Donor Platelet Count Research Articles

Is Systemic heparinization necessary during living donor hepatectomy?

Systemic heparinization has traditionally been performed during living donor hepatectomy (LDH) at most transplant centers because of the possibility of graft vascular thrombosis. However, no consensus on the use of systemic heparinization during LDH has yet emerged. The aims of the present study were to compare donor and recipient outcomes with reference to systemic heparinization and to determine whether or not systemic heparin needs to be administered to living donors. Via a retrospective review, we analyzed the outcomes of 137 LDHs performed at our institution from January 2011 to October 2013; 79 donors received systemic heparinization (group I), whereas 58 did not, but the liver graft was flushed with a heparinized perfusate (group II). Patient demographics, intraoperative parameters, laboratory data, postoperative complications, and survival rates were compared between the 2 groups. The overall complication rates did not differ significantly between the 2 groups, but postoperative bleeding requiring red blood cell transfusions occurred more frequently in group I versus group II (7.6% versus 0.0%, P = 0.03). The incidences of graft vascular thrombosis were similar in the 2 groups, and no graft loss caused by vascular thrombosis was evident during the early postoperative period. Moreover, no difference in either posttransplant graft function or survival was apparent between the 2 groups. The rates of decreases in donor hemoglobin, hematocrit, and platelet count levels during the early postoperative period were significantly higher in group I versus group II. In conclusion, the omission of systemic heparinization during LDH is both feasible and safe, with no adverse effects on donor or recipient outcomes.

Giant Platelets in Platelet Donors - A Blessing in Disguise?

Inherited thrombocytopenias, including inherited giant platelet disorders (IGPD) are relatively rare, but their prevalence is probably underestimated. Harris platelet syndrome, the most common IGPD reported from Indian subcontinent, mostly from eastern part, is characterised by a low platelet count, high mean platelet volume (MPV) and absence of bleeding. A short study was conducted to assess the prevalence of giant platelets in voluntary donors of single donor platelets (SDP) and analyse the effect of transfusion of such SDPs in patients. Voluntary donors of SDPs were screened as per standard guidelines prior to the procedure. A complete blood count (including MPV) along with a peripheral smear was done. A total of 45 donors were screened for plateletpheresis. Following plateletpheresis from these donors, a platelet count from the collection bag was done after one hour. The SDP was transfused as a single unit or divided into two and transfused to the same patient at two different occasions, as per clinical need. Platelet counts on pateints were done after one hour and the platelet recovery was noted. Out of the 45 donors who were screened, 30 (66.67%) were found to have giant platelets. It was observed that the pre procedure platelet counts in donors having giant platelets were relatively low (1.5 -1.7 lacs) and so also the platelet yield (2.7-3x10(11)) compared to donors who did not, but the post transfusion platelet recovery was greater. Since presence of giant platelets has been seen to be common in the Eastern part of India, a peripheral smear examination should always be considered during screening of plateletpheresis donors to avoid rejecting donors with giant platelets whose platelet counts are given falsely low by autoanalysers.

Platelet count reduction and outcomes in living liver donors

Platelet count reduction in living donors after graft harvesting is very common. The mechanisms and the subsequent adverse consequences are not clear. The present study was to explore the mechanisms and the consequences of platelet count reduction in living donors. We collected data from 231 living liver donor patients who donated at our transplant center between July 2002 and August 2009. Baseline and post-operative platelet counts were collected and analyzed. Multivariate logistic regression analysis was used to compare the risk factors for the persistent decrease in platelet counts. Complications and other post-operative recovery were compared between the donors. Platelet count decreased differently at each of the follow-up intervals, and the average reduction from baseline evaluation to year 3 was 18.2%. A concomitant decrease in white blood cells was observed with platelet count reduction. All of the splenic volumes at the post-operative follow-up time points were significantly higher than those at baseline (P<0.01). Multivariate logistic regression analysis indicated that the graft-to-donor weight ratio was a risk factor for low post-operative platelet counts in living donors at the three follow-up time points: one week (P=0.047), one month (P=0.034), and three months (P=0.047). At the one week follow-up time, 77 donor platelet counts were higher (group 1) and 151 donor platelet counts were lower (group 2) than baseline levels. Two hemorrhage events (1.3%) were observed in group 2, while three hemorrhage events (3.9%) were observed in group 1 (P=0.211). The overall complication rate was comparable between the two groups (P=0.972). An increase in harvesting graft may decrease platelet counts, but this reduction does not produce short- or long-term damage in living liver donors.

