Your own white blood cells or “leukocytes” ward off infectious agents and help to maintain the immune function in your body. However, when leukocytes are present in donated blood, they serve no purpose, but are transfused along with red blood cells, platelets or plasma. Leukocytes may carry viruses that cause immune suppression and release toxic substances. Studies have shown that removing leukocytes from donated blood may have a number of benefits for patients. The American Red Cross believes that use of “leukoreduced” blood products, which have had the contaminating leukocytes removed, serves as means to further increase the safety of the blood supply and improve patient outcomes. The American Red Cross distributes both leukoreduced and non-leukoreduced blood, as requested by each hospital.
Removal of leukocytes from blood transfusions cannot be used to prevent one type of serious transfusion complication, called transfusion graft versus host disease. For this problem, special treatment, such as irradiation of blood, is typically required.