Nokea
A child cut his leg with a piece of glass while playing and was brought to the clinic for the injection of tetanus toxoid. In order to prevent the development of anaphylactic shock the serum was administered by Bezredka method. What mechanism underlies this method of desensitization of the body?
Correct Answer: A
Rationale: The correct answer is A: Binding of IgE fixed to the mast cells. The Bezredka method involves injecting small, gradually increasing doses of the antigen (tetanus toxoid) to desensitize the body and prevent anaphylactic shock. This process works by binding the IgE antibodies fixed to mast cells, thereby reducing the release of allergic mediators like histamine. This prevents the cascade of events that lead to anaphylactic shock.
Choice B (Blocking the mediator synthesis in the mast cells) is incorrect because the Bezredka method does not block mediator synthesis but rather prevents the release of mediators by binding IgE.
Choice C (Stimulation of immune tolerance to the antigen) is incorrect as the Bezredka method does not primarily focus on inducing immune tolerance but rather on preventing anaphylactic reactions.
Choice D (Stimulation of the synthesis of antigen-specific IgG) is incorrect because the Bezredka method targets IgE antibodies on mast cells