Platelet Dose Research Articles

Survival after ultramassive transfusion: a review of 1360 cases

Information about patient survival after transfusion of multiple blood volumes is limited, and most reports have focused on trauma patients. Retrospective study of blood use and survival at 11 hospitals in six nations between 2009 and 2013. Ultramassive transfusion (UMT) was defined as transfusion of 20 or more red blood cell (RBC) units over the course of any 2 consecutive calendar days. A total of 1975 patients received UMT and a representative sample of 1360 patients was studied in detail. Patients were grouped into seven diagnostic categories: solid organ transplantation (n = 411), cardiac or major vascular surgery (n = 317), general surgery (n = 228), trauma (n = 221), general medicine (n = 124), obstetrics (n = 23), and other (n = 36). During the 7 days after initiation of UMT, these patients used more than 120,000 blood components. The median (interquartile range) blood use was 35 (26-50) RBC units, 30 (20-47) plasma units, and 7 (4-13) platelet doses. Five- and 30-day survival significantly declined with increasing RBC use. Overall survivals of patients receiving UMT were 71% (5 day) and 60% (30 day), and in the subset of 165 patients receiving 60 or more RBC units over 2 consecutive days, 5-day survival was 54% ranging from 17% (trauma) to 75% (solid organ transplant). The decline in survival with increasing RBC transfusions was minimal for patients undergoing solid organ transplantation and was most pronounced for trauma and nonsurgical bleeding patients. Trauma was not the leading cause of UMT. Increasing RBC requirements were significantly associated with decreasing survival. However, survival was more strongly associated with diagnostic category than total RBCs transfused, with highest survival rates in solid organ transplant surgery.

Thrombocytopenia after autologous stem cell transplantation

Aim. Characteristics of thrombocytopenia and finding ways of predicting platelet transfusions at autologous hematopoietic stem cell transplantation in patients with hematologic and autoimmune diseases. Methods. Thrombocytopenia period after autologous hematopoietic stem cell transplantation in patients with autoimmune (group I, n=87) and hematological (group II, n=82) diseases was evaluated. Results. It was revealed that in patients with hematological oncologic diseases platelet count before the transplantation and on the first day after it is connected with the length of thrombocytopenia and the number of transfused platelets units. In patients with autoimmune diseases, low platelet count on the first day after transplantation might be used as a predictor for the transfusion risk. Day of thrombocytopenia onset is predictive of its duration and the need for blood components. In patients with hematological oncologic diseases, severe thrombocytopenia at day 14 before the transfusion is associated with further transfusion of 3 or more units of platelets. Platelet count at the first day after the transfusion is related to the number of platelet units transfused and thrombocytopenia duration. Onset of thrombocytopenia with platelet count lower than 20 and 10×109/L is predictive of its duration and the need for blood components. In patients with hematological oncologic diseases, early onset of thrombocytopenia is associated with further transfusion of larger doses of platelets. Conclusion. The revealed differences may be used as the criteria for predicting platelet transfusions in patients after autologous hematopoietic stem cell transplantation.

Limitations of component therapy for massive haemorrhage: is whole blood the whole solution?

Limitations of component therapy for massive haemorrhage: is whole blood the whole solution?

Namibia's transition from whole blood-derived pooled platelets to single-donor apheresis platelet collections.

Few African countries separate blood donations into components; however, demand for platelets (PLTs) is increasing as regional capacity to treat causes of thrombocytopenia, including chemotherapy, increases. Namibia introduced single-donor apheresis PLT collections in 2007 to increase PLT availability while reducing exposure to multiple donors via pooling. This study describes the impact this transition had on PLT availability and safety in Namibia. Annual national blood collections and PLT units issued data were extracted from a database maintained by the Blood Transfusion Service of Namibia (NAMBTS). Production costs and unit prices were analyzed. In 2006, NAMBTS issued 771 single and pooled PLT doses from 3054 whole blood (WB) donations (drawn from 18,422 WB donations). In 2007, NAMBTS issued 486 single and pooled PLT doses from 1477 WB donations (drawn from 18,309 WB donations) and 131 single-donor PLT doses. By 2011, NAMBTS issued 837 single-donor PLT doses per year, 99.1% of all PLT units. Of 5761 WB donations from which PLTs were made in 2006 to 2011, a total of 20 (0.35%) were from donors with confirmed test results for human immunodeficiency virus or other transfusion-transmissible infections (TTIs). Of 2315 single-donor apheresis donations between 2007 and 2011, none of the 663 donors had a confirmed positive result for any pathogen. As apheresis replaced WB-derived PLTs, apheresis production costs dropped by a mean of 8.2% per year, while pooled PLT costs increased by an annual mean of 21.5%. Unit prices paid for apheresis- and WB-derived PLTs increased by 9 and 7.4% per year on average, respectively. Namibia's PLT transition shows that collections from repeat apheresis donors can reduce TTI risk and production costs.

