tools in allergic diseases to improve efficacy of the treatment and proper allergen selection to specific immunotherapy. Serum levels of allergen specific IgE were measured with equine monoclonal antibody, using 15 individual and 5 mix allergens in North European Panel. The study revealed season dependent increased levels of allergen specific IgE in normal horses. It is noteworthy that healthy horses show high percentage of positive reactions, most commonly towards to domestic mites D. farinae (80%), D. pteronyssinus (35.71%) and storage mites T. putrenscentiae (42.86%), Acarus siro (40.48%). These allergens play an important role in equine, canine and feline atopic dermatitis. We also demonstrated high IgE levels in the group of horse specific insect allergens. Tabanus sp. (35.71%), Culicoides sp. (28.57%) and Simulium sp. (26.19%) were the most frequent insect positive reaction allergens. No positive reactions in all groups of allergens were found in winter season, low and merely detectable levels of antibodies have been found relating to D. farianae and T. putrescentiae allergen. We observed elevated mould-IgE levels in horses that live in stables, while outdoor living horses showed very low levels. Amongst all positive reactions we observed only weak and moderate reactions but no strong positive reactions were found. No significant differences were observed between three breeds of horses with the exception of moulds and D. pteronyssinus allergens