Apheresis Platelet Units Research Articles

Determination of Citrate Content of Commonly Transfused Blood Products

Abstract Background Citrate is a calcium-chelating anion used as an anticoagulant in the collection and manufacturing of blood products for transfusion. Overwhelming of normal hepatic catabolism of infused citrate, such as in liver failure or in massive transfusion, may cause citrate toxicity. Resultant hypocalcemia, impaired coagulation, and metabolic alkalosis results in increased patient mortality and morbidity. The citrate load per blood product unit is rarely known to the transfusionist, precluding precise calcium repletion. Manufacturing data of citrate content is available, but it is unreliable and often contradictory. The aim of this project is to directly measure the citrate concentrations of common blood products including packed red blood cells (pRBCs), plasma, and apheresis platelets. Methods Blood products (or samples thereof) were obtained, centrifuged, and assayed using a benchtop enzymatic citrate assay (Sigma-Aldrich). This technique generates a chromogenic product detectable via spectrophotometry at 570nm via conversion of citrate to a pyruvate intermediate. Blood products were serially diluted to the assay’s concentration measurement range based on estimations from the product manufacturing processes. Validation studies were performed to verify no significant interference from native pyruvate or from hemolysis at the dilutions used. All samples were run with a paired reference standard. Product type, storage duration, volume, and anticoagulant/preservative solution were recorded. Results Preliminary testing was performed on eleven pRBC units, twelve apheresis platelet units, and four whole blood(WB)-derived plasma. Measured citrate content of AS-1 and AS-5 units ranged from 43.56 - 114.5 mg while that of AS-3 units ranged from 327.23 – 816.82 mg, compared to manufacturing estimates of 188 mg and 883 mg, respectively. Measured citrate content of apheresis platelets ranged from 822-1533 mg compared to manufacturing estimates of 805 mg. Measured citrate content of WB-derived plasma also exceeded the manufacturing estimate of 1201 mg. Interference from pyruvate and hemolysis were insignificant at the dilutions used for testing. Validation of pRBC segment sampling is ongoing. Conclusion Varying guidelines exist for the correction of hypocalcemia during ongoing trauma resuscitation; however, guidance is limited regarding repletion by specific blood product. Our investigation affirms significant heterogeneity in pRBC citrate concentrations by collection method and identifies lower citrate concentrations than expected. This may be due to citrate metabolism by RBCs during storage. Platelet and FFP products contain significantly greater citrate masses by comparison, with a high degree of variation observed due to inherent product volume variability. Further sampling and testing are ongoing to establish reliable expected citrate loads for commonly transfused blood products.

Bacterial Contamination of Platelet Products.

Transfusion of bacterially contaminated platelets, although rare, is still a major cause of mortality and morbidity despite the introduction of many methods to limit this over the past 20 years. The methods used include improved donor skin disinfection, diversion of the first part of donations, use of apheresis platelet units rather than whole-blood derived pools, primary and secondary testing by culture or rapid test, and use of pathogen reduction. Primary culture has been in use the US since 2004, using culture 24 h after collection of volumes of 4-8 mL from apheresis collections and whole-blood derived pools inoculated into aerobic culture bottles, with limited use of secondary testing by culture or rapid test to extend shelf-life from 5 to 7 days. Primary culture was introduced in the UK in 2011 using a "large-volume, delayed sampling" (LVDS) protocol requiring culture 36-48 h after collection of volumes of 16 mL from split apheresis units and whole-blood derived pools, inoculated into aerobic and anaerobic culture bottles (8 mL each), with a shelf-life of 7 days. Pathogen reduction using amotosalen has been in use in Europe since 2002, and was approved for use in the US in 2014. In the US, recent FDA guidance, effective October 2021, recommended several strategies to limit bacterial contamination of platelet products, including pathogen reduction, variants of the UK LVDS method and several two-step strategies, with shelf-life ranging from 3 to 7 days. The issues associated with bacterial contamination and these strategies are discussed in this review.

Cold platelet transfusion: The effects of a fluid warmer on platelet function.

