Thrombin generation before and after multicomponent blood collection

The development of apheresis technology has increased efficiency in donor blood use by collecting specific blood components in several combinations. The question of donor safety raised by the contact of donor blood with foreign, only in part biocompatible surfaces remains. The aim of this study was to estimate the effect of multicomponent blood collection on thrombin generation performing an overall function test of coagulation. DONORS, METHODS: 26 blood donors were included. Per apheresis two units of platelets and one unit of RBCs were collected by two cell separators (Amicus and Trima Accel). Each donor underwent the procedure on both apheresis systems. Samples were collected before, immediately after, and 48 hours after apheresis. Thrombin generation was measured by means of calibrated automated thrombography (CAT). RESULTS: CAT-data changed only slightly and no significant changes were seen before, immediately after, and 48 hours after apheresis. The parameters did not differ significantly between the two different apheresis devices. CONCLUSION: No change in parameters of continuous thrombin generation occurred, suggesting that apheresis did not lead to severe alterations in the haemostatic system.     

Prolonged circulation of activated platelets following plasmapheresis

The extent and duration of in vivo platelet activation were determined in 12 volunteer donors undergoing automated plasmapheresis. Expression of P-selectin, activated GpIIb/IIIa, and platelet microparticle formation were measured by flow cytometry on peripheral blood samples obtained immediately before and after plasmapheresis and at 24 hour intervals thereafter for up to 3 days. Although no adverse effects were noted in any donor, immediately after apheresis 3 87% of circulating platelets expressed P-selectin: by 48 hours. 0.5 50% expressed P-selectin; and by 72 hours, all donors studied had fewer than 5% P-selectin expression on circulating platelets. Results were similar for the expression of the activated conformation of GpIIb/IIIa. There was a positive correlation with in vitro P-selectin expression in response to ADP in the pre-apheresis sample and the number of platelet microparticles detected in the donor following plasmapheresis. In addition, the percent expression of P-selectin and activated GpIIb/IIIa in response to ADP was reproducible in each individual studied on five separate occasions (CV ≤ 8%). Platelets activated during plasmapheresis using an automated device may circulate for at least 48 hours, and pre-plasmapheresis response of platelets to the agonist ADP correlated with platelet microparticle formation post-plasmapheresis. © 1994 Wiley-Liss, Inc.     

Donor exposure to the plasticizer di(2-ethylhexyl)phthalate during plateletpheresis

BACKGROUND: Di(2-ethylhexyl)phthalate (DEHP) is a plasticizer that is contained in most PVC devices, including apheresis disposables. Because DEHP can be extracted from apheresis disposables as the blood passes through the apheresis device, DEHP exposure was determined in healthy donors undergoing plateletpheresis performed with commercially available apheresis systems. STUDY DESIGN AND METHODS: The study population consisted of 36 healthy PLT donors undergoing plateletpheresis with either continuous or discontinuous apheresis devices. Serum concentrations of DEHP were determined from peripheral blood obtained before and after plateletpheresis, with gas chromatography-mass spectroscopy. RESULTS: Plateletpheresis performed with standard collection disposables resulted in a median increase of 232 percent of serum DEHP compared to levels before apheresis, corresponding to a total amount of DEHP exposed during a single apheresis of a median of 6.46 (range, 1.8-20.3) microg per kg of body weight. Endogenous levels of triglycerides showed a positive correlation with the amount of DEHP released. Increase in serum DEHP was short-term as serum DEHP rapidly returned to levels obtained before apheresis within 3 hours after completion of the apheresis course. Donor exposure to DEHP led to no variation in liver cell function within 48 hours after plateletpheresis. CONCLUSION: Commercial plateletpheresis disposables release considerable amounts of DEHP during the apheresis procedure, but the total dose of DEHP retained by the donor is within the normal range of DEHP exposure of the general population.     

