bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of citrate concentration on the quality of plasma obtained by automated plasmapheresis: a prospective study
Authors: Beeck H. , Becker T. , Kiessig S.T. , Kaeser R. , Wolter K. , Hellstern P. 
Published: March 2003

BACKGROUND: There is a need for more comprehensive work dealing with the quality of plasma collected by automated plasmapheresis using different final concentrations of citrate anticoagulant. A prospective study was performed to examine the influence of three concentrations of sodium citrate on the levels of clotting factors and markers of activated hemostasis and fibrinolysis.STUDY DESIGN AND METHODS: Fifty‐one experienced plasma donors were recruited for subsequent 750‐mL plasmapheresis procedures using 4‐percent (wt/vol) sodium citrate. Anticoagulant‐to‐blood ratios of 1:16.6, 1:14.2, and 1:12.5 were used, corresponding to sodium citrate concentrations of 6 percent, 7 percent, and 8 percent (vol/vol), respectively. Between two plasmapheresis procedures, there was a washout period of 7 days. Determinations were made of the plasma levels of fibrinogen and factors V, VII, VIII, and IX, as well as antithrombin, tissue‐type plasminogen activator, and several markers of activated hemostasis and fibrinolysis: activated factor VII, prothrombin splits products, d‐dimers, and β‐thromboglobulin.RESULTS: The plasma samples anticoagulated with 6‐percent citrate contained significantly higher levels of factors V, VIII, and IX than the samples anticoagulated with 8‐percent citrate (p<0.0001, p≤0.0001 and p = 0.009, respectively). The citrate concentration had no influence on the levels of fibrinogen, factor VII, antithrombin, or tissue‐type plasminogen activator. There was no evidence that the plasma samples containing lower citrate concentrations were more prone to activation of hemostasis or fibrinolysis.CONCLUSION: A reduction in the final citrate concentration of plasma collected by automated plasmapheresis results in higher yields of factors V, VIII, and IX without activation of hemostasis. More comprehensive studies should confirm previous work dealing with the establishment of the lowest citrate concentration acceptable in plasma used as therapeutic fresh‐frozen plasma or as starting material for the manufacture of plasma derivatives.
Lookback on donors who are repeatedly reactiveon first‐generation hepatitis C virus assays:justification and rational implementation
Authors: Tobler L.H. , Tegtmeier G. , Stramer S.L. , Quan S. , Dockter J. , Giachetti C. , Busch M.P. 
Published: March 2003

BACKGROUND: The purpose of this study was to explore strategies to minimize the number of unwarranted consignee notifications resulting from hepatitis C virus (HCV) first‐generation (single‐antigen) enzyme immunoassay (EIA 1.0) targeted lookback.STUDY DESIGN AND METHOD: The four blood centers participating in this study contributed data on 3753 HCV EIA 1.0‐repeatably reactive (RR) donations. The analysis focused on 1) statistical evaluation of HCV EIA 1.0 signal‐to‐cutoff (S/CO) ratios versus HCV second‐generation recombinant immunoblot assay (RIBA 2.0) interpretation from all participating blood centers and 2) RNA testing using transcription‐mediated amplification on all HCV EIA 1.0 RR/RIBA 2.0‐positive or ‐indeterminate specimens and a subset of RIBA 2.0‐negative donations for which specimens were available.RESULTS: Analysis of HCV EIA 1.0 S/CO ratios versus RIBA 2.0 indicated that 1180 (89%) of 1326 RIBA 2.0‐positive specimens had an S/CO ratio >2.5, while 146 (11%) had a ratio ≤2.5. In contrast, of 2253 RIBA 2.0‐negative specimens, 299 (13%) had an S/CO ratio >2.5, while 1954 (87%) had a ratio ≤2.5. Of 248 HCV EIA 1.0‐RR/RIBA 2.0‐positive samples with stored specimens available for additional testing, 198 (80%) were HCV RNA positive; 15 (7.5%) of these specimens had an S/CO ratio ≤2.5, while 183 (92%) had a ratio >2.5. HCV RNA was detected in only 2 (1.5%) of 137 HCV EIA 1.0‐RR/RIBA 2.0‐negative specimens: 1 of these 2 specimens had an S/CO >2.5, while the other had an S/CO ≤2.5.CONCLUSION: A highly significant (<0.0001) correlation was found between the S/CO ratio on HCV EIA 1.0‐ and RIBA 2.0‐positive or ‐negative results. An S/CO ratio >2.5 yielded an 89‐ percent sensitivity for RIBA 2.0‐positive specimens, and donations with an S/CO ratio >2.5 had a 75‐percent probability of being RIBA 2.0 positive. A policy recommendation to use the S/CO ratio to triage lookback would prevent unwarranted notification of 87 percent of recipients of blood from RIBA 2.0‐negative donors and would result in a failure to notify only 5 to 10 percent of recipients potentially exposed to infectious units.
Preparation and storage characteristics of white cell‐reducedhigh‐concentration platelet concentrates collected by anapheresis system for transfusions in utero
Authors: Dumont L.J. , Krailadsiri P. , Seghatchian J. , Taylor L.A. , Howell C.A. , Murphy M.F. 
Published: March 2003

