Influence of Ionizing Radiation on the Allergic Reactivity of Tuberculosis-Infected Laboratory Animals

Abstract

Allergic examination using PPD-tuberculins is the main method of life-time tuberculosis diagnostics in farm animals and poultry. However, it is known about a decrease in the diagnostic value of allergic reactions after irradiation of animals, the occurrence of non-specific, pseudo-allergic reactions. One of the reasons for the manifestation of non-specific reactions may be autosensitisation (autoallergisation) of the body by the breakdown products of personal tissues, which is especially pronounced with radiation damage. Ionizing radiation affects the manifestation of tuberculin sensitivity, the course of tuberculosis and autoimmune processes in the body. Differential diagnostics of non-specific tuberculin reactions remains not yet a fully solved problem, although there are many tests for its implementation. After the accident at the Chernobyl nuclear power plant, a considerable number of animals remained in the adjacent territories contaminated with radioactive substances, including those infected with the causative agent of tuberculosis and atypical mycobacteria. It is known that irradiation leads to autosensitisation of the body by the breakdown products of its own tissues and the development of non-specific pseudoallergic reactions to heterologous allergens. Therefore, work was carried out to study the allergic reactivity of tuberculosis patients and laboratory animals sensitised with atypical mycobacteria irradiated with gamma radiation (200 guinea pigs). It was established that 14-60 days after infection with tuberculosis pathogens, 90-100% of cavies developed allergic reactions to PPD-tuberculin for mammals and poultry, mainly to a homologous allergen. Allergic reactivity persisted until 90 days of the study. After exposure to sublethal (non-lethal) doses of gamma rays, infected and intact cavies developed non-specific reactions to tuberculin and heterologous allergens: mallein and brucellin. In cavies uninfected with the causative agent of tuberculosis, 7 days after gamma radiation exposure, non-specific reactions to mycobacterial allergens were observed at a dose load of 200 R in 16.6%; 150 R – 5.3% in the group, and after 27 days in irradiated doses of 50 R and 100 R in 25% and 33% of the studied animals, respectively. Isolated reactions to brucellin and mallein occurred in animals infected with the causative agent of tuberculosis and intact animals 60 days after irradiation with doses of 50 R, 100 R and 150 R. The manifestation of non-specific allergies in irradiated animals depended on the radiation dose rate and radiosensitivity of the animals

Keywords

• tuberculin
• heterologous allergens
• gamma radiation
• mycobacteria
• allergic studies