Storing apheresis platelets without agitation with simulated shipping conditions during two separate periods: immediately after collection and subsequently between Day 2 and Day 3

BACKGROUND: Apheresis platelet (PLT) units are not routinely agitated during transit. Our study compared the in vitro properties of apheresis PLT units that were stored with continuous agitation (CA) and without continuous agitation (WCA) during two separate periods, immediately after collection and between Day 2 and Day 3 of storage. STUDY DESIGN AND METHODS: Two identical apheresis PLTs units were prepared from collections with Amicus (n = 11, Fenwal, Inc.) and Trima (n = 10, CaridianBCT) cell separators. One apheresis PLT unit was continuously agitated, starting routinely within 30 minutes of collection, and an identical apheresis PLT unit was held without agitation initially for 7 to 8 hours and subsequently for 24 hours between Day 2 and Day 3 of storage. The apheresis PLT units were maintained WCA at 20 to 24°C in a shipping box. In vitro PLT properties were evaluated on Day 1 (day after collection), after 5 and 7 days of storage. RESULTS: With both Amicus and Trima apheresis PLT units, the mean PLT content and concentration of CA and WCA were comparable and essentially constant throughout storage. Mean pH levels (±1 SD) after 5 days for Amicus apheresis PLT units were 6.97 ± 0.20 (WCA) and 7.13 ± 0.16 (p < 0.001, CA) and for Trima apheresis PLT units 6.97 ± 0.21 (WCA) and 7.22 ± 0.17 (p < 0.001, CA). In vitro variables, including percentage of disc PLTs, extent of shape change, and hypotonic stress levels, after 5 days of storage, showed mean differences between WCA and CA that were less than 15%. CONCLUSION: The in vitro results show that apheresis PLT units can be stored without agitation for 7 to 8 hours immediately after collection and also subsequently during storage for 24 hours with minimal influence on in vitro PLT properties compared to continuously agitated PLTs.     

Thrombelastographic evaluation of the influence of 2-RBC apheresis on donor’s coagulation system

Rotation thrombelastogram (ROTEM®/TEG®) assays allow rapid global assessment of hemostatic function using whole blood. Since published data about the effects of automated red cell collection on coagulation system are scarce, we aimed to investigate the effects of 2-RBC apheresis on donor’s coagulation system using ROTEM® assays.In INTEM assay, CFT was significantly shortened 24 h after apheresis compared with baseline value (p < 0.05) and MCF was significantly prolonged immediately after apheresis and 24 h after apheresis compared with baseline value (p < 0.05 and p < 0.01, respectively). In EXTEM assay, CFT was significantly prolonged immediately after apheresis and 24 h after apheresis compared with baseline value (p = 0.001 and p < 0.001, respectively) and MCF was significantly prolonged 24 h after apheresis compared with baseline value (p < 0,001).Our results demonstrate thromboelastographic signs of hypercoagulability in donors undergoing 2-RBC apheresis.     

Change in CD34+ cell concentration during peripheral blood progenitor cell collection: effects on collection efficiency and efficacy

BACKGROUND: An understanding of factors affecting CD34+ cell collection efficacy is essential to minimize donor toxicity and cost. STUDY DESIGN AND METHODS: Peripheral blood CD34+ cell (CD34) measurements were determined at various intervals before, during, and after automated cell collection (Cobe Spectra 6.0). The serial mean of multiple, intraprocedural CD34 levels was calculated for each procedure as an estimate of the mean, inlet-line CD34 level. RESULTS: The CD34+ concentration fell a mean of 30 percent in the first 30 to 70 minutes of collection. The degree of decline was inversely correlated with donor blood volume (BV), but was not due to hemodilution. The mean of the CD34 level before and after collection slightly overestimated the serial mean CD34 level. Cell yields, normalized for the CD34 level before collection, were higher from donors with larger BVs. CONCLUSIONS: The CD34 concentration rapidly decreased to a relative equilibrium level during the collection procedure. The degree of decrease in the CD34 level inversely correlated with the BV of the donor and was consistent with cell pooling in the collection set. The higher equilibrium CD34 levels in donors with larger BVs resulted in increased collection of CD34+ cells, and therefore, large-volume apheresis should be most efficient in these donors.     

