Standardization of bacterial allergens

One of the prerequisites for the standardization of bacterial allergens consists in the development and formulation of uniform requirements for the assessment of the specific activity of allergens, taking into account the problems to be solved by means of these allergens: a) the screening of large groups of population in order to select those that should be vaccinated or b) the evaluation of the extent of allergic conversion in humans. The data presented here have been obtained in the Laboratory of Allergens of L.A. Tarassevich State Research Institute for Standardization and Control of Medical Biological Preparations. They show that the frequency of skin reactions depends on the concentration of protein in a single dose (e.g. with hemolytic streptococcus allergen) as well as on the properties of the bacterial strain (e.g. with staphylococcal allergens). The standardization of allergens involves the use of special in vitro reactions of blood leukocytes. In 1962 Fradkin proposed the NDI (neutrophile damage index) test based on the enhancement of the amoeboid activity of neutrophiles after the incubation of blood smears to which allergen has been added. The results of differentiation of infections and postvaccinal allergy in children by means of NDI test are discussed. It is suggested that specific forms of allergens should be manufactured for in vitro cellular reactions.