Study of the common wormwood allergoid

BACKGROUND: Allergens from the pollen of wormwood (Latin: Artemisia absinthium) are among the most dangerous in terms of allergization in central Russia, Europe and a number of other regions. The use of allergoids created using glutaraldehyde instead of native allergen extracts is due to the reduced risk of developing allergic reactions while maintaining immunogenicity and eliminating the highly toxic element formalin from the production process, which makes allergoids safer for use in allergen-specific immunotherapy.

AIM: Obtaining an allergoid from wormwood pollen by treatment with glutaraldehyde to evaluate its properties prior to preclinical testing.

MATERIALS AND METHODS: Purified extract of wormwood pollen, isolated by defatting and water-salt extraction, was dissolved in phosphate-buffered saline (PBS) pH 7.5, after which it was polymerized in 0.1 % glutaraldehyde solution. Stabilization was performed with sodium borohydride solution. The extract and allergoid of wormwood pollen were studied using chromatographic analysis and competitive enzyme-linked immunosorbent assay (ELISA). Then, intraperitoneal immunization with the obtained allergoid was carried out in CBA × C57Bl/6 (F1) mice.

RESULTS: After evaluation of the specific allergenic activity using competitive immune assay ELISA with biotinylated extract of wormwood pollen allergen, it was shown that the 50 % inhibition point for the allergoid is determined at a drug concentration of 0.03 mg/ml, and for the allergen – already at 0.0008 mg/ml. Consequently, the allergenicity of wormwood pollen allergoid is significantly reduced compared to that of the original extract. In addition, the immunogenic activity of the obtained allergoid was confirmed in mice: the average optical density of the ELISA reaction, indicating the amount of IgG, in the group immunized with the allergoid was more than at least 1.5 times higher than the values for the allergen extract.

CONCLUSIONS: During the work, an extract containing allergens of wormwood pollen was obtained. An allergoid was obtained on its basis by polymerization with glutaraldehyde. The obtained allergoid has a high molecular weight (the range shifted to 44–66 kDa), while it has low allergenic activity, in comparison with the original extract, and also retains immunogenicity. In this regard, this allergoid can become the basis for obtaining new ASIT treatments.