BACKGROUND: Important concerns with regard to in utero platelet transfusions are avoidance of volume overload and the immunomodulatory effects of residual white cells (WBCs). This study evaluated a modification of a leukocyte‐reduction system (LRS, Spectra, COBE BCT) for apheresis, which collects high‐concentration WBC‐reduced platelets (HCPs) for in utero transfusion.STUDY DESIGN AND METHODS: The LRS procedure was modified by running the platelet collection pump at specified low flow rates (Qcol) for the first part of the procedure, collecting HCPs by gently purging them from the LRS chamber into a designated collection bag and then restoring the original LRS procedure settings to collect a second standard apheresis platelet concentrate (PC). Two centers carried out 32 procedures. Platelet yield, residual WBCs, and in vitro platelet function studies were evaluated.RESULTS: Platelet concentrations in 60 mL of HCPs were predictable according to Qcol (r2 = 0.735). HCP yields varied from 0.9 to 3.2 × 1011, depending on the desired final platelet concentrations in 60 mL, with an overall average of 1.92 × 1011 (n = 32). Apheresis PCs had a mean platelet yield of 2.9 × 1011 (1.3‐4.4 × 1011, n = 20) and 3.9 × 1011 (2.2‐5.8 × 1011, n = 12) at concentrations of 1.3 × 1012 per L for single‐needle and dual‐ needle procedures, respectively. Median WBC counts were 5.6 × 103 for HCPs and 2.0 × 104 for apheresis PCs, with >99 percent expected to be less than 1 × 106. HCP in vitro characteristics were equivalent to those of apheresis PCs at 24 hours after collection. In vitro performance declined over storage as a function of HCP yield. HCP pH at 22oC was maintained at a level of >6.2 for more than 3 days for yields >1.6 × 1011, less than 2 days for yields 1.6 to 2.2 × 1011, and less than 24 hours for yields >2.2 × 1011. HCPs showed good in vitro characteristics and could be stored for 1 to 3 days, depending on the total number of platelets collected.CONCLUSION: A standard apheresis PC and an HCP requiring no secondary processing can be collected with the Spectra LRS. The platelet concentration may be determined by clinical need. HCPs meet the requirements for components that are transfused in utero.
Apheresis‐induced platelet activation:comparison of three types of cell separators
Authors: Hagberg I.A. , Akkøk Ç.A. , Lyberg T. , Kjeldsen‐Kragh J. 
Published: March 2003

BACKGROUND: Platelet‐harvesting technology differs in various cell separators. Alteration in shear stress and biocompatibility of surfaces may give variable platelet activation and thereby affect the quality of the component.STUDY DESIGN AND METHODS: Four groups (n = 10) of single‐needle apheresis procedures using three cell separators, were compared: 1) Spectra LRS, 90‐minute harvesting time; 2) MCS+, 90‐minute harvest; 3) Amicus, 90‐minute; and 4) Amicus, 45‐minute. Whole‐blood samples were collected from the donors as were samples from the final components at intervals during the first 4 hours after cessation of the apheresis. Platelet activation status and platelet activation capacity after agonist stimulation were assessed by flow cytometry.RESULTS: No activated platelets were found in preapheresis and postapheresis samples from the donors. The platelets in the components from the Amicus (90‐min) were significantly more activated than those in the other groups of components: that is, there was increased size of platelet aggregates, increased fraction of microparticles, increased degranulation, increased fibrinogen receptor activation, and decreased von Willebrand factor receptor expression. Moreover, the response of these platelets to agonist stimulation was reduced for all activation variables.CONCLUSIONS: After 90 minutes' processing time, platelets obtained with the Amicus cell separator were significantly more activated than platelets harvested with the Spectra and the MCS+.
A comparison of prestorage WBC‐reduced whole‐blood‐derived platelets and bedside‐filtered whole‐blood‐derived platelets in autologous progenitor cell transplant
Authors: Sweeney J.D. , Kouttab N.M. , Penn C.L. , McHugh K.E. , Nelson E.J. , Oblon D.J. 
Published: March 2003