Era of blood component therapy: Time for mandatory pre-donation platelet count for maximizing donor safety and optimizing quality of platelets

Blood bank regulatory agencies including the Drug and Cosmetics Act (DCA) of India do not mandate a predonation platelet count in whole blood donation. Mandating such practice will definitely optimize the quality of random donor platelets (RDP) in terms of platelet yield and patient therapeutic benefit. We observed poor platelet yield in RDP concentrates prepared at our center with a significant number not meeting the DCA guideline of ≥ 4.5 × 10(10) per bag processed from 450 ml of whole blood. Therefore we planned this study to evaluate the pre-donation hematological values in our blood donor population and effect of these values on the quality of platelet concentrates. The prospective study included 221 blood donors eligible for donating 450 ml of whole blood (WB). Following the departmental standard operating procedure (SOP) RDPs were prepared using the 'Top & Bottom' quadruple bag system and automated component extractor. Quality of RDP was assessed as per departmental protocol. All results were recorded and subsequently transcribed to SPSS working sheet. A significant (p<0.001) decrement of donor blood counts has been observed after WB donation. Mean donor Hb and platelets reduced by 0.72 g/dl and 22.1 × 10(6)/ml respectively. Quality of RDPs in terms of platelet yield was significantly better (p<0.001) when donor platelet count was >200 × 10(6)/ml. Although platelet yield significantly correlated with the donor platelet count however quality of RDPs in terms of red cell contamination showed no correlation with the donor hematocrit. Platelet yield in random donor platelets is a concern in Eastern India. A platelet yield of 4.5 × 10(10) per bag as mandated by the DCA of India was only achieved when the donor platelet count was >200 × 10(6)/ml. Posttransfusion platelet recovery (PPR) was unsatisfactory in the transfused patient. Introduction of pre-donation platelet count in whole blood donation will maximize donor safety and optimize patient platelet transfusion management.

Feasibility and safety of triple dose platelet collection by apheresis

Blood cell separators of the newest generation allow for the collection of high-dose platelet concentrates. The aim of this study was to evaluate triple dose platelet collection with respect to feasibility and safety. Four hundred eighty plateletphereses were performed targeting to collect a triple platelet dose. Platelet counts were performed before and after apheresis and in platelet concentrates. Furthermore, donors were monitored for adverse events. Triple dose platelet collection was achieved in 96% according to European and national guidelines. Mean donor platelet count before apheresis was 303 +/- 64/nl and decreased to 195 +/- 48/nl after plateletpheresis. The lowest platelet count after apheresis was 111/nl. Twenty-one donor adverse events were observed (4.4%). Triple dose platelet collection is feasible and safe provided that donors are carefully checked for triple dose eligibility.

The effect of double‐ and triple‐apheresis platelet product donation on apheresis donor platelet and white blood cell counts

Concerned about the effect of multiple platelet (PLT) product donation on donor health, in 2005 the FDA proposed restrictions limiting the number of PLT products donated in 12 months. This was based on limited published evidence. To provide information on the effect of PLT donation on PLT and lymphocyte (LYM) count, hematologic variables were examined in a group of multiple PLT product donors. Donors with at least two apheresis PLT donations, one of which was a double- or triple-PLT product, were examined. Donor demographics, number of blood donations, and number of apheresis PLT products donated were determined. Hematologic variables were evaluated at the first and last donation. A total of 471 donors (median age, 48.8 years; 55% male; median time between first and last donations, 72 weeks) were studied. The median number of PLT donations was 4 (range, 1-34) with the median number of PLT products donated being 7 (range, 2-65). The median PLT count demonstrated a significant increase (14 x 10(9)/L, p = 0.0001) while both white blood cell and LYM counts showed significant decreases (-0.2 x 10(9)/L, p = 0.0052; and -0.06 x 10(9)/L, p = 0.0001, respectively). After adjusting for sex and whole-blood donations, LYM count demonstrated a significant decline associated with both number of donations (-0.01 x 10(9)/L, p = 0.01) and number of products donated (-0.005 x 10(9)/L, p = 0.02). PLT count demonstrated a significant increase associated with number of products donated (0.42 x 10(9)/L, p = 0.03). Significant but small LYM decrease and PLT increase were seen. Limitations on the number of apheresis PLT products donated within 12 months do not seem warranted due to PLT or LYM count changes.

