History, biological mechanisms of action and clinical indications of intravenous immunoglobulin (IVIG) preparations

Intravenous immunoglobulin (IVIG) preparations were initially introduced as replacement therapy in primary antibody deficiency disorders and, as time passed by, have been found beneficial in patients with autoimmune disorders and systemic inflammatory disease as well. In spite of its widespread use, the precise mechanism of action of IVIG is still largely unknown. Different mechanisms have been proposed, such as Fcgamma receptor blockade, inhibition of complement deposition, neutralization of superantigens, neutralization of cytokines and manipulation of the idiotypic network. Although well tolerated by most patients, IVIG may induce side effects in some patients. The fact that most of the commercially available IVIG preparation are free of complement-activating activity suggests that other effector mechanisms are involved. In this review, different biological mechanisms of action of IVIG as well as the causes of side effects are discussed. (C) 2002 Lippincott Williams Wilkins.