BACKGROUND : Prestorage WBC‐reduced platelet concentrates (PCs) can be manufactured from platelet‐rich plasma (PRP) by in‐line filtration of PRP. There are few published data on the clinical use of these products, as compared to bedside‐filtered pools of standard PCs (S‐PCs) manufactured from PRP.STUDY DESIGN AND METHODS : A prospective, randomized trial was conducted in autologous progenitor cell transplant patients requiring platelet transfusions with each patient as his or her own control who was given a pool of 5 units of WBC‐reduced PCs and a pool of 6 units of S‐PCs within a 3‐hour period. The pools were characterized before transfusion for platelet and WBC content, P‐selectin expression, and IL‐8. The patients were monitored with platelet counts and vital signs and observed for reactions. Data were analyzed using Mann‐Whitney U tests.RESULTS : Thirty‐three transfusions were administered to 13 patients. Median platelet content in the WBC‐reduced PC pools was lower than that in the S‐PC pools (3.3 vs. 4.0 × 1011, p<0.01). Median WBC content was 4 to 5 log less in the WBC‐reduced PC pools (2.5 × 104 vs. 4.6 × 108, p<0.01). Median IL‐8 levels (pg/mL) were lower in the WBC‐reduced PC pools (2 vs. 36, p<0.01). No differences were observed in CCI, but the median absolute increase after transfusion of the S‐PC pools was higher (25 vs. 19 × 109/L, p<0.01), which reflected the larger size of the S‐PC pools. No overall differences in vital signs were recorded. Two reactions were observed, both in temporal association with the transfusion of pools of S‐PCs.CONCLUSIONS : A pool consisting of 5 units of WBC‐reduced PCs gave a median platelet increment of 19 × 109 per L in these thrombocytopenic patients and has a median WBC content 1 to 2 log below the accepted threshold for primary alloimmunization or CMV transmission.
The cost‐effectiveness of postoperative recovery of RBCs in preventing transfusion‐associated virus transmission after joint arthroplasty
Authors: Jackson Brian R. , Umlas Joel , AuBuchon James P. 
Published: March 2003

BACKGROUND: The return of joint drainage after hip and knee arthroplasty is a widely used but expensive blood‐conservation technique.STUDY DESIGN AND METHODS: A Markov decision analysis model was used to evaluate the cost‐effectiveness of postoperative RBC recovery in preventing viral complications of allogeneic transfusion.RESULTS: In the baseline analysis, using an RBC‐recovery device saves 5 quality‐adjusted minutes of longevity at an average incremental cost of $53. This corresponds to $5.7 million per quality‐adjusted life year. This figure was most sensitive to the direct cost differences of allogeneic versus recovered RBCs and to the volume of RBCs recovered per device. Such devices would save health care resources if they cost less than $73 or if they were applied only in cases where joint drainage was between 600 and 1100 mL.CONCLUSION: For most clinical situations, postarthroplasty RBC recovery does not appear to be as cost‐effective as most other medical interventions. Clinical attention should be directed toward developing protocols for the preferential use of postoperative RBC‐recovery devices in situations where they provide the greatest benefit.
Storage of G–CSF‐mobilized granulocyte concentrates
Authors: Lightfoot Thomas , Leitman Susan F. , Stroncek David F. 
Published: March 2003