Platelet-Rich Plasma Enhances the Cellular Function of Equine Bone Marrow-Derived Mesenchymal Stem Cells

Rationale: Equine mesenchymal stem cells (eMSCs) and platelet-rich plasma (PRP) are cell-based therapies being used clinically to repair damaged tissue of horses. Numerous reports including data from our laboratory show that there are variations in the biological properties of MSCs and platelet – rich plasma, which can impact their biological functions. A single study describes the use of the eMSCs and PRP in tendon healing, with minimal success. The exact mechanism of action using the combination of the two therapies is unknown. This study was performed to evaluate and understand the effects of PRP, if any on the cellular performance of eBMMSCs in culture. Objective: To assess the effects of PRP in vitro on the rate of proliferation, expression of protein markers and osteogenic and chondrogenic differentiation of the primary cultures of eBMMSCs. Methods and Results: A commercially available stall side, portable kit was used to isolate PRP. To investigate the effect of PRP on eBMMSCs, the rate of proliferation of eBMMSCs was measured using the MTS assay, and subsequently the viability and the stemness of eBMMSCs was assessed using fluorescent staining and the expression of CD90. Finally, the osteogenic and chondrogenic differentiation of eBMMSCs was assessed by lineage-specific staining and the expressions of lineage – specific mRNAs. All assays were performed at a concentration of 50 million platelets/mL. Significant increase in proliferation and the differentiation profiles were observed in presence of PRP. Most importantly, the stem cell characteristics of inferior eBMMSCs showed a marked improvement in presence of PRP. Conclusions: The addition of PRP improves the in vitro function of eBMMSCs by enhancing the proliferation and osteo - and chondro - genesis. The presence of an optimal dose of platelets may enhance the in vivo performance of eBMMSCs and may be indicated when using autologous eBMMSCs therapy in the clinic.

Aspirin in Philadelphia-Negative Myeloproliferative Neoplasms: What Is the Optimal Dose ?