Recently the US Food and Drug Administration has granted variances to select blood centers to supply cold-stored platelet components (CSP). In hemorrhage resuscitation warming of blood components with approved fluid warming devices is common. Pathogen-reduced apheresis platelet units were collected and stored in one of two ways: (1) CSP-I, (2) CSP-D. CSP-I were collected and immediately stored at 1-6°C until used. CSP-D were collected and stored at 20-24°C for 5 days and transferred to storage at 1-6°C until use. Aggregometry using arachidonic acid (AA), adenosine diphosphate (ADP) and collagen as agonists was performed on the unit samples before and after the units were infused through a Ranger blood-warming device. CSP-I, 23 units, had very high aggregation responses to all agonists (all ≥47.6 ± 20.7). There was a statistically significant reduction in ADP-induced aggregometry results from 55.1 ± 23.2 before compared to 33.5 ± 14.6 following infusion of the PLT through the blood warmer (p < .001). There were no differences in AA and collagen aggregometry results before and after the infusion of the platelets through the blood warmer. CSP-D had 5 of the 15 units with visible clotting in the bag. The 10 CSP-Ds studied had lower aggregation than all agonists before and after infusion through the blood-warming device (all ≤49.9 ± 35.9). We detected a statistically significant reduction in ADP-induced aggregometry in CSP-I run through a Ranger blood-warming device with no change with AA or collagen agonist aggregometry.

T-cell lymphopenia in frequent volunteer platelet donors.

In the United States, more than 2 000 000 apheresis platelet units are collected annually from volunteer donors. Platelet donors in the United States and elsewhere are permitted to donate up to 24 times per year. Recently, frequent apheresis platelet donation has been associated with severe T-cell lymphopenia. Several frequent platelet donors have been found to have peripheral blood CD4+ T-cell counts below 200 cells/µL, the threshold for AIDS in HIV-positive individuals. Independent risk factors for plateletpheresis-associated lymphopenia include lifetime donations, age, and donations on the Trima Accel instrument (Terumo BCT), which uses a leukoreduction system (LRS) chamber to trap white blood cells. Less often, severe lymphopenia can occur in donors collected on the Fenwal Amicus instrument (Fresenius Kabi), which has no LRS. For Trima Accel donors, lymphopenia can be partially mitigated by performing a plasma rinseback step at the end of collection. To date, there is no definitive evidence that plateletpheresis-associated lymphopenia is harmful. In a study of frequent platelet donors with lymphopenia who were administered COVID-19 messenger RNA vaccines, immune responses were normal. The homeostatic mechanisms responsible for maintaining a normal peripheral blood T-cell count remain obscure, as do the causal mechanisms underlying plateletpheresis-associated lymphopenia.

Structural analysis of platelet fragments and extracellular vesicles produced by apheresis platelets during storage

AbstractPlatelets (PLTs) for transfusion can be stored for up to 7 days at room temperature (RT). The quality of apheresis PLTs decreases over storage time, which affects PLT hemostatic functions. Here, we characterized the membranous particles produced by PLT storage lesion (PSLPs), including degranulated PLTs, PLT ghosts, membrane fragments, and extracellular membrane vesicles (PEVs). The PSLPs generated in apheresis platelet units were analyzed on days 1, 3, 5, and 7 of RT storage. A differential centrifugation and a sucrose density gradient were used to separate PSLP populations. PSLPs were characterized using scanning and transmission electron microscopy (EM), flow cytometry (FC), and nanoparticle tracking analysis (NTA). PSLPs have different morphologies and a broad size distribution; FC and NTA showed that the concentration of small and large PSLPs increases with storage time. The density gradient separated 3 PSLP populations: (1) degranulated PLTs, PLT ghosts, and large PLT fragments; (2) PEVs originated from PLT activation and organelles released by necrotic PLTs; and (3) PEV ghosts. Most PSLPs expressed phosphatidyl serine and induced thrombin generation in the plasma. PSLPs contained extracellular mitochondria and some had the autophagosome marker LC3. PSLPs encompass degranulated PLTs, PLT ghosts, large PLT fragments, large and dense PEVs, and low-density PEV ghosts. The activation-related PSLPs are released, particularly during early stage of storage (days 1-3), and the release of apoptosis- and necrosis-related PSLPs prevails after that. No elevation of LC3- and TOM20-positive PSLPs indicates that the increase of extracellular mitochondria during later-stage storage is not associated with PLT mitophagy.

