Don't neglect the rare adverse event with intravenous immunoglobulin: Hemolytic anemia.

Intravenous immunoglobulin (IVIG) associated hemolytic anemia is an under-recognized complication of IVIG therapy. The incidence of this adverse event is not clear. Patients at high risk for IVIG-associated hemolytic anemia include non-O blood group recipients and those undergoing high-dose administration for inflammatory or autoimmune disorders. Here, two different cases of IVIG-associated hemolytic anemia are demonstrated. The first patient, a 66 year-old male with Guillain-Barré syndrome, had a severe attack for which erythrocyte replacement was required. Mild hemolysis was detected during IVIG administration in the second patient, a 57 year-old female with chronic immune thrombocytopenic purpura. Following IVIG termination, the hemolysis diminished gradually. Although it is rare and often manageable, clinicians should be aware of and monitor patients for hemolytic anemia following IVIG therapy.