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

Abstract. 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.     

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

Abstract. (1) Sterile filtration of whole blood or blood cell suspensions in saline through columns of tightly packed cotton wool results in removal of over 95% of the leukocytes. (2) From whole blood, thrombocytes are inefficiently removed by the filtration procedure; filtration of blood cell suspensions in saline results in a better removal. (3) A system is designed by which filtration of 500 ml portions can be performed in less than 1 h at room temperature. (4) Red cell recovery with this system is over 90%. (5) Neither pyrogen tests nor toxicity tests did reveal the elution of harmful substances from properly prepared columns.     

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

Abstract. 1,820 units of leukocyte- and platelet-poor erythrocyte suspensions were prepared by filtration through cotton wool. On the average more than 98% of the leukocytes and 90–95% of the platelets could be removed. The red cell recovery was 96%. 97% of the units given to polytransfused patients did not cause febrile reactions. Serological follow-up of future transplantation recipients indicated that immunization may be avoided by using erythrocyte suspensions of fresh, filtered blood.     

Removal of Leucocytes from Whole Blood and Erythrocyte Suspensions By Filtration Through Cotton Wool

Abstract. (1) Blood was stored in polyvinyl-chloride bags containing citrate-phosphate-dextrose (CPD) with adenine in a final concentration of 0.25 mM. (2) Red cell ATP was well maintained (>70% of original) for 4 weeks in whole blood as well as in red cell concentrate (PCV 85 ± 2%). After 5 weeks the ATP level was about 70% in whole blood and about 40% in red cell concentrate. (3) Red cell 2,3-diphosphoglycerate (DPG) was about 60% of the original after 2 weeks and about 30% after 3 weeks of storage when stored both as whole blood and as red cell concentrate. (4) The red cell 24-hour post-transfusion viability was about 80% after 4 weeks of storage both as whole blood and as red cell concentrate. After 5 weeks of storage the 24-hour viability was 78.7 ± 3.5% in whole blood and 76.5 ± 6.7% in red cell concentrate. (5) 820 patients received 3,238 units of CPD-adenine blood, and 761 patients serving as controls received 2,807 units of acid-citrate-dextrose (ACD) blood. The frequency of transfusion reactions was 3.5% for patients receiving CPD-adenine blood and 4.1% for the control group. (6) The maximum storage time was set at 5 weeks for the CPD-adenine blood and 3 weeks for the ACD blood. The longer preservation time decreased out-dating by at least 50%.     

Preparation of Leukocyte-Free Platelets for Transfusion by Filtration through Cotton Wool

Abstract. Filtration through Imugard filters of random platelet concentrates or platelets obtained by plateletpheresis allow the preparation of leukocyte-free platelets for transfusion. The procedure is simple and determines only a small platelet loss (less than 10%). Filtered platelets seem to function normally in vivo. The use of leukocyte-free red cell and platelet transfusions for the support of patients suffering from leukemia or aplastic anemia could prevent major complications, such as refractoriness to platelet transfusion and to bone marrow transplantation.     

Removal of Leukocytes from Blood by Fibre Filtration: A Comparison Study on the Performance of Two Commercially Available Filters

Abstract: Two different kinds of filters suitable for the almost complete removal of leukocytes from blood-cell concentrates were tested. The maximal retention of filter I was 1.9-3.4×10⁹ leukocytes per filter, whereas filter II could retain 3.6–7.8×10⁹ leukocytes per filter before the leukocyte concentration in the filtrate passed the level of 500 leukocytes/μl. The leukocytes, once absorbed by the fibre material, could be released by washing the filters I, whereas the leukocytes were retained by the material of the filters II. No detectable particles were released after the first 100 ml of filtrate during the washing procedure of either kind of filters. From more than 20% of the filters I, more than 500 pg/ml of endotoxin could be released during the prewashing, whereas none of the filters II was contaminated with endotoxin. The filter II released acetic acid which could be completely removed during the prewashing with 250 ml of saline solution. Operation according to the prescribed conditions of 25 filters of both kinds revealed that the residual leukocyte content in the filtrate was more than 0.25 ×10⁹ leukocytes in 8 out of 25 of the filtrates when filters I were used, whereas with all filters II, this content remained lower than 0.1×10⁹ leukocytes per filtrate. It was concluded that only filter II has sufficient capacity to guarantee the removal of 97% of all leukocytes and 90% of the thrombocytes present in 500 ml of fresh human blood.     

Preparation of Platelet Suspensions from Whole Blood in Buffer

A simple method for preparation of platelet suspensions from whole blood in buffer is described. The platelets and a fraction of the erythrocytes are processed simultaneously, whereby the erythrocytes serve as a supporting cushion in the centrifugation steps. Using this earlier described principle of platelet separation, platelet yields of 90–100% from whole blood could be achieved. Investigations of platelet aggregation and platelet morphology indicate that this method of separation is gentle. By obviating the selection of certain platelet populations this method may facilitate the interpretation of the results of in vitro and in vivo platelet-function studies.     

