Elevated immunoglobulin levels mean that the body's immune system has produced antibodies in response to a threat, such as bacteria, viruses, fungus, animal dander or cancer cells. Immunoglobulins, also known as antibodies, attach themselves to foreign objects so that the immune system can destroy them, notes WebMD.
The body produces antibodies specific to each type of foreign substance. The five major types of antibodies are IgA, IgG, IgM, IgE and IgD. The levels of each type of antibody give doctors information about the specific cause of a medical problem, states WebMD.
High levels of IgA antibodies may indicate that an autoimmune disease, such as rheumatoid arthritis or systemic lupus erythematosus, or a liver disease, such as cirrhosis or hepatitis, is present. Inflated levels of IgG could indicate the presence of a long-term infection, such as HIV. High levels of IgM are linked to a variety of conditions, including mononucleosis, kidney damage or a parasite infection, and a high level of IgE can be found in people with allergic reactions and certain autoimmune diseases, explains WebMD.
It is not clear how IgD works in the immune system. Inflated levels of IgD may mean that IgD multiple myeloma is present, states WebMD.