Background: Myeloproliferative neoplasms (MPN) are associated with an increased risk of arterial and venous thrombosis with an annual incidence varying from 1.1% to 6.6% (Patrono, Blood 2013). Comparable to that recommended in non-MPN high-risk patients, low-dose aspirin (81-100 mg/day) is recommended in primary and secondary prophylaxis of thrombosis in polycythemia vera and essential thrombocytemia (Tefferi, Am J Hematol 2012). However, the daily dose of aspirin to optimize efficacy and safety for MPN patients has never been challenged.Aim of the study: Determine the optimal dose of aspirin to achieve biological efficacy in Philadelphia-negative MPN patients.Methods: Patients with Philadelphia-negative MPN who were treated with low-dose aspirin 75 or 100 mg/day were enrolled in this observational study. Patients without any cytostatic drug and patients treated with either pegylated interferon alpha or hydroxyurea were eligible. Major exclusion criteria included inability to adhere to aspirin therapy and chronic oral anticoagulation. Biological efficacy to aspirin was evaluated by platelet aggregation induced by arachidonic acid 1.33 mM on platelet rich plasma and tested at trough level and 24 hours after last aspirin intake. Resistance to aspirin was defined as a maximal platelet aggregation over 20%. According to the results of platelet aggregation, aspirin dose and dosing regimen were modified as follows: from 100 mg/day to 160 mg/day or 75 mg x2/day. Patients enrolled in this have a median follow up of at least 6 months after the analysis.Results: Between January 2012 and February 2014, 77 patients with Philadelphia-negative MPN were included. 53 were treated with aspirin 75 mg/day (69%) and 24 with aspirin 100 mg/day (31%).Out of the 53 patients treated with aspirin 75 mg/day, 12 patients (23%) were resistant to aspirin.Resistance to aspirin was not correlated to sex, age, presentation, JAK2 status, treatment, history of thrombotic or bleeding and hematologic values (see following table). Table 1:The MPN Grade 1 Fibrosis PhenotypePMF (N:33)PV/ET (N:58)Total (N:91)Median age63 yrs55 yrs58 yrsSex1:31:11:2JAK V617F +16/33: (49%)40/58: (69%)56/91: (62%)Median Hgb(g/dL)11.9 (range 7.9-16.4)12.5 (range 8.0-19.8)12.2 (range 7.9-19.8)Median WBC(X10 (9))26.9 (range 1.3-188)8.9 (range 3.5-51.3)10.8 (range 1.3-188 )Median Platelet(X10 (9))179 (range 18.0-1194)505 (range 67-2286)370 (range 18-2286)Leukoerythroblastic Blood Smear15/33 (45%)PV: 17 ET: 5 Total: 22/58 (38%)37/91 (41%)Splenomegaly(cm below costal margin)18/33: (55%) Median: 1025/58: (43%) Median: 643/91(48%) Median: 4Transfusion dependence6/33: (18%)2/58: (4%)8/91: (9%)Presence Of ³ 1 symptom17/33: (52%)33/58: (57%)50/91: (55%)DIPSS risk intermediate 2 or higher13/33: (39%)17/58: (29%)30/91: (33%)2 or more prior therapies9/33: (27%)36/58: (62%)45/91: (49%)Vital Status (Alive)25/33: (76%)53/58: (91%)78/90: (86%)Median follow up time (yrs)1.9 (range 0.1-9.8)5.7 (range 0-34.5)3.1 (range 0-34.5)An increased dose of 100 mg/day for at least 7 days overcame this biological resistance in 8 out of 8 re-tested patients. The 2 remaining 75mg resistant patients received an increased dose of aspirin but were not retested.Out of the 24 patients under 100 mg/day, only two (8%) were resistant to aspirin. In these patients, increasing the dose to 160 mg/day did not modify their biological response. However a 75 mgx2 /day was effective to overcome biological resistance.No thrombotic or bleeding event was observed during the 6-month follow-up regardless of the aspirin dose.Conclusions: This is the first study to measure in standardized conditions the biological resistance of aspirin in 77 well-characterized Philadelphia-negative MPN patients. Although this does not reach statistical significance a higher proportion of patients treated with aspirin 75mg/day was resistant to anti-platelet therapy compared to patients treated with aspirin 100 mg/day. Increasing the dose of aspirin from 75 to 100 mg once daily overcomes this biological resistance without increasing bleeding side effects and seems the best compromise. Interestingly in rare cases of extreme resistance to 100mg doubling the dose twice daily (75mgX2) was better than an increase of 160mg in one take. This pilot study on a small number of patients with a limited 6-month follow up compared to the low annual incidence of thromboses in these MPNs will be followed by a prospective study on a larger number of patients with an extended follow-up period to determine if biological resistance to aspirin is correlated to the occurrence of thrombotic events. DisclosuresNo relevant conflicts of interest to declare.