The Mean Filtration Pressure of Leukocyte Suspensions and Its Relation to the Passage of Leukocytes through Nuclepore Filters and Capillary Networks

Objective: To quantitatively evaluate the deformability of bulk suspensions of leukocytes (WBCs), account for the variance of individual cell mechanical properties, and deduce the potential for WBC entrapment within the capillary network in response to alterations in cell properties. Methods: The transient washout of WBCs initially trapped under low perfusion pressure in 5-μm pores of Nuclepore filters was analyzed for a 0.2-ml bolus of WBCs (derived from hamsters) with equal numbers of filter pores and cells, to characterize the statistical distribution of pressures, p_yield, required to dislodge the cells. Contributions of the variance in WBC diameter, pore diameter, and cremaster muscle capillary diameter to p_yield were estimated with a WBC cortical shell model and an analysis of the probability function of the ratio of WBC to pore diameter, Λ. Results: For normal WBCs, p_yield exhibited a log-normal distribution with mean ((p_yield)) of 0.59 cmH₂O. Incubation of cells in cytochalasin-B reduced (p_yield) almost 50%, whereas phorbol myristate acetate increased (p_yield) twofold. Incubation in N-formyl-methiolnyl-leucyl-phenylalanine had no significant effect on (p_yield), as polymorphonuclear cells became permanently trapped in the filter. The fluorescent dyes acridine orange, acridine red, and tetramethylrhodamine isothiocyanate increased (p_yield) as much as 10-fold, whereas steady-flow filtration methods showed no alteration. Analysis of the distribution of Λ revealed that due to their smaller pore diameters, in vitro filtration methods may overestimate in vivo values of (p_yield) by almost twofold. Conclusions: The transient filtration of WBC suspensions appears to be much more sensitive to subtle alterations in WBC deformability than steady-flow methods and may provide greater insight into the determinants of capillary perfusion. Estimates of (p_yield) are comparable to those obtained with micropipettes and permit analysis of substantially greater numbers of cells within a sample. Fluorescence labeling techniques should be used with caution, as they may dramatically alter cell properties to an extent undetectable by direct in vivo observations.     

Evaluation and Modification of Whole Blood Filtration in the Measurement of Erythrocyte Deformability in Pregnancy and the Newborn

S ummary . SUMMARY. This study was designed to investigate the deformability of erythrocytes from pregnant women and full-term newborn infants, with healthy female adults as a comparison, using a whole blood filtration method. Delay in measurement, white cells, haematocrit, plasma viscosity, temperature and pH all significantly affected the rate of whole blood filtration and could thereby obscure or exaggerate changes in erythrocyte deformability.
A new method was developed which eliminated or minimized these sources of error and the study was completed. Fetal erythrocytes were found to be significantly less deformable than adult erythrocytes which were in turn found to be significantly less deformable than erythrocytes from pregnant women. These differences appear to be related to the varying plasma fibrinogen concentrations in the three groups of subjects. The significance of these findings in the special haemodynamic situations found in the neonate and during pregnancy are discussed.     

Removal of Buffy Coat from Stored ACD Blood by Dextran: Agglomeration and Subsequent Filtration

Abstract. A method for preparing buffy coat-poor red cell suspensions from stored ACD blood is described. Stored ACD blood is sedimented in presence of dextran and then passed through nylon fibre niters. A removal of 94% of leukocytes and 97% of platelets is achieved with this procedure. Red cell recovery is over 70%.     

Effect of High Concentrations of Leukocytes on Whole Blood Viscosity

Whole blood viscosity of patients withleukemic leukocytosis was compared tothat of normals with a similar totalpacked cell volume (TPCV). Leukocytesin suspension were also studied andfound to have a greater viscosity thanerythrocytes. We found no relation between the magnitude of the leukocytecount and whole blood viscosity. Thepresence of anemia in the patients withleukemia prevented elevation of theirTPCV. This, as well as the normal variability of blood viscosity obscured anyincrease that could have been producedby the greater viscosity of massed leukocytes.

