2-2.Allergy
	●Immunity is an important mechanism that our body is defended. However, it is likely to act in the disadvantage oppositely for the body. It is a reaction that is called, this is 'Allergy'. The allergic reaction greatly divides into four types.
	�Ttype(Immediate type reaction） When the antigen invades the inside of the body, the reaction will be seen in a short time. The allergy doesn't happen to this antigen material in meeting once. However, the antibody of "IgE type" of antibodies that can have been done by the first meeting unites with a special cell such as "Mast cell". The mast cell holds histamine with a very strong pharmacologic action in the cell. The mast cell breaks when the antibody invades there again, the held histamine is discharged rapidly, and panic is caused. It dies at times occasionally.
	�Utype（Hypersensitivity） The macrophage (phagocyte) etc. attack this antibody and the symptom appears when antibodies such as IgE and IgM unite with the antigen in the organization on the cell mebrane.
	�Vtype（Arthus reaction） The antibody unites with a liquid antigen by the allergic reaction that occurs because the antibody reacts to the antigen in the organization on the cell membrane surface, and the immune complex is made. It is a reaction caused by the flow of this complex to the inside of the body, and the deposition to the organization.
	�Wtype（Delayed hypersensitivity reaction） It is a the tuberculin reaction that is known by the delayed hypersensitivity reaction well. There are. It is cell immune reaction. It is a presentation cell and a macrophage (phagocyte) of the antigen though the allergy caused by the reaction of the antigen and the lymphocyte. The antigen invades and after 48 hours, it is called a delayed hypersensitivity reaction that the reaction appears strongly from 24.