BACKGROUND: Current standards limit granulocyte storage to 24 hours. Since G–CSF inhibits granulocyte apoptosis, it may be possible to store G–CSF‐mobilized granulocytes for longer periods while maintaining cell viability and function. However, G–CSF mobilization increases the yield of granulocytes several times, and the resulting higher cell concentrations may diminish viability during storage and significant levels of pyrogenic cytokines may be produced.STUDY DESIGN: Ten granulocyte donors were given dexamethasone (8 mg PO), G–CSF (5 μg/kg SQ), or both and on the next day granulocyte concentrates were collected using a blood cell separator. Component cell counts, cell viablilities, pH, and IL‐1β, IL‐6, IL‐8 and TNF levels were measured at 2 to 4 (2), 20 to 28 (24), and 44 to 52 hours (48 hours).RESULTS: Significantly more granulocytes were collected when donors were given G–CSF (4.2 ± 2.3 × 1010) or G–CSF plus dexamethasone (6.4 ± 2.5 × 1010) compared with that collected with dexamethasone alone (2.2 ± 1.2 × 1010); p = 0.03 and p = 0.002, respectively. Storage had little effect on WBC count. Slight but significant increases in IL‐1β and IL‐8 occurred after 24 and 48 hours as compared to the levels at 2 hours' storage. Levels of IL‐6 and TNF did not change. The pH dropped significantly with time in granulocytes mobilized with each regimen. Granulocytes mobilized with G–CSF plus dexamethasone were acidic immediately after collection, and pH was below 6.0 after 24 hours. To assess the effect of cell concentrations on pH, serial dilutions were performed on 13 granulocyte concentrates in autologous plasma prior to storage. The pH remained above 7.0 only when dexamethasone‐mobilized granulocytes were diluted 1‐in‐8 and when the G–CSF plus dexamethasone‐mobilized granulocytes were diluted 1‐in‐16.CONCLUSIONS: To optimize storage pH, mobilized granulocyte concentrates require a 1‐in‐8 to 1‐in‐16 dilution, which is operationally impractical. Clinical‐grade granulocyte preservative solutions are needed to maintain pH during storage.
Apparent rejuvenation of transfused donor blood in the fetus is due to accelerated removal of the older RBCs
Authors: Huisman Margriet A. , Egberts Johannes 
Published: March 2003

BACKGROUND: In severely anemic fetuses of women alloimmunized to RBC antigens, transfused donor RBCs disappear faster than in adults. This may result from an accelerated linear or nonlinear decline with time. It was investigated whether changes in donor RBC age characteristics after circulation in the fetus may reflect the main type of cellular decline.STUDY DESIGN AND METHODS: Donor RBC age characteristics (density, mean cell volume [MCV], and mean cell Hb content [MCHC]) were determined before intrauterine transfusions. Density gradient centrifugation was used to obtain RBCs of different ages. The results from gradient centrifugation were used to calculate mean values for the density, MCV, and MCHC to be expected after the transfusion interval, assuming a linear decline in RBCs of 1 percent per day. Donor and fetal RBCs, taken just before the second transfusion, were separated by agglutination with IgM D MoAb. For these donor cells, the observed mean values for density, MCV, and MCHC were compared with the calculated, expected values (n = 12).RESULTS: The mean ± SD transfusion interval was 17.9 ± 3.6 days. The Hb declined by 1.75 ± 0.62 percent per day (n = 9). After the transfusion interval and contrary to the expected changes, cell density and MCHC decreased and MCV increased significantly (0.001<p<0.02). This difference between actual and calculated values decreased with increasing intervals; for MCV, it was also associated with a greater decline in Hb per day (p<0.05).CONCLUSION: All donor cells age during circulation in the fetus. However, after the transfusion interval, the donor RBC population remaining is apparently younger than the RBC population before transfusion. This results from a preferential disappearance of older donor RBCs and not from a linear loss of cells with time. The removal of older RBCs before the transfusion may increase the time between transfusions and thereby reduce the total number of transfusions required.
An in vitro method for predicting the efficacy of WBC separation using different starch preparations and anticoagulant ratios
Authors: Rock Gail , Berger Rachel , Romans Robert A. , Russell Norma M. , Owens Wendy A. 
Published: March 2003

BACKGROUND: Separation of blood components depends on a number of factors, including the viscosity of the plasma and the number and size of the various cellular elements. To enhance granulocyte collection, it is common practice to alter the plasma environment by the addition of sedimenting agents such as hydroxyethyl starch. Recently, because of its prolonged persistence in the circulation, the higher‐molecular‐weight form of hydroxyethyl starch, Hespan (HP), has been replaced by the lower‐molecular‐weight form, pentastarch (PS). However, the yield appears to be lower. A rapid in vitro approach was used to permit comparison of the efficiency of separation of WBCs by the use of PS and HP and different ratios of anticoagulants that also alter the sedimenting characteristics of blood.STUDY DESIGN AND METHOD: Blood from individual persons was collected into sodium citrate at ratios of 1:8, 1:12, and 1:16. Samples were evaluated either before or after the addition of PS or HP and after centrifugation.RESULTS: The addition of HP increased the sedimentation rate to at least four times that of plasma (10.9 vs. 47.9 mm); PS approximately doubled the rate. Viscosity was altered by the introduction of either starch. These changes (ranging from a rate of 4.2 in HP with a 1:16 anticoagulant to 3.6 in PS with a 1:8 ratio of anticoagulant) reflected the anticipated effects of anticoagulant dilution and carbohydrate addition. Granulocyte recovery was highest, with a 1:12 anticoagulant ratio in all tests with HP producing the greatest yield (HP, 101%; PS, 89%; control, 78%).CONCLUSION: HP is far more effective than its lower‐molecular‐weight substitute PS in the generation of granulocytes in the buffy coat of whole blood. This method provides a simple, rapid, in vitro approach to evaluating the separating efficiency of solutions.
Isolation and flow cytometric analysis of T‐cell‐depleted CD34+ PBPCs
Authors: Debelak Joan , Shlomchik Mark J. , Snyder Edward L. , Cooper Dennis , Seropian Stuart , McGuirk Joel , Smith Brian , Krause Diane S. 
Published: March 2003

