AbstractThe infusion of high‐dose (275 mg/kg body weight) immune globulin intravenous (IGIV) after 466 plasma exchanges in 64 patients with autoimmune disease was studied. Side effects occurred during 15% of IGIV infusions. For the most part they were transient and mild, and could be controlled by slowing the infusion rate. Two percent of infusions had to be terminated because of more persistent or severe side effects. Chills were the most common side effect, followed by nausea, flushing, anxiety, and nausea. Serum IgG levels were immediately restored into the normal range by IGIV infusions, and they were much more effective in restoring IgG levels after plasma exchange than intramuscular injection of 9.9 g of immune serum globulin (ISG). Up to 15 weekly high‐dose IGIV infusions were well tolerated without unusual side effects. These patients did not have any major bacterial infections, but were not protected from developing Herpes zoster at the dosages used. In patients with myasthenia gravis, a short term impact of a single IGIV infusion on titers of antibody to acetylcholine receptor could not be demonstrated. This study showed IGIV to be a safe and effective preparation for the replacement of normal IgG removed during plasma excha