Pilot Study of Centralized Management System in Shanghai: A Promising Solution to Platelet Collection and Supply Imbalance in Small Blood Banks

Background and Objectives: While there exists a significant wastage of platelets on one side (volatile demands and short lifetime), there is also a shortage for use on the other (lack of donors and emergency transfusions). A new centralized management system was established to tackle this dilemma. Methods: To assess the function of this system, data were collected from the Fengxian Blood Bank (FBB) Collection and Supply Information System during 2016 and 2018, then analyzed by IBM SPSS Statistics version 20. Results: Since implementing the centralized management system, a total of 1340 units of apheresis platelets were distributed by FBB. However, the number of units collected was 2737, twice as much as what had been distributed. With the aid of the system, the excess of 1644 units of apheresis platelets were transferred to the Shanghai Blood Center (SBC) inventory at their disposal. On the other hand, 247 units (included in 1340 distributed units) were compensated by SBC during the platelet shortage. In addition, the hospital demand meeting rate shows a significant increase from 82.61% to 99.78%, especially for type AB which increases from 62% to 100%. Conclusions: In conclusion, the centralized management system vastly improved the efficiency of platelet collection and distribution by the regional supply and demand. Such success would be a superb example of blood banks facing similar problems.

Young apheresis platelet donors show significant and sustained growth over the last decade in the US, 2010-2019: A favorable sign of the resiliency of the platelet supply.

Platelet demand continues to rise and US hospitals frequently face shortages. The peak median age of apheresis platelet donors (APD) is believed to have increased over the last decade, raising concerns that the APD base is not being adequately replenished with young donors. American Red Cross (ARC) apheresis platelet collections were evaluated from calendar years 2010 through 2019. APD, products per procedure/split rate (PPP) and donation frequencies were stratified into age groups. The number of unique APD from calendar year 2010 through 2019 in the ARC donor pool increased from 87,573 to 115,372 donors, representing a 31.7% overall growth. Donors in the 16-40 year-old (y) age group increased by 78.8% overall, with the largest absolute increases seen in the 26-30 y (4852 donors, 99.9% growth), followed by the 31-35 y (3991, 94.1%) group. Donors aged 56+ increased by 50.4% overall, with the largest increase seen in the 66-70 y (5988 donors, 108.1% growth) group. Middle-aged donors, aged 41-55 y, demonstrated a decrease of 16.5%. Over the last decade, the youngest age groups (16-40 y) comprised 61.3% of first-time donors (FTD). Annual donation frequency increased with increasing age and PPP. The highest donation frequencies were seen in the oldest age groups. Although the peak median age of APD increased over the study period, relative contribution of the 16-40 y APD base also increased. Older donors exhibited the highest donation frequencies and thus contributed the largest volume of apheresis platelet units. Platelet donor activity declined in the middle age (41-55 y) group.

Hyperbaric treatment of platelets is comparable to cold storage alone over 14 days.

Platelets stored at room temperature (22-24°C) for transfusion purposes have a shelf life of 5-7 days, or 72 h when stored refrigerated (1-6°C). The limited shelf life of platelet products severely compromises platelet inventory. We hypothesized that cold storage of platelets in 100% plasma using xenon gas under high pressure would extend shelf life to 14 days. Double apheresis platelet units were collected and split equally between two bags. One unit was placed in a hyperbaric chamber, pressurized to 4 bars with a xenon/oxygen gas mixture, and placed in a refrigerator for 14 days (Xe). The remaining unit was aliquoted into mini-bags (10 ml) for storage at room temperature (RTP) or in cold (CSP). Samples were assayed on days 5 (RTP) or 14 (Xe and CSP) for count, metabolism, clot strength, platelet aggregation, and activation markers. The platelet count in Xe samples was lower than that of RTP but significantly higher than CSP. Despite similar levels of glucose and lactate, the pH of Xe samples was significantly lower than CSP. Glycoprotein expression was better preserved by Xe storage compared to CSP, but no differences in activation were observed. Thromboelastography and aggregometry results were comparable between all groups. Cold storage of platelets in plasma with hyperbaric xenon provides no significant improvement in platelet function over cold storage alone. The use of a hyperbaric chamber and the slow off-gassing of Xe-stored units complicate platelet storage and delivery logistics.