BACKGROUND: To extend allogeneic HPC transplantation to a greater range of patients, the use of partially matched related donors is under development. Because of the inherently higher degree of histoincom‐patibility in such transplants, there is increased risk of GVHD as well as of graft failure. Ex vivo depletion of donor‐derived T‐lymphocytes from PBPCs is one of the most effective methods of preventing GVHD. Thus far, individual centers have used custom‐developed procedures to deplete the graft of T cells that are responsible for alloreactivity, often employing relatively impure, nonstandardized reagents such as soybean agglutinin and complement. In addition, with improved methods of T‐cell depletion, it has been difficult to accurately assess the number of T cells remaining. Because different centers have used different protocols to assay T cells, it has been difficult to reproduce and validate the results between institutions, and this has limited direct comparison of data between centers.STUDY DESIGN AND METHODS: A standardized approach for T‐cell depletion was developed by using a Good Manufacturing Practice‐manufactured magnetic cell separator (Isolex 300i, Nexell Therapeutics) and commercially available OKT3 antibody. T‐cell depletion was performed on PBPCs from six haploidentical donors.RESULTS: CD34+ cell recovery was 47 percent (range, 31‐63%) with a median purity of 94 percent (range, 75‐99%) and median T‐cell log depletion of 4.72 (range, 3.90‐5.83). Because this high degree of depletion makes it challenging to accurately quantitate the remaining T cells, two highly sensitive flow cytometric protocols were developed, each of which accurately detects T cells with a sensitivity of 2 per 10,000 (0.02%). The purified CD34+ cells administered to the patients (dose range, 6.13‐13.50 × 106/kg) provided rapid neutrophil and platelet engraftment.CONCLUSION: With the Isolex 300i and a MoAb directed against T cells, a high degree of T‐cell depletion is obtained. Sensitive, accurate, and reproducible assays have now been developed for T‐cell enumeration in these highly purified cell populations.
Release of WBC‐derived IL‐1 receptor antagonist into supernatants of RBCs: influence of storage time and filtration
Authors: Büttnerova Ivana , Bäumler Hans , Kern Florian , Radtke Hartmut , Volk Hans‐Dieter , Kiesewetter Holger , Döcke Wolf‐Dietrich 
Published: March 2003

BACKGROUND: Transfusion‐associated immunodepression may be related to the transfer of immunoinhibitory cytokines with blood components.STUDY DESIGN AND METHODS: After evidence of increasing concentrations of IL‐1 receptor antagonist (IL‐1RA) but not of IL‐10 was obtained in supernatants of stored RBC units that were WBC‐reduced by centrifugation (C‐RBCs) in a pilot study, IL‐1RA concentrations were determined weekly in supernatants of C‐RBCs and in units that underwent prestorage WBC reduction by in‐line filtration (F‐RBCs) over a 49‐day storage. For assessing total IL‐1RA content, complete cell lysis by repeated freezing and thawing was done. The results were related to the changes in WBC count during storage. The dependency of IL‐1RA content on preparation procedures was assessed.RESULTS: The prestorage IL‐1RA concentration in C‐RBCs (859 ± 218 pg/mL) was significantly higher than in F‐RBC (75 ± 13 pg/mL). Whereas no changes were seen in F‐RBCs during storage, IL‐1RA levels in C‐RBC supernatants drastically increased to levels about 50 times those in normal plasma (16,327 ± 2,686 pg/mL on Day 49). Follow‐up analysis revealed stringent correlation between IL‐1RA release into supernatants and the current loss of WBCs (r = 0.79, n = 42; p<0.001). The total IL‐1RA content did not change during storage and was directly dependent on prestorage WBC count. Preparation procedures altered the IL‐1RA content only by WBC reduction.CONCLUSION: The immunosuppressive cytokine IL‐1RA is transmitted by RBCs in relation to WBC content and storage time.