Plant Food Anthocyanins Induced Platelet Apoptosis Via BCL-2/BCL-XL Pathway

Background: Platelets are versatile cells and play important roles in hemostasis/thrombosis, inflammation, and atherosclerosis. The pathogenesis of cardiovascular diseases (CVDs) is linked to platelet hyperactivity which is considered an independent risk factor for CVDs. Platelets are critical for promoting the progression of CVDs, and platelet apoptosis have been reported to be involved in platelet activation. Anthocyanins are major phytochemicals abundant in plant food and have been shown to play a protective role against CVDs. Our previous studies demonstrated that anthocyanins from plant food significantly inhibited platelet activation, adhesion, aggregation and granule secretion, as well as attenuated thrombus growth at both arterial and venous shear stresses in vitro and in vivo, however, the effects of anthocyanin on platelet apoptosis and its mechanisms have not been explored. In the present study, we examined whether anthocyanin Cyanidin-3-glucoside (Cy-3-g) affect platelet apoptosis and the BCL-2/BCL-XL intrinsic apoptotic pathway.Methods: Cy-3-g, the predominant bioactive compound of anthocyanin preparations, was obtained from Polyphenol AS Company in Norway.Purified gel-filtered platelets from healthy volunteers were incubated at 37oC for 40 minutes with different concentrations of Cy-3-g (0.5、5、50μM) or PBS buffer as a control. the activated platelets were triggered with 0.5U thrombin for 15min to induce apoptosis. Mitochondria membrane potential (Δψm) and membrane phospholipid phosphatidylserine (PS) exposure in both activated and resting platelets were assessed by flow cytometry. Cytochrome C release, activation of caspase-3, caspase-8, caspase-9, cleavage of gelsolin, the levels of anti-apoptotic BCL-2 family proteins such as BCL-2, BCL-XL and proapoptotic BCL-2 family proteins Bax, Bak, Bad, Bid and tBid in both activated and resting platelets were measured by western blotting.Results: Cy-3-g at 5μM and 50μM directly induced significant ΔΨm dissipation in activated platelets dose dependently. Correspondingly, 50μM Cy-3-g increased cytochrome C release compared to control. The expression of pro-caspase-8 and pro-caspase-9 decreased, activation of caspase-3, caspase-8 and caspase-9 was induced in activated platelets in both 5μM and 50μM Cy-3-g groups. Both PS exposure and the cleavage of gelsolin increased in activated platelets, however these effects were only observed at Cy-3-g doses as high as 50μM. Cy-3-g did not induce the above changes in resting platelets. The intrinsic apoptotic pathway was initiated by Cy-3-g treatment in activated platelets; Cy-3-g significantly inhibited the expression of BCL-2, BCL-XL and increased the levels of Bax, Bak, Bad and Bid in activated platelets dose dependently. No significant difference was observed in resting platelets.Conclusions: Our data demonstrate for the first time that purified anthocyanin Cy-3-g directly accelerated apoptosis in activated platelets via the BCL-2/BCL-XL pathway. Anthocyanins may possess therapeutic potential for patients suffering from thrombotic conditions. DisclosuresNo relevant conflicts of interest to declare.

Guidance on platelet transfusion for patients with hypoproliferative thrombocytopenia.

Patients with hypoproliferative thrombocytopenia are at an increased risk for hemorrhage and alloimmunization to platelets. Updated guidance for optimizing platelet transfusion therapy is needed as data from recent pivotal trials have the potential to change practice. This guideline, developed by a large international panel using a systematic search strategy and standardized methods to develop recommendations, incorporates recent trials not available when previous guidelines were developed. We found that prophylactic platelet transfusion for platelet counts less than or equal to 10 × 10(9)/L is the optimal approach to decrease the risk of hemorrhage for patients requiring chemotherapy or undergoing allogeneic or autologous transplantation. A low dose of platelets (1.41 × 10(11)/m2) is hemostatically as effective as higher dose of platelets but requires more frequent platelet transfusions suggesting that low-dose platelets may be used in hospitalized patients. For outpatients, a median dose (2.4 × 10(11)/m2) may be more cost-effective to prevent clinic visits only to receive a transfusion. In terms of platelet products, whole blood-derived platelet concentrates can be used interchangeably with apheresis platelets, and ABO-compatible platelet should be given to improve platelet increments and decrease the rate of refractoriness to platelet transfusion. For RhD-negative female children or women of child-bearing potential who have received RhD-positive platelets, Rh immunoglobulin should probably be given to prevent immunization to the RhD antigen. Providing platelet support for the alloimmunized refractory patients with ABO-matched and HLA-selected or crossmatched products is of some benefit, yet the degree of benefit needs to be assessed in the era of leukoreduction.

Platelet transfusion: a systematic review of the clinical evidence.

Platelet (PLT) transfusion is indicated either prophylactically or therapeutically to reduce the risk of bleeding or to control active bleeding. Significant uncertainty exists regarding the appropriate use of PLT transfusion and the optimal threshold for transfusion in various settings. We formulated 12 key questions to assess the role of PLT transfusion. We performed a systematic review (SR) of randomized controlled trials (RCTs) and observational studies. A comprehensive search of PubMed, Web of Science, and Cochrane registry of controlled trials was performed. Methodologic quality of included studies was assessed and a meta-analysis was performed if more than two studies with similar designs were identified for a specific question. Seventeen RCTs and 55 observational studies were included in the final SR. Results from RCTs showed a beneficial effect of prophylactic compared with therapeutic transfusion for the prevention of significant bleeding in patients with hematologic disorders undergoing chemotherapy or stem cell transplantation. We found no difference in significant bleeding events related to the PLT count threshold for transfusion or the dose of PLTs transfused. Overall methodologic quality of RCTs was moderate. Results from observational studies showed no evidence that PLT transfusion prevented significant bleeding in patients undergoing central venous catheter insertions, lumbar puncture, or other surgical procedures. The methodologic quality of observational studies was very low. We provide a comprehensive assessment of evidence on the use of PLT transfusions in a variety of clinical settings. Our report summarizes current knowledge and identifies gaps to be addressed in future research.

