Immunoglobulin A

Immunoglobulin A, or IgA, is the primary antibody on the mucosal surface and is essential for controlling the immune response. IgA is often divided into two subtypes: IgA1 and IgA2. In plasma, bone marrow, and the spleen, IgA1 is the most prevalent isotype, whereas IgA2 contains a longer amino-acid hinge region. There are three different types of IgA: monomeric, dimeric, and secretory. IgA in its secretory and dimeric form is typically present on mucosal surfaces. IgA that is monomeric or dimeric has a tendency to attach to the IgA receptor.