Rh alloimmunization following transfusion of one apheresis platelet unit

TransfusionVolume 63, Issue 3 p. 656-657 LETTER TO THE EDITOR Rh alloimmunization following transfusion of one apheresis platelet unit Elizabeth Abels, Elizabeth Abels Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USASearch for more papers by this authorThomas C. Binns, Thomas C. Binns orcid.org/0000-0003-1246-8957 Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USASearch for more papers by this authorJeremy W. Jacobs, Corresponding Author Jeremy W. Jacobs jeremy.jacobs@yale.edu orcid.org/0000-0002-5719-9685 Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USA Correspondence Jeremy W. Jacobs, Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, USA. Email: jeremy.jacobs@yale.eduSearch for more papers by this authorKristin Stendahl, Kristin Stendahl Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USASearch for more papers by this authorChristopher A. Tormey, Christopher A. Tormey orcid.org/0000-0003-1785-2245 Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USASearch for more papers by this author Elizabeth Abels, Elizabeth Abels Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USASearch for more papers by this authorThomas C. Binns, Thomas C. Binns orcid.org/0000-0003-1246-8957 Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USASearch for more papers by this authorJeremy W. Jacobs, Corresponding Author Jeremy W. Jacobs jeremy.jacobs@yale.edu orcid.org/0000-0002-5719-9685 Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USA Correspondence Jeremy W. Jacobs, Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, USA. Email: jeremy.jacobs@yale.eduSearch for more papers by this authorKristin Stendahl, Kristin Stendahl Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USASearch for more papers by this authorChristopher A. Tormey, Christopher A. Tormey orcid.org/0000-0003-1785-2245 Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USASearch for more papers by this author First published: 20 March 2023 https://doi.org/10.1111/trf.17258Read the full textAboutPDF 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 onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume63, Issue3March 2023Pages 656-657 RelatedInformation

Improvement in Platelet Product Wastage and Reduction of Costs through Implementation of the Pan Genera Detection Test.

The aim of this study was to evaluate the effects of Pan Genera Detection (PGD) testing on reducing platelet product wastage and transfusion service costs. We conducted a retrospective cross-sectional study comparing the number of platelet apheresis units wasted before (March 2017 to February 2019) and after (March 2019 to February 2021) PGD implementation. The PGD testing was performed before transfusion on days 6 and 7. Cost analysis considered the costs of platelet units wasted ($500.00/unit) and PGD test supplies and performance (estimated $26.50 per test). Paired samples t-test was used to compare platelet wastage pre- and post-PGD implementation. The number of wasted platelet units decreased from pre-PGD (419) to post-PGD (195), representing a significant decrease in platelet wastage from 17.5% to 9.2% (P < .0001). During the post-PGD period, 366 and 133 units were tested on days 6 and 7, with 28 and 36 units discarded each day, allowing transfusion of an additional 302 platelet units. Costs from platelet wastage decreased from $209,500.00 pre-PGD to $97,500.00 post-PGD. Our results showed that PGD testing effectively reduced platelet wastage, extended platelet availability, and reduced transfusion service costs.

Cryopreservation of apheresis platelets treated with riboflavin and UV light

BackgroundPathogen reduction technology (PRT) is increasingly used in the preparation of platelets for therapeutic transfusion. As the Czech Republic considers PRT, we asked what effects PRT may have on the recovery and function of platelets after cryopreservation (CP), which we use in both military and civilian blood settings. Study design and methods16 Group O apheresis platelets units were treated with PRT (Mirasol, Terumo BCT, USA) before freezing; 15 similarly collected units were frozen without PRT as controls. All units were processed with 5–6% DMSO, frozen at − 80 °C, stored > 14 days, and reconstituted in thawed AB plasma. After reconstitution, all units were assessed for: platelet count, mean platelet volume (MPV), platelet recovery, thromboelastography, thrombin generation time, endogenous thrombin potential (ETP), glucose, lactate, pH, pO2, pCO2, HCO3, CD41, CD42b, CD62, Annexin V, CCL5, CD62P, and aggregates > 2 mm and selected units for Kunicki score. ResultsPRT treated platelet units had lower platelet number (247 vs 278 ×109/U), reduced thromboelastographic MA (38 vs 62 mm) and demonstrated aggregates compared to untreated platelets. Plasma coagulation functions were largely unchanged. ConclusionsSamples from PRT units showed reduced platelet number, reduced function greater than the reduced number would cause, and aggregates. While the platelet numbers are sufficient to meet the European standard, marked platelets activation with weak clot strength suggest reduced effectiveness.

