[Intravenous immunoglobulin-induced thrombocytopenia in patient with chronic inflammatory demyelinating polyneuropathy].

A 69-year-old man was admitted to our hospital because of dysesthesia in right palm and left upper limb, gait disturbance, and muscle weakness in both lower limbs. At the same time of neurological impairment appeared, he developed pemphigoid. Lumber MRI showed swelling of cauda equina nerve root. We diagnosed as chronic inflammatory demyelinating polyneuropathy based on an electrophysiological examination, and 2 courses of intravenous immunoglobulin therapy (IVIG) were initiated. After the treatments, symptoms improved immediately. However, thrombocytopenia was seen after each treatment which began on the second day of treatment start, reaching the lowest point from about 10 to 14 days, and improved naturally from 10 to 15 days after the end of IVIG. Difficulty in hemostasis was seen during dialysis due to thrombocytopenia. As a cause of thrombocytopenia, formation of IgG-platelet complexes could be considered, and the presence of multiple inflammatory diseases which activated Fcγ receptors play key roles could be a risk for IVIG related thrombocytopenia.