Frequent plateletpheresis does not clinically significantly decrease platelet counts in donors

In October 2005, the US Food and Drug Administration (FDA) issued draft guidance on collecting platelets (PLTs) by automated methods. The FDA proposed limiting collections to 24 components, rather than 24 procedures, annually with up to 3 components per procedure. The rationale was from literature suggesting frequent PLT collection resulted in significant declines in donor PLT counts. Additional requirements for minimal interdonation intervals were proposed. Plateletpheresis records at a regional blood center with predonation PLT counts were used to assess the impact of the restriction on PLT collections. They were reviewed to demonstrate the effects of collection frequency, number of products collected, and interdonation interval on donor PLT counts. Total protein and albumin levels were compared in a subset of 24-times-per-year PLT donors and control whole-blood donors. A limit of 24 components would require replacement of approximately 20 percent of the donor base to recover lost components. No clinically important decrease in PLT counts before donation was seen in donors donating multiple PLT components up to 24 times per year, regardless of interdonation interval. No frequent donor was deferred for a PLT count less than 150 x 10(9) per L. Short interdonation intervals were associated with statistically but not clinically important decreases in PLT counts. Protein levels were not distinguishable between PLT donors and controls. The proposed restrictions are not required to prevent thrombocytopenia in frequent PLT donors and would adversely impact the supply of apheresis PLTs. Protein levels are maintained in these high-frequency donors.

Influence of the application of platelet‐enriched plasma in oral mucosal wound healing

The aim of this study was to describe and quantify the therapeutic value of platelet concentrate on the capillary density in oral mucosal wound healing. The subjects included 10 healthy edentulous patients who underwent bilaterally a sinus floor elevation procedure and a buccal onlay graft with autologous iliac crest bone for maxillary reconstruction. During surgery, platelet-rich plasma (PRP) was prepared from a blood sample taken from the patient. After randomization in a split-mouth design, at one side PRP was administered in the wound and at the contralateral side a placebo. At baseline, microvascular capillary density was scored with the orthogonal polarization spectral (OPS) imaging technique and repeated measurements were performed postoperatively on a daily basis until the tenth day, after which measurements were continued weekly until the fifth postoperative week. Ten patients, five males and five females, were included in the study with a mean age of 54.2+/-9.1 years for females and 57.6+/-6.9 years for males. Donor platelet counts from whole blood had a mean value of 248.5+/-13.5 x 10(9)/l, while the value of platelet counts in the PRP had a mean of 975.9+/-97.9 x 10(9)/l. Wound healing was significantly accelerated in the PRP-treated mucosal wounds during the first 10 postoperative days. After the second week, no obvious differences between the PRP or placebo side could be noted. PRP has a strong stimulant effect on capillary regeneration in wound healing. These effects are mainly noticeable during the early stages of wound healing.