Where did platelets go in 2012? A survey of platelet transfusion practice in the North of England.

To record the fate of transfused platelet doses in the North of England, and thereby assist with demand-planning and help target teaching on appropriate use. Platelet use has risen recently to the extent that donation practice has changed to meet demand. Two national comparative audits have shown inappropriate use and the 2010 audit concluded that current U.K. guidelines for platelet usage should be completely implemented at a local level. It is necessary to know how platelets are used and by whom in order to facilitate guideline concordance. All hospital trusts in the North East and Cumbria recorded data on all platelet doses transfused in two separate 4-week periods in 2012. Data were entered onto an electronic survey tool. One thousand and five hundred and seventy-four reports were received, documenting 1937 transfused doses--96% of total issues for the study periods. One thousand and forty-five platelet doses (54%) were given for haematological indications. The second commonest indication was cardiac surgery (201 doses, 10% of the total) followed by non-haematological oncology (127 doses, 6.5%), critical care (106 doses, 5%) and liver disease (50 doses, 2.5%). The commonest haematological indication was acute myeloid leukaemia, 310 doses, (16% of all platelet use), followed by stem cell transplantation, 271 doses (14%). Seventy-two percent of platelet doses were given prophylactically, the majority without any planned procedure. The commonest indication for platelet use, where reinforcement of guidelines will be productive, is prophylaxis in haematological disease. Use of platelets in cardiac surgery is also worthy of close scrutiny.

Anti‐HLA alloantibodies in surgical patients refractory to platelet transfusion

Alloimmune platelet refractoriness (alloPR) among actively bleeding surgical patients with thrombocytopenia represents a life-threatening problem. Here we present three cases in which surgical bleeding was complicated by life-threatening thrombocytopenia and alloPR. We demonstrate that the human leukocyte antigens (HLA) antibodies associated with alloPR are broadly reactive and in high concentration, are not removed by hemodilution, and are not absorbed by transfusion of multiple doses of platelet concentrates. HLA alloPR may be under-recognized among surgical patients. Research is needed to develop pre-operative screening methods that will identify patients in need of specialized platelet support using HLA compatible donor products.

Characterization and Comparison of 5 Platelet-Rich Plasma Preparations in a Single-Donor Model

The purpose of this study was to compare the biological characteristics of platelet-rich plasma (PRP) obtained from 4 medical devices and a preparation developed in our laboratory using a single-donor model. Ten healthy persons donated blood that was processed to produce PRP by use of 4 commercial preparation systems and a protocol developed in our laboratory. Volumes and platelet, white blood cell (WBC), and red blood cell concentrations were recorded. The platelet activation status was assessed by flow cytometry. Enzyme-linked immunosorbent assay was used to determine the concentrations of vascular endothelial growth factor, platelet-derived growth factor AB, epidermal growth factor, and transforming growth factor β1. We calculated platelet capture efficiency, relative composition, and increase factors from whole blood in platelets and WBC, as well as platelet and growth factor (GF) doses, provided from each preparation. Leukocyte-rich PRP was obtained with RegenPRP (RegenLab, Le Mont-sur-Lausanne, Switzerland) and the Mini GPS III System (Biomet Biology, Warsaw, IN) and provides PRP with higher proportions of red blood cells, WBCs, and neutrophils than leukocyte-poor PRP obtained with the Selphyl System (Selphyl, Bethlehem, PA), Arthrex ACP (Arthrex, Naples, FL), and the preparation developed in our laboratory. The highest platelet and GF concentrations and doses were obtained with the Mini GPS III System and the preparation developed in our laboratory. Different centrifugation protocols did not show differences in the percentages of activated platelets. Finally, a positive correlation between platelet doses and all the GFs studied was found, whereas a positive correlation between WBC doses and GFs was found only for vascular endothelial growth factor and epidermal growth factor. In a single-donor model, significant biological variations in PRP obtained from different preparation systems were highlighted. The observed differences suggest different results for treated tissue and could explain the large variability in the clinical benefit of PRP reported in the literature. Our findings will help clinicians to choose a system that meets their specific needs for a given indication.