Predicting donor-related factors for high platelet yield donations by classification and regression tree analysis

Collecting high-dose (HD) or double-dose (DD) apheresis platelets units from a single collection offers significant benefit by improving inventory logistics and minimizing the cost per unit produced. Platelet collection yield by apheresis is primarily influenced by donor factors, but the cell separator used also affects the collection yield. To predict the cutoff in donor factors resulting in HD and DD platelet collections between Trima/Spectra Optia and MCS+ apheresis equipment using Classification and Regression Trees (CART) analysis. High platelet yield collections (target ≥ 4.5×1011 platelets) using MCS+, Trima Accel and Spectra Optia were included. Endpoints were ≥ 6×1011 platelets for DD and ≥ 4.5 to < 6×1011 for HD collections. The CART, a tree building technique, was used to predict the donor factors resulting in high-yield platelet collections in Trima/Spectra Optia and MCS+ equipment by R programming. Out of 1,102 donations, the DDs represented 60% and the HDs, 31%. The Trima/Spectra Optia predicted higher success rates when the donor platelet count was set at ≥ 205×103/µl and ≥ 237×103/µl for HD and DD collections. The MCS+ predicted better success when the donor platelet count was ≥ 286×103/µl for HD and ≥ 384×103/µl for DD collections. Increased donor weight helped counter the effects of lower donor platelet counts only for HD collections in both the equipment. The donor platelet count and weight formed the strongest criteria for predicting high platelet yield donations. Success rates for collecting DD and HD products were higher in the Trima/Spectra Optia, as they require lower donor platelet count and body weight than the MCS+.

Passive transfer of SARS-CoV-2 antibodies with platelet transfusions.

BackgroundAlthough over 5000 platelet transfusions occur daily in the United States, the presence of SARS‐CoV‐2 antibodies in platelet units is not commonly evaluated for. The effects of platelet transfusions with SARS‐CoV‐2 antibodies remain largely unknown. We evaluated single‐donor (apheresis) platelet units for SARS‐CoV‐2 antibodies and determined if platelet transfusions passively transferred antibodies to seronegative recipients.Study Design and MethodsWe conducted a retrospective analysis as part of a quality assurance initiative during February to March 2021 at a tertiary referral academic center in suburban New York. Platelet units and platelet recipients were evaluated for the presence of SARS‐CoV‐2 antibodies using the DiaSorin LIASON SARS‐CoV‐2 S1/S2 IgG assay. There were 47 platelet recipients eligible for study inclusion. The primary outcome was the presence of SARS‐CoV‐2 spike protein IgG antibodies in the recipient's blood after platelet transfusion.ResultsTwenty‐three patients received platelets with SARS‐CoV‐2 spike protein IgG antibodies; 13 recipients had detection of SARS‐COV‐2 antibodies (56.5%), and 10 recipients did not. The median antibody titer in the platelet units given to the group with passive antibodies detected was significantly higher compared to the median antibody titer in the platelet units given to the group without antibodies detected (median [interquartile range]: 306 AU/ml [132, 400] vs. 96.1 AU/ml [30.6, 186], p = .027).ConclusionsOur study demonstrated a significant rate of passive transfer of SARS‐CoV‐2 spike protein IgG antibodies through platelet transfusions. Considering the volume of daily platelet transfusions, this is something all clinicians should be aware of.

Donor and Storage Duration Impact Cold-Stored Platelet Function More Than Handling Protocols

