Current topics on centrifugal plasmapheresis technologies.

In the field of plasmapheresis centrifugal technology has recently focused on the collection of peripheral blood stem cells (PBSCs) for both autologous and allogeneic transplantation in patients with malignancies or hematological diseases and on donor plasmapheresis. PBSC transplantation is rapidly replacing bone marrow transplantation in such patients. Various kinds of apheresis equipment were applied and described for PBSC collection. Comparison among machines is described. Allogeneic PBSCs were collected from healthy normal donors. Specific attention to the dose and administration duration of granulocyte colony-stimulating factor and a careful apheresis procedure should be made for donor safety. In platelet transfusion practice, a platelet concentrate product derived plateletpheresis from a single donor is preferable to minimize and to prevent adverse transfusion reactions. The status of platelet collection and its efficacy by various kinds of plateletpheresis equipment are discussed. The Amicus and CCS might be preferable plateletpheresis machines because of their collection efficiencies and wider indication for donors. With the limited number of donors, it is essential that plateletpheresis should be more effectively performed and managed by each regional blood center. The status of plasma and red cell collection by apheresis technologies is described also briefly.     

How do we collect better granulocyte?

We studied retrospectively the factors affecting the product quality in 459 donor granulocyte apheresis procedures from 420 donors for 71 neutropenic patients from 2004 to 2010 in a single center. The counts of the granulocyte and platelet collected were measured to evaluate the product quality. The data was analyzed to determine a possible relationship between product quality and several parameters including gender, preleukapheresis neutrophil count, type of anticoagulation and separator type and mode of the apheresis system. We found that collection of better granulocyte is possible from a donor in a single procedure by changing anticoagulation type and separator mode during apheresis.     

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.     

Multicomponent collection as of 2005.

Multicomponent apheresis (MCA) begun in Genoa in 1985 in autologous terms. Named "sequestration" it was the preoperative collection of autologous components (RBC-plasma-platelets) using the same apparatus and harness ready for intraoperative blood salvage. In 1986 the technique was applied to donor platelet apheresis with the goal of reducing the costs of platelet collection and concurrently reducing the risks of viral disease transmission to haematological patients who did receive, in the same transfusion event, the necessary blood components obtained from the same donor. The results of this application were maximized by the so called aggressive MCA by which in selected donors, it is possible to collect 2 units of platelets along with 1 or 2 units of PRBCs. These applications were made possible by the development of the concept of dry-platelet collection according to which platelets are collected in only 20-25 mL of plasma and subsequently resuspended in non-plasma solutions such as T-Sol. A last development of MCC is for RBC apheresis, with the collection of 1-2 units of RBC independently of platelet collection. This is going to be the first step of apheresis as the unique modality of collecting blood leaving the bags to history of blood transfusion. Interestingly it took 15 years to MCC to be rediscovered and appreciated worldwide both for its intrinsic cost saving capabilities offered along with an increasing safety for patients. In terms of donor acceptance it is our experience that, since 1989 no donor has refused MCC, consisting at least in the concurrent collection of plasma along with platelets, but also RBC and or a second unit of platelets.     

Feasibility study on donor apheresis red cell and platelet simultaneous collection for blood center routine use.

This study was conducted to determine if single donor platelet and red cell simultaneous collection by apheresis technique can be applied to routine blood product collection at blood centers. Both apheresis red cell product and platelet product were successfully collected and mannitol, adenine, and phosphate (MAP) additive solution was added to the red cell concentrates during collection. During a 49 day storage study period, the red cell product quality was maintained and found to be equivalent to that of red cell products derived from whole blood collected by the traditional method. This study demonstrated the possibility of applying this collection method for routine use for single donor apheresis platelet product and red cell product preparation at blood centers.     

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.     

The impact of policies to restrict the use of plasma containing products and apheresis platelets from female donors to mitigate transfusion related acute lung injury (TRALI) in Brazil

Background and ObjectivesAlthough the incidence of TRALI is unknown in Brazil, some blood centers have adopted strategies to prevent TRALI. We evaluated the impact of three policies to mitigate TRALI on the supply of blood products: to divert the production of whole blood-derived plasma from female donors; to defer all female donors from apheresis platelet collections, and to defer only multiparous female donors from apheresis platelet collections.Materials and MethodsData from allogeneic whole blood and apheresis platelet donations from April 2008 to December 2009 were collected in three Brazilian blood centers and the impact of the aforementioned strategies was evaluated.ResultsOf 544,814 allogeneic blood donations, 30.8% of whole blood plasma and 24.1% of apheresis platelet donations would be reduced if only male donor plasma was issued for transfusion and all female donors were deferred from apheresis donation, respectively. If only multiparous donors were deferred from apheresis donation, there would be a 5% decrease of all apheresis platelet collections.ConclusionRestricting the use of whole blood derived plasma to male-only donors and deferring all female apheresis platelet donors would impact two out of three Brazilian blood centers. A deferral policy on multiparous apheresis platelet donors may be acceptable as a temporary measure, but may cause more stress on a system that is already working at its limit.     

