Clinical effects of leucoreduction of blood transfusions.

For many years filtration for removal of leucocytes from red blood cell (RBC) and platelet transfusions was applied for selected patients to prevent cytomegalovirus (CMV) (re)activation, HLA immunisation and recurrent febrile nonhaemolytic transfusion reactions (FNHTR ). Since the 1980s, there was also growing concern about cancer recurrence and postoperative infections. In this review we discuss the studies on possible benefits of leucoreduction. In 2001 the Dutch Health Council decided that all blood products should undergo leucoreduction by filtration, as a precautionary measure to reduce possible transmission of variant Creutzfeld-Jacob disease (vCJD). The incidences of transfusion-transmitted CMV infection, HLA immunisation and FN HTR are decreased by universal leucoreduction. However, transfusion-related immunomodulation with presumed negative effects on cancer immunosurveillance, postoperative infections or aggravating organ failure, investigated in randomised controlled trials, revealed no support for extended indications for leucoreduction. An exception was seen in cardiac surgery where leucoreduction reduced short-term mortality by approximately 50%. The exact mechanism(s) for this effect is (are) not known. Pro-inf lammatory cytokines induced by eucocytecontaining RBC transfusions in combination with the inflammatory response after cardiac surgery may aggravate morbidity and could lead to mortality. In this review we discuss the evidence for the benefits of universal leucoreduction. Based on the available evidence, reversal to the use of buffy-coat depleted RBCs and restricted indications for leucoreduction by filtration (extended with open-heart surgery) is a safe option.