Comparison of plateletpheresis with a standard and an improved collection device

A blood cell separator with a specialized separation chamber ([TNX-6]CS- 3000 Plus) was developed for the collection of platelet concentrates with higher platelet yields and lower white cell contamination than obtained with the standard blood cell separator (CS-3000). To compare these devices, normal donors were scheduled for paired plateletpheresis procedures spaced 4 weeks apart, with one procedure using the CS-3000 Plus and the other using the CS-3000. Overall, the platelet yield per unit (mean +/− SEM) was 4.3 +/− 0.1 × 10(11) with the CS-3000 Plus versus 3.7 +/− 0.1 × 10(11) with the CS-3000 (p < 0.001), and the white cell contamination per unit (mean +/− SEM) with the former was 2.4 +/− 0.7 × 10(6) versus 84.1 +/− 21.1 × 10(6) with the latter (p < 0.001). The sequence of procedures (i.e., the order in which the devices were paired) was selected randomly, and similar results were found regardless of sequence. When donors with predonation platelet counts of > or = 200 × 10(9) per L (n = 21) were studied separately, 76 percent of the collections by the CS-3000 Plus contained > or = 4 × 10(11) platelets versus 34 percent of those by the CS-3000 (p < 0.01), and 93 percent of the collections by the former contained < 5 × 10(6) white cells (69% contained < 1 × 10(6)) versus 0 percent of those by the latter (p < 0.01). Thus, platelet collections with the TNX-6 chamber consistently demonstrated high platelet yields and strikingly low white cell contamination–qualities that justify converting standard devices to devices with a TNX-6 chamber.     

Comparison of plateletpheresis using two cell separators and identical donors

For prospective comparison of product yield and volume, collection efficiency, white cell (WBC) and red cell (RBC) contamination, donor acceptability, and staff acceptance, each of 31 donors underwent plateletpheresis on two different cell separators (the Fenwal CS-3000 and the COBE Spectra). The same operator performed the paired procedures and collected all study data. The instruments provided equivalent high-yield platelet products (CS-3000: 5.3 x 10(11); Spectra: 5.7 x 10(11]. Platelet collection efficiency was greater with the Spectra (81%) than with the CS-3000 (57%) (p less than 0.0005). All products contained less than 1 mL of RBCs, but the Spectra products were more likely to contain less than 10(6) WBCs (14/31) than those of the CS-3000 (1/31) (p less than 0.001). In the remaining products, the mean WBC contamination was 1.0 x 10(8) for the CS-3000 and 0.03 x 10(8) for the Spectra (p less than 0.001). More ACD-A anticoagulant was infused with Spectra (463 mL) than with CS-3000 procedures (400 mL) (p = 0.002). Although postdonation ionized calcium (Ca2+) levels and the percentage of decrease in Ca2+ were not significantly different between groups, more Spectra donors experienced symptoms of hypocalcemia (20/31 vs 9/31; p = 0.015). CS-3000 products had lower mean volumes (217 mL) than Spectra collections (300 mL) (p less than 0.0005). Both instruments were accepted well by volunteer donors and the technical staff.     

Comparison of intermittent- and continuous-flow cell separators for the collection of autologous peripheral blood progenitor cells in patients with hematologic malignancies

