Clinical aspects of platelet transfusion.

Several clinical complications of platelet transfusions relate to contaminating donor leucocytes, and a number of strategies have been devised to leucodeplete platelet products before transfusion. Both alloimmunization to class I human leucocyte antigens (HLA), which causes febrile transfusion reactions and refractoriness to transfused platelets, and transmission of cytomegalovirus have been shown to be reduced by 3-log10 leucodepletion by filtration. Lesser degree of leucodepletion, e.g. by platelet preparation from buffy coats, will control febrile transfusion reactions, but will not reliably prevent other complications. The clinical implications and cost-effectiveness of different strategies of platelet production remain a matter of debate.