Clinical uses of intravenous immune globulin

The preparation, pharmacokinetics, clinical uses, dosage and administration, and adverse effects of intravenous immune globulin (IVIG) are reviewed. IVIG, which consists primarily of immunoglobulin G (IgG), is initially prepared from pooled human plasma by using the Cohn-Oncley fractionation procedure. Secondary treatments render the preparation suitable for i.v. use. The specific antibody content of IVIG depends on the geographic location of the plasma donors, the product, and the product lot. The metabolism of IgG appears to follow a multicompartmental, first-order process. The half-life of IgG is dependent on the half-lives of the IgG subclasses; three of the four subclasses have half-lives in the range of 23-25 days. IVIG is indicated in the treatment of idiopathic thrombocytopenic purpura (ITP) and as replacement therapy in primary humoral immunodeficiencies (PHI). IVIG has also been used for antimicrobial prophylaxis in bone marrow transplant and burn patients and in patients with malignancies. Patients with HIV infection, cystic fibrosis, neonatal sepsis, and respiratory syncytial virus infection may also benefit from prophylaxis or treatment with IVIG. The recommended dosage of IVIG in ITP is 400 mg/kg/day for two to five days. For the treatment of PHI, the usual dosage is 100-400 mg/kg every three or four weeks. Adverse reactions are often mild and are usually related to the infusion rate. Intravenous immune globulin is a valuable therapeutic tool in several immunodeficiency and autoimmune states, but IVIG products are expensive, and conclusive data on their efficacy in the treatment of many disorders remain to be obtained.