Intravenous immune globulin (IVIg) therapy

It is normal for the immune system to make antibodies to fight bacterial or viral infections. Nearly everyone has a pool of antibodies circulating in their blood ready to go to battle should there be an invasion by an infectious agent. Another name for these antibodies is immunoglobulin, often abbreviated as Ig. 

Many years ago, techniques were developed to isolate and purify Ig from donated blood. This allowed doctors to administer these protective antibodies to people who were suffering from recurrent bacterial infections because their own bodies were unable to produce these antibodies. IVIg, which stands for intravenous immune globulin, refers to highly purified antibodies that are isolated from donated blood and administered in a large dose through the vein, or “intravenous.”

There are several reasons for using IVIg as a treatment for lupus. First, IVIg can protect against infections. People who have very low antibody levels in their blood and thus are susceptible to infections have fewer infections if they receive regular infusions of IVIg. Although this situation is unusual in people with lupus, sometimes the powerful immune-suppressing treatments doctors use to control lupus disease activity will lower antibody levels to the point that IVIg supplementation is needed to protect against infection.

More often in lupus, however, IVIg is administered to boost abnormally low platelet counts or, in particular situations, low red blood cell counts. It turns out that, in these rare situations, IVIg can block the person’s own white blood cells from gobbling up and destroying platelets or red blood cells, which can cause autoimmune thrombocytopenia and autoimmune hemolytic anemia, respectively.  

IVIg can also favorably affect immune system function. It has been proven to be an effective treatment for certain inflammatory diseases such as myositis, a condition where the immune system inappropriately attacks and destroys the muscle cells. While this process can occur by itself -- in which case it is known as polymyositis or dermatomyositis -- it is sometimes seen in lupus. 

IVIg treatment is reserved for very specific situations since it is an expensive and time-consuming treatment.