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PubMed1994

Prestorage leukocyte reduction of cellular blood components.

With the increasing demand for leukoreduced cellular blood components, many blood centers in Europe, North America, and Asia have begun to prepare leukocyte depleted cellular blood components prior to storage. Increased understanding of transfusion complications resulting from recipient exposure to residual donor leukocytes has focused attention on donor leukocytes during blood storage. This review examines production options for prestorage leukocyte removal, considers approaches to quality control, discusses proposed laboratory and clinical advantages of leukoreduction prior to storage compared with after storage, and suggests a strategy for cost-effective implementation of widespread prestorage leukocyte removal.

Blood Banks↗
PubMed2006

Clearance of prions during plasma protein manufacture.

Protein products isolated from human plasma are an important class of therapeutics that are used to treat patients afflicted with hereditary deficiencies, trauma, and severe infections. Because of the human origin of the starting material for the production of these biological products, there is a risk of transmitting infectious agents, including viruses and the infectious agents that cause transmissible spongiform encephalopathies (TSEs). The agent that is thought to cause TSEs is a disease-associated, misfolded form of the prion protein or PrP(Sc). Unlike viruses, there are no donor screening tests for TSEs available, and PrP(Sc) is resistant to traditional viral inactivation methods. Therefore, manufacturers of plasma products are faced with special challenges to ensure product safety with respect to TSEs. Fortunately, a growing body of evidence supports the capacity of manufacturing processes to remove infectious prions from the product stream during the purification of plasma products. This can be attributed in part to the unusual physicochemical nature of PrP(Sc), which is distinct from that of soluble therapeutic proteins. Although there is no reported TSE transmission through the use of plasma products to date, many unknowns remain to be addressed through long-term epidemiologic monitoring and further experimental studies.

Blood Component Removal↗
PubMed1993

Leukocyte-depleted platelets prepared from pooled buffy coat post-transfusion increment and "in vitro bleeding time" using the Thrombostat 4000/2.

A technique for preparation of platelet concentrate (PC) from pooled buffy coat (BC) is described in this study. The yield of platelets from 4 BCs was 310+/-48x10 9 per unit with a leukocyte content of 21+/-20x10 6 per unit. When a leukocyte removing filter was interconnected, Sepacell 5N and Pall PL-50 filters, no leukocytes could be found in 56 of 59 and in 36 of 37 PCs, with a maximum content of 2.3 and 0.54x10 6 leukocytes per PC, respectively. The platelet yield was 276+/-37 and 279+/-54x10 9 per unit, respectively. The in vitro bleeding time (IVBT), using the Thrombostat 4000/2, corresponded with the corrected count increment in most of 11 thrombocytopenic patients receiving platelet transfusions. However, in two transfusions no correction of IVBT was obtained. This technique offers a new possibility to investigate the functional capacity of transfused platelets.

Bleeding Time↗
PubMed1990

Effectiveness of the Imugard E leukocyte removal filter for preparation of leukocyte-poor concentrated red cells.

Concentrated red cells (CRC) were filtered through a new leukocyte removal filter, the Imugard E, which consists of a polyvinyl alcohol porous sheet. CRC were filtered through the Imugard E with neither priming before filtration nor rinsing after filtration. Leukocyte removal was 99.1 +/- 0.6, 99.6 +/- 0.3 and 99.6 +/- 0.4% on the 1st, 5th and 10th day after blood collection, respectively. Platelet removal was 96 +/- 2, 81 +/- 6 and 85 +/- 3% on the 1st, 5th and 10th day, respectively. Red cell recovery was 86 +/- 2, 86 +/- 1 and 86 +/- 1% on the 1st 5th and 10th day, respectively. Filtration time was 3.9 +/- 0.8, 5.8 +/- 0.9 and 6.1 +/- 0.8 min on the 1st, 5th and 10th day, respectively. Direct filtration of CRC through the Imugard E resulted in no significant changes in the ATP or 2,3-DPG concentrations, and no hemolysis due to filtration was noticed. It may be concluded that the Imugard E is a good filter that is simple to use and effective in leukocyte removal.

Blood Component Removal↗
PubMed1997

Should hospitals collect blood components? Yes: hospitals put patients first.

