immunoglobulin D

Immunoglobulin D (IgD) is a type of antibody found in the immune system, primarily on the surface of certain white blood cells called B cells. It helps the immune system recognize and respond to pathogens like bacteria and viruses. Although less abundant than other antibodies such as IgG or IgA, IgD plays a role in activating B cells and regulating immune responses, particularly in the respiratory tract and on the surface of B cells in the blood and tissues. Its exact functions are still being studied, but it’s an important part of the body’s defense system.