Preparation and preservation of red cells.
BACKGROUND
The production of blood components has undergone several changes during the last decades.


METHODS
Red blood cells will have slightly different properties depending on the way of preparation: whether a hard or soft spin has been used, whether platelets and/or leukocytes have been removed or not, and whether the red cells have been suspended in part of the original plasma or in an additive solution. Automated techniques are now often used for the separation of buffy coats, red cells and plasma. Recently, apheresis techniques have been applied for the preparation of red cells, mostly in combination with plasma or platelets. Continuous addition of the anticoagulant during collection reduces the delay between collection and separation, but the cost is higher and donor time longer.


RESULTS
Most of the methods for the preparation and storage of red cells allow 35-42 days of storage with a mean in vivo recovery of > 75%. However, the content of erythrocyte 2,3-DPG is commonly lost within 1-2 weeks, caused by the accumulation of acid metabolites, but can be maintained longer with new systems of storage. Leukodepletion of red cells by filtration is used increasingly, but its importance in the majority of transfusions is still unclear.


CONCLUSIONS
New options for the preparation and storage of red blood cells are available and undergo continuous evaluation.
Department of Clinical Immunology and Transfusion Medicine, University Hospital, Uppsala, Sweden.
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Högman
D019794:2,3-Diphosphoglycerate / Q000097:blood; D000925:Anticoagulants / Q000494:pharmacology; D001781:Blood Component Removal; D001793:Blood Preservation / Q000295:instrumentation / Q000379:methods*; D002469:Cell Separation / Q000295:instrumentation / Q000379:methods; D002498:Centrifugation; D017707:Erythrocyte Transfusion / Q000379:methods*; D004912:Erythrocytes / Q000737:chemistry / Q000166:cytology / Q000187:drug effects; D005069:Evaluation Studies as Topic; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007962:Leukocytes; D008212:Lymphocyte Depletion / Q000379:methods; D013696:Temperature
D000925:Anticoagulants; D019794:2,3-Diphosphoglycerate