Donor leukocytes in transfused blood products

Donor leukocytes in transfused blood products are residual white blood cells (WBCs) that remain in blood components such as red blood cells, platelets, or plasma after collection from a donor. These cells are biologically active and can trigger various adverse transfusion reactions in the recipient by recognizing host antigens or releasing inflammatory cytokines (StatPearls, 2023). Specifically, donor T-lymphocytes are responsible for Transfusion-Associated Graft-Versus-Host Disease (TA-GVHD), a rare but often fatal condition where the donor cells mount an immune attack against the recipient's tissues (NIH, 2022). To prevent these complications, therapeutic interventions focus on the depletion or inactivation of these cells. Common methods include leukoreduction through filtration, which physically removes the WBCs, and pathogen reduction technologies or irradiation, which damage the DNA of the leukocytes to prevent them from proliferating (AABB, 2021). These processes are essential for protecting immunocompromised patients and reducing the incidence of febrile reactions and HLA alloimmunization. Furthermore, removing or inactivating these cells significantly reduces the risk of transmitting intracellular pathogens, such as Cytomegalovirus (CMV).

Other names

Residual white blood cellsPassenger leukocytesAllogeneic leukocytesDonor WBCs

Physical removal via leukoreduction filtration or inactivation of proliferative capacity through DNA cross-linking (using psoralens or riboflavin with UV light) and nucleic acid damage (via gamma or X-ray irradiation).