IgG

Immunoglobulin G (IgG) is the most abundant and comprehensive type of antibody in the immune system. It is synthesized and secreted only by B lymphocytes and plasma cells, and has various functions such as anti-infection defense, immune memory and immune regulation. In clinical practice, IgG can be used to assist in the diagnosis of lymphoma. For example, high expression of IgG is considered as a pathological feature of primary cutaneous lymphoma. Some research also suggested that IgG may be closely related to the occurrence of MALT lymphoma. Meanwhile, IgG type multiple myeloma (MM) is the most common subtype of MM, and the IgG level is negatively correlated with curative effect and prognosis of tumors. In addition, some epithelial tumors such as liver cancer, gastric cancer, colorectal cancer, breast cancer, cervical cancer, and ovarian cancer may undergo gene rearrangement and abnormally secrete IgG, which may mediate immune escape by closing killer cell surface receptors, or utilize growth factor activity to promote tumor development, suggesting that this tumor derived IgG can be a new therapeutic target.