Plateletpheresis in 90- to 110-pound donors using the CS-3000 blood cell separator

BACKGROUND: Increases in the use of single-donor apheresis components have increased the need for platelet donors. In the United States, persons must weigh 110 pounds or more to qualify as blood donors, and the same weight limitation has been placed on apheresis donors. Because automated plateletpheresis with some instruments differs considerably from whole-blood donation with respect to the volume of blood removed from the donor, the feasibility of using persons weighing between 90 and 110 pounds as platelet donors was evaluated by the use of the CS- 3000 blood cell separator. STUDY DESIGN AND METHODS: The study was performed using female subjects who met all usual donor requirements except for minimum weight. The standard platelet collection procedure of the instrument was used, except that the blood processing rate was manually selected so as to optimize the blood withdrawal and return rate in individuals. Vital signs were recorded before and after donation as were signs or symptoms of any type of donor reaction. RESULTS: Twenty-six of 28 women completed the donation procedure; in two instances, collection was terminated prematurely because of an inability to maintain adequate venous access. An average of 4.5 × 10(11) platelets were collected during a mean donation time of 110 minutes. All donors tolerated the procedure well, and no serious adverse reactions were seen. Because of the administration of priming solution and anticoagulant during apheresis, there was a net positive fluid balance following the procedure, in spite of the removal of approximately 220 mL of platelet concentrate. CONCLUSION: These preliminary studies suggest that 90- to 110-pound persons may serve as plateletpheresis donors. Additional studies are needed to more fully document the safety and efficacy of this approach. The use of lower- weight donors may significantly increase the number of persons available to provide single-donor platelet components.     

AutoPBSC程序与MNC程序采集外周血造血干细胞的比较研究

目的比较COBE Spectra血细胞分离系统的自动采集程序(AutoPBSC程序)与4.7版半自动采集程序(MNC程序)采集健康供者外周血造血干细胞的差异及对供者血常规相关指标的影响。方法 2002年3月~2008年3月期间对53例健康供者随机采用Auto PBSC程序和MNC程序进行了113例次造血干细胞采集,其中采用AutoPBSC程序63例次,MNC程序50例次。分析比较2种程序采得外周血造血干细胞(PBSC)的采集体积、单个核细胞百分数及总数、CD34+细胞百分数及总数等指标,采集前后供者红细胞、血小板变化。结果 2种程序采集外周血造血干细胞的体积、单个核细胞百分数、CD34+细胞百分数、CD34+细胞总数、采集袋中血小板及红细胞混入量、采集前后供者血小板计数的变化存在显著性差异(P<0.01);2种程序采集的单个核细胞总数无显著性差异;血小板计数在应用MNC程序组呈下降趋势,较AutoPBSC程序更加明显(P<0.01);1例地中海贫血供者应用Auto PBSC程序采集失败。结论 2种程序均可有效采集外周血造血干细胞,与MNC程序比较AutoPBSC程序具有以下优势:单个核细胞和CD34+细胞百分数提高、采集物体积减少有利于采集物的冻存、采集物中血小板数少对供者血小板影响小。地中海贫血供者需慎用Auto PBSC程序。     

Allogeneic donor peripheral blood "stem cell" apheresis: prospective comparison of two apheresis systems

BACKGROUND: Granulocyte–colony‐stimulating factor–mobilized peripheral blood stem cells, collected by white blood cell apheresis, are used for more than 80% of allogeneic and most autologous hematopoietic stem cell transplantations. Optimal donor and recipient outcomes require maximized stem cell collection efficiency and minimized non–target cell contamination. Therefore, improved apheresis technology is desirable. The safety and feasibility of apheresis collections with the novel, electronics‐assisted apheresis system Spectra Optia v.5.0 (CaridianBCT) were recently demonstrated. An unpublished optimization trial had furthermore determined that different settings than manufacturer‐installed default might result in improved apheresis yields. STUDY DESIGN AND METHODS: The first prospective comparison of allogeneic peripheral blood stem cell apheresis with the Spectra Optia versus the COBE Spectra (CaridianBCT) mononuclear cell (MNC) in a routine clinical setting is reported here; “optimized” machine settings were used. Assessed variables included collection efficiency, product characteristics, donor outcomes, and frequency of operator interventions. Outcomes were additionally compared with historical data from the Spectra Optia in default mode. RESULTS: The mean CD34+ cell collection efficiency CE1 was 7.9% greater with the Spectra Optia than with the COBE Spectra MNC. Variability of outcomes was equally great. Reduced platelet (PLT) attrition necessitated 90% fewer autologous PLT reinfusions. Spectra Optia products contained 50% fewer red blood cells, but 50% more granulocytic lineage cells. Less operator input was required, although 26% of Spectra Optia apheresis procedures required triggering of the first chamber flush. Apheresis yield and collection efficiency were also markedly greater than in default‐mode Spectra Optia collections. CONCLUSION: Using optimized machine settings, peripheral blood stem cell apheresis outcomes with the automated apheresis system Spectra Optia exceed results with the COBE Spectra MNC or the Spectra Optia in the default mode.     