Cold storage of platelets has the potential to mitigate the logistical and financial burdens associated with platelet inventory management. In addition, cold-stored platelets (CS-PLT, stored at 2-6°C) have better preserved hemostatic function than room temperature (RT)-stored platelets (RT-PLT), suggesting that CS-PLT may provide improved hemostatic resuscitation in actively bleeding patients as compared to RT-PLT when transfused. With CS-PLT clinical use on the rise, questions regarding CS-PLT inventory management have been raised - specifically how should CS-PLT be stored and handled over the course of storage (after collection and prior to transfusion). RT-PLT are currently stored flat on specialized porous racks and agitated at 18-22°C, which allows for oxygenation. These products are stored out to 5 days, with 7 days allowed for large volume delayed sampling collections. In contrast, refrigerated blood products (i.e., packed red blood cells and whole blood) are stored vertically in pull out drawers, with the goal of reducing harmful oxidizing damage to red blood cells. Notably, refrigeration is known to induce aggregation of platelets, a feature historically associated with bacterial contamination in RT-PLT. In order to diminish concerns regarding aggregate formation, it may be beneficial to massage CS-PLT briefly each day to reduce aggregate formation, yet how this may impact hemostatic function is unknown. To this end, optimal storage and handling conditions for CS-PLT remain to be determined.The objective of our study was to measure CS-PLT hemostatic function in response to two major storage and handling variables: agitation and massage to reduce aggregation in the bag. Single donor apheresis platelet units (single Trima collection in plasma, split equally into two bags to control for donor variability; n=20 donors in 40 bags) were purchased from our regional blood center and delivered to our lab on day of collection. Upon arrival, units were spiked and sampled under sterile conditions for baseline (day 0) profiling, assigned to one of the study groups, and stored accordingly. Our study groups were as follows: “Agitated” (n=10 units), “Not Agitated” (n=10 units, paired with Agitated donors), “Massaged Daily”, (massaged 60s daily, n=10 units), and “Massaged at Sampling” (massaged only at sampling, n=10 units, paired with Massaged Daily donors). “Agitated” platelet units were stored in a custom refrigerated shaker (courtesy Helmer Scientific). For the other groups, platelet units were stored in a walk-in cold room. All units were stored on the same style perforated agitator rack, with agitation either powered on or off as assigned. Units from all groups were sampled under sterile conditions at days 2, 5, 7, 14, and 21 of storage, using 8 mL draws at each time point to ensure equal volume removal over the course of storage. Hemostatic function was assayed using light transmission aggregometry (LTA; ADP, collagen, epinephrine agonists), rotational thromboelastometry (ROTEM; ExTEM, InTEM agonists), and thrombin generation in response to 5 pM tissue factor. Platelet counts (x10 3/µL) were obtained using a hematology analyzer.During the first week of storage, there were no significant differences in the hemostatic profiles between study groups. While platelet counts, endogenous thrombin potential, and ROTEM clot formation time and maximum clot firmness were fairly stable over the first 7 days of storage across all groups, there was a > 50% reduction from baseline in aggregation responses to both ADP and collagen across all 4 groups, suggesting that platelet aggregation, as detected by LTA, may not be the best representative of CS-PLT function. By day 21 of storage, there was a robust increase in endogenous thrombin potential in all study groups when compared to baseline (Agitated, 22%; Not Agitated, 70%; Massaged Daily, 51%; Massaged at Sampling, 47%). Despite this increase in thrombin generation, after extrinsic activation day 21 CS-PLT in all groups had two-fold increased clot formation times compared to baseline (Agitated, 185%; Not Agitated, 223%; Massaged Daily, 236%; Massaged at Sampling, 190%), and reduced maximum clot firmness compared to baseline (Agitated, -44%; Not Agitated, -36%; Massaged Daily, -54%; Massaged at Sampling, -43%). These data suggest that storage duration, and not agitation nor massaging to reduce aggregates, has the most impact on CS-PLT hemostatic function. DisclosuresSpinella: Cerus Corporation: Consultancy, Research Funding; Secure Transfusion Services: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company.

Efficient inactivation of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in human apheresis platelet concentrates with amotosalen and ultraviolet A light.

ObjectivesThe detection of SARS-CoV-2 RNA in blood and platelet concentrates from asymptomatic donors, and the detection of viral particles on the surface and inside platelets during in vitro experiments, raised concerns over the potential risk for transfusion-transmitted-infection (TTI). The objective of this study was to assess the efficacy of the amotosalen/UVA pathogen reduction technology for SARS-CoV-2 in human platelet concentrates to mitigate such potential risk.Material and methodsFive apheresis platelet units in 100% plasma were spiked with a clinical SARS-CoV-2 isolate followed by treatment with amotosalen/UVA (INTERCEPT Blood System), pre- and posttreatment samples were collected as well as untreated positive and negative controls. The infectious viral titer was assessed by plaque assay and the genomic titer by quantitative RT-PCR. To exclude the presence of infectious particles post-pathogen reduction treatment below the limit of detection, three consecutive rounds of passaging on permissive cell lines were conducted.ResultsSARS-CoV-2 in platelet concentrates was inactivated with amotosalen/UVA below the limit of detection with a mean log reduction of > 3.31 ± 0.23. During three consecutive rounds of passaging, no viral replication was detected. Pathogen reduction treatment also inhibited nucleic acid detection with a log reduction of > 4.46 ± 0.51 PFU equivalents.ConclusionSARS-CoV-2 was efficiently inactivated in platelet concentrates by amotosalen/UVA treatment. These results are in line with previous inactivation data for SARS-CoV-2 in plasma as well as MERS-CoV and SARS-CoV-1 in platelets and plasma, demonstrating efficient inactivation of human coronaviruses.

Supplemental findings of the 2019 National Blood Collection and Utilization Survey.