BACKGROUND: The transplantation of autologous peripheral blood progenitor cells (PBPCs) after high-dose chemotherapy is a valuable therapy for patients with hematologic and solid malignancies. Several methods are used for harvesting PBPCs. The efficiency of intermittent- and continuous-flow blood cell separators in collecting progenitor cells from the blood of patients undergoing myeloablative treatment for cancer was compared. STUDY DESIGN AND METHODS: PBPC components (n = 133) were obtained from 72 patients by leukapheresis with continuous-flow machines (Spectra, COBE; CS 3000 Plus, Baxter) and with an intermittent-flow machine (MCS 3P, Haemonetics). The data were analyzed retrospectively. Blood samples obtained from the patients before leukapheresis and samples of the leukapheresis components themselves were analyzed for their content of RBCs, WBCs, platelets, and CD34+ cells. RESULTS: The Spectra processed more than twice the blood volume in the shortest time (15 L in 178 min), whereas the Baxter CS 3000 Plus (10 L in 185 min) and the MCS 3P (4.8 L in 239 min) processed significantly smaller volumes in a longer time. The mean ACD consumption was 403 mL with the MCS 3P, 900 mL with the CS 3000 Plus, and 1000 mL with the Spectra. The product volumes were 50 mL (CS 3000 Plus), 69 mL (MCS 3P), and 166 mL (Spectra). In all groups, differences in the preapheresis hemograms were not significant, but the Spectra group had fewer CD34+ cells than the other groups. Despite this, the differences in the number of CD34+ cells in the leukapheresis components of all groups were without statistical significance. In the Spectra group, the collection of MNCs of 104 percent and CD34+ cells of 154 percent was significantly more efficient than that in the MCS 3P group (42.2% and 56%, respectively) or the CS 3000 Plus group (50.8% and 47.15%) as related to the patients' blood volume. CONCLUSION: PBPC collection can be performed successfully with continuous-flow and intermittent-flow blood cell separators. The Spectra had the best recovery of CD34+ cells within the shortest time. Leukapheresis with the MCS 3P is indicated if only a single venous access is available.     

In vitro collection and posttransfusion engraftment characteristics of MNCs obtained by using a new separator for autologous PBPC transplantation

BACKGROUND: A clinical study was performed to evaluate the peripheral blood progenitor cell (PBPC) collection, transfusion, and engraftment characteristics associated with use of a blood cell separator (Amicus, Baxter Healthcare). STUDY DESIGN AND METHODS: Oncology patients (n = 31) scheduled for an autologous PBPC transplant following myeloablative therapy were studied. PBPCs were mobilized by a variety of chemotherapeutic regimens and the use of G-CSF. As no prior studies evaluated whether PBPCs collected on the Amicus separator would be viable after transfusion, to ensure patient safety, PBPCs were first collected on another cell separator (CS-3000 Plus, Baxter) and stored as backup. The day after the CS-3000 Plus collections were completed, PBPC collections intended for transfusion were performed using the Amicus instrument. For each transplant, >2.5 x 10(6) CD34+ PBPCs per kg of body weight were transfused. RESULTS: Clinical data collected on the donors immediately before and after PBPC collection with the Amicus device were comparable to donor data similarly obtained for the CS-3000 Plus collections. While the number of CD34+ cells and the RBC volume in the collected products were equivalent for the two devices, the platelet content of the Amicus collections was significantly lower than that of the CS-3000 Plus collections (4.35 x 10(10) platelets/bag vs. 6.61 x 10(10) platelets/bag, p<0.05). Collection efficiencies for CD34+ cells were 64 +/- 23 percent for the Amicus device and 43 +/- 14 percent for the CS-3000 Plus device (p<0.05). The mean time to engraftment for cells collected via the Amicus device was 8.7 +/- 0.7 days for >500 PMNs per microL and 9.7 +/- 1.5 days to attain a platelet count of >20,000 per microL-equivalent to data in the literature. No CS-3000 Plus backup cells were transfused and no serious adverse events attributable to the Amicus device were encountered. CONCLUSIONS: The mean Amicus CD34+ cell collection efficiency was better (p<0.05) than that of the CS-3000 Plus collection. Short-term engraftment was durable. The PBPCs collected with the Amicus separator are safe and effective for use for autologous transplant patients requiring PBPC rescue from high-dose myeloablative chemotherapy.     

