Platelet Concentrates Transfusion Research Articles

Platelet concentrates modulate myeloid dendritic cell immune responses

Platelet transfusion has been reported to modulate the recipients’ immune system. To date, the precise mechanism(s) driving poor patient outcomes (e.g., increased rate of mortality, morbidity, infectious complications and prolonged hospital stays) following platelet transfusion are largely undefined. To determine the potential for platelet concentrates (PC) to modulate responses of crucial immune regulatory cells, a human in vitro whole blood model of transfusion was established. Maturation and activation of human myeloid dendritic cells (mDC) and the specialized subset blood DC antigen (BDCA)3+ DC were assessed following exposure to buffy-coat derived PC at day (D)2 (fresh) and D5 (date-of-expiry). In parallel, to model recipients with underlying viral or bacterial infection, polyinosinic:polycytidylic acid or lipopolysaccharide was added. Exposure to PC had less of an impact on mDC responses than BDCA3+ DC responses. PC alone downregulated BDCA3+ DC expression of co-stimulatory molecules CD40 and CD80. In the model of viral infection, PC downregulated expression of CD83, and in the bacterial model of infection, PC downregulated CD80, CD83, and CD86. PC alone suppressed mDC production of interleukin (IL)-8, IL-12 and tumor necrosis factor (TNF)-α and BDCA3+ DC production of IL-8, IL-12, and IL-6. In the model of viral infection, production of IL-12 and interferon-gamma inducible protein (IP)-10 was reduced in both DC subsets, and IL-8 was reduced in BDCA3+ DC following PC exposure. When modeling bacterial infection, PC suppressed mDC and BDCA3+ DC production of IL-6 and IL-10 with a reduction in TNF-α evident in mDC. This study assessed the impact of PC “transfusion” on DC surface antigen expression and inflammatory mediator production and provided the first evidence that PC transfusion modulates blood mDC and BDCA3+ DC maturation and activation, particularly in the models of infection. Results of this study suggest that patients who receive PC, particularly those with underlying infectious complications, may fail to establish an appropriate immune response precipitating poor patient outcomes.

Platelet Septic Transfusion Reactions in Patients With Hemato-Oncological Diseases

Bacterial, contamination of blood components are a significant risk for transfusion reactions. Inherently, platelet concentrates (PCs) are vulnerable to bacterial contamination, due to the storage condition of processed PCs at room temperature, which provide very suitable conditions for the proliferation of microorganisms.The current study aimed at investigating the transfusion associated septic reaction rate in patients with hemato-oncological diseases in Imam Khomeini Hospital, Tehran, Iran, and identifying the contaminating bacteria. A total of 3056 adult patients of the Cancer Center of Imam Khomeini Hospital in Tehran transfused with PCs were studied based on the clinical symptoms of septic transfusion reaction from June 1, 2010 to May 31, 2011. Patient presented with the criteria of reaction and the residual components were evaluated for bacterial contamination by Bac T/Alert system. Patients with leukemia or lymphoma transfused with random-donor PCs were evaluated the signs and symptoms of transfusion reaction occurred only in 12 (%0.4) cases. Automated cultivation found 3 positive blood cultures. Among these a male recipient was categorized as possible septic transfusion reaction and Citrobacterfreundii was isolated from blood sample. Appropriate clinical utilization of PCs transfusion, and ongoing vigilance to recognize, investigate, promptly treat, and report all suspicious transfusion reactions are necessary to manage the transfusion complication including transfusion-transmitted infections (TTI).

Immature platelets do not reliably predict platelet recovery in patients with intensive chemotherapy or stem cell transplantation.

It has been reported that immature platelets may indicate imminent platelet (PLT) recovery following intensive chemotherapy and/or haematopoietic stem cell transplantation with the perspective to withhold unnecessary transfusions. The objective of our prospective study was to test immature PLTs as measured by two haematology analysers to predict PLT recovery. This study monitored 51 courses of severe thrombocytopenia after chemotherapy in 35 adult haematology/oncology patients starting at a PLT count <70 × 109 /l until PLT recovery (>20 × 109 /l) or discharge from hospital. Immature platelets as measured by immature platelet fraction (IPF) (Sysmex XE-5000) and retPLT (Abbott CD-Sapphire) as well as reticulocyte and leucocyte count were evaluated regarding their usefulness to predict PLT recovery. Furthermore, the influence of platelet concentrate (PC) transfusions upon IPF and retPLT was assessed. With beginning of thrombocytopenia, most patients demonstrated elevated IPF% (median 8·6%) and retPLT% (median 6·8%). These elevated values significantly dropped after transfusions of PCs. IPF and retPLT values during nadir and at imminent PLT recovery were largely overlapping and receiver operating characteristics analysis demonstrated poor separation between both clinical situations. A reasonable cut-off could not be established to prospectively predict imminent PLT recovery for either of the parameters investigated. Measurements of IPF and retPLT lack predictive power regarding imminent PLT recovery in patients with severe thrombocytopenia following intensive chemotherapy. Decisions regarding prophylactic PC transfusions should not be based on these parameters.