Washing platelets with new additive solutions: aspects on the in vitro quality after 48 hours of storage

BACKGROUND: Rare clinical conditions cause the need for washed platelet (PLT) concentrates (PCs). Saline-washed PCs can only be stored shortly, however, owing to lack of substrates for PLT metabolism. New PLT additive solutions (PASs) contain such substrates and might be used alternatively. The in vitro quality of apheresis PCs washed with Composol-PS or modified PAS-III (PAS-IIIM) stored up to 48 hours after wash was compared. STUDY DESIGN and METHODS: Twelve blood donors underwent two apheresis procedures (A and B) collecting 6.0 x 10(11) PLTs in 500 mL of plasma with a least 2 weeks in between. The PCs collected by Apheresis A were stored for 3 days and then split in two equal units before washing with Composol-PS or PAS-IIIM. The PCs collected by Apheresis B were split after collection. One unit was released for transfusion and 1 unit was stored unwashed up to Day 6 and used as reference unit. In vitro testing was performed before and after washing as well as 24 and 48 hours after wash. RESULTS: After 48 hours of postwash storage, the units washed with either PAS showed acceptable results for hypotonic shock response (HSR), P-selectin expression, and pH, whereas PLT aggregability was significantly impaired. Throughout the storage, unwashed units showed better in vitro quality. HSR and P-selectin expression were similar before and immediately after the washing procedure. CONCLUSION: Based on these in vitro results, 48-hour postwash storage of washed PCs with the two PASs seems to be feasible. In vivo recovery studies, however, must confirm this finding in the future.     

The American Red Cross donor hemovigilance program: complications of blood donation reported in 2006

BACKGROUND: The American Red Cross (ARC) initiated a comprehensive donor hemovigilance program in 2003. We provide an overview of reported complications after whole blood (WB), apheresis platelet (PLT), or automated red cell (R2) donation and analyze factors contributing to the variability in reported complication rates in our national program. STUDY DESIGN AND METHODS: Complications recorded at the collection site or reported after allogeneic WB, apheresis PLT, and R2 donation procedures in 36 regional blood centers in 2006 were analyzed by univariate and multivariate logistic regression. RESULTS: Complications after 6,014,472 WB, 449,594 PLT, and 228,183 R2 procedures totaled 209,815, 25,966, and 12,282 (348.9, 577.5, and 538.3 per 10,000 donations), respectively, the vast majority of which were minor presyncopal reactions and small hematomas. Regional center, donor age, sex, and donation status were independently associated with complication rates after WB, PLT, and R2 donation. Seasonal variability in complications rates after WB and R2 donation correlated with the proportion of donors under 20 years old. Excluding large hematomas, the overall rate of major complications was 7.4, 5.2, and 3.3 per 10,000 collections for WB, PLT, and R2 procedures, respectively. Outside medical care was recorded at similar rates for both WB and automated collections (3.2 vs. 2.9 per 10,000 donations, respectively). CONCLUSION: The ARC data describe the current risks of blood donation in a model multicenter hemovigilance system using standardized definitions and reporting protocols. Reported reaction rates varied by regional center independently of donor demographics, limiting direct comparison of different regional blood centers.     