Plateletapheresis: Comparison of processing times,platelet yields,and white blood cell content with several commonly used systems

In this study we compare processing times and platelet yields of eight systems: five double-needle (DN)—Fenwal CS3000 Plus with interface offset (IO) of 6 (Fen 6) and IO of 10 (Fen 10), a prototype Fenwal Amicus (AM-DN), Spectra version 4 (Spec 4-DN) and version 5 with leukoreduction system (Spec 5-LRS); and three single-needle (SN) systems—Haemonetics MCS Plus (MCS+), prototype Amicus (AM-SN), and Spectra version 4 (Spec 4-SN). Twenty-five procedures from each of the systems (except AM-SN, N = 13) were compared; each system had comparable preprocedure platelet counts and similar endpoints. Five systems—MCS+, Fen 6, Fen 10 with leukoreduction filter (MCS + LRF), (Fen 6 LRF), (Fen 10 LRF), as well as AM-DN, and Spec 5-LRS—were compared for WBC content. P-selectin expression was compared in the MCS+; Fen-10 with A-35 (Fen 10-A35) and PLT-30 (Fen 10-PLT30) collection chambers; Spec 4-DN; and platelet-rich plasma. We found AM-DN (63 ± 16 min) had a significantly lower average processing time than all other systems except AM-SN. Spectra 4-DN (5.6 ± 1.7 × 10¹¹ Plt) produced significantly more platelets and had a significantly higher incidence of products ⩾6.0 × 10¹¹ (56%) and higher incidence of products ⩾6.6 × 10¹¹ Plt (32%) than all other systems. AM-DN (0.073 ± 0.017 × 10¹¹ Plt/min) had a significantly higher collection rate than all other systems except AM-SN. The WBC content comparison indicated MCS+ with a filter; and AM-DN and Spectra 5-LRS without filters were capable of consistently (99.32–100%) producing products with <5 × 10⁶ WBC, but were less consistent (86.36–99.26%) at <1 × 10⁶ WBC. MCS+ and Fen 10-PLT30 had significantly (p < .05) less p-selectin expression than all other systems but not between each other. From the data in this study, if leukoreduced platelets were needed in the shortest processing time, the first and second choices would be Amicus-DN and Spectra 5-LRS, respectively. J. Clin. Apheresis 12:170–178, 1997. © 1997 Wiley-Liss, Inc.     

Collection of peripheral blood mononuclear cells as a byproduct of plateletpheresis with two different blood cell separators

Peripheral blood mononuclear cells (PBMC) were collected as a byproduct of plateletpheresis of normal blood cell donors using modifications to standard automated protocols on either the CS-3000 or Spectra blood cell separator machine. Comparison of the PBMC products obtained showed X ± SD WBC yields of 5.3 ± 3.4 vs. 3.8 ± 2.0 × 10⁹ with the CS-3000 and Spectra, respectively (P < .0001). The majority of the cells were lymphocytes, with 13–15% monocytes with both machines. Sixteen percent of the WBC collected with the Spectra, but only 1% of those collected with the CS-3000, were granulocytes. The CS-3000 PBMC product contained fewer RBC (0.2 ± 0.1 × 10¹¹ vs. 2.4 ± 0.6 × 10¹¹) and more platelets (1.6 ± 0.6 × 10¹¹ vs. 0.35 ± 0.39 × 10¹¹) in a smaller volume (40 ± 14 ml vs. 229 ± 37 ml) than the Spectra products. Comparison of the platelet collections harvested when PBMC were also collected to platelets harvested using standard procedures on the same machine showed no change in platelet. WBC, or RBC yields for the Spectra. A significant increase in mean WBC contamination from 40 ± 56 × 10⁷ to 112 ± 205 × 10⁷ and a small, but statistically insignificant, decrease in platelet yield from 4.1 ± 1.2 × 10¹¹ to 3.9 ± 1.8 × 10¹¹ was observed in the CS-3000 platelet collections when PBMC were harvested. There was no sustained change in donor lymphocyte counts and no change in acute donor side effects or time requirements when PBMC were collected. The procedural modifications were easily learned by multiple operators, and required about 15 and 5 min additional operator time on the CS-3000 and Spectra, respectively. Thus, harvest of large numbers of PBMC as a byproduct of plateletpheresis can be readily accomplished with either of 2 different blood cell separator machines. The cells obtained have been useful for a variety of purposes in both clinical hospital and basic research laboratories. © 1992 Wiley-Liss, Inc.     