Pre-apheresis donor platelet count: An important platelet yield predictor

Journal of Clinical ApheresisVolume 21, Issue 4 p. 274-274 Letter to the Editor Pre-apheresis donor platelet count: An important platelet yield predictor Karan Saluja, Karan Saluja Department of Transfusion Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, IndiaSearch for more papers by this authorBeenu Thakral, Beenu Thakral Department of Transfusion Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, IndiaSearch for more papers by this authorRatti Ram Sharma, Ratti Ram Sharma Department of Transfusion Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, IndiaSearch for more papers by this authorNeelam Marwaha, Corresponding Author Neelam Marwaha neelam2918@yahoo.com Department of Transfusion Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, IndiaDepartment of Transfusion Medicine, PGIMER, Chandigarh, 160012 IndiaSearch for more papers by this author Karan Saluja, Karan Saluja Department of Transfusion Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, IndiaSearch for more papers by this authorBeenu Thakral, Beenu Thakral Department of Transfusion Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, IndiaSearch for more papers by this authorRatti Ram Sharma, Ratti Ram Sharma Department of Transfusion Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, IndiaSearch for more papers by this authorNeelam Marwaha, Corresponding Author Neelam Marwaha neelam2918@yahoo.com Department of Transfusion Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, IndiaDepartment of Transfusion Medicine, PGIMER, Chandigarh, 160012 IndiaSearch for more papers by this author First published: 17 July 2006 https://doi.org/10.1002/jca.20100Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume21, Issue4December 2006Pages 274-274 RelatedInformation

Mobilisation and Harvest of Peripheral Blood Stem Cells from 187 Healthy Donors. A Comparison of Two Different Apheresis Machines and Three Apheresis Programs.

Background:Between January 1995 and July 2004, mobilisation and harvest of peripheral blood stem cells for allogeneic transplantation was performed in 136 related and 51 unrelated healthy donors. Four related and one unrelated donor were harvested on two separate occasions after renewed G-CSF mobilisation. For logistic reasons, automated harvest programs were used until recently. Automated apheresis programs for peripheral blood stem cell harvest are less labour intensive but unfortunately also less efficient. One of the potential health hazards for donors is the depletion of platelets, thus it is essential to minimize platelet depletion.Method:Between 1995 and 1999 CS3000 (Baxter) cell separator with an automated stem cell harvest program was used. Since 1995 Cobe Spectra (Gambro) cell separator is used, initially with the automated program AutoPBSC and since March 2004 with the “manual” program MNC. The 187 medical reports were analysed retrospectively.Results:Median age was 40 years (range 14–71), median weight was 75 kg (range 42–130) and the male/female ratio was 1.3 (107/80). In a majority of donors (97%) antecubital veins were used as access to the circulation. In 4% of donors antecubital veins were unsuitable, and a femoral catheter was therefore employed.Donors were mobilised with G-CSF 10 ug/kg and harvested on days five and six. Transplantation dose was median 6,3 x 10(6) CD34+ cells/kg recipient (range 1,2–98,6). Harvest yield was median 5,8 x 10(6) CD34+ cells/kg donor (range 1,4–16,3). Donor platelet count after second apheresis was median 129 x 10(9)/L (range 57–268) (normal range 150–400).There were no significant differences regarding yield of CD34+ cells between male and female donors or between the two automated apheresis programs CS3000 and CobeSpectra AutoPBSC but the shift to CobeSpectra MNC-program led to a significantly increased yield only after six (three male and three female) donors (Mann-Whitney Test p<0,005) and median yield doubled to 10 x 10(6) CD34+ cells/kg donor.There was no significant difference between CS3000 and Cobe Spectra MNC regarding platelet depletion but Cobe Spectra AutoPBSC was significantly less platelet depleting compared both to CS3000 (Mann-Whitney Test p<0,001) and Cobe Spectra MNC (Mann-Witney Test p<0,001).Conclusion:1.No serious side effects were reported during G-CSF mobilisation or apheresis.2.Cobe Spectra MNC program is significantly more efficient regarding yield of CD34+ cells than the two automated programs.3.Cobe Spectra AutoPBSC is significantly less platelet depleting than both CS3000 and Cobe Spectra MNC.