Stand-alone blood collection centers throughout the world have suffered in recent years from cost overruns, quality and regulatory problems of major proportion, and a subsequent deterioration of service levels to their communities. Their leaders have been probed by public interest groups, the media and governmental bodies, removed from positions of authority, and sadly, subpoenaed, vilified in public and even jailed. Patients, healthcare providers and hospitals have suffered through this period as well, and continue to search for alternatives to their largely monopoly suppliers. In most cases, the best alternative is the one they control themselves. Should hospitals collect blood components? Yes, since their mission--patient care--takes precedence over that of any non-provider healthcare organization. Patients and the public-at-large gain many things by the continued presence of hospitals in the provision of donor services: provider and patient needs are given first billing, and innovation in blood services is encouraged by the transfusion medicine physicians and allied health professionals who are closest to the patient. Service requirements are recognized and met faster and in simpler ways, and quality concerns are addressed with a minimum of bureaucracy and a maximum of common sense. Finally, when hospitals control their own donor programs, costs are more easily tracked and better controlled.

Blood Component Removal↗
PubMed2002

Studies on the characterisation of the cause of leucoreduction failures, with particular reference to extra gatal events.

The causes of leucodepletion failure are multifactoral and can be related to haematological variability in blood donors or donation, defective filters, poor specimen handling or ageing, and/or the presence of non-adhering leucocyte/platelets. Since refiltering removes all types of leucocytes, including the populations appearing as extra gated events, we have developed a practical method for refiltering the failed leucodepleted components on standard filters and back-flushing the second filter to assess the nature of the WBC sub-population. In practice, recovered leucocytes from red cell filters and whole blood mainly consist of neutrophils. Those from platelet and plasma filters were mainly lymphocyte with considerable differences depending on the type of leucodepletion process. Atypical leucocytes are often seen in some pre-/post-cellular leucofiltered components. These appear characteristically as small WBC with a lower affinity for filter matrix, or as cell fragment, pinched leucocyte or apoptotic cells. Different reagents in use show variable sensitivity in identifying these extra gatal events. Storage of leucodepleted samples also induces different types of abnormality in leucocyte dot plot. A useful practical approach for characterisation of the nature of leucocyte sub-populations causing failure in leucodepleted components is provided.

Blood Cell Count↗
PubMedDate not supplied

An effective method for the preparation of leukocyte-poor platelets.

Febrile transfusion reactions are encountered occasionally in patients receiving platelet concentrates that contain contaminating leukocytes. To remove heavier cellular elements, a 400-ml platelet pooling bg with tapered sides and a pouch at the base was designed to trap these cells after centrifugation. Two versions of this bag were tested: the initial prototype with a 3-ml pouch and a modified version with a 4-ml pouch. Platelet concentrates were pooled in batches of 6 per bag and, after sampling, were centrifuged between 186 and 600 x g for 7 to 10 minutes. The pouch on each bag was then clamped off, and samples from the primary bag were withdrawn so tht the percentage of cellular elements remaining could be determined. At optimal centrifugation conditions (390 x g for 10 minutes) with the initial prototype of the bag, average cellular decreases were: leukocytes, 75.9 percent; red cells, 84.1 percent; and platelets, 9.8 percent. Twenty-two components prepared in this manner were infused into 12 patients with histories of febrile transfusion reactions. Febrile reactions were markedly reduced or absent in ten patients, a strong febrile reaction due to incorrect component preparation occurred in one, and a marked allergic reaction occurred in one. The 4-ml pouch gave much better production results with greater than 95 percent leukocyte removal and less than 5 percent platelet loss. This system removes sufficient leukocytes from platelet concentrates that the risk of febrile transfusion reactions is reduced significantly.

Blood Component Removal↗
PubMed2003

WBC reduction in cryopreserved RBC units.