Comparison of COBE white cell-reduction and standard plateletpheresis protocols in the same donors

BACKGROUND: It is necessary to protect patients from white cell (WBC)- caused side effects of platelet transfusion by reducing the WBC contamination in single-donor platelets. STUDY DESIGN AND METHODS: A new COBE Spectra WBC (leuko)-reduction system (LRS) was compared to the COBE standard plateletpheresis (standard) procedure. Each of 62 donors underwent plateletpheresis under the two protocols (LRS and standard). The collection efficiency and WBC contamination in the components collected using the techniques were compared. Platelets were counted in a cell counter and WBCs were counted using two full grids of a Nageotte chamber. RESULTS: The preseparation and postseparation numbers for red cells, WBCs, and platelets as well as the number of collected platelets were not different in the two techniques. Collection efficiency in the LRS procedures was 96.2 +/− 13.0 percent of that in the standard procedures. Median WBC contamination in the platelet components was 10,160 per LRS procedure and 56,500 per standard procedure. The purity of the LRS components was significantly improved (p = 0.001), as seen in a comparison of the WBC numbers in components per procedure after log10 transformation (LRS: 0.096 +/− 0.195 × 10(6); standard: 0.390 +/− 1.075 × 10(6)). CONCLUSION: These data suggest that the LRS procedure produces platelet concentrates with a collection efficiency that is comparable to that obtained with the standard technique and with a residual WBC content that satisfies even the most stringent criteria for filtered platelets. As this purity can be achieved without platelet loss or alteration, conventional fiber filtration no longer seems necessary or useful in this type of single-donor platelet component.     

WBC subset analysis of WBC-reduced platelet components

BACKGROUND: WBC-reduced platelet components may be prepared by filtration or apheresis processing. Both methods have previously been shown to result in a residual total WBC content <5 x 10(6) per component. However, there may be differences in the efficacy of these techniques for removing certain WBC subsets. STUDY DESIGN AND METHODS: Two multiparameter flow cytometric assays were developed and validated to perform WBC analysis on WBC-reduced platelets collected with two apheresis instruments (Amicus and COBE Spectra) and on 6 units of filtered pooled random-donor platelet concentrates. RESULTS: All components contained <1 x 10(5) WBCs. The COBE Spectra and Amicus apheresis platelet components contained more WBCs than did filtered pooled platelets (p<0.05). Lymphocytes (T and B), monocytes, and granulocytes were identified in all components. Granulocyte content was lowest in the Amicus components and filtered pools. Monocytes were lowest in filtered pools. Amicus platelet components had fewer granulocytes and monocytes than the COBE Spectra platelets. Amicus and COBE Spectra components contained more lymphocytes than the filtered pools. CONCLUSION: Multiparameter flow cytometry can be used to quantify and characterize WBCs in WBC-reduced platelet components. WBC reduction by filtration or apheresis was highly effective. WBCs from each subset were identified in all components. Although filtered pools had the lowest numbers of WBCs, the very low numbers observed in all components suggests that the absolute quantitative differences in WBC subset content are of questionable clinical significance.     

Evaluation of the Amicus Separator in the collection of apheresis platelets

BACKGROUND: A new apheresis instrument, the Amicus Separator with software versions 2.13 and 2.34, was evaluated for component yields, collection efficiency, and incidence of donor and transfusion recipient reactions. The Amicus was also compared to the Spectra Leukocyte Reduction System (LRS) with version 5 software. STUDY DESIGN AND METHODS: Single and double apheresis platelets (APs) were collected at two locations. The targeted platelet yields were 4.0 × 10(11) for single APs and 6.8 × 10(11) for double APs. One location used a double- needle procedure, and the other used a single-needle procedure. Along with 28 of the Amicus procedures (14 at each of two locations), the same donors underwent single or double AP collections on the Spectra LRS. APs were tested for platelet yields and residual white cells. APs were transfused in three hospitals. Donor and transfusion recipient reactions and technical problems were documented. RESULTS: The Amicus Separator efficiently collected single APs (n = 59) and double APs (n = 62) with mean platelet yields of 4.2 × 10(11) and 6.5 × 10(11), respectively. When inlet line alarms occurred in single-needle procedures, platelet yields were lower and collection times were longer. All APs were white cell-reduced below 5.0 × 10(6), and all but one AP were white cell-reduced below 1.0 × 10(6) without filtration. Component yields from the paired Amicus and Spectra LRS procedures were comparable. Collection times (excluding reinfusion/rinseback) were 20 to 23 minutes faster on the Amicus Separator. No serious donor or transfusion recipient reactions occurred. CONCLUSION: The Amicus Separator provided satisfactory platelet yields and collection efficiency, with shorter collection times than did the Spectra LRS, and it white cell-reduced components without filtration.     

