Immunoglobulins are proteins produced by cells of the B-lymphocyte lineage that are the major effector molecules of the humoral immune system. Immunoglobulin molecules are antibodies that react with specific antigens, although in many circumstances the specificity of a given immunoglobulin antibody is unknown. Immunoglobulin preparations from human blood were first used in clinical medicine in 1952 to treat immunodeficiency conditions. At that time, the only available preparations required intramuscular (IM) administration. In the past decade, several immunoglobulin preparations for intravenous administration have become available. Although initially used for immunodeficiency states, intravenous immunoglobulin (IVIG) has also been utilized as a prophylactic and therapeutic reagent in a variety of other conditions. The use of IVIG has undergone tremendous growth in the past several years. This rapid growth in use is the result of improvements in the preparations of IVIG, which have led to reduced morbidity and reports of its benefits in a