Identification and follow-up of pregnant women with platelet-type human platelet antigen (HPA)-1bb alloimmunized with fetal HPA-1a.

IntroductionPregnant women negative for human platelet antigen 1a (HPA-1a) are at risk of alloimmunization with fetal HPA-1a antigen inherited from the father, and their offspring may develop fetal and neonatal alloimmune thrombocytopenia (FNAIT). The aim of this study was to analyze the frequency of HPA-1a alloimmunization in pregnant Polish women, the feasibility of using maternal platelets for intrauterine transfusions in women subjected to diagnostic fetal blood sampling (FBS) and to discuss potential consequences of alloimmunization.Material and methodsFifteen thousand two hundred and four pregnant women were typed for HPA-1a; HPA-1a negative were screened for anti-HPA-1a. Alloimmunized women received specialist perinatology care; some of them were subjected to FBS, followed by transfusion of HPA-1a negative platelet concentrates (PC) prepared from maternal blood.ResultsThree hundred seventy-three (2.5%) women were HPA-1a negative, and 32 (8.6%) tested positively for anti-HPA-1a. Antibodies were detected in 22 women during pregnancy. Diagnostic FBS followed by PC transfusion was performed in 14 woman, who were platelet donors for their 16 unborn babies. Blood donations were tolerated well by the patients, and also intrauterine platelet transfusions were uneventful. Pharmacotherapy with intravenous immunoglobulins was implemented in 11/22 patients.ConclusionsHPA-1a negative women (ca. 2.5% of all pregnant patients) are at risk of alloimmunization with HPA-1a antigen and developing FNAIT. Alloimmunized women can be donors of platelets for their offspring providing removal of antibodies from PC. Owing to potential complications, special care should be taken if an alloimmunized woman was qualified as a blood or stem cell recipient.

In vitro evaluation of the haemostatic capacity of cryopreserved platelets and platelet substitutes

The short shelf life of platelet concentrates (PCs) presents logistic problems in providing timely PC transfusions for patients highly alloimmunized by HLA/HPA antibodies, and when long or major transportation barriers exist (e.g. rural care settings, severe weather, military operations). Several strategies have been tried to circumvent the limited storage time of PC. Among them, the cryopreservation of human platelets using dimethyl sulfoxide, the freeze‐drying of outdated human platelets and even the manufacture of artificial phospholipids that might act as artificial platelets. Several in vitro techniques are currently available to characterize the structure and function of those products. Among other we can use, complete blood count, flow cytometry combined to monoclonal antibodies, platelet aggregation, studies under flow conditions and thromboelastography/thromboelastometry. The combined use of those in vitro techniques provides valuable information about the structure and functional haemostatic capacities of those platelet components. Depending on the results, the decision can be made if the product can be or cannot be tested on human volunteers and patients. As for instance was the case of artificial phospholipids that after observing a very high procoagulant activity in vitro, this approach has not gone further in its development.

Mitochondrial damage-associated molecular patterns as potential proinflammatory mediators in post-platelet transfusion adverse effects.

Platelet concentrates (PCs) are the most common blood components eliciting nonhemolytic transfusion reactions (NHTRs), such as allergic transfusion reactions and febrile reactions. However, the precise mechanisms of NHTRs in PC transfusion remain largely unknown. Previous studies reported that mitochondria-derived damage-associated molecular patterns (DAMPs) could be important mediators of innate cell inflammation. Platelets (PLTs) represent a major reservoir of mitochondria in the blood circulation. The aim of this study was to determine the possible involvement of mitochondrial DAMPs in NHTRs. The amount of mitochondrial DAMPs was determined as an index of total copy numbers of mitochondrial DNA (mtDNA), including mtDNA itself and free mitochondria, using quantitative real-time polymerase chain reaction. To examine whether neutrophils, monocytes, and basophils were activated by mitochondrial DAMPs in vitro, an in vitro whole blood cell culture assay was performed. In blood components associated with NHTRs, the mean total mtDNA concentration was highest in PCs followed in order by fresh-frozen plasma and red blood cells. The amount of mtDNA in NHTR PCs was higher than that in control PCs without NHTRs. The mitochondrial DAMPs present in NHTR PCs was high enough to activate neutrophils, monocytes, and basophils, when costimulated with N-formyl-l-methionyl-l-leucyl-l-phenylalanine or HLA antibodies. PLT-derived mitochondrial DAMPs are candidate risk factors for the onset of NHTRs.

Functional characteristics and clinical effectiveness of platelet concentrates treated with riboflavin and ultraviolet light in plasma and in platelet additive solution.