Improving technology for collecting platelets by apheresis: Five-year experience in one blood center

Over the past decade, newly introduced methods for apheresis platelet collection have led to increased collection yields. This has resulted in “splitting,” which allows transfusion of 2 patients from 1 high-yield collection. Although many small studies exist, no large studies have described the impact of methodological changes on routine blood center collections. We constructed a database containing selected parameters from 45,224 apheresis collections spanning July 1997 to April 2002, using Gambro BCT Spectra (Lakewood, CO), Fenwal CS-3000+ (Baxter Healthcare Corp, Fenwal Division, Deerfield, IL), and Baxter Amicus instruments. A Baker 9110+ hematology analyzer (Bio Chem Immunosystems, Inc., Allentown, PA) was used for platelet counting. Monthly average collection yields, distribution yields (product platelet contents after splitting), and split rates (the fraction of donations which may be split) were determined. The monthly mean collection yield and split rate correlated very closely. Both rose throughout the study period. The split rate climbed from 25% to 70% by study end. However, mean monthly distribution yields decreased by 7% because split and unsplit platelet yields both rose as split rates rose. Overcollections with the Amicus correlated with underestimation of donors’ true preprocedure platelet counts during machine programming. Undercollections occurred in donors with low counts and, with-single needle Amicus, microcytic platelet collection. These results may assist in the optimization of an apheresis program. Increased collection yields correlated with cell separator type, dual-needle access, donor platelet count >250 × 10 9/L, programming with true preprocedure platelet counts and capacity for triple product preparation from collection yields exceeding 2-bag storage capacity.

Comparative study of plateletpheresis using Baxter CS 3000 plus and Haemonetics MCS 3P

Platelet concentrates made from cell separators are used more frequently due to less donor exposure and leucodepletion. This retrospective study was done to compare plateletpheresis done on two cell separators: Baxter CS 3000 plus and Haemonetics MCS 3p. Plateletpheresis procedures, done from January 1997 to April 2002, were included in the study. One hundred and seven procedures were done on Haemonetics MCS 3p using SDP protocol, 49 procedures were done on Haemonetics MCS 3p using PLP protocol, and 107 were done on Baxter CS 3000 plus. Pre-procedure donor's platelet count and haemoglobin were comparable in all the groups. Platelet yield was comparable in PLP (6.44 x 10(11) platelets) and SDP (5.27 x 10(11)) protocols, but significantly less in Baxter (4.05 x 10(11) platelets, P < 0.001 for PLP and P < 0.05 for SDP). Efficiency of platelet removal was statistically significantly different in all the groups (P < 0.0001), however it was more in PLP (PLP-55.02%, SDP-47.38%, Baxter 38.98%). A significant number of products (19.51%) of Baxter failed to comply platelet count of product < or = 2,435 x 10(9)/l compared to 5.13% in PLP and 1.23% in SDP group; 36.96% of units from PLP and 28% from SDP qualified for split products compared to 1.18% of Baxter. PLP protocol of Haemonetics MCS 3p gives better platelet yield compared to Baxter CS 3000 plus and SDP protocol of Haemonetics MCS 3p.

Automated collection of blood components: their storage and transfusion.

The performance of an automated device, the Gambro TRIMA, was evaluated for component production, and an in vivo assessment of the platelets was carried out. Red cell concentrates (RCCs), platelets and plasma were collected and stored according to standard blood bank procedures and evaluated for quality by in vitro measurements. Additionally, single-donor platelets (n=10) were transfused to thrombocytopenic patients after 5 days of storage. Platelet counts were measured after 1 h and the corrected count increment (CCI) was calculated. No significant changes were seen before or after procedure in donor haemoglobin, haematocrit, coagulation factors or platelet count. Return-line samples showed no increase in the level of plasma haemoglobin. Plasma haemoglobin and potassium increased following RBC storage, but there was no change in the red cell number. Platelet aggregation decreased from 52 to 11% (adenosine diphosphate) and the Kunicki morphology score dropped from 379 to 174. Little change was seen in the hypotonic shock response (69-63%) or in the percentage of CD62 expression (4.8-19.8) over time. The CCI averaged 28+/-26 x 10(3) microL(-1) in 10 patients 1 h after transfusion. The TRIMA machine collects RCCs, platelets and plasma in a variety of combinations in one session. For autologous collection, two units of RCC plus platelets can be collected at one time, reducing administrative and testing costs. The platelets have good in vivo recovery, as shown by the CCI values. An added advantage is that the TRIMA machine can be used in hospitals to generate components in times of shortage without the need for a component's laboratory.

