Clinical and investigational considerations for the use of IGIV therapy

Purpose. Clinical uses of immunoglobulin intravenous (IGIV) therapy for a number of autoimmune and inflammatory diseases are discussed, as well as the probable mechanisms by which IGIV exerts its immunoregulatory and antiinflammatory actions. Case studies are also presented to examine practical considerations in the selection of IGIV products for patients at risk for adverse events. Summary. At present, the Food and Drug Administration has approved IGIV for use in six conditions, including replacement therapy for patients with antibody-deficiency disease, adjunct therapy in patients with poor antibody-producing capabilities, prophylaxis against certain types of infections, and several autoimmune disorders, including idiopathic thrombocytopenic purpura and Kawasaki disease. Numerous mechanisms have been proposed to explain the beneficial effects of IGIV, including the interaction of infused IgG with fragment crystallizable (Fc) receptors and complement proteins, the modulation of synthesis and release of cytokines and cytokine antagonists, and neutralization of circulating autoantibodies. IGIV products differ significantly in methods of production, virus elimination, formulation, and composition. These differences can potentially have an impact on safety, tolerability, and efficacy. The major features affecting tolerability include volume load, sugar and salt content, and osmolality. Case studies highlight how these product characteristics could affect patient outcomes. Conclusion. While numerous mechanisms have been proposed to explain the beneficial effects of IGIV, the specific mechanisms remain elusive. Patient outcomes can be affected by IGIV product characteristics. The choice of an IGIV product should be matched to the patient's risk-factor profile.