Comparison of CD34+ cell collection on the CS-3000+ and Amicus blood cell separators

BACKGROUND: Mobilized PBPCs, detectable on the basis of CD34 expression, can be collected on various cell separators. The CD34+ cell collection efficiencies of two cell separators (CS-3000+ and Amicus, Baxter) were tested on two comparable groups of oncology patients. STUDY DESIGN AND METHODS: Leukapheresis assisted by the standard manufacturer's software and variables settings was performed in 37 (CS-3000+) and 34 (Amicus) patients (total of 83 and 67 collections, respectively) after chemotherapy plus G-CSF treatment. RESULTS: The total CD34+ cell count per leukapheresis components as well as per kg of patient's body weight were twofold higher by using the Amicus than the CS-3000+ device. Platelet contamination in Amicus components was twice as low compared to the CS3000+. Mean Amicus CD34+ collection efficiency (CD34+eff) (54.9 +/- 27.2%) was significantly higher (p < 0.015) than the CS-3000+ (46.4 +/- 16.7%) one. However, Amicus CD34+eff decreased progressively as the peripheral blood CD34+ concentrations increases over 200 CD34+ cells per microL. A parallel increase in the WBC counts in these cases seems to be the principal cause of decrease in CD34+eff (evident for WBCs >40 x 10(3)/microL and most pronounced for WBCs >60 x 10(3)/microL). CONCLUSIONS: Mean CD34+eff and CD34+ cell yields were better on Amicus than on CS-3000+. CD34+eff of Amicus, however, seems to be related to the initial WBC counts, decreasing progressively when WBC increased over 4 x 10(3) per microL that coincided with the increase in CD34+ cell concentrations. For these cases, the volume and duration of cycles should be adapted to optimize CD34+ collections by using Amicus separators.     

Comparison of a new WBC-reduction system and the standard plateletpheresis protocol in the same donors

BACKGROUND: A cell separator (Spectra, Gambro BCT) with an integrated leukoreduction system (LRS) for producing WBC-reduced single-donor platelet concentrates has been shown to result in a slightly reduced collection efficiency as compared to the former Spectra system without LRS. A novel modified system for improved collection efficiencies (LRS Turbo, Gambro BCT) was evaluated. STUDY DESIGN AND METHODS: Each of 37 donors underwent plateletpheresis using the LRS Turbo (LRS-T) and the standard LRS (LRS) of the Spectra cell separator. The collection efficiency and WBC contamination of the different techniques were compared. Platelets were counted automatically and WBCs were counted by using one or two full grids of a Nageotte chamber. RESULTS: The preseparation and postseparation numbers of RBCs, WBCs, and platelets, as well as the number of collected platelets, did not differ for the two techniques. In the LRS-T separations, the collection efficiency was 112 percent of that in the LRS procedures. Median residual WBCs in the platelet components were 0.0256 x 10(6) per LRS-T procedure and 0.0253 x 10(6) per LRS procedure. The purity of the LRS-T components was not less than that of the standard LRS components, whereas the collection efficiency of the LRS-T was significantly greater, 44.9 percent versus 40.7 percent. CONCLUSIONS: The LRS-T procedures produced platelet concentrates with WBC-reduction capacity that is comparable to that obtained with the standard LRS procedures, which have previously been described as satisfying the most stringent criteria for WBC-reduced platelets. The new technique significantly improved the collection efficiency of the plateletpheresis procedure.     

