Leukodepleted

Leukodepleted, also known as leukoreduced, describes blood components from which the majority of donor leukocytes have been removed before transfusion. This processing is applied to red blood cells, platelets, and other cellular components to lower the leukocyte content and reduce the risk of immune reactions and infection associated with transfusion.

Preparation methods include prestorage leukoreduction, where filtration occurs soon after collection during component manufacture, and poststorage filtration as an alternative in some settings. Filtration with specialized leukocyte reduction filters is the common technique, and leukoreduction can be implemented during collection for apheresis products as well as for traditionally collected components.

Clinical rationale and effects include a reduction in febrile non-hemolytic transfusion reactions and a decrease in alloimmunization to leukocyte antigens such as HLA. Leukodepleted products also substantially lower the risk of cytomegalovirus transmission in susceptible recipients. In many centers, leukoreduction is part of a broader patient-safety strategy, particularly for immunocompromised or chronically transfused patients, and may be used alongside irradiation in settings aimed at preventing transfusion-associated graft-versus-host disease.

Limitations and context: leukodepleted products do not eliminate all transfusion risks; some residual leukocytes may remain, and irradiation remains relevant for higher-risk individuals to prevent GVHD in certain cases. Costs, logistics, and national or institutional guidelines influence the adoption and universal application of leukoreduction across blood services.