Effects of ex vivo platelet supplementation on platelet aggregability in blood samples from patients treated with acetylsalicylic acid, clopidogrel, or ticagrelor

BackgroundTransfusion of platelet concentrate is often used to treat bleeding in patients on platelet inhibitors, but little is known about its efficacy between different inhibitors. We assessed the effect of ex vivo platelet supplementation on platelet aggregability in blood samples from patients treated with acetylsalicylic acid (ASA), clopidogrel, or ticagrelor. MethodsPlatelet aggregability was investigated with multiple electrode aggregometry with adenosine diphosphate (ADP), arachidonic acid (to assess ASA-dependent aggregability), and thrombin receptor activating peptide-6 (TRAP) as activators in whole-blood samples from patients treated with ASA (n=10), ASA+clopidogrel (n=15), or ASA+ticagrelor (n=15), and from healthy controls (n=10). Aggregability was measured before and after supplementation of AB0-compatible fresh apheresis platelets (+46, +92, and +138×109 litre−1). ResultsBoth ASA-dependent and ADP-dependent aggregability improved in a dose-dependent fashion after platelet supplementation. ASA-dependent aggregability was completely restored in all patient groups, but there was only a small improvement in ADP-dependent aggregability in patients on dual antiplatelet therapy. There was less effect of platelet supplementation on ADP- and ASA-dependent aggregability in ticagrelor-treated patients than in clopidogrel-treated patients [3.9 (95% confidence interval 1.6–6.3) vs 9.0 (5.2–12.8) AU×min (P=0.021) and 48 (36–59) vs 69 (60–78) AU×min (P=0.004), respectively, at the highest platelet dose]. ConclusionsPlatelet supplementation improved platelet aggregability independently of antiplatelet therapy. The effect on ADP-dependent platelet inhibition was limited however. Reduced effect of platelet transfusion is more likely within 2 h of drug intake in patients treated with ASA+ticagrelor compared with ASA+clopidogrel.

Platelet Utilization: A Canadian Blood Services Research and Development Symposium

Considerable progress has been made in recent years in understanding platelet biology and in strengthening the clinical evidence base around platelet transfusion thresholds and appropriate platelet dosing. Platelet alloimmunization rates have also declined. Nevertheless, controversies and uncertainties remain that are relevant to how these products can best be used for the benefit of platelet transfusion recipients. Platelets are unique among the blood products directly derived from whole blood or apheresis donations in requiring storage, with shaking, at ambient temperature. Storage is accordingly constrained between the need to limit the growth of any microbes in the product and the need to minimize losses in platelet function associated with storage. Proteomic and genomic approaches are being applied to the platelet storage lesion. Platelet inventory management is made challenging by these constraints. Although bacterial screening has enhanced the safety of platelet transfusions, pathogen reduction technology may offer further benefits. Continuing clinical investigations are warranted to understand the value of transfusing platelets prophylactically or only in response to bleeding in different patient groups and how best to manage the most grievously injured trauma patients. Patients refractory to platelet transfusions also require expert clinical management. The engineering of platelet substitute products is an active area of research, but considerable hurdles remain before any clinical uses may be contemplated. Roles for platelets in biological areas distinct from hemostasis are also emerging. Platelet utilization is variably affected by all of the above factors, by demographic changes, by new medications, and by new patient care approaches.

Single-donor (apheresis) platelets and pooled whole-blood-derived platelets--significance and assessment of both blood products

Single-donor (apheresis) platelets and pooled whole-blood-derived platelets--significance and assessment of both blood products

Experience of buffy coat pooling of platelets as a supportive care in thrombocytopenic dengue patients: A prospective study.

Random donor platelet (RDP) is not sufficient to improve the platelet count in most thrombocytopenic patients. Single donor platelet (SDP) or buffy coat pooled platelet (BCPP) are the two choices to provide a full therapeutic dose of platelets. However, there are constraints in the preparation of SDP due to stringent donor selection procedure, time required for procedure, and need of special expensive equipments and kits. BCPP is widely practiced, especially in the European countries, since 1995. In India, we decided to adopt the procedure of buffy coat pooling of platelets, especially for economically backward patients and for emergencies. This study was prospectively conducted from September 2009 to September 2010. A total of 129 units of BCPP [tested prior for viral markers by enzyme-linked immunosorbent assay (ELISA) and individual donor nucleic acid amplification test (ID-NAT)] were issued to 129 patients suffering from dengue and were included in this study. For comparison between efficacy of SDP and BCCP, patients were divided into two groups of 50 each. The post-transfusion platelet counts of the patients were noted after 2 hours of transfusion for each type of component. The platelet yield varied from 2.5 to 4.4 Χ 1011 in BCPP samples. The samples analyzed were sterile without any contamination. The different biochemical parameters were analyzed in detail. The observed post-transfusion platelet recovery and corrected count increment (CCI) at 1 hour and 24 hours after BCPP transfusion were similar to that after SDP transfusion. Hence, we concluded that BCPP can be a low cost alternative to SDP in the times of emergencies like dengue and non-affordability by the patient for SDP.

