Immunoglobulin m

Immunoglobulin M (IgM) is one of the several forms of antibody that are produced by the immune system in all vertebrates. It is the first antibody to appear in response to initial exposure to an antigen.

Structure

Immunoglobulin M is a large pentameric molecule, with each monomer composed of two heavy chains (mu chains) and two light chains, with the constant region of the mu chains forming the core of the pentameric structure. Each IgM has five binding sites for antigens, making it highly effective in agglutination and pathogen elimination.

Function

The primary functions of IgM are to detect and eliminate pathogens at the early stages of primary immune response. It is particularly effective against bacteria and viruses, and is also involved in the activation of the complement system, a part of the immune system that enhances the ability of antibodies and phagocytic cells to clear microbes and damaged cells.

Clinical significance

Abnormally high or low levels of IgM in the blood can be an indicator of various health conditions. High levels can indicate recent infection, immune disorders, or certain types of cancer, such as Waldenström's macroglobulinemia. Low levels can indicate immune deficiencies, such as Selective IgM deficiency.

See also

• Immunoglobulin G
• Immunoglobulin A
• Immunoglobulin E
• Immunoglobulin D