BACKGROUND: WBC reduction of blood components by filtration is widely practiced to decrease the incidence of alloimmunization. Freezing RBCs reduces the WBC load but is insufficient to achieve the currently recommended US limit of 5 x 10(6) cells per unit. STUDY DESIGN AND METHODS: Blood units were WBC reduced by filtration or by buffy-coat (BC) removal and then frozen in the presence of a high-glycerol concentration. The count of residual WBCs was determined by flow cytometry after deglycerolization. RESULTS: Without WBC reduction, the total number of WBCs present after freezing and thawing was 11.5 +/- 9.2 x 10(6) WBCs per unit (n = 18). Particulate residues from monocytes and neutrophils that were detected in the remaining cell populations were positive for CD66b, CD3, CD14, and CD41. Removal of 40 mL of BC at the time of blood collection lowered the number of WBCs after freezing and deglycerolization to 1.9 +/- 1.20 x 10(6) per unit (n = 11). Similar results were obtained when only 20 mL of BC was removed using a modified blood-bag design. Unfiltered RBC units that were stored for 15 days at 4 degrees C after BC removal contained fewer than 5 x 10(6) WBCs after deglycerolization. Units WBC reduced by filtration before freezing had no detectable WBCs after thawing and washing (n = 14) and did not contain particulate residues. Filtration after deglycerolization was effective in reducing the WBC count below 10(6), although some debris was still present. CONCLUSION: RBC freezing alone will not reduce residual counts to recommended levels. However, initial removal of BC can provide an economical alternative to WBC filtration for cryopreserved units. Units that were not WBC reduced before freezing can be filtered after deglycerolization when needed.

Blood Component Removal↗
PubMed2006

Arsine toxicity treated with red blood cell and plasma exchanges.

BACKGROUND: Acute toxicity due to inhalation of arsine gas (AsH(3)) has no known antidote. Exchange transfusion may be beneficial, and dialysis is often required because arsine may cause acute intravascular hemolysis and renal failure. A patient with arsine toxicity has recently been treated by both red blood cell exchange (RBC-E) and plasma exchange (PE) therapy and our experience is reported. CASE REPORT: A 46-year-old man was accidentally and unknowingly exposed to arsine gas while observing an industrial procedure. Within 6 hours he developed fatigue, nausea, vomiting, and tingling in his extremities and voided dark urine. He quickly developed renal failure secondary to acute arsine toxicity (arsenic level, 1250 microg/L). Laboratory findings were a hematocrit level of 24 percent; blood urea nitrogen and creatinine, 84 and 5.5 mg per dL, respectively; bilirubin, 9.1 mg per dL; indirect bilirubin, 6.8 mg per dL; haptoglobin, less than 6 (normal, 30-200); and lactic dehydrogenase, 10,413 units per L (normal, 265-580). An emergent 1-vol RBC-E transfusion by continuous-flow method revealed dramatic black, grossly hemolyzed plasma. After two additional RBC-E and two PE and daily hemodialysis, he completely recovered over the course of 1 month. CONCLUSION: Patients with arsine toxicity resulting in intravascular hemolysis should receive RBC-E as soon as possible. In addition, PE may be beneficial in removing the components of RBC lysis and further reducing arsenic levels.

Acute Kidney Injury↗
PubMed1993

A process for enhancing selectivity and limiting plugging in plasmafractionation for APOB removal.

A new process using pressure and flow pulsations was investigated in the second stage of cascade filtration for ApoB removal. Due to enhanced filtration by the pulsations, the retentate flow vanished naturally without clamping the line, which reduced albumin and ApoA1 losses. The performance of Eval 4A and cellulose PF100 filters in this case were compared with that of classical dead end mode at a plasma flux of 18 ml/(min m2). The apparent sieving coefficient for small proteins (albumin, ApoA1) under pulsed conditions increased with increasing pressure instead of dropping as in dead end mode. In both cases the ApoB sieving coefficients remained below 0.02. These encouraging results were accompanied by a slower rise of transmembrane pressure showing a decrease of membrane plugging. Thus, the recovery of albumin and ApoA1 is increased while ApoB removal remains constant, which improves the selectivity of the fractionation stage.

Apolipoproteins B↗
PubMed1997

Assessment of the availability of intraoperative autotransfusion in urological operations.