PLT-30: An improvement for platelet collection on the baxter CS-3000 plus

The CS-3000 is a well-established blood cell separator. To increase the efficiency of platelet collection, Baxter developed a new separation chamber, the TNX-6, for the follow-up model of the CS-3000, the CS-3000 Plus. To reduce the occurrence of platelet aggregates and to increase platelet yield and efficiency the collection chamber A-35 has been replaced by a new, volume-reduced chamber called PLT-30. We analyzed on the basis of 201 platelet separation procedures with the CS-3000 Plus fitted with both new chambers the efficiency of platelet collection. The platelet yield per unit (mean ± SE) was 4.55 × 10¹¹ M-1 0.07 × 10¹¹ and the efficiency was 50.79 ± 0.76%; only 3.98% of the platelet concentrates were below 3 × 10. To compare our data with results from the A-35 we enrolled 33 random donors (17 in Innsbruck, 16 in Vienna) in a controlled study. Using both chambers in a randomly selected sequence within a period of 1 month on each chamber, we evaluated platelet yield, efficiency, and the contamination with white blood cells (WBCs). We found a platelet yield per unit (mean ± SE) of 3.74 × 10n ±0.11 × 10¹¹ using the A-35 and of 4.4 × 10¹¹ ±0.21 × 10¹¹ with the new PLT-30 (P = .0001). The efficiency of the collecting process (mean ± SE) was higher with the PLT-30 (47.76 ±2.11 %)than with the A-35 (40.68 ± 1.29%). The difference is statistically significant (P= .0001). Comparing the contamination of the platelet concentrates with WBCs no significant differences could be found (P= .35). Our results demonstrate that the use of the new collection chamber PLT-30 in combination with the separation chamber TNX-6 significantly increases platelet yield and efficiency per unit, while no decrease of the contaminating WBCs could be obtained.     

A multicenter evaluation of the routine use of a new white cell- reduction apheresis system for collection of platelets

BACKGROUND: Residual white cells (WBCs) cause serious side effects in platelet transfusion. An in-line WBC-reduction system based on fluidized particle bed technology was recently developed as a modification of an existing plateletpheresis system. STUDY DESIGN AND METHODS: In an investigational phase, three flow profiles were evaluated using prototype software in five centers, each using their standard conditions. In the confirmatory phase, the released software was tested in three centers. WBCs were counted in two full Nageotte grids (dilution 1-in-5). RESULTS: With the prototype software, WBC levels were always below 1 × 10(6) per procedure (median, 25,000/procedure; n = 314). One profile proved to be superior to the other two with respect to platelet yield and residual WBCs, and it was incorporated in the released WBC-reduction system, together with a built-in process control. Median residual WBCs in these WBC-reduction system components not rejected by the process control were 19,000 per procedure (n = 211/225 total), with 99.5 percent of the platelet components having less than 1 × 10(6) WBCs. CONCLUSION: The protocol selected in the initial phase, now available as a WBC-reduction system, results in platelet concentrates with very low residual WBC levels. This satisfies even the most stringent criteria for WBC reduction in platelets, without the platelet loss typically seen with conventional fiber filtration.     

A randomized comparison of plateletpheresis with the same donors using four blood separators at a single blood center

At one blood center, each of 20 donors underwent plateletpheresis on four blood cell separators in random order. We compared the CS3000+, Amicus V 2.41, MCS Plus, and Spectra LRS V 7 Turbo regarding platelet (PLT) yield, pre- and post-procedure PLT counts, percent fall in donor PLT count, process time, efficiency, PLT product and donor PLT volume (MPV). Using >or= 150 x 10(9) PLTs/L pre-donation counts, a goal was set of 4.5 x 10(11) PLTs unit in up to 100 minutes processing time. Results were (mean values) PLT yields of Amicus, Spectra, CS3000+, and MCS Plus: 4.3, 4.6, 4.3, 4.0 x 10(11) PLTS, respectively; percent donor PLT fall: 24, 32, 30, 29%, respectively; processing times: 50, 74, 87, 101 minutes, respectively; relative efficiency (RE): 2.2, 1.6, 1.2,1.0, respectively (based on the MCS Plus performance with RE of 1 = 4 x 10(9) PLTS/min); PLT product MPV: 6.7, 7.4, 6.8,7.1 fL, respectively; pre-procedure donor MPV: 7.7, 7.3, 7.6 and 7.6 fL, respectively; and percent donor MPV change: -5.2, 0, -6.6, and -10%, respectively. Significant changes in the donor MPV were noted (P < 0.05) but could not be related to product MPV. Spectra seemed to collect larger PLTs (higher MPV); the significance remains unknown for both donors and recipients. Importantly, all four separators gave acceptable and comparable PLT yields (P < 0.05) with Spectra trending higher. The short process time and high RE together indicate highly efficient collections particularly by Amicus and Spectra.     

