IgA immunoglobulin complex, circulating polymeric IgA immunoglobulin complex cellular_component Note that an IgA immunoglobulin complex has the function of antigen binding if a suitable antigen is available. Dimeric IgA is by far the most common form of polymeric IgA. In human only the IgA1 isotype is capable of a polymeric forms. A protein complex composed of two, three, or four monomeric IgA immunoglobulin complexes linked through both direct disulfide bonds and through disulfide binded monomers of J chain acting as a bridge. Each IgA monomer consists of two identical immunoglobulin heavy chains of an IgA isotype and two identical immunoglobulin light chains, held together by disulfide bonds. Dimeric IgA is sometimes complexed additionally with secretory component, and present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. 2010-03-24T01:44:53Z pIgA antibody mah polymeric IgA antibody pIgA1 antibody GO:0071749 polymeric IgA1 antibody