Pathogen reduction technologies may affect platelet quality during storage. We studied functional characteristics and clinical effectiveness of platelet concentrates (PCs) treated with Mirasol in plasma and in platelet-additive solution SSP+. Mirasol-treated, gamma-irradiated and untreated apheresis PCs were examined on days 0, 1, 3 and 5 of storage. Phosphatidylserine, P-selectin and active glycoprotein IIb/IIIa were analysed using flow cytometry before and after platelet stimulation. Platelet count increments, the numbers of inefficient transfusions and post-transfusion reactions were analysed to estimate clinical effectiveness. A significant increase in all platelet activation markers occurred during storage in all PC groups. Activation markers in Mirasol-treated samples were already significantly higher compared with the control ones on the day of harvesting, and continued to grow during the storage. Mirasol treatment increased the number of platelets with a mitochondrial membrane potential loss. On the 3rd day of storage, 50% of Mirasol-treated platelets did not respond to activation; on the 5th day, none did. This agreed well with a decrease (approximately twofold) in the effectiveness of Mirasol-treated PC transfusions. Transfusions of PCs stored in SSP+ were accompanied by fewer inefficient transfusions and post-transfusion reactions than of PCs stored in plasma. Treatment with Mirasol decreased platelet function, particularly profoundly on the 5th day of storage, and led to a decrease in the effectiveness of transfusions. SSP+ did not affect laboratory parameters significantly compared with plasma, but decreased the percentage of transfusion complications.

Incidence of hypotension and acute hypotensive transfusion reactions following platelet concentrate transfusions.

Platelet concentrates (PCs) are associated with transfusion reactions involving hypotension, particularly bradykinin-mediated acute hypotensive transfusion reactions. This study aims to determine the incidence of hypotensive events and more specifically acute hypotensive transfusion reaction associated with PC transfusions. We also sought to ascertain whether these reactions are associated with elevated bradykinin levels. This is a prospective descriptive study of PCs administered at Sainte-Justine Hospital over 28 months. All PCs administered during this period were screened for hypotension through review of all transfusion-associated reaction reports (TARRs) sent to the blood bank. All residual PC bags were returned to the blood bank. TARRs associated with hypotension were reviewed by adjudicators that established the imputability of the PC transfusion to the reaction. Bradykinin levels were sampled in the first 168 PC bags returned to the blood bank. Levels were compared between PCs associated with hypotension and control PCs not associated with hypotension. A total of 3672 PC bags were returned to the blood bank; 25 PCs were associated with hypotension. Adjudicators ascertained that five hypotensive events were imputable to PCs of which one was an acute hypotensive transfusion reaction (incidence: 0·03%). Bradykinin level in the latter PC was 10 pg/ml, whereas levels were 226·2 ± 1252 pg/ml in the 143 control PCs. Our results show a low incidence of hypotension after PC transfusion. We identified only one acute hypotensive transfusion reaction. No correlation between bradykinin level and the occurrence of acute hypotensive reactions could be observed given that only one event was identified.

Transfusion dependency at diagnosis and transfusion intensity during initial chemotherapy are associated with poorer outcomes in adult acute myeloid leukemia.

Blood transfusions can modify host immunity and clinical outcomes in hematological malignancies. One thousand sixty-seven patients with acute myeloid leukemia (AML) were studied for their transfusion dependency at initial presentation and transfusion frequency during induction chemotherapy. Three hundred five patients (29%) showed initial dependence to red blood cell (RBC) transfusion and 109 (10%) to platelet transfusion. Transfusion dependency at presentation was associated with a poorer prognosis. Both initial RBC and platelet transfusion needs were associated with lower response rates (P = 0.04 and P = 0.03). Median overall survival (OS) was 10.8months for patients with RBC need vs 18.8months for the other patients (P = 0.02) and 6.8months for patients with platelet transfusion need vs 13.6months for the others (P = 0.01). Similarly, transfusion intensity during induction therapy influenced negatively treatment outcome. Median transfusion burden per week was 2.5 (range 0-25.7) RBC units and 1.6 (range 0-15.7) platelet concentrates (PCs). Both high RBC and PC transfusion intensities were associated with lower response rates (P = 0.003 and P < 0.0001). Median OS was 9.08months for patients with RBC transfusions >3/week vs 18.29months for those with RBC transfusions ≤3/week (P = 0.0003) and 10.75months for patients with PC transfusions >2/week vs 19.96months for those with PC ≤2/week (P = 0.0003). RBC and platelet transfusion intensities during induction therapy remained of prognostic value in multivariate analysis. Transfusion need at presentation and the frequency of transfusions during induction chemotherapy appear as strong prognostic factors.

Comparison of harvesting methods and clinical application of apheresis platelet concentrates with additive solution

Platelet concentrates (PC) are used worldwide in the fields of oncology, oncohaematology and bone marrow transplantation. One of the main tasks of clinical transfusiology is the development and improvement of technologies aimed to increase quality and safety of PC. In particular, such technologies are represented by using of platelet