High dose intravenous gammaglobulins in autoimmune disorders: mode of action and therapeutic uses.

Gammaglobulins administered intramuscularly have been used for more than 40 years to treat antibody deficiency states. In the last decade intravenous preparations were developed. They do not aggregate and contain IgG molecules with intact recognition and effector functions. These compounds are safe and only minor side effects were reported even when high doses were given. While studying their effect when given in high doses to hypogammaglobulinemic patients, an accidental finding was observed regarding their beneficial effect in idiopathic thrombocytopenic purpura (ITP). This observation led to many studies looking at the effect of high dose gammaglobulin in several other autoimmune diseases. While the effect in acute ITP is well established, there are encouraging reports in respect to the effect of intravenous gammaglobulin in many other disorders, but no final conclusion can be drawn due to the small numbers of cases studied. The mechanism by which intravenous gammaglobulin exerts its function is still unclear. It may work through the Fc receptor in the reticuloendothelial system, as an immunoregulator agent or interact in the idiotype-antiidiotype network. Intravenous gammaglobulin seems to be an important therapeutic tool in a large number of autoimmune disorders of various etiologies.