Supplemental data from the 2019 National Blood Collection and Utilization Survey (NBCUS) are presented and include findings on donor characteristics, autologous and directed donations and transfusions, platelets (PLTs), plasma and granulocyte transfusions, pediatric transfusions, transfusion-associated adverse events, cost of blood units, hospital policies and practices, and implementation of blood safety measures, including pathogen reduction technology (PRT). National estimates were produced using weighting and imputation methods for a number of donors, donations, donor deferrals, autologous and directed donations and transfusions, PLT and plasma collections and transfusions, a number of crossmatch procedures, a number of units irradiated and leukoreduced, pediatric transfusions, and transfusion-associated adverse events. Between 2017 and 2019, there was a slight decrease in successful donations by 1.1%. Donations by persons aged 16-18 decreased by 10.1% while donations among donors >65 years increased by 10.5%. From 2017 to 2019, the median price paid for blood components by hospitals for leukoreduced red blood cell units, leukoreduced apheresis PLT units, and for fresh frozen plasma units continued to decrease. The rate of life-threatening transfusion-related adverse reactions continued to decrease. Most whole blood/red blood cell units (97%) and PLT units (97%) were leukoreduced. Blood donations decreased between 2017 and 2019. Donations from younger donors continued to decline while donations among older donors have steadily increased. Prices paid for blood products by hospitals decreased. Implementation of PRT among blood centers and hospitals is slowly expanding.

Economic Analysis of Posaconazole Prophylaxis in Patients with Acute Myeloid Leukemia Undergoing Remission Induction Chemotherapy from a Hospital Management Perspective

▪IntroductionInvasive fungal infections (IFI) are an important and trending causes of mortality in patients with acute leukemia. Especially during the remission induction, as well as stem cell transplantation, the patients bear the highest risk of IFI due to the prolonged severe neutropenia, long term exposure to broad spectrum antibiotics and cytotoxic chemotherapy.In a meta analysis of primary antifungal prophylaxis (PAT) in patients with malignancy receiving cytotoxic treatment and/or stem cell transplantation, antifungal prohylaxis was related with dramatic decrease in infection related mortality and decreased IFI. In another meta analysis focusing on prophylaxis with mould-active agents or fluconazole in hematologic malignancies has reported a significant decrease in IFI proven or probable, IFI related mortality and also with a concern, increased risk of adverse effects in the mould-active receiving group.Patients and Methods225 patients who have been diagnosed with acute myeloid leukemia (AML) and undergoing intensive treatment (idarubicin 12mg/m2 for three days and cytarabin 100mg/m2 24 h infusion for 7 days) for remission induction have been enrolled in the study in a retrospective manner. Direct health expenses like days of hospitalization, number of CT scans for thorax, development of complications, number of platelet apheresis infusions, mortality during remission induction treatment and total inpatient hospital costs. The benefits included cost reductions after adoption of primary antifungal prophylaxis.Results124 patients were male (55,4%) while 100 were female (44,6%). 90 patients received prophylactic treatment during remission induction therapy (40,2%). 43 patients died during remission induction therapy (19,2%). Mean number of thorax CT scans during remission induction was 1,73 (0-6). Mean number of days for hospitalization was 29,36 (14-88) days. Mean number of units of transfused thrombocyte apheresis was 9,9 (0-43) units. Mean cost of whole remission induction treatment was 9.151,6 (2.872,6-20.483,3) US dolars. Within patients who are not on PAT, 116 patients (86,5%) were treated with an intravenous antimould antifungal treatment while 5 of the patients on PAT (5,5%) received parenteral antimould antifungal treatment, 4 of which were related with neutropenic enterocolitis (p<0.005). 32 of the patients who are not on PAT died during remission induction (23,88%) while 11 of the patients who are on PAT died during remission induction (12,22%) (p=0.021). Mean days of hospitalization for remission induction treatment was 22,61 days for patients on PAT and 33,89 days for patients who are not on PAT (p<0.005). In patients on PAT, mean number of transfused platelet units was 6 (0-9) while 12,51 (4-43) units for patients who are not on PAT (p<0.005). When grouped as paients who are and who are not on PAT, there were significant difference between groups regarding total days of hospitalization, number of transfused platelet apheresis units, number of CT scans for thorax, death during remission induction and total cost of remission induction treatment in favor of patients on PAT. All significant data were analyzed with logistic regression analysis and observed as statistically significant. Results were summarized in Table.DiscussionIn Turkey, social security covers all the treatment for malignancies and complications, with rules and statements that lead the clinicians for decisions. Health Application Communiqué regulates the practice for reimbursement and since 2010, antimould antifungal agents are approved for prophylaxis in patients with AML who are undergoing remission induction therapy or patients undergoing hematopoietic stem cell transplantation. According to the physicians' or center's practices, PAT may be used and reimbursed.In our study, oral suspension form of posaconazole was effective to prevent IFI with a significant decrease in mortality during remission induction treatment. Likewise, PAT with posaconazole was observed to be cost-beneficial regarding the number of CT scans for thorax, number of platelet transfusion and over all costs of hospitalization for remission induction treatment. With its limitations regarding adherence as oral suspension form, tablet form may overcome these limitations. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

P38 mitogen activated protein kinase inhibitor improves platelet in vitro parameters and in vivo survival in a SCID mouse model of transfusion for platelets stored at cold or temperature cycled conditions for 14 days.

Platelets for transfusion are stored at room temperature (20–24°C) up to 7 days but decline in biochemical and morphological parameters during storage and can support bacterial proliferation. This decline is reduced with p38MAPK inhibitor, VX-702. Storage of platelets in the cold (4–6°C) can reduce bacterial proliferation but platelets get activated and have reduced circulation when transfused. Thermocycling (cold storage with brief periodic warm ups) reduces some of the effects of cold storage. We evaluated in vitro properties and in vivo circulation in SCID mouse model of human platelet transfusion of platelets stored in cold or thermocycled for 14 days with and without VX-702. Apheresis platelet units (N = 15) were each aliquoted into five storage bags and stored under different conditions: room temperature; cold temperature; thermocycled temperature; cold temperature with VX-702; thermocycled temperature with VX-702. Platelet in vitro parameters were evaluated at 1, 7 and 14 days. On day 14, platelets were infused into SCID mice to assess their retention in circulation by flow cytometry. VX-702 reduced negative platelet parameters associated with cold and thermocycled storage such as an increase in expression of activation markers CD62, CD63 and of phosphatidylserine (marker of apoptosis measured by Annexin binding) and lowered the rise in lactate (marker of increase in anaerobic metabolism). However, VX-702 did not inhibit agonist-induced platelet aggregation indicating that it does not interfere with platelet hemostatic function. In vivo, VX-702 improved initial recovery and area under the curve in circulation of human platelets infused into a mouse model that has been previously validated against a human platelet infusion clinical trial. In conclusion, inhibition of p38MAPK during 14-days platelet storage in cold or thermocycling conditions improved in vitro platelet parameters and platelet circulation in the mouse model indicating that VX-702 may improve cell physiology and clinical performance of human platelets stored in cold conditions.

The apheresis platelet donation was increased after a nationwide ban on family/replacement donation in China

BackgroundA nationwide ban on family/replacement donation (FRD) went into effect on April 1, 2018 in China. To date, no reports relevant to the trend of plateletpheresis donations before and after a nationwide ban on FRD were found.MethodsWe used two independent full samples, consisting of 135,851 and 82,129 plateletpheresis donors from Guangzhou and Chengdu between October 2012 and September 2019, respectively. A pseudo-panel data approach was applied by grouping three time-invariant covariates – gender, blood donation history, and birth year across 14 cross-sections (a 6-month interval each) to form a total of 24 cohort groups (14 × 24 = 336 cohorts, i.e., cells) with each having common covariates. The outcome was average apheresis platelet units per donor in each cell. We performed a two-piecewise linear mixed model with the cross-section (i.e., time) just right before the ban as a time breakpoint (i.e., 11th cross-section) to examine the trend of outcome with the adjustment of three time-invariant covariates. We removed the FRDs in each of the first 11 cross-sections to detect its possible influence on the trend.ResultsThe final model for the samples from Guangzhou presented a two-piecewise linear trend of the outcome over time with a horizontal line to the left of the breakpoint (βtimeBefore11 = 0.0111, p = 0.0976) and a significantly positive linear trend to the right (βtimeAfter11 = 0.0404, p < 0.0001). The male donors and the donors with plateletpheresis donation history had an increased baseline outcome and a significant outcome change over time after the ban. Such a two-piecewise linear trend pattern can be replicated using the samples from Chengdu with some minor variations. Removing the FRD before the ban can change the pattern.ConclusionThe significant increase of the average apheresis platelet units per donor over time after the FRD ban may be related to the implement of the FRD ban and the improved donation behavior of male donors and/or donors with platelet donation history after the ban. Our findings may potentially motivate the policymakers in other countries where the FRD for plateletpheresis donation is still legitimate to phase out their FRD strategy and ultimately achieve 100% voluntary plateletpheresis donation.

Paid platelet donors: Points to consider

Paid platelet donors: Points to consider