[Advancement in the preparation of red cell concentrates and platelet concentrates].

Both Japan Society of Blood Transfusion and Cell Therapy and Japan Society of Anesthesiologists have made a "Guideline of Management at Critical Bleeding in the Operating Room" in 2007. Since 2008, Japan Red Cross Blood Center (JRC) introduced leuko-reduction filter and diversion technique to prevent bacterial contamination. This improvement can easily introduce ABO compatible transfusion at critical situation. We proved the safety of transitional anti-A, anti-B antibody at compatible transfusion. 1) anti-A, anti-B antibody of leuko-reduced red cell concentrates (RCC-LR): Due to 90% plasma removal by centrifugation, antibody titer of anti-A, anti-B antibodies in RCC-LR is less than 2 times dilution. This level of antibodies does not cause hemolysis when more than 100 compatible ABO mismatch RCC-LR bags transfused at once. 2) Neutralization of ant-A, anti-B antibody due to A, B substance containing patient's plasma: ABO blood type is composed by glucan antigen, and it is contained in the plasma, saliva and many organs. When ABO incompatible transfusion has been done, transitional anti-A, anti-B antibodies are neutralized by A, B substances. Our experiment showed neutralizing titer 64 times equal volume of ABO incompatible plasma. 3) Anti-A, anti-B antibody titer of Fresh Frozen Plasma (FFP) and Platelet Concentrates (PC): With ABO mismatch transfusion, FFP and PC do not contain incompatible red cells at all. Therefore, the risk of hemolysis will be caused by transitional anti-A, anti-B antibodies. Both with PC and FFP, anti-A, anti-B antibodies keep normal level (average: 16 times dilution). The safe volume of ABO mismatch PC and FFP administration has limited within 3 liters. When such mismatch transfusion necessarily performed, hydration therapy to protect kidney function should be applied immediately after hemostasis. 4) Red Cell Volume in a PC bag: PC in Japan have processed by single donor apheresis alone since 2004. Our results showed that each PC bag contains less than 5 mm(-3) of RBCs. If this level of RBCs caused hemolysis in ABO mismatch patient, it is too small to cause DIC or renal failure.