Submitted on February 25, 1971 Revised on April 6, 1971 Accepted on April 7, 1971     

In vitro and In vivo Evaluation of Platelet Concentrates after Cotton Wool Filtration

Removal of leukocytes from platelet concentrates (PC) may decrease the incidence of alloimmunization to HLA antigens on white cells and prevent or delay refractoriness. Cotton wool filtration, which effectively removes leukocytes from PC with minimal platelet loss, may cause platelet or complement activation. In this study, the effect of cotton wool filtration (Imugard IG-500) on platelet activation, in vitro function, posttransfusion survival, and complement activation was investigated. Five paired autologous in vivo percent recovery and survival studies were performed with fresh (6-8h) PC or with 5-day-stored PC prepared from CPD-anticoagulated blood and stored in PL-732(TM) containers using standard methods. In the paired design, PC from the same donor were filtered on one occasion, and not filtered on another, prior to labeling with indium-III-oxine and reinfusion. Percent recovery and survival were then determined by the standardized method. Filtration had no statistically significant effect on percent recovery on PC stored for 6-8h or for 5 days. There was, however, a slight decrease in survival hours of the filtered PC which was statistically significant at 6-8h (203 +/- 14 vs. 179 +/- 18h; p less than 0.05) but not at 5 days (166 +/- 28 vs. 132 +/- 27h; p greater than 0.05). Samples taken before and after filtration of single units (fresh and 5-day) and pooled units (3-day) for measurement of release of granular content (beta-thromboglobulin), lysis (LDH), and in vitro viability - ATP, extent of shape change with ADP, and hypotonic shock response (3-day only)-demonstrated no effect of filtration on these parameters.(ABSTRACT TRUNCATED AT 250 WORDS)     

Changes in Erythrocyte Membranes during Cold Storage of Whole Blood

Abstract. Various assays and physicochemical methods were used to observe changes taking place in membrane proteins from erythrocytes that had been stored up to 42 days at 4°C. Red cell membranes were found to decrease in hydrophobicity, flexibility, and sulfhydryl content on storage. These changes are not due to proteolysis, but related to an unresolved change in the structural characteristics of the lipoproteins comprising the 'membrane superstructure'.     

Polymorphonuclear Leukocytes Prepared by Continuous-Flow Filtration Leukapheresis: Viability and Function

Preparation of granulocytes for transfusionin high yield and relatively free of contamination by other cell types has beenmade possible by the technique of continuous-flow filtration leukapheresis (CFFL).Since previous work suggested thatgranulocytes collected in this manner mayhave impaired viability and function, adetailed study of the bactericidal, metabolic, and chemotactic properties of suchcells was performed and compared tocontrol cells obtained from the samedonors prior to CFFL. The granulocytepercentage of the cell suspensions obtained by CFFL averaged 94.5% ± 1.5%compared to 82.5% ± 1.8% for the controls (p < 0.001) with viability of thePMNs determined by trypan blue exclusion being 97.5% ± 0.9% and 98.2% ±0.5%, respectively. The phogocytic, metabolic (¹⁴C-I-glucose oxidation and proteiniodination) and chemotactic properties ofboth cell types were equivalent in suspensions equalized for granulocyte content.These findings indicate that CFFL technique employed does not impair granulocyte viability or function in vitro. Studiesof the in vivo survival and function of CFFLgranulocytes are necessary to evaluatetheir efficacy in combating infection inseverely leukopenic patients.

Submitted on February 27, 1974 Accepted on April 30, 1974     

Prestorage Leukocyte Depletion with In-Line Filtration of Whole Blood in Comparison with Blood Component Leukocyte Depletion

In-line filtration of blood components appears to be an effective method to reduce white-cell-induced adverse reactions. We have investigated whether whole blood filtration (WBF), prior to component preparation, is comparable with filtration of already prepared blood components (CF), i.e. the red cell concentrate (RCC) and fresh plasma. Conventionally prepared nonfiltered blood components served as a control. No significant differences for most parameters investigated were found between leukodepleted RCCs and plasma units prepared by CF or WBF. All filtered RCCs and plasma units (CF and WBF) had white blood cell contaminations <1'10⁵ per unit. Platelets were reduced in all filtered components: 95% in plasma and 99% in RCCs. Fresh-frozen plasma (FFP) prepared by CF and WBF had normal amounts of factors V, VIII, von Willebrand factor and thrombin-antithrombin-III complexes, whereas platelet factor 4 (PF-4) was slightly increased in FFP prepared by WBF. RCCs and plasma units prepared from filtered whole blood (n = 20) had a significantly greater volume (RCC: 288±19 ml; plasma: 274±20 ml) than conventionally prepared (n = 20) and filtered products (RCC: 257±19 ml, plasma: 259±19 ml). For early filtration of blood components, WBF prior to component preparation seems to offer an interesting technique for obtaining a leukocyte-depleted RCC and FFP.     

Comparison of Different Methods Used in the Preparation of Leucocyte-Free Whole Blood and Erythrocyte Concentrates

Abstract. The authors studied the degree of qualitative and quantitative deleucocytation of whole blood that can be obtained by washing and filtering. Based on the studies of 20 samples of blood it was established that successful deleucocytation can be expected only it combined procedures of washing and filtering are employed.
The purpose of our present investigations was to determine to what extent can whole blood be deleucocyted by using current methods of blood preservation, or by combining these methods, as well as to assess the degree of damaging effects on red blood cells produced by these methods.     