Automatic volumetric capillary cytometry for counting white cells in white cell-reduced plateletpheresis components

BACKGROUND: As the benefits of white cell (WBC)-reduced blood components become increasingly apparent, the need has arisen for a simple, automated WBC-counting technique that is sensitive to low WBC concentrations. Automated volumetric capillary cytometry was evaluated for its ability to quantify residual WBCs in WBC-reduced plateletpheresis components. STUDY DESIGN AND METHODS: The volumetric capillary cytometry system evaluated uses a laser to excite fluorescent dye-labeled nucleated cells. The number of nucleated cells per microliter is reported. Four studies were performed: linearity, precision of results near the value of 5 × 10(6) WBCs per unit, the limit of detection, and correlation to the Nageotte manual counting method. RESULTS: Assay values correlated to expected values (range, 0- 125 WBC/microliter) with an r2 > 0.99. In the range of 5 × 10(5) WBCs per unit the CV was 8.5 percent, and concentration differences of 0.15 log10 were detectable. The limit of detection was 1.0 WBCs per microliter (95% upper confidence limit). The assay correlated to the Nageotte method with an r2 of 0.98, slope of 1.0, and y-intercept of 2.0 WBCs per microliter. Assay results were 10 to 15 percent higher than Nageotte results, in samples with values near 5 × 10(6) WBCs per unit. Technician time per sample was 2 to 3 minutes. CONCLUSION: Volumetric capillary cytometry is precise and sensitive to small differences in WBC concentration in the range of clinical interest. The device provides an efficient new method for quality assurance and control of WBC-reduced plateletpheresis products.     

White cell reduction in platelet concentrates and packed red cells by filtration: a multicenter clinical trial. The Trap Study Group

BACKGROUND: Most previous studies on white cell (WBC) reduction by filtration have been small-scale studies conducted under tightly controlled laboratory conditions. Their results would be the ideal, rather than what might be expected during routine operation. STUDY DESIGN AND METHODS: To obtain information on routine filtration of blood components, data have been collected from a large-scale, ongoing, multicenter clinical trial designed to determine the effectiveness of WBC reduction in or ultraviolet B radiation of platelet concentrates before transfusion in preventing platelet alloimmunization and platelet transfusion refractoriness. The WBC content of blood components both before and after filtration was determined by automated cell counters and a manual propidium iodide-staining method, respectively. Platelet and red cell losses during filtration were measured. RESULTS: The average platelet losses after filtration were 24 +/? 15 percent and 20 +/? 9 percent for apheresis platelets and pooled platelets, respectively. The frequencies at which filtered platelet concentrates contained high levels of residual WBCs (> 5 × 10(6)) were 7 percent and 5 percent for apheresis platelets and pooled platelets, respectively. Further analysis of the platelet filtration data showed that greater numbers of total initial WBCs in the pooled platelets were associated with increased percentages of filtration failure (> 5 × 10(6) residual WBCs). For packed red cells, the average losses during filtration were 23 +/? 4 percent and 15 +/? 3 percent for CPDA-1 units and Adsol units, respectively. The frequencies at which filtered red cells contained > 5 × 10(6) residual WBCs were 2.7 percent for one type of filter and 0.3 percent for another type of filter. CONCLUSION: There were significant losses of platelets during filtration, which could add to the costs of WBC reduction and lead to possible increases in donor exposures. Filtration failures still occurred, despite careful observation of the standard filtration procedures. The number of total WBCs in pooled platelets before filtration has been identified as an important factor in determining the success of WBC reduction.     

