IMMUNOLOGY

Detailed explanation-1: -Type I hypersensitivity is also known as an immediate reaction and involves immunoglobulin E (IgE) mediated release of antibodies against the soluble antigen.

Detailed explanation-2: -A type II hypersensitivity is said to occur when damage to the host tissues is caused by cellular lysis induced by the direct binding of antibody to cell surface antigens. While the antibodies involved in type I HS are of the IgE isotype, those involved in type II HS reactions are mainly of the IgM or IgG isotype.

Detailed explanation-3: -Type I, II and III hypersensitivity reactions are known as immediate hypersensitivity reactions because they occur within 24 hours of exposure to the antigen or allergen. Immediate hypersensitivity reactions are predominantly mediated by IgE, IgM, and IgG antibodies.

Detailed explanation-4: -Type I reactions (i.e., immediate hypersensitivity reactions) involve immunoglobulin E (IgE)–mediated release of histamine and other mediators from mast cells and basophils. Examples include anaphylaxis and allergic rhinoconjunctivitis.