Thrombin generation before and after multicomponent blood collection

BACKGROUND: Apheresis technology has made tremendous progress up to the development of automated blood component collection, which offers increased efficiency in donor blood use, but the concern about the contact of donor blood with artificial surfaces remains. Activation of the hemostatic system is a major issue in this context and is controversial. The aim of this study was to estimate the effect of apheresis on continuous thrombin generation (TG), representing a new tool to examine the overall function of the plasmatic clotting system. STUDY DESIGN AND METHODS: Twenty-six voluntary blood donors, fulfilling the law requirement for apheresis donation, participated in the study. Two units of platelets (6 x 10(11)) and 1 unit of red cells (250 mL; hematocrit level, 80%) were collected using two types of cell separators (Amicus, Fenwal, Inc.; and Trima Accel, Gambro BCT). Each donor underwent collection on both apheresis systems with at least 8 weeks in between. Samples of blood were collected before, immediately after, and 48 hours after apheresis. TG was measured using a slow fluorogenic substrate 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 (p > 0.05). The variables did not differ significantly between the two different apheresis systems (p > 0.05). CONCLUSION: Using a CAT-based technique, no change in variables of continuous TG were observed, suggesting that multicomponent blood collection did not lead to severe alterations in the hemostatic system of the donors.     

Clinical and laboratory factors underlying refractoriness to platelet transfusions

Of the spectrum of clinical and laboratory factors responsible for refractoriness to platelet transfusions, some are amenable to intervention, some to circumvention, and others only to acceptance and support for complications. Identification of the likely reason for refractoriness in a given individual patient is critical to determine the optimum management strategy. The blood bank or transfusion service can and perhaps should play a direct role in that strategy through the provision of single donor platelets collected by apheresis. Single donor platelets offer a number of real and theoretical advantages over random donor platelets, including the potential for crossmatching, reduction in net donor exposures, maintenance of ABO-compatibility, improved inventory management, and perhaps diminished rate of alloimmunization. The sole perceived benefits of random donor platelets are cost and availability. The cost differential, however, needs to take into account a variety of factors beyond the immediate concern of platelet collection and distribution, including many highly dependent upon local factors. The optimum management of the platelet refractory patient requires more appropriate use of single donor apheresis platelets coupled with platelet crossmatching when necessary. Data from outcomes studies presented indicates that increased reliance upon single donor apheresis platelets at the expense of pooled random donor units can improve the overall quality of transfusion practice by decreasing platelet utilization, resource consumption, donor exposures, and platelet wastage. © 1996 Wiley-Liss, Inc.     

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.     

Severe citrate toxicity complicating volunteer apheresis platelet donation

We report a case of severe citrate toxicity during volunteer donor apheresis platelet collection. The donor was a 40-year-old female, first-time apheresis platelet donor. Past medical history was remarkable for hypertension, hyperlipidemia, and depression. Reported medications included bumetanide, pravastatin, and paroxetine. Thirty minutes from the start of the procedure, the donor noted tingling around the mouth, hands, and feet. She then very rapidly developed acute onset of severe facial and extremity tetany. Empirical treatment with intravenous calcium gluconate was initiated, and muscle contractions slowly subsided over approximately 10 to 15 minutes. The events are consistent with a severe reaction to calcium chelation by sodium citrate anticoagulant resulting in symptomatic systemic hypocalcemia. Upon additional retrospective analysis, it was noted that bumetanide is a loop diuretic that may cause significant hypocalcemia. We conclude that careful screening for medications and underlying conditions predisposing to hypocalcemia is recommended to help prevent severe reactions due to citrate toxicity. Laboratory measurement of pre-procedure serum calcium levels in selected donors may identify cases requiring heightened vigilance. The case also illustrates the importance of maintaining preparedness for managing rare but serious reactions in volunteer apheresis blood donors.     

Pseudothrombocytopenia in plateletpheresis donors

BACKGROUND: EDTA pseudothrombocytopenia (PTCP) is an in vitro artifact in which the anticoagulation of blood with EDTA is associated with in vitro agglutination of platelets, resulting in a spuriously low platelet count. In apheresis donors, whole-blood samples for complete blood counts are routinely drawn into tubes anti-coagulated with EDTA. STUDY DESIGN AND METHODS: Records of apheresis donors were examined to identify persons in whom the postdonation counts were less than 100 × 10(9) per L. Identified donors were studied to confirm the presence of PTCP by drawing blood samples into EDTA, heparin, and trisodium citrate for serial platelet counts at room-temperature incubation. Platelet counts in citrated plasma were measured before and after the addition of EDTA. A single HLA-matched component from an identified PTCP donor was monitored for response by corrected count increment in the recipient. RESULTS: A total of nine donations were identified, involving 2 donors from a population of 945 donors (prevalence 0.2%). On testing, both donors were confirmed to have PTCP. The addition of EDTA to citrated plasma did not affect the platelet count. Response in a recipient to an HLA-matched component showed an acceptable corrected count increment. CONCLUSION: PTCP may occur in plateletpheresis donors and result in needless medical referral or donor deferral. PTCP does not appear to alter the yield content of the component or to be passively transferred to a recipient.     