Hemoglobin and Platelet Count Effect on Platelet Yields in Plateletpheresis

Background Platelet transfusion in thrombocytopenic patients, especially those with marrow failure, remains one of the most important support measures available. Treatment success depends on rational use of platelet transfusion. Platelet yield, reflected in transfused platelet dose, influences platelet recovery in the patient and allows prolonging intervals between transfusions. In this study, our main objective was to identify donor laboratory and clinical factors that showed some influence on platelet yield obtained by apheresis. Methods Healthy donor laboratory and clinical data were analyzed prior to performing plateletpheresis. Platelet yield was quantified after plateletpheresis procedure was concluded in two different ways: a) prefixed volume of 5,000 mL processed, and b) volume determined according to manufacturer recommendations. Age, gender, hemoglobin concentration, platelet and leukocyte count, height, and weight were included as yield-predicting donor variables. Results In group A, two variables were significant: donor platelet count and hemoglobin (Hb) concentrations with r = 0.554, and in group B, donor platelet count, Hb concentrations, and volume with r = 0.758. Conclusions Donor platelet count and hemoglobin concentrations influence platelet yield: higher platelet count corresponds to higher yield, while hemoglobin shows an inverse relationship, i.e., the lower the hemoglobin concentrations, the higher the platelet yield.

Growth factor levels in platelet-rich plasma and correlations with donor age, sex, and platelet count

Introduction: Platelet-rich plasma contains autologous thrombocyte growth factors and might be promising for acceleration of dentoalveolar bone regeneration. In this study, it was analysed for platelet counts and growth factor concentrations. Material and method: Platelet-rich plasma was isolated by discontinuous cell separation from 158 healthy men and 55 women aged 17–62 years. One hundred and fifteen specimens (stratified for age and gender of the donor) were analysed for growth factor concentrations and platelet count. Results: The platelet count in platelet-rich plasma (1,407,640±320,100/μl) was 5 times higher than in donor blood (266,040±60,530/μl). Platelet-derived growth factor AB (117±63 ng/ml), transforming growth factor (TGF) β -1 (169±84 ng/ml), and insulin-like growth factor (IGF) I (84±23 ng/ml) were found in large amounts, while platelet-derived growth factor (PDGF) BB (10±8 ng/ml) and transforming growth factor β -2 (0.4±0.3 ng/ml) were found in small amounts only. The growth factor content was not well correlated with the platelet count in whole blood nor with the platelet-rich plasma (rp=0.35). No influence of gender or age on platelet count or growth factor concentrations was discovered (except IGF-I). Conclusions: While there was substantial variation in the growth factor content of platelet-rich plasma, the factors influencing this are still worthy of further investigation. Furthermore, a technique whereby the growth factor content could be rapidly assessed in platelet-rich plasma may be of therapeutic benefit. Copyright 2002 European Association for Cranio-Maxillofacial Surgery. Published by Elsevier Science Ltd. All rights reserved.

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.

Thrombopoietin therapy increases platelet yields in healthy platelet donors

The recombinant thrombopoietins have been shown to be effective stimulators of platelet production in cancer patients. It was therefore of interest to determine if one of these, pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), could be used to increase platelet counts and consequently platelet yields from apheresis in healthy platelet donors. In a blinded, 2-cycle, crossover study, 59 platelet donors were randomized to receive a single subcutaneous injection of PEG-rHuMGDF (1 microg/kg or 3 microg/kg) or placebo and 15 days later undergo platelet apheresis. Donors treated with placebo had a median peak platelet count after PEG-rHuMGDF injection of 248 x 10(9)/L compared with 366 x 10(9)/L in donors treated with 1 microg/kg PEG-rHuMGDF and 602 x 10(9)/L in donors treated with 3 microg/kg PEG-rHuMGDF. The median maximum percentage that platelet counts increased from baseline was 10% in donors who received placebo compared with 70% in donors who received 1 microg/kg and 167% in donors who received 3 microg/kg PEG-rHuMGDF. There was a direct relationship between the platelet yield and the preapheresis platelet count: Placebo-treated donors provided 3.8 x 10(11) (range 1.3 x 10(11)-7.9 x 10(11)) platelets compared with 5.6 x 10(11) (range 2.6 x 10(11)-12.5 x 10(11)) or 11.0 x 10(11) (range 7.1 x 10(11)-18.3 x 10(11)) in donors treated with 1 microg/kg or 3 microg/kg PEG-rHuMGDF, respectively. Substandard collections (<3 x 10(11) platelets) were obtained from 26%, 4%, and 0% of the placebo, 1 microg/kg, and 3 microg/kg donors, respectively. No serious adverse events were reported; nor were there events that met the criteria for dose-limiting toxicity. Thrombopoietin therapy can increase platelet counts in healthy donors to provide a median 3-fold more apheresis platelets compared with untreated donors.

