igd is produced by:
Immunoglobulin D, also called IgD, is an uncommon antibody that is produced by  immature B cells. The exact purpose of this antibody is unknown, though it has something to do with the humoral immune response in humans and other animals. It is similar in function to immunoglobulin M, which is also produced by B cells. Like many other immunoglobulins, IgD is made up of four chains of amino acids. Two heavy and two light chains are connected by a hinge in the middle.