Leukocyte Reduction Filters to Prevent Transfusion-Transmitted Cytomegalovirus
Leukocyte reduction filters to prevent transfusion-transmitted cytomegalovirus infections. Certain infectious organisms, including cytomegalovirus, are associated ‘exclusively’ with blood leukocytes (WBC), and their transmission by transfusion is strikingly diminished by marked WBC-reduction of cellular blood components. Based on several reports of WBC-reduction, it is clear that the risk of CMV is nearly eliminated by consistently removing WBC to a level < 1–5 × 106 WBCs/unit (≤ 1 × 106 preferred in Europe; ≤ 5 × 106 in the United States). Alternatively, the rate of CMV infections is reduced by transfusing blood components collected from donors negative for CMV antibody. However, neither technique is perfect, with a failure rate of 1–4%. Although WBC-reduction is favored by many experts, practitioners must choose the method that they believe to be most efficacious – being mindful that data do not exist to establish additive protection by combining WBC-reduction and transfusion of blood components collected from antibody negative donors.