Sustained decreases in platelet count associated with multiple, regular plateletpheresis donations.

Transient but significant decreases in platelet counts have been documented to occur in donors undergoing single and serial short-term plateletpheresis collections. The effect of long-term regular plateletpheresis on donor platelet counts has not been characterized. A retrospective study was performed to evaluate the effects of long-term regular plateletpheresis donation on donor platelet counts. A computerized database containing records of 11,464 apheresis collections from 939 donors over a 4-year period was queried for serial preapheresis platelet counts. Donors were categorized by sex, age, and cumulative number of donations. The average difference in platelet counts (mDeltaPC) between each donor's first and last platelet count during this period was calculated for each category. A subgroup of frequent donors was selected for analysis of mDeltaPC, using the baseline platelet count obtained before the first plateletpheresis procedure. A significant and sustained decrease in platelet count was identified for all donation frequency categories. The frequency of donation correlated directly with decrease in platelet count for all but the highest-frequency donation group, in which deferrals for low platelet count blunted the extent of the mDeltaPC. A mean decrease of 40,000 per microL from baseline occurred in the frequent-donor subgroup. A total of 84 donors (9%) were deferred for low platelet count. The majority returned to donate successfully after temporary deferral. Regular plateletpheresis donors develop sustained decreases in platelet count. However, clinically significant thrombocytopenia is unusual when rigorous ongoing review and prudent deferral policies are established and followed.

Platelet transfusion therapy.

The relative merits of apheresis platelets and platelet concentrates are undergoing debate due to evolving issues of safety, inventory, and cost. The application of photochemical inactivation technology may eliminate any rationale for the use of apheresis platelets rather than pooled platelet concentrates, so that the relative merits of these two alternatives will be debated over costs and inventory. Doses of apheresis platelets are determined by donor platelet count and by platelet yield. The generation of a platelet apheresis inventory has been accompanied by a decline in whole blood inventory; research into the impact of these distinct donor pools on national blood policy is needed.

Economic Impact of Donor Platelet Count and Platelet Yield in Apheresis Products: Relevance for Emerging Issues in Platelet Transfusion Therapy

Abstract Introduction: We analyzed donor platelet counts and platelet product yields in 708 consecutive platelet aphereses in our program in order to define the importance of this relationship for emerging issues in platelet transfusion therapy. Methods: Aphereses performed on the Spectra 3.6 (COBE, Lakewood. Colo.) the CS‐3000 Plus (Fenwall‐Baxter, Deerfield, III.) were analyzed. Results: Mean platelet count was 237±49 × 103/mm3 (mean ± SD), and mean yield was 4.24±1.09 × 1011 platelets. Eighty‐five (12%) procedures generated less that 3 × 1011 platelets. Only thirty‐eight (5.4%) procedures yielded 6 × 1011 platelets, so that ‘split products’ could be obtained. Platelet yields were primarily related to the biologic contribution (baseline platelet count) of the donor. Procedure parameters selected for harvest, and the efficiency of the device also had a significant, but less important role in determining the final platelet yield. An increase in mean donor platelet count achieved with Mpl ligand therapy from 240,000 to 320,000/mm3 would reduce the cost from USD 378 to 267 for each apheresis product, since the fraction of split products would exceed 50% of apheresis procedures. Conclusion: Increasing the donor platelet count would have a significant economic impact on platelet apheresis programs, as well as important clinical consequences for the role of platelet apheresis products in future transfusion strategies.