The purification of red cells for transfusion by freeze-preservation and washing. IV. The use of micropore filtration to reduce the residual HL-A antigenicity of previously frozen, washed red cells

Leukocyte-poor blood

The conventional techniques used to prepare leukocyte-poor red cell concentrates are described. These techniques conveniently group by their primary processing modalities which are centrifugation, freeze thawing, cell washing, and filtration. Each of these procedures has unique logistical requirements. The complexity, need of dedicated capital equipment, and stringent quality assurance requirements make the use of some of these techniques impractical for the hospital blood bank laboratory. The majority of patients benefit from the receipt of leukocyte-poor blood products prepared by an "in-line" microaggregate filtration technique. Those patients with symptoms which prove to be refractory to microaggregate-filtered blood products and those who require highly purified red cell concentrates to forestall sensitization to transplantation antigens should receive blood prepared either by the cryopreservation/deglycerolization technique or by cotton wool filtration.

Preparation of leukocyte-poor blood: a comparison of IBM 2991 washing and Huggins freeze-thawing

Frequently, forzen blood is requested in order to provide a leukocyte-poor red cell transfusion and a reduced level of exposure to hepatitis virus rather than in an effort to find serological compatible red blood cells. However, this usage of frozen blood is expensive and, as recently reported, does not eliminate the risk of transmission of hepatitis. To assess the feasibility of substituting washed cell preparations, we have compared the Huggins frozen blood process with the IBM 2991 cell washing technique and have evaluated the efficiency of leukocyte removal and red cell recovery from homologous pools of fresh blood. The results of these experiments combined with the greatly decreased cost (approximately 1/3) and time required (approximately 1/6) indicate that many of the requests which blood banks receive for frozen blood could, in fact, be better met by using cells which have been washed in the IBM 2991.