成都市2010-2015年机采血小板献血者的调查研究

目的 探讨成都市2010-2015年机采血小板捐献现状及其变化趋势,为制定机采血小板采集计划、献血者招募方案和指导临床用血提供科学依据.方法 选择2010-2015年,于成都市血液中心捐献机采血小板的73 106人次无偿献血者为研究对象.通过本中心血站信息管理系统查询、收集及整理机采血小板献血者的年龄、性别、献血人次等资料,计算2010-2015年成都市机采血小板献血人次的发展速度和增长速度,并且采用统计学方法比较不同性别及年龄机采血小板献血者的构成比差异.结果 ①2010-2015年,成都市机采血小板献血人次由6 798人次增加至17 684人次,累计绝对增加量为10 866人次,年平均增长量为2 173人次,年平均增长速度为21.1％.2010-2015年,成都市机采血小板献血人次环比增长速度分别为22.4％、28.4％、31.1％、11.6％和13.2％,其中2012年和2013年环比增长速度较高.②2010-2015年,成都市机采血小板献血者中,男性献血者为52 650人次(72.02％),女性为20 456人次(27.98％),各年男性献血者均多于女性,并且所占比例均＞60％,其中2014年男性献血者所占比例最高,为76.88％(12 010/15 622).2010-2015年,成都市机采血小板献血者性别构成比比较,差异有统计学意义(x2 =691.483,P＜0.001).③2010-2015年,成都市机采血小板献血者中,各年均以18～25岁人群为主要机采血小板献血人群,其中2010年机采血小板献血者中,18～25岁献血人群所占比例最高,为62.80％(4 269/6 798).2010-2015年,18～25岁机采血小板献血者所占比例呈下降趋势,而＞25～30岁和＞30～35岁机采血小板献血者所占比例均呈增加趋势.自2012年起,有年龄为＞55～60岁献血者参与机采血小板献血,2012-2015年该年龄段机采血小板献血者各年所占比例分别为0.46％(49/4 561)、1.09％(153/14 002)、1.42％(222/15 622)及1.19％(210/17 684).2010-2015年,成都市机采血小板献血者不同年龄构成比比较,差异有统计学意义(x2=2 542.556,P＜0.001).结论 2010-2015年,成都市机采血小板献血人次呈逐年增加趋势,各年机采血小板献血者均以男性多于女性,且以18～25岁人群为主要机采血小板献血人群.应根据成都市机采血小板捐献特点,制定科学的机采血小板采集计划和献血者招募方案,确保为临床提供充足、安全的机采血小板制品.     

Quality of packed red blood cells and platelet concentrates collected by multicomponent collection using the MCS plus device

The demand for blood components is constantly increasing, while the exclusion criteria for donors are strengthened in order to reach maximal safety for donors and patients. To counterbalance reduced availability of volunteers, multicomponent collections (MCC) is an attractive approach to produce more than one component during a single apheresis procedure from one donor, such as packed red blood cells (PRBCs) and platelet concentrates (PCs). Further, the exposures of patients to a limited number of donors reduces the possibility of alloimmunization and transfusion-related diseases. We measured the quality of PRBCs and PCs obtained by MCC, using the MCS+ device with the LDPRBC program, Revision B, and compared them with the quality of manually collected PRBCs and PCs collected with the Revision C2 of the MCS+. We found higher pH levels and lower hemolysis assessed by means of fHb and K+ in the supernatant of PRBCs over the whole storage period of 42 days in MCC-derived PRBCs. The functional metabolism assessed by intracellular ATP was higher in PRBCs collected by MCC than in manually collected units. Furthermore, PCs obtained during MCC showed an increase in p-selectin expression on day 5 of storage compared to PCs collected with the Revision C2 of the MCS+. The p-selectin expression on MCC platelets was within the range of p-selectin expression found in PCs obtained by other apheresis devices. These results indicate less storage lesion in MCC-derived PRBCs compared to manually collected units and no compromise in the quality of MCC PCs obtained in the same apheresis procedure.     

Status of platelet collection and platelet transfusion.

