Preoperative deposit of autologous blood. Effects on inflammatory mediators

Sammanfattning: Blood contains complex cascade systems and substances that can be activated during the processing of blood components and storage. Allogeneic blood, i.e. blood from someone else, is normally separated into components before storage and transfusion, while autologous blood (the patient s own blood) often is used as whole blood. Allogeneic transfusions are associated with a variety of risks and preoperative autologous blood donation (PABD) has therefore become an established alternative. For patients with cancer, the immunosuppressive effect of allogeneic blood may be detrimental, but PABD is difficult because of the urgency of surgery. Normally, PABD begins 4-6 weeks before the scheduled operation and blood is tapped weekly. The additional use of recombinant erythropoietin (rHuEPO) therapy increases the volume of tapped autologous blood before surgery. However, other studies indicate that rHuEPO therapy suppresses postoperative endogenous erythropoietin (EPO) production and stimulates inflammatory mediator release. The aim of the present thesis was to investigate the effects on perioperative erythropoiesis, and the inflammatory mediator release during the predeposit and storage of autologous blood. In the present study, blood from healthy blood donors was collected and stored as whole blood or as separate components. Complement activation and release of pro-inflammatory cytokines were followed during the storage time. In addition, the effect of prestorage leucocyte filtration on inflammatory mediators was studied. Women undergoing radical hysterectomy were scheduled to predeposit three units of autologous blood during two weeks before surgery, with or without rHuEPO therapy. Erythropoiesis and the immune response were investigated during the pre- and postoperative follow-up.The results demonstrate that complement is activated during storage of whole blood and plasma, and the cytokine IL-8 is released during storage of whole blood. Prestorage filtration of plasma activates the complement cascade but does not influence cytokine generation. Clearly, it was possible for women to predeposit three units of blood in only two weeks prior to surgery. A haemoglobin level below the 100 g/l donation limit can be prevented in one patient out of seven, by treating women with rHuEPO. The use of rHuEPO increases the postoperative endogenous EPO response but does not influence the cytokine release. The present thesis suggests that PABD can be offered to female patients undergoing cancer surgery, and that autologous blood can be transfused as whole blood.