Alloimmunization is a response by the body's immune system to donated blood or bone marrow or a transplanted organ. In alloimmunization, a person's body develops antibodies—proteins that attack and destroy foreign substances—that target the donated material.
A person receiving repeat blood transfusions may develop antibodies to the donor blood. Alloimmunization makes repeated transfusions more difficult.
Medical Review:E. Gregory Thompson MD - Internal Medicine & Adam Husney MD - Family Medicine & Martin Steinberg MD - Hematology