Randomized placebo-controlled study of oral calcium carbonate supplementation in plateletpheresis: II. Metabolic effects

BACKGROUND: The metabolic effects of oral calcium (Ca) supplementation during plateletpheresis were evaluated in a randomized, placebo-controlled trial. STUDY DESIGN AND METHODS: Twenty-three donors underwent four plateletpheresis procedures each, receiving in random order, elemental Ca (Ca) 1 or 2 g orally, or a corresponding placebo, 30 minutes before donation. Ten of these donors underwent a fifth procedure using a 4-g Ca dose. All procedures were performed at a fixed citrate infusion rate of 1.5 mg per kg per minute. RESULTS: Oral Ca induced dose-sensitive changes in parathyroid hormone (iPTH), total (tCa), and ionized (iCa) calcium levels. Compared to placebo, the greatest improvement in tCa and iCa levels occurred after the 2-g Ca dose (tCa of 73, 89, and 25% above placebo levels at 60 min, using 1, 2, and 4 g of oral Ca, respectively). Twenty-four hours after apheresis, serum tCa and iCa levels were higher, and iPTH levels lower, in donors who received oral Ca rather than placebo. Marked increases in urinary Ca and magnesium (Mg) excretion occurred at the completion of apheresis, were unaffected by Ca dose, and returned to baseline within 24 hours. Plateletpheresis also induced significant changes in serum alkaline phosphatase, 1,25-dihydroxyvitamin D, and osteocalcin levels immediately and at 24 hours after apheresis. CONCLUSION: Plateletpheresis induces marked acute metabolic effects, with sustained changes evident up to 24 hours after the completion of apheresis. Oral Ca supplementation exerts a significant but clinically modest impact on selected laboratory variables associated with these effects. Further studies are indicated to examine the long-term impact of plateletpheresis, with or without Ca supplementation, on donor Ca balance and bone density.     

Impact of a transfusion-related acute lung injury reduction strategy on apheresis platelet collections

Background: Most blood centers in the US have implemented transfusion‐related acute lung injury (TRALI) mitigation strategies for apheresis platelet (AP) donations based on theoretical impact of donor loss. The aim of this study is to determine the actual impact of a TRALI mitigation strategy in a US blood center. Study Design and Methods: Daily collection events and resulting products were retrospectively obtained before and after implementation of a TRALI reduction strategy (HLA antibody testing female AP donors four or more pregnancies) for comparison. The retention rate of reassigned donors was determined by reviewing whole blood (WB) and/or apheresis red blood cell (AR) donations post reassignment. Data were obtained to compare donor frequency and split rate from reassigned (historical data) and new AP donors. Results: Mean daily collections (27.7 vs. 30.0) and total products (12,211 vs. 12,957) were significantly higher after implementation, but the number of products/collection event was lower (1.49 vs. 1.40). Mean collections/donor/year (4.0 vs. 1.8) and split rate (36% vs. 27%) were historically higher for reassigned (n = 45) versus new AP donors (n = 1,090). Seventy‐three of 112 donors (65%) testing positive for HLA antibodies returned for WB or AR donations, 31 of 45 (69%) active AP donors returned. Conclusions: Donor loss may not be adequate to estimate impact on AP inventory, as donation characteristics may differ between new donors and those reassigned. We show successful implementation of a TRALI mitigation strategy by increasing collection goals and AP donor recruitment efforts beyond donor loss. Retaining the majority of reassigned donors is feasible. J. Clin. Apheresis 2012. © 2012 Wiley Periodicals, Inc.     

Efficacy of Fenwal Amicus blood cell separator in double dose platelet collection.

BACKGROUND: The aim of this retrospective study was to document our double dose platelet collection experience using the Fenwal Amicus (version 2.51) continuous flow apheresis device and to obtain information on the donors selected for this device. MATERIALS AND METHODS: Between January and December 2004, double dose collection procedures were performed on a total of 479 donors (474 male and 5 female). Donors with a pre-procedure platelet count 225 x 10(9) L(-1) and body weight of 63 kg were directed to the Fenwal Amicus for double dose platelet collection (> 6.0 x 10(11)). RESULT: More than 500 procedures were performed. Four hundred and seventy-nine procedures were included in this evaluation. 21 procedures were not included either because the procedures were not completed due to a donor reaction or lack of data. In 289 of 479 (60.3%) donors, double dose collection was achieved. The average leukocyte contamination was 0.31 x 10(6) in 22 randomly selected products. CONCLUSIONS: The cost of platelet apheresis can be reduced by directing donors with high pre-platelet counts to suitable double dose collection devices in blood centers.     