Platelet product derived from single donor plateletpheresis is required to reduce the risks of adverse reactions by blood transfusion. The objectives of this study are to evaluate the status of platelet collection and its efficacy by various kinds of plateletpheresis equipment and to assess the achievement of platelet transfusion by platelet product derived from a single donor. Since the blood centers have introduced some kinds of efficient plateletpheresis equipment, large units of platelet products have been supplied mainly for the patients. Amicus and CCS might be preferable plateletpheresis machines because of their collection efficiencies and wider indication for donors. The average number of donors of platelet product per patient has recently reached nearly 1.0, and around 90% of patients have received platelet product derived from a single donor in the recent several years. However, platelet transfusion derived from a single donor has not yet been completely achieved. Each regional blood center should seriously consider the efficacy of each plateletpheresis equipment and arrange the equipment to collect platelets more effectively to achieve platelet transfusion from a single donor.     

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.     

Prediction of number of apheresis procedures necessary in healthy donors to attain minimally required peripheral blood CD34+ cells

BACKGROUND: Allogeneic peripheral blood stem cell (PBSC) transplantation is widely performed as a curative therapy for hematopoietic malignancies. Donors for PBSC harvest (PBSCH) are usually healthy subjects and undergo granulocyte–colony-stimulating factor treatment and apheresis procedures. A considerable proportion of donors experience poor mobilization, necessitating additional harvesting or marrow collection or remobilization. Although some characteristics have been reported to correlate with poor mobilization, they may not be taken into account in selecting PBSC donors. To protect healthy donors, it is preferable to predict the number of apheresis procedures needed for PBSCH before the procedure is initiated.
STUDY DESIGN AND METHODS: A retrospective cohort study of 83 subjects was conducted, using statistical models to predict the probability of obtaining a sufficient number of CD34+ cells (≥2.0 × 10⁶/kg) in the first to the third apheresis procedures and the probability of failure to obtain sufficient cells within three apheresis sessions. This study explored potential candidate factors in an ordinal probit regression analysis.
RESULTS: Significant factors predicting successful PBSCH were donor age, donor sex, and body weight difference between donor and recipient. The predictive model showed good agreement with the observed number of apheresis sessions. Simulation tables are presented with this model.
CONCLUSION: The statistical model developed to predict the number of apheresis procedures for PBSCH may be useful for planning PBSCH in clinical practice.     

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.     

Strategies to recruit plateletpheresis donors from a registry of HLA- typed, unrelated, bone marrow donors

Rising demand for single-donor platelet components–from random donors, to maintain platelet inventories, or from HLA-compatible donors, to support alloimmune platelet-refractory patients–necessitated increasing the size of a community plateletpheresis donor registry. This study compares two strategies for recruiting whole-blood donors into a plateletpheresis program. The whole-blood donors who were asked to participate in this study had recently joined an unrelated bone marrow donor registry and had been HLA-typed as part of that process. An in-person recruitment strategy, which was time-intensive for the apheresis donor coordinator, served as the standard. A by-mail strategy involved the mailing of recruitment materials to marrow-donor registry participants. Marrow-donor registry participants were approached about apheresis participation after they had indicated an interest in the plateletpheresis program by returning a tear-off section of an informational brochure that was sent to them along with their marrow- donor registry materials. A total of 852 marrow-donor registry participants were randomly assigned to one of two recruitment strategies, and the recruitment rates were the same (46%) for both methods. In addition, levels of apheresis participation and attrition rates of donors recruited by either strategy were comparable. Thus, the simple strategy of mailing information about a plateletpheresis program is a very cost-effective method of recruiting donors.     

Platelet production methods in the United Kingdom

Platelets had traditionally been produced in the United Kingdom (U.K.) either from random donor blood by centrifugation of the platelet rich plasma or by plateletpheresis using various apheresis machines. The proportions of apheresis versus non-apheresis derived platelets varying from centre to centre depending on local policy. The production of platelets from random donor blood is labour intensive and in the late 1980s and early 1990s, biotechnology manufacturers developed newer automated techniques to derive platelets from buffy coats aiming to produce a more standard product and reduce the labour intensity of platelet production. At the same time, apheresis technology has continued to develop with the aim of maximising platelet yields from single donors by yielding 4-6 single unit equivalent of platelets per donor while eliminating the need for further laboratory processing. The trend in some European countries and in North America has been to move away from platelets recovered from whole blood either by buffy coat method or by centrifugation of platelet-rich plasma to plateletpheresis. Intense pressure is being put on blood centres to introduce newer technologies which are inevitably more expensive methods of platelet production. Since 1992, centres in the U.K. have gradually changed their method of platelet production and a survey was conducted to examine the status of platelet production within the U.K. This has shown that many centres are moving away from the production of random donor unit platelets derived by secondary centrifugation of platelet rich plasma (25%) towards buffy-coat derived platelets (45.3%) while plateletpheresis remains fairly static (29.7).