Therapeutic apheresis

Kobayashi K, Nakamura N, SumiA, OhmuraT,Yokoyama K (1998) Therapeutic Apheresis 2 257... 

Canaud, B., Leray-Moragues, H., Kamoun, K., and Garrigue, V., Temporary vascular access for extracorporeal technologies, Therapeutic Apheresis, 2000 4(3) 249-255. 

Membranes have been used in clinics for therapeutic purposes since 1943, when Kolff successfully treated a uremic patient with his rotating dmm membrane dialyzer (Kolff and Berk, 1943). Nowadays, hemodialysis, hemofiltration, hemodiafiltration, therapeutic apheresis, and gas exchange during cardiopulmonary bypass surgery have become clinically established treatments. In the following, feamres and therapeutic objectives of these treatments are briefly presented. 

American Society for Apheresis (ASFA), Nashville, TN (2005). Therapeutic Apheresis. A Guide to Billing and Securing Appropriate Reimbursement. ASFA. 

AsahiKasei (2008). Therapeutic apheresis and CRRT. Available http y7www.asahikasei.co.jp/ medical/en/apheresis/department/index.html, accessed Feb. 2008. 

Zydney, A. L. (1995). Therapeutic apheresis and blood fractionation. In J. D. Bronzino (Ed.), The Biomedical Engineering Handbook. CRC Press, Boca Raton, EL, p. 1936. 

The need to transfuse blood components such as plasma, platelets, factor VIII, in addition to red blood cells (RBC) has generated the development of plasmapheresis (plasma separation from whole blood) and more generally that of apheresis (fractionation of blood components). Plasma collection from donors by centrifugation of blood bags began only in 1944. This technique was extended to therapeutic plasma purification in 1950, but RBCs were fragilized by the centrifugation and the plasma was not completely platelet-free. 

Favorable results of exchange transfusion in a variety of diseases in adults, for example sickle cell disease, severe clotting disorders, hepatic failure, and acute hemolytic transfusion reactions, have been published (1). Today, however, machine apheresis procedures are more effective and safer for patients requiring exchange of cellular elements or plasma. Exchange transfusion is the most effective therapeutic procedure in the treatment of hemolytic disease of the newborn. Bilirubin removal prevents damage to the central nervous system caused by hyperbilirubinemia. In addition, sensitized erythrocytes are replaced by normally surviving cells and anemia is corrected. 

Severe thrombocytopenia is most often observed in connection with cancer chemotherapy. The availability of platelet concentrates has improved the therapeutic possibilities. Platelet concentrates are obtained by the differential centrifugation of several units of fresh blood or by apheresis from single donors using a blood cell separator. The quality of platelet concentrates obtained by apheresis deteriorates rapidly after storage for more than 24 hours. Of all blood components, platelet concentrates are the most vulnerable to bacterial contamination. 

Apheresis procedures are considered to be relatively safe when performed by experienced personnel. However, they are not without dangers, and there are some health risks to both patients and donors. Not unexpectedly, the risks are greater with therapeutic plasmapheresis on account of the underlying disease, with an estimated 3 deaths per 10 000 procedures (2). 

Weinshenker BG. Therapeutic plasma exchange for acute inflanmiatory demyelinating syndromes of the central nervous system. J Chn Apheresis 1999 14 144-148. 

The clinical consequences of alterations in platelets are well known, ranging from severe thromboembolic episodes to hemorrhage resulting from thrombocytopenia. In the latter situation, platelet transfusion can be lifesaving. It was observed in 1911 that transfusion of fresh whole blood boosted the platelet count in some cases of thrombocytopenia and controlled bleeding. Nowadays, platelets are often collected from blood donors by apheresis (Simon, 1994). This approach allows the supply of a therapeutically beneficial component, and platelets collected by apheresis have not been shown to be haemostatically different from platelets separated from whole blood donations. 

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