Volunteer donor apheresis.

Volunteer donor apheresis has evolved from early plasmapheresis procedures that collected single components into technically advanced multicomponent procedures that can produce combinations of red blood cells, platelets, and plasma units. Blood collection and utilization is increasing annually in the United States. The number of apheresis procedures is also increasing such that single donor platelet transfusions now exceed platelet concentrates from random donors. Donor qualifications for apheresis vary from those of whole blood. Depending on the procedure, the donor weight, donation interval, and platelet count must be taken into consideration. Adverse effects of apheresis are well known and fortunately occur in only a very small percentage of donors. The recruitment of volunteer donors is one of the most challenging aspects of a successful apheresis program. As multicomponent apheresis becomes more commonplace, it is important for collection centers to analyze the best methods to recruit and collect donors.     

Characterization and functional analysis of granulocyte concentrates collected from donors after repeated G-CSF stimulation

BACKGROUND: Neutropenic patients often develop bacterial or fungal infections not responding to broad-spectrum antibacterial or antifungal agents. Clinical efforts were made with transfusion of granulocyte concentrates; however, functions of granulocytes after multiple G-CSF stimulations and after apheresis are not yet investigated and described sufficiently. STUDY DESIGN AND METHODS: The aim of this study was to characterize functional and immunologic variables of granulocytes in blood samples drawn from donors before and after each stimulation episode with G-CSF, in the resulting granulocyte concentrates and in the patients 8 hours after transfusion. RESULTS: Chemotaxis was not influenced, neither by G-CSF application nor by apheresis. Multiple G-CSF stimulations enhanced oxidative burst and phagocytosis of Escherichia coli in donor granulocytes. These values returned to basal levels in granulocyte concentrates. Expression of granulocytic surface antigens was downregulated after application of G-CSF but returned to normal and in part enhanced values in concentrates. A clinically relevant increase of proinflammatory cytokines could not be detected. Leukotriene B4 production was reduced after the fourth G-CSF stimulation in the donor blood and enhanced in the granulocyte concentrate after apheresis. Results in recipients indicate that changes of granulocyte function noted in concentrates were only transient. CONCLUSION: Stimulation of healthy donors with repeated G-CSF injections and subsequent granulocyte apheresis does not dramatically change decisive functions of granulocytes.     

The future of automated red blood cell collection.

Automated red blood cell (RBC) collection is a newer but well-established form of donor apheresis. The technologies comprising and supporting apheresis have undergone significant advancements through the past 50 years, and we anticipate further improvements in devices and systems for automated RBC collection. Multiple factors must be considered in implementing automated RBC collections, but these procedures provide a way to draw additional RBC products that meet cGMP, regulatory, blood collector economic and donor objectives while maintaining or improving RBC availability. The continuing need for RBCs, accompanied by shrinking donor availability, would indicate that automated RBC collections will grow.     

Allogeneic blood progenitor cell collection in normal donors after mobilization with filgrastim: the M.D. Anderson Cancer Center experience

BACKGROUND: Information on the safety and efficacy of allogeneic peripheral blood progenitor cell (PBPC) collection in filgrastim-mobilized normal donors is still limited. STUDY DESIGN AND METHODS: The PBPC donor database from a 42-month period (12/94-5/98) was reviewed for apheresis and clinical data related to PBPC donation. Normal PBPC donors received filgrastim (6 microg/kg subcutaneously every 12 hours) for 3 to 4 days and subsequently underwent daily leukapheresis. The target collection was > or =4 x 10(6)CD34+ cells per kg of recipient's body weight. RESULTS: A total of 350 donors were found to be evaluable. Their median age was 41 years (range, 4-79). Their median preapheresis white cell count was 42.8 x 10(9) per L (range, 18.3-91.6). Of these donors, 17 (5%) had inadequate peripheral venous access. Leukapheresis could not be completed because of apheresis-related adverse events in 2 donors (0.5%). Of the 324 donors evaluable for apheresis yield data, 221 (68%) reached the collection target with one leukapheresis. The median CD34+ cell dose collected (first leukapheresis) was 462 x 10(6) (range, 29-1463).The main adverse events related to filgrastim administration in donors evaluable for toxicity (n = 341) were bone pain (84%), headache (54%), fatigue (31%), and nausea (13%). These events were rated as moderate to severe (grade 2-3) by 171 (50%) of the donors. In 2 donors (0.5%), they prompted the discontinuation of filgrastim administration. CONCLUSION: PBPC apheresis for allogeneic transplantation is safe and well tolerated. It allows the collection of an "acceptable" PBPC dose in most normal donors with one leukapheresis, with minimal need for invasive procedures.     

