Removal of Leukocytes from Whole Blood and Erythrocyte Suspensions by Filtration through Cotton Wool

A histological and immunohistochemical investigation of slices from the Cellselect leukocyte filter showed that the capture of lymphocytes within these filters depended on trapping of the cells in the cellulose acetate fiber network more than on adherence. Probably, additional mechanisms played a role in granulocyte removal. Microaggregates of granulocytes and platelets were found at the top of the Cellselect leukocyte filter. Therefore, it is likely that granulocyte and platelet removal, at least in part, is due to the formation of cell clusters on the surface of the fibers. Although a part of the original, nonfiltered, leukocytes already showed morphologic characteristics of cell necrosis, more necrotic leukocytes were detected within the filter.

Section: Discussionsupporting

confidence: 92%

Histological and Immunohistochemical Studies on the Preparation of Leukocyte‐Poor Red Cell Concentrates by Filtration: The Filtration Process on Cellulose Acetate Fibers

Steneker

Biewenga

1990

“…Collection of blood andpreparation of red cell concentrates. Blood was collected in the evening prior to the experiments, as described earlier [2], and either cooled in the usual way or immediately after collection. Cooling in the usual way was effected as follows: bottles were put in a cold room (2°C) approximately 4 h after collection, PVC bags were put in a metal box containing ice cubes approximately 1 h after collection.…”

Section: Methodsmentioning

confidence: 99%

“…Filtration was performed using the filter system described earlier [2]. Part of each unit was not filtered but kept to serve as a noniiltered control sample.…”

Section: Filtrationmentioning

confidence: 99%

“…Blood was collected in the evening prior to the experiments, as described earlier [2], and either cooled in the usual way or immediately after collection. Cooling in the usual way was effected as follows: bottles were put in a cold room (2°C) approximately 4 h after collection, PVC bags were put in a metal box containing ice cubes approximately 1 h after collection.Rapid cooling was obtained by putting bottles and PVC bags in melting ice immediately after collection, followed by storage in a cold room (2°C).When needed, erythrocyte concentrates were prepared by centrifugation (30 min at 1,350 g ) and aspiration of the plasma.In one experiment, a pool was made of several units of ACD erythrocyte concentrate with the same ABO blood group and Rh factor.…”

mentioning

confidence: 99%

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Removal of Leukocytes from Whole Blood and Erythrocyte Suspensions by Filtration through Cotton Wool

Diepenhorst

Reijnierse

1972

Self Cite

Abstruct. Using the filtration method described earlier, leukocytes were removed from units of fresh whole blood and erythrocyte suspensions (hematocrit 50%). After filtration, the units were stored for one or two weeks.Units of whole blood and erythrocyte concentrates were stored for periods up to three weeks, the leukocytes were then removed by filtration, and the units were stored for another week.During the storage period, the following parameters were measured: pH and concentrations of ATP + ADP, 2,3-diphosphoglycerate, hemoglobin and potassium (Hb and K+ in the cell-free supernatant). The parameters used in the present study indicate that removal of leukocytes by filtration did not cause significant alteration to stored whole blood and erythrocyte concentrates, compared to unfiltered blood stored for the same time. D~PENHOR~//SPROKHOLT/PRINS(DPG), free hemoglobin, and potassium (Hb and K + in the cell-free supernatant). We measured ATP + ADP because of the close correlation between ATP level and erythrocyte viability [l, 51. DPG was measured as low levels are known to cause decreased oxygen release to the tissues [9]. Materials and MethodsCollection of blood andpreparation of red cell concentrates. Blood was collected in the evening prior to the experiments, as described earlier [2], and either cooled in the usual way or immediately after collection. Cooling in the usual way was effected as follows: bottles were put in a cold room (2°C) approximately 4 h after collection, PVC bags were put in a metal box containing ice cubes approximately 1 h after collection.Rapid cooling was obtained by putting bottles and PVC bags in melting ice immediately after collection, followed by storage in a cold room (2°C).When needed, erythrocyte concentrates were prepared by centrifugation (30 min at 1,350 g ) and aspiration of the plasma.In one experiment, a pool was made of several units of ACD erythrocyte concentrate with the same ABO blood group and Rh factor. Filtration.Filtration was performed using the filter system described earlier [2]. Part of each unit was not filtered but kept to serve as a noniiltered control sample.Storage. In one experiment, units of whole blood and erythrocyte concentrates were stored in the bottle in which they were taken for periods up to three weeks at 2°C prior to filtration.In two other experiments, the storage period was limited to one night. After filtration, the suspensions were put in screwcapped, sterile plastic tubes, one for each day of storage, and stored at 2°C; so were the nonfiltered control samples. Determination of p H , ATP + ADP, DPG, free hemoglobin and potassium.Each day during the experiment, a tube of each series was opened after thorough mixing.The pH was determined on the day of opening and samples for the other determinations were stored at -20°C. After approximately one week, the other parameters were measured simultaneously.The glycolytic intermediates: ATP + ADP, DPG, were determined in 900 and 27,000fold dilutions of blood samples by mechanized enzymatic methods [...

“…The quality control of the filtration procedure poses a problem because reliable counting of leukocytes in RCC at levels equal to or below 0.1 X 10y/l is hard to achieve. In 1972, Diepenhorst et al [14] described discrepancies between manual hemocytometer counting and electronically measured leukocyte numbers in filtered RCC, the results of electronic counting being approximately 10 times higher than those obtained manually. Various techniques have since been described to improve the determination of these low leukocyte counts in hemocytometers [15-171. The aim of this study was to compare 5 commercially available leukocyte depletion filters for RCC filtration by assessing the reduction in leukocyte number and the red cell recovery.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Five Different Filters for the Removal of Leukocytes from Red Cell Concentrates

Pietersz¹,

Steneker²,

Reesink³

et al. 1992

The leukocyte depletion capacity and performance of 5 filters designed for filtration of red cell concentrates (RCC) were compared by counting leukocytes, measuring red cell volumes and by histological examination of the filters after use. To eliminate interdonor differences, 5 buffy-coat-poor RCC were pooled (in each of 10 experiments) and subsequently split up into the original bags. The RCC were passed over the Cellselect filter, a column filled with cellulose acetate, and over flat-bed polyester filters: the Cellselect Optima, the Pall RC 50, the Leukostop and the Sepacell R-500. The filtration was shortest with the Pall RC 50 (p less than 0.001 compared to the other 4 filters). Leukocyte removal was most effective with the cellulose acetate filter (p less than 0.01 compared to the other 4 filters) followed by the Cellselect Optima polyester filter (p less than 0.02 compared to the remaining 3 filters). Residual leukocytes did not exceed 50 x 10(6) for any brand of filter. Red cell recovery was similar for all 5 filters with mean values from 86.1 to 89.2%. The leukocyte numbers, counted in Türk's solution or in propidium iodide, gave comparable values in hemocytometers applying light microscopy or fluorescent microscopy, respectively. Histological examination showed that lymphocytes were mainly removed by trapping, whereas granulocytes showed a variable pattern: adhesion in presence of platelets or trapping.