PURPOSE: Intraoperative autotransfusion in urological operations has the risks of reinfusing urine constituents, bacteria and cancer cells. We assessed the efficacy of intraoperative autotransfusion and leukocyte removal filters to separate red blood cells from these constituents. MATERIALS AND METHODS: Concentrated red blood cells were mixed with urine, bacteria (Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) and tumor cells (KK47 and ACHN), and processed with the intraoperative autotransfusion device. Biochemical analyses of erythrocytes collected in reinfusion bags (collected erythrocyte solution) from the mixtures of concentrated red blood cells and urine (mixture 1), and cultures of collected erythrocyte solution from the mixtures of concentrated red blood cells and bacteria (mixture 2) were performed. Cytology was done on collected erythrocyte solution from the mixtures of concentrated red blood cells and tumor cells (mixture 3) and filtrates were passed through leukocyte removal filters. RESULTS: Biochemical analyses of collected erythrocyte solution from mixture 1 indicated complete removal of urine constituents, while cultures from mixture 2 yielded bacterial growth. Tumor cells from both cell lines were found in the collected erythrocyte solution from mixture 3 although tumor cells were not found in filtrates through leukocyte removal filters. CONCLUSIONS: Our results suggest that intraoperative autotransfusion is safe for urological operations in which bacteria and tumor cells are not present in the operative field. Our data also indicate that intraoperative autotransfusion may be safe for urological cancer operations if it is combined with leukocyte removal filters to prevent unexpected reinfusion of tumor cells.

Blood↗
PubMed2001

Evaluation of performance of white blood cell reduction filters: an original flow cytometric method for detection and quantification of cell-derived membrane fragments.

BACKGROUND: Contamination of blood products by white blood cells leads to a risk of transmission of infectious agents, particularly abnormal prion protein, the probable causative agent of new-variant Creutzfeldt-Jakob disease. Blood product filtration could reduce this risk, but the filtration systems might generate potentially infectious membrane fragments. We developed an original flow cytometric method that allows the detection and quantification of membrane fragments in filtered products and the evaluation of the quantity of destroyed cells. METHODS: This method has four technical requirements: cytofluorometric acquisition of forward scatter parameters on a log scale, use of a fluorescent aliphatic reporter molecule (PKH26-GL) to identify membrane fragments, quantification with fluorescent beads, and the drawing up of a standard curve on the basis of cells destroyed by freezing/thawing to generate cell debris (i.e., quantity of membrane fragments measured versus quantity of destroyed cells). RESULTS AND CONCLUSIONS: This original method can be used to test new filtration devices and it allows optimization of the filtration process or comparison of different filtration systems. We tested the method with three commercial white cell removal filters. We demonstrated that it is possible to evaluate the filter quality, particularly the likelihood of fragment removal during the filtration process.

Blood Component Removal↗
PubMed1998

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. CONCLUSION: New options for the preparation and storage of red blood cells are available and undergo continuous evaluation.

2,3-Diphosphoglycerate↗
PubMed1997

Removal of ABO-incompatible red cells from lymphocytapheresis and granulocytapheresis components before transfusion.

BACKGROUND: The collection of allogeneic lymphocytapheresis and granulocytapheresis components containing significant volumes of ABO-incompatible red cells is sometimes necessary. STUDY DESIGN AND METHODS: Twenty-nine ABO-incompatible lymphocytapheresis components collected for transfusion to three patients and 11 ABO-incompatible granulocytapheresis components collected for transfusion to five patients were depleted of red cells by gravity sedimentation aided by the addition of hetastarch solution. The efficacy of red cell depletion and white cell retention and the complications of transfusion were analyzed. RESULTS: Lymphocytapheresis components contained 82 +/- 13 percent of the original white cells and 5 +/- 3 mL of red cells after depletion; however, for those components containing < 70 mL of red cells before depletion (n = 12), white cell recovery was 92 +/- 5 percent. After depletion, granulocytapheresis components contained 96 +/- 3 percent of the original white cells and 6 +/- 2 mL of red cells. No clinical or laboratory evidence of hemolysis was observed after the transfusion of any leukapheresis component. CONCLUSION: Red cells can be effectively removed from leukacytapheresis components by a simple gravity sedimentation technique with added hetastarch. This allows safe transfusion of ABO-incompatible components.

ABO Blood-Group System↗
PubMed1989

[Kinetics of lipids and lipoproteins with determination of the recovery rate in the non-steady state following plasma, membrane filtration and dextran sulfate adsorption apheresis in hypercholesterolemia].