Collection of peripheral blood progenitor cells with an automated leukapheresis system

BACKGROUND: Apheresis devices designed for the collection of mature blood elements are being used for the collection of peripheral blood progenitor cells (PBPCs).The collection of PBPCs differs from that of other cells in the rarity of the target cell and in the fact that donors may undergo several days of collection. A consequence of this process may be a depletion of blood cells such as platelets from the blood. The disposable set and operating software for an apheresis device (Spectra, COBE BCT) was modified by the manufacturer to automate the collection of PBPCs and reduce the collection of unwanted blood cells. STUDY DESIGN AND METHODS: A study was initiated to compare the collection of PBPCs with the new device, the AutoPBSC (version [V]6.0 with AutoPBSC tubing set), and that with the MNC (mononuclear cell) procedure (V4.7 with white cell tubing set), for patients and healthy donors. RESULTS: Patients whose blood was processed by either theV6.0 orV4.7 procedure achieved the target dose of 5 x 10(6) CD34+ cells per kg of patient weight in similar numbers of procedures, even though the calculated collection efficiency for CD34+ cells using the automated V6.0 procedure was significantly less than that with the V4.7 procedure for both allogeneic donors and patients donating PBPCs. The collection efficiency for platelets was lower with the V6.0 procedure, and components collected in this manner contained fewer platelets. Apheresis by the V6.0 procedure required 30 to 60 more minutes per procedure than apheresis by the V4.7 procedure. Review of engraftment kinetics after transplantation did not reveal any effect of the collection procedure on recipients of either allogeneic or autologous transplants. CONCLUSION: The collection efficiencies of the V6.0 procedure for both CD34+ cells and mature blood cells are lower than those of the V4.7 procedure.The lower collection efficiency for platelets results in a smaller drop in peripheral blood platelet count after the procedure.The automated features of the V6.0 procedure may simplify PBPC collection, but this procedure requires a longer apheresis.     

Factors affecting mobilization of CD34+ cells in normal donors treated with filgrastim

BACKGROUND: Multiple days of apheresis are required for some normal peripheral blood progenitor cell (PBPC) donors, to ensure a sufficient collection of CD34+ cells for allografting. It would be of practical value to be able to identify the patients with poor mobilization on the basis of simple pretreatment clinical or hematologic variables. STUDY DESIGN AND METHODS: Clinical characteristics and laboratory data for 119 normal PBPC donors who underwent apheresis on Days 4 to 6 of treatment with granulocyte-colony-stimulating factor (filgrastim) were analyzed for correlations with CD34+ cell yield from the first day of apheresis. RESULTS: The CD34+ cell yield was significantly lower in donors who were more than 55 years of age, who underwent apheresis on Day 4 of filgrastim therapy, or who were not obese. There were weak direct correlations between CD34+ cell yield and the baseline white cell count, preapheresis white cell count, and preapheresis mononuclear cell count, and there was a weak inverse correlation with age. Twenty- one donors (18%) were considered to have poor mobilization (< 20 × 10(6) CD34+ cells/L blood processed). In the multivariate analysis, the only significant factor was age greater than 55 years, which conferred a 3.8 times greater risk (95% CI, 1.1-13.7) of poor mobilization (p = 0.04). However, poor mobilization occurred in all age groups, so the predictive value of the model was low. CONCLUSION: Donor variables correlated with CD34+ cell yield only weakly, so no particular clinical characteristic can be used to exclude an individual as a PBPC donor if he or she is otherwise suitable for the apheresis procedure.