Alloimmunization

Development of antibodies in response to foreign substances such as antigens. Allogeneic blood transfusion introduces a multitude of foreign antigens and living cells into the recipient that will persist for a variable time. A recipient who is immunocompetent often mounts an immune response to the donor antigens, resulting in a variety of clinical consequences depending on the blood cells and specific antigens involved. The antigens most commonly involved are human leukocyte antigens, granulocyte-specific antigens, platelet-specific antigens and RBC-specific antigens.