In the work presented here, the efficiency of the following techniques was determined in the period 1983-1988 with respect to the elimination of lipids, lipoproteins and apoproteins in patients with severe hypercholesterolemia; firstly with plasmapheresis, then with membrane-filtration apheresis, and recently with dextran sulfate adsorption apheresis. Furthermore, the loss resulting from removal by apheresis in lipids, lipoproteins and apoproteins was calculated by means of a single-compartment model from pool size and recovery rates. It could be shown that the individual lipids (TG, CH, LDL-CH, P) in the serum as well as in the lipoprotein fractions (VLDL, LDL, HDL) attained new steady states at differing rates, the recovery times for cholesterol being the longest, those of HDL-CH and apoproteins AI, AII, CII, CIII and E the shortest. The absolute replacement in "mg/kg BW/d" was 35 for beta-lipoprotein, 18-22 for total-CH, 13-17 for LDL-CH, 10-12 for apoprotein B; for the antiatherogenic lipids HDL-CH it was 1.72-2.7 mg/kg BW/d; for alpha-lipoprotein 14-23 mg/kg BW/d; for apoprotein HDL 16-19 mg/kg BW/d. The recovery rates for anti- and atherogenic lipids for women with heterozygous FH were higher than for men with FH. Rates of 0.235; 0.510 and 0.183 mg/kg BW/d were measured for CII, CIII and apoprotein E respectively. Dextran sulphate adsorption apheresis (Kaneka) is a more specific method for eliminating LDL-CH and apoprotein B than plasmapheresis and membrane filtration apheresis. The amounts removed in LDL and apo B with the Kaneka technique are largely identical with those taken out by membrane filtration. Larger relative and absolute recovery rates for LDL-CH, total-CH and apo B were found after Kaneka's DSA-apheresis, which may be explained by the more specific removal in LDL-CH and apo B.

Blood Component Removal↗
PubMed1994

Cell processing protocol for allogeneic peripheral blood stem cells mobilized by granulocyte colony-stimulating factor.

Although there is a growing body of information available regarding restoration of hematopoiesis with peripheral blood stem cell (PBSC) autografts, few studies have explored this procedure using allografts. In this study with healthy donors, we investigated the feasibility of a protocol for mobilizing PBSC using recombinant human granulocyte colony-stimulating factor (G-CSF) and subsequent bulk depletion of T cells from apheresis-harvested cells. Nine informed healthy donors were given G-CSF subcutaneously at two different dosing schedules (5 micrograms/kg/d in five donors and 2 micrograms/kg/d in four) for 5 consecutive days, and serial changes in blood components, including hematopoietic progenitor cells, were monitored. After 5 days of stimulation with G-CSF, PBSCs were collected by apheresis, and yields were compared. The number of white blood cells (WBC) reached a plateau level on either day 2 (5 micrograms) or 3 (2 micrograms), but the numbers of red blood cells and platelets were not affected. Circulating colony-forming unit-granulocyte/macrophage (CFU-GM) levels started to increase 1 or 2 days after the increase in the WBC count. By performing a 3L apheresis, the number of CFU-GM harvested was 4.6 +/- 3.3 x 10(6) (mean +/- standard error of the mean [SEM]) in the 5-micrograms group and 1.8 +/- 0.7 x 10(6) in the 2-micrograms group. Different procedures for depleting T cells, including the use of L-phenylalanine methyl ester (PME) and flasks coated with anti-CD5/CD8 monoclonal antibodies or neuraminidase-treated sheep red blood cells (SRBC), were also tested on the harvested cells. We found that cell lysis with PME before selective removal of T cells was very effective in reducing the number of cells that required further processing and was suitable for routine use. However, our current procedure resulted in unsatisfactory depletion of T cells (99.5% removal) while retaining hematopoietic progenitor cells (7.5% recovery). Further research is required in this area.

Adult↗
PubMed1975

Cytotoxic mechanisms detected in vitro following sheep renal allografts.

Cytotoxic effects of lymph and blood components, removed from sheep following renal allografting were determined by in vitro assay using 51Cr labelled donor sheep lymphocytes as target cells. Lytic antibodies were detected in lymph efferent from the node draining the graft site and at lower concentrations in blood serum and in lymph leaving the graft. The cytotoxic antibodies had both complement-dependent and leucocyte-dependent functions; the complement-dependent antibodies were fractionated and shown to be of IgM and IgG1 subclasses. Cytotoxic cells were found in lymph leaving the graft but not in blood or in lymph efferent from the draining node; those detected in the renal lymph were non-specific in action and their appearance correlated with increased numbers of macrophages.

Animals↗