全血金标免疫渗滤法快速检测棘球蚴病的现场应用

目的?摇建立一种检测全血标本的棘球蚴病现场快速诊断方法。 方法 制备检测棘球蚴病抗体的全血金标免疫渗滤法（DIGFA）快速诊断试剂盒，以土豆凝集素与全血混合达到快速凝血的目的，并对1 678名流行区健康体检者、38例棘球蚴病患者、52名非流行区健康体检者、40例其他肝肺占位患者做棘球蚴病全血现场诊断试验，评价其作为初筛棘球蚴病普查手段的实际应用价值。 结果 全血DIGFA对1 678份流行区体检者阳性检出率为8.46%，其中肝脏B超及胸部透视阳性检出率为3.04%，对比免疫学检查142例阳性结果和影像学检查51例阳性结果：影像学检查阳性51例中有43例全血DIGFA为阳性，对其余8例影像学检查阳性而全血DIGFA阴性体检者进行16个月随访，经CT检查或病理学检查证实为肝棘球蚴坏死（3例）、肝钙化（2例）、肝囊肿（2例）、肝癌（1例)。而免疫学检查阳性的142例体检者中43例B超为阳性，对其余99例全血DIGFA阳性而影像学检查阴性的体检者进行16个月随访，发现肺部棘球蚴3例（随访仍在继续，数据统计截止到2003年6月）。对临床手术和病理检查确诊的38例棘球蚴病患者的阳性检出率为89.5%，对52份非流行区无狗羊接触史的健康体检者全血血样阳性检出率为0，与40例其他非棘球蚴性肝肺占位疾病（肝囊肿10例、肝血管瘤10例、肝癌10例、肺结核6例、肺癌4例）全血血样无交叉反应。随机抽取各组全血标本190例分别提取全血和血清标本，进行全血DIGFA、血清DIGFA和血清ELISA单盲法检测，三者检测结果差异无显著性(P＞0.05)。 结论 棘球蚴病全血快速诊断试剂盒操作简便和快速，适合普查和流行病学调查。     

Prestorage Leukocyte Reduction with In-Line Filtration of Whole Blood: Evaluation of Red Cells and Plasma Storage

Objectives: Prestorage filtration of blood components appears to be an effective method to reduce leukocyte-induced adverse reactions and other complications. To determine whether it is better to filter whole blood before component separation, we compared the efficiency of in-line filtration of whole blood with that of postseparation filtration. Methods: Blood was collected from normal, healthy donors into either regular triple-bag containers or into whole-blood integral-filter container systems. We then compared the in vitro storage values of leukocyte-depleted red blood cell concentrates (RBCC) kept at 4 °C, and plasma frozen for 1 year with nonfiltered blood components as control. Results: All counts of white blood cells after filtration were < 1 × 10⁶ per unit. For almost all storage parameters no significant differences were found between leukocyte-reduced RBCC and control units. The plasma fibrinopeptide A values below 30 ng/ml prior to freezing indicate that filtration does not activate the coagulation factors. Furthermore, the filtration did not influence either the biological values or the coagulation factors of plasma units. Conclusions: Whole blood filtration prior to component preparation seems to offer a useful alternative technique for obtaining leukocyte-reduced RBCC and plasma.     

Platelet and Erythrocyte Volume and Count: Epidemiological Predictors of Impedance Measured ADP-Induced Platelet Aggregation in Whole Blood

Variation in the threshold dose of ADP necessary to induce platelet aggregation in whole blood is significantly related to constituent factors of whole blood among 242 men from the Caerphilly Collaborative Heart Disease Study. Increased platelet count, mean platelet volume, and primary ADP-induced aggregation in platelet rich plasma are associated with lower ADP threshold doses, while increased red cell count and mean corpuscular volume are associated with higher ADP threshold doses. Marginal relations involving plasma fibrinogen concentration completely disappear upon taking into account the platelet indices. The platelet indices also appear to mediate relations between the ADP threshold dose and smoking status. Limitations in the data do not allow a more thorough assessment of how such constituents may mediate a relation between ADP threshold dose and past myocardial infarction. However, the analyses do not discount such an association for the platelet indices.     

Separation of Platelets from Whole Blood by the Use of Silicone Liquids

A method of separating platelets from whole blood has been developed.The method involves simple centrifugation with blended silicone fluids.Quantitative recovery of platelets is achieved. Platelets appear to have no lossof ability to promote clot retraction in platelet poor plasma.

Submitted on March 15, 1961 Accepted on May 6, 1961