Transfusion practice varies widely in cardiac surgery: Results from a national registry

Evidence is accumulating of adverse outcomes associated with transfusion of blood components. Ifthere are differences in perioperative transfusion rates in cardiac surgery, and what hospital factors may contribute, requires further investigation. Analysis of 42,743 adult patients who underwent 43,482 procedures from 2005 to 2011 at 25Australian hospitals, according to the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database. Multiple logistic regression examined associations of patient and hospital characteristics with transfusion of ≥1 red blood cell (RBC) unit; platelet (PLT), fresh frozen plasma (FFP), and cryoprecipitate (CRYO) doses; and ≥5 RBC units, from surgery until hospital discharge. Procedures included 24,222 (55%) isolated coronary artery bypass grafts, 7299 (17%) isolated valve, 4714 (11%) coronary artery bypass graft and valve, and 7247 (17%) other procedures. After adjustment for various patient and procedure characteristics, transfusion rates varied across hospitals for ≥1 RBC unit from 22% to 67%, ≥5 RBC units from 5% to 25%, ≥1 PLT dose from 11% to 39%, ≥1 FFP dose from 11% to 48% and ≥1 CRYO dose from 1% to 20%. Hospital characteristics, including state or territory, private versus public, and teaching versus nonteaching, were not associated with variation in transfusion rates. Variation in transfusion of all components and large volume RBC was identified, even after adjustment for patient and procedural factors known to influence transfusion, and this was not explained by hospital characteristics.

Corticosteroids Plus Intravenous Immune Globulin (IVIg) Versus Corticosteroids Alone In The Treatment Of Newly Diagnosed Primary Immune Thrombocytopenia In Adults: A Retrospective Study

Background Primary immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by the immunologic destruction of platelets defined as a peripheral platelet count < 100 x109/L in the absence of other causes or disorders that may be associated with thrombocytopenia. Corticosteroids are generally utilized as the initial agent of choice in the first-line treatment for newly diagnosed ITP in non-emergent situations. There is limited evidence available to help guide the use of intravenous immune globulin (IVIg) in the management of newly diagnosed ITP except in cases of emergent bleeding. It is unknown whether the addition of IVIg to corticosteroids leads to improved short-term or long-term outcomes. We conducted a retrospective study to investigate whether the addition of IVIg to corticosteroid therapy improved time to response and duration of response in the treatment of adults with newly diagnosed primary ITP. Methods Patients 18 years of age or older who were hospitalized with newly diagnosed primary ITP with an initial platelet count ≤30 x 109/L were identified from charts dating January 2000 until January 2010. Excluded patients included those with a history of previously treated ITP, HIV, hepatitis C, cirrhosis, active pregnancy, active infection requiring concurrent antibiotic therapy, concomitant malignancy requiring chemotherapy, active rheumatologic disease, and recent use of medications associated with drug-induced ITP. Data collected included rates of bleeding, initial and serial platelet counts, and dose and formulation of steroid and IVIg used. Endpoints of interest were time to achieve partial response (PR; defined as a platelet count ≥30 x 109/L), time to achieve complete response (CR; defined as platelet count ≥100 x 109/L), duration of PR, and duration of CR. Chi-square tests were used to determine statistical differences between categorical variables; continuous variables were compared using the Mann-Whitney test. Time-to-event analyses were performed using Kaplan-Meier log-rank tests. P-values <0.05 were considered statistically significant. Results Fifty patients were identified of whom 29 (58%) were female and 21 (42%) were male. The median age of patients was 56 (range 19-96). Four patients (8%) presented with Grade III or IV bleeding. Twenty-two patients (44%) were given IVIg in the first three days of treatment concomitantly with steroids, and the remainder of patients (56%) was given steroids only. Ninety-one percent (20/22) of patients in the IVIg + steroids group achieved a PR, while 93% (26/28) of patients achieved a PR in the steroids alone group (p=0.80). Seventy-eight percent (17/22) of patients in the IVIg + steroids group achieved a CR, whereas 79% (22/28) of patients achieved a CR in the steroids alone group (p=0.78). Of those who achieved PR, the median time to achieve PR was 2 days versus 3 days in the IVIg + steroids group and steroids alone group, respectively (p=0.56). The median time to achieve CR was 10 days versus 22 days, respectively, with a trend toward statistical significance (p=0.11). Median duration of PR was not significant between the IVIG + steroids and steroids alone groups (median duration 646 days versus 893 days, respectively; p=0.83). Median duration of CR was not reached for the IVIg + steroids group and was 394 days in the steroids alone group (p=0.44). Discussion Patients diagnosed with acute primary ITP are typically treated with steroids, but no clear guidelines exist regarding who would benefit from the addition of IVIg. While the data suggests a trend towards a shorter time to achieving PR and CR as well as a trend toward longer duration of response in patients who received IVIg in addition to steroids, the differences are not significant in our cohort, probably due to small sample size. Rates of achievement of PR and CR were not different between the two groups. In an era focused on providing cost conscious health care, the lack of benefit from the addition of IVIg to corticosteroids could be a potential cost-saving measure. Further data in a larger retrospective study may improve the ability to discern a statistically significant difference between these two groups and further validation is needed through a prospective study. Disclosures: No relevant conflicts of interest to declare.

