TO THE EDITOR: Intravenous immunoglobulin (IVIG) therapy has gained popularity for the treatment of neuromuscular diseases (i.e., myasthenia gravis, inflammatory myopathy, chronic inflammatory demyelinating polyneuropathy), although adverse events are associated with high-dose IVIG infusions.1,2 Common adverse reactions to IVIG therapy are anxiety, headache, fever, chills, chest pain, dyspnea, nausea, and abdominal pain.3 More serious adverse events include anaphylaxis, hemolytic anemia, hepatitis C, and thrombosis.3 Studies have shown documented effects of IVIG on blood rheology. It increases plasma viscosity in a dose-related response and may also activate platelets.2–4 High-dose IVIG therapy is approximately 24–54 g/d.4