IMMUNOLOGY

Detailed explanation-1: -There are five main classes of heavy chain C domains. Each class defines the IgM, IgG, IgA, IgD, and IgE isotypes.

Detailed explanation-2: -There are five immunoglobulin classes (isotypes) of antibody molecules found in serum: IgG, IgM, IgA, IgE, and IgD. They are distinguished by the type of heavy chain they contain.

Detailed explanation-3: -Immunoglobulin E is one of the five classes of immunoglobulins (IgM, IgG, IgD, IgA, IgE). IgE has a unique chemical structure and an array of physiological functions, such as Type I hypersensitivity reactions, parasitic infections, autoimmune processes, and venom protection.

Detailed explanation-4: -IgG is the most common class of immunoglobulin. It is present in the largest amounts in blood and tissue fluids. Each IgG molecule consists of the basic four-chain immunoglobulin structure-two identical H chains and two identical L chains (either kappa or lambda)-and thus carries two identical antigen-binding sites.

Detailed explanation-5: -IgG is composed of four subclasses: IgG1, IgG2, IgG3, and IgG4 [1-9]. The structure, genetics, and function of the IgG subclasses are reviewed in this section. Detailed discussions of these topics as they apply to immunoglobulins in general are presented separately.