Immune globulin injection is used to prevent or treat diseases that occur when your body has a weak immune system. Immune globulin contains antibodies that make your immune system stronger. It is used for patients who have primary humoral immunodeficiency (PI), idiopathic thrombocytopenic purpura (ITP), chronic immune thrombocytopenic purpura, or chronic inflammatory demyelinating polyneuropathy (CIDP). It is also used to improve muscle strength and disability in patients with multifocal motor neuropathy (MMN). Immune globulin injection belongs to a group of medicines known as immunizing agents. Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, immune globulin is used in certain patients with the following medical conditions: Chronic parvovirus B19 infection (treatment). Dermatomyositis (treatment). Guillain-Barré syndrome (treatment). Hyperimmunoglobulinemia E syndrome (treatment). Infections in low birth weight preterm high-risk neonates (prevention and treatment). Lambert-Eaton myasthenic syndrome (treatment). Relapsing-remitting multiple sclerosis...