Validation of use of the Nageotte hemocytometer to count low levels of white cells in white cell-reduced platelet components

BACKGROUND: Determination of the white cell (WBC) count in WBC-reduced platelet components requires methods that have a detection limit in the range of approximately 5.0 × 10(2) to 5.0 × 10(4) per mL. STUDY DESIGN AND METHODS: With a 50-microL Nageotte hemocytometer and bright-field microscopy (200x magnification), studies were conducted to develop and validate a method that could be used routinely with filtered and apheresis-harvested platelets. A 1-in-5 dilution of sample with a commercially available blood-diluting fluid was used because, with a lower (1-in-2) dilution, the observed number of WBCs was substantially less than the number expected at relatively high platelet counts (> 1.9 × 10(9)/mL). RESULTS: The observed and expected WBC counts in WBC- reduced platelet samples correlated well at levels between approximately 5 and 1100 WBCs per counting area (5.0 × 10(2)-1.1 × 10(5)/mL). At levels of more than 300 to 400 WBCs per counting area, accurate counts were obtained when 10 of the 40 rectangles were counted. CONCLUSION: These studies provide data to confirm that the 50- microL Nageotte hemocytometer can be used to accurately count low levels of WBCs in platelet components.     

Peripheral blood stem cell collection with a blood cell separator

Forty-three patients with malignant nonmyeloid diseases underwent peripheral blood stem cell collections on an apheresis system (Spectra, COBE BCT, Lakewood, CO). Collections took place during the white cell (WBC) recovery phase following conditioning chemotherapy. One hundred two procedures were done after chemotherapy alone, and 72 procedures after chemotherapy plus granulocyte-colony-stimulating factor (G-CSF). Four centrifugal separation factors were tested. One and one-half patient blood volumes were processed in each procedure. The mean volume of the collected component was 158 +/− 16 mL. After chemotherapy alone, the procedures provided a mean of 0.8 × 10(8) WBCs per kg and 2.3 × 10(4) colony-forming units-granulocyte macrophage (CFU-GM) per kg of recipient body weight. The mononuclear cell percentage in the components increased with the centrifugal separation factor from 85 to 96 percent. In parallel, platelet contamination increased from 2.1 to 3.8 × 10(11). The collect hematocrit ranged from 1.0 to 2.5 percent (0.01-0.025). The collection efficiency for mononuclear cells and CFU- GM also increased with the centrifugal separation factors from 52 to 70 percent for mononuclear cells and from 55 to 68 percent for CFU-GM. Collections performed after G-CSF-stimulated mobilization were characterized by a higher neutrophil contamination independent of centrifugal separation factor, which gave a mean mononuclear cell percentage of 64 percent in the collected component. The average yield for these procedures was 2 × 10(8) WBCs per kg and 28 × 10(4) CFU-GM per kg.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of two continuous-flow cell separators

Two blood processors (IBM 2997 and Fenwal CS-3000) were evaluated under similar conditions. Fifty-four leukapheresis procedures with the 2997 resulted in a mean granulocyte yield of 19.4 X 10(9) (42.5% efficiency), with a mean of 2.1 X 10(11) platelets (10.9% efficiency) per product. The CS 3000, at a whole blood flow rate of 50 ml/min, yielded a mean of 13.3 X 10(9) granulocytes (39.2% efficiency) and 4.0 X 10(11) platelets (28.5% efficiency) during 63 leukapheresis procedures. At a flow rate of 60 ml/min, the mean yields of 20 leukapheresis procedures with the CS 3000 were 14.2 X 10(9) granulocytes (30.5% efficiency) and 4.3 X 10(11) platelets (27.8% efficiency). Thirty-four plateletpheresis procedures with the 2997 yielded a mean of 3.62 X 10(11) platelets (53.12% efficiency), and 2.70 X 10(9) white cells. The mean CS-3000 yield for 88 plateletpheresis procedures was 3.15 X 10(11) platelets (49.13% efficiency) with a mean white cell content of 0.67 X 10(9). Granulocyte yields with the 2997 were greater than those obtained with the CS-3000.