IgD

Immunoglobulin D (IgD) is a type of antibody in the immune system, divided into serotype IgD and membrane-bound IgD, involved in B cell activation, immune tolerance, mucosal protection, and other activities. In clinical practice, IgD can assist in lymphoid and hematopoietic system tumors such as mantle cell lymphoma, lymphoplasmacytic lymphoma, and chronic lymphocytic leukemia. Meanwhile, IgD expression can exist in some diffuse large B cell lymphomas, and it may participate in tumorigenesis by binding to IgD receptors. Moreover, IgD type multiple myeloma (MM) is a rare malignant disease of plasma cells, and the patients have shorter survival time and higher mortality rate compared to those with other types of MM, which is speculated to be related to the 1q21 amplification commonly associated with this tumor. In addition, some epithelial tumors such as esophageal cancer, colorectal cancer, breast cancer and endometrial cancer may undergo gene rearrangement and abnormally secrete IgD, which may promote cell proliferation by activating signal pathways, or mediate immune escape by interfering with immune response.