Intravenous Immunoglobulin (IVIG) is a plasma product used in the treatment of certain conditions related to the immune system. This treatment is approved for use in people with immune deficiencies, autoimmune diseases, some inflammations, and infections, and it is also used in several off-label ways, such as the prevention of miscarriages. In order to receive it, a patient must go to a transfusion center or get a healthcare professional to come to his or her home, as the treatment requires several hours of sitting while the IVIG is delivered, and medical personnel must be available to monitor the patient for signs of an allergic reaction or any other complications related to the treatment.
The critical component in IVIG is Immunoglobulin-G, also known as IgG. This substance helps the body build long-lasting antibodies to fight disease. In people with immune deficiencies, it can help to bolster the immune system, allowing the body to fight disease more effectively. The disease-fighting ability is also sometimes harnessed in off-label use: IVIG treatment for pregnant women, for example, is supposed to prevent the body from viewing the fetus as foreign by interfering with the formation of certain antibodies known as Natural Killer cells.
To make IVIG, companies that specialize in blood products take blood donations and centrifuge them to derive plasma, before treating the plasma to extract the desired IgG antibodies. It can also, of course, be extracted from plasma donations. Each batch contains donations from at least 1,000 people, creating a broad cross-section of antibodies by pooling donations.
An IVIG treatment lasts between two and 12 weeks, and typically requires re-administration. It can interfere with vaccinations, so people are generally advised to schedule treatments at least a month after vaccination, and to avoid new vaccinations for at least 12 weeks after IVIG. Common side effects include skin irritation, nausea, and headaches. It can also cause edema and damage to some organs, especially the liver and kidneys. In rare cases, people may also experience allergic reactions, including anaphylaxis, a life-threatening condition.
Like other blood products, IVIG does come with some safety concerns. Blood and plasma donations used in its production must be carefully screened for a variety of blood-borne diseases, and the blood product must also be treated to kill any viruses that might have passed the screening. Illnesses caused by contaminated blood products are extremely rare, thanks to an extensive international system which is designed to keep these products safe.