[Mechanism of action of immunoglobulin applied intravenously]

Intravenously applied immunoglobulin (IVIg) are used in medicine over 50 years. Beneficial effects of IVIg therapy have been described in the treatment of primary immunodeficiencies, inflammatory and autoimmune diseases, and new applications are still searched. Nevertheless, the mechanisms responsible for the therapeutic effectiveness of antibodies have not been exactly known. The efficacy of IVIg preparates used in therapeutic doses in infectious and autoimmune diseases indicates on the anti-inflammatory activity resulting from the inhibition of immune cells via different ways. These mechanisms include blocking Fc gamma receptors, modulation of cytokines synthesis and secretion and modulation of antigens on surface of immunocompetent cells. By contrast, IVIg therapy used in the replacement dose gives quite the opposite effect. Substitutive immunoglobulins not only complement the deficiency of antibodies in primary and secondary immunodeficiencies but also have the immunomodulatory and even proinflammatory effect.