Intravenous immunoglobulin (IVIG) therapy is an infusion of immunoglobulins used for three purposes; for patients who do not produce antibodies or gammaglobulin, for patients with specific infections, and for patients with autoimmune and inflammatory diseases.  IVIG is composed primarily of IgG, one of five classes of antibodies, which include IgG, IgM, IgA, IgE, and IgD. IgG is the predominant immunoglobulin in plasma and the main source of humoral immunity. 

Primary immunodeficiency diseases are described as disorders of the immune system in which the primary defect is intrinsic to the cells/tissues of the immune system.  In America alone, up to 1/2 million people suffer from one of the 100 known Primary Immunodeficiency diseases for example, Severe Combined Immune Deficiency “boy-in-the-bubble disease.” [Click here for more info]

Secondary immunodeficiency diseases are described as disorders of the immune system in which the defect in the cell/tissues of the immune system are secondary to an extrinsic agent.  Those affected by these diseases were born with normal immune responses but some secondary factor such as HIV infection leading to Acquired Immunodeficiency Syndrome or AIDS [Click here for more info]