Reversal strategy in antagonizing the P2Y12‐inhibitor ticagrelor

Patients on antiplatelet therapy have a higher incidence of bleeding complications. Reversal of antiplatelet drug effects is an important issue at trauma or emergency departments. For old and conventional anticoagulants, reversal strategies are established. While the effects of ticagrelor are reversible, developing a method to restore platelet function in patients is of importance due to its longer half-life (approximately 8h), compared with other P2Y12 -inhibitors. We report an ex vivo model to reverse the effects of the novel and highly effective P2Y12 -inhibitor ticagrelor in 20 healthy volunteers. To normalize platelet reactivity, we added increasing amounts of autologous platelet-rich plasma (PRP) to whole blood which was obtained 3h after the intake of 180mg of ticagrelor. Platelet aggregation was assessed by whole blood multiple electrode aggregometry (MEA), which is based on impedance aggregometry. The basal ADP-induced platelet aggregation averaged 71±16U (Units). Ticagrelor decreased ADP-induced platelet aggregation to 16±8U. A clear dose-response was obtained after spiking whole blood with increasing amounts of PRP. It is estimated that ≥2 units of apheresis platelet concentrates will be necessary to completely restore baseline platelet aggregation in the majority of patients after ticagrelor. Platelets dose dependently improve ex vivo platelet aggregation of subjects after a loading dose of 180mg of ticagrelor, making transfusion of platelet concentrates potentially useful in bleeding patients and those who need to undergo emergency surgery.

Analysis on the Safety of Collecting Two Therapeutic Doses of Apheresis Platelet

Objective To explore the safety of blood donors who donated two therapeutic doses of apheresis platelet (PLT),and set up a scientific,reasonable and safe screening standard of blood donors.Method From June 2011 to June 2012,a total of 389 blood donors who donated two therapeutic doses of apheresis PLT in our blood station were included in this study.According to the different of PLT count before donation,all the donors were divided into three groups,such as:A group (PLT＜250 × 109,n=118),Bgroup [PLT were (250-299)×109,n=150] and C group (PLT≥300× 109,n=121).The influnence of blood donors' PLT level on PLT product quality and safety indicators of donors were investigated.Results In this study,the safety index compliance rate of 389 cases of blood donors was 97.17 ％ ; each group between safety evaluation index difference was statistically significant (P＜0.05).Thedonors' PLT,hematocrit (HCT),red blood cell (RBC) decreaded significantly (P＜0.05),but all the indicators were still within the safe range.12 cases of blood donors occurred blood donation reaction,as the rate of 3.08％.383 bags of PLT products qualified,as the pass rate of 98.46％.Conclusions It would be safe to collect two therapeutic dose of apheresis PLT from the donors whose weigh≥60 kg and PLT≥220 ×109(before the donation),HCT=0.40-0.48 (before the donation) with the intelligentized blood cell separator. Key words: two therapeutic dose of platelet by hemapheresis; quality of blood product; safety of blood donation