Evaluation of Three Procedures for the Preparation of Leukocyte‐Poor and Leukocyte‐Free Red Blood Cells for Transfusion

Abstract

Abstract. Three methods of leukocyte deprivation of blood for transfusion have been evaluated. Filtration of relatively fresh packed red cells (up to 5 days old) through Erypur filters appears to be the method of choice for the preparation of leukocyte‐free red cells, used to prevent the production of antileukocyte antibodies in nonimmunized, nontransfused patients undergoing repeated blood transfusions. Double dextran sedimentation plus saline washings also yields leukocyte‐free red cells, although with a lower frequency, and represents an alternative to Erypur filtration, especially because of the lower cost and no need of special equipment. Imugard filtration appears to be a simple and effective way for preparing leukocyte‐poor red blood cells. For all the three procedures, results are definitely better when buffy coat‐free packed red cell units are processed. In a given hospital the choice of the technique(s) for the preparation of leukocyte‐poor (free) red blood cells for transfusion depends on a number of factors, such as type of patients to be transfused (immunized or nonimmunized, small children or boys and adults), aim of the procedure (prevention of the febrile transfusion reaction or prevention of antileukocyte antibody production), continuous availability of materials, cost, length and easiness of the procedure; these three latter parameters are in turn related to a number of local situations and facilities.

A New Cellulose Acetate Filter to Remove Leukocytes from Buffy-Coat-Poor Red Cell Concentrates

“…Our results indicate that the new Cellselect-A filter equals the original Cellselect filter in removing more than 99% of the leukocytes from buffy-coat-poor RCC, in accordance with the findings of others [2][3][4][5][6], who have investigated in the Cellselect filter. Dependent on the hematocrit of the RCC, the filtration time is only 10 min with the Cellselect-A filter.…”

“…We compared the efficiency of both filters. Removal of leukocytes from red cell concentrates (RCC) is the method of choice to avoid or delay immu nization against leukocyte and platelet antigens in multi transfused patients, i.e., patients with various hematolog ical diseases, patients on hemodialysis, and prospective candidates for multiple platelet transfusions or bone mar row or kidney transplants [1,2], One of the most simple and reliable methods to remove more than 95% of the leukocytes from whole blood or RCC is filtration of the red cell suspension through a sterile column prepacked with cellulose acetate (Cellselect, NPBI, The Netherlands; identical with Erypur, Organon Teknika, The Netherlands) or cotton wool (Imugard, Terumo, Japan) [3][4][5][6].…”

Effectiveness of Red Blood Cells Filtered Through Cotton Wool to Prevent Antileukocyte Antibody Production in Multitransfused Patients

“…In the present paper, we have considered the trans fusion of red cell units rendered leukocytefree by filtration through cotton wool to patients suffering from thalassemia major. This filtration procedure has been shown previously to be simple and effective in vitro, since a high percentage of filtered blood units show no detectable leukocytes [8,19]. It must be noted, however, that lack of de tectable leukocytes in the processed blood unit does not mean absence of immunogenic Number of transfusions activity: in fact, not only is there impreci sion when white blood cells are counted, due to their low concentration, but it is also known that cell fragments may be present in blood units processed to get rid of leukocytes which are not detectable by usual methods [1,6,11], The most striking example is per haps frozen blood ; red cells frozen with the low glycerol technique, in spite of the lack of detectable leukocytes, have been shown to maintain part of their immunogenic capac ity [15].…”

“…Data are shown in table I, where three classes of residual leukocytes defined by two limits (1 and 50 millions per unit, less than 1 million indicating no detectable leukocytes) are taken into account, since these two limits seem to us appropriate for the prevention of the production of antileukocyte antibodies and the febrile transfusion reaction, respec tively [19]. It appears that Erypur filtration is particularly effective in producing leukoPacked Red Blood Cell Units 450 ml of blood were drawn from healthy donors into Terumo multiple plastic bags containing CPD anticoagulant.…”

“…Previous investigations [8,19] have shown that leukocyte-free red cells for transfusion can be produced by filtering blood through cotton wool. However, it is not clear as yet if these leukocyte-free filtered red cells do pre vent the formation of antileukocyte antibod ies in multitransfused patients.…”