This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Type I hypersensitivity, the mediator is - 
Select and explain. 
A. IgE, B. IgD, C. IgM, D. IgC
A: IgE
Answer: A: IgE 
Explanation: Type I hypersensitivity reaction is IgE dependent. Cytotoxic IgE antibodies are fixed on the surface of tissue cells ( mast cells and basophils) in sensitized individuals. The antigen combines with the cell fixed antibody, leading to release of pharmacologically active substance that produces the clinical reaction. Reference : Anathanarayan & paniker's 9th edition, pg: 162 <\p>