Autologous Predeposit: To Leukocyte Deplete Or Not to Leukocyte Deplete?

In five studies comparing different forms of storage of autologous blood the allogenic transfusion rate, humoral and cellular immune parameters and the postoperative infection rate were investigated. In a prospective, randomized study 21 volunteers donated one unit of blood. Retransfusion of stored autologous whole blood, but not of autologous packed red cells and fresh frozen plasma, induced a limited response of the immune system. Four prospective, randomized, partially or totally blinded studies investigating autologous donation in primary hip arthroplasty were carried out: In the first study including 94 patients, in which autologous blood was stored as whole blood, leukocyte-depleted whole blood or as blood components, the allogenic transfusion rates were compared. The type of storage of autologous blood did not influence homologous transfusion requirements. In a second study dealing with humoral immune factors, 97 patients were allocated at random to two groups. In one group, the autologous donation was stored as whole blood, in the other group the donation was separated into blood components before storage. With respect to the parameters studied, there were no significant differences between patients transfused with whole blood and those transfused with blood components. Moreover, these values also did not differ from those of patients not transfused. In a third study, the phagocytosis and respiratory burst activity of neutrophil granulocytes and of monocytes was measured in 58 patients who were randomly allocated to two groups as in the previous study. Neither the time course of phagocytosis nor that of respiratory burst activity showed a significant difference between both groups. In a fourth multicenter study, 953 patients were allocated to either of two groups. The first group of patients received autologous blood stored as whole blood, in the second group leukocyte depletion was done before storage. When comparing the outcomes of both groups, it could be shown that leukocyte depletion of autologous whole blood did not reduce the number of postoperative infections in primary hip surgery. It is therefore concluded that neither leukocyte depletion nor blood component separation is mandatory when using autologous predeposit in primary hip arthroplasty.