Immunomodulation with intravenous immunoglobulin.

Since its introduction over a decade ago for the treatment of primary immunodeficiencies, intravenous immunoglobulin (IVIG) has demonstrated activity in a variety of autoimmune disorders. An understanding of IVIG's immunomodulatory effects provides the rationale for its potential application in the management of autoimmune disorders. The agent has exhibited the ability to block fragment crystallizable receptors on phagocytes, interact with the idiotype-anti-idiotype network, and modulate T lymphocyte, B lymphocyte, and natural killer cell populations, as well as complement activity. Its immunomodulatory effects have been demonstrated in a variety of disorders such as idiopathic thrombocytopenic purpura, Guillain-Barré syndrome, Kawasaki disease. Numerous case reports and small studies revealed IVIG's activity in a variety of other autoimmune disorders, but controlled clinical trials are necessary to clarify these initial observations.