Immunoglobulin therapy

Immunoglobulin therapy is the use of a mixture of antibodies (normal human immunoglobulin or NHIG) to treat several health conditions. These conditions include primary immunodeficiency, immune thrombocytopenic purpura, chronic inflammatory demyelinating polyneuropathy, Kawasaki disease, certain cases of HIV/AIDS and measles, Guillain-Barré syndrome, and certain other infections when a more specific immunoglobulin is not available. Depending on the formulation it can be given by injection into muscle, a vein, or under the skin. The effects last a few weeks. Common side effects include pain at the site of injection, muscle pain, and allergic reactions. Other severe side effects include kidney problems, anaphylaxis, blood clots, and red blood cell breakdown. Use is not recommended in people with some types of IgA deficiency. Use appears to be relatively safe during pregnancy. Human immunoglobulin is made from human blood plasma. It contains antibodies against many viruses. Human immunoglobulin therapy first occurred in the 1930s and a formulation for injection into a vein was approved for medical use in the United States in 1981. It is on the World Health Organization's List of Essential Medicines. Each formulation of the product is somewhat different. A number of specific immunoglobulin formulations are also available including for hepatitis B, rabies, tetanus, varicella infection, and Rh positive blood exposure. Immunoglobulin therapy is used in a variety of conditions, many of which involve decreased or abolished antibody production capabilities, which range from a complete absence of multiple types of antibodies, to IgG subclass deficiencies (usually involving IgG2 or IgG3), to other disorders in which antibodies are within a normal quantitative range, but lacking in quality – unable to respond to antigens as they normally should – resulting in an increased rate or increased severity of infections. In these situations, immunoglobulin infusions confer passive resistance to infection on their recipients by increasing the quantity/quality of IgG they possess.