The mechanisms of action of IVIG in autoimmune and inflammatory diseases

Abstract

Human intravenous immunoglobulin (IVIg) is constituted by pooled immunoglobulin (IgG) from several thousand healthy donors. IVIg consists of antibodies to external antigens and naturally occurring autoantibodies (NAbs) with germline or close to germline configurations. The NAbs are independent of deliberate immunization with cognate antigens. It is well established that NAbs play an important role in maintaining tissue and immune homeostasis. It is therefore logical to attribute the therapeutic beneficial effects of IVIg to NAbs. Apart from immunodeficiency conditions, IVIg is indicated for the treatment of a variety of autoimmune and inflammatory conditions. Despite its use in a wide range of autoimmune and inflammatory conditions, the mechanisms underlying the beneficial effects have not been fully elucidated. Understanding the mechanisms by which IVIg operates under different clinical settings is of critical significance. In this review, we summarize the current status of the mechanisms of action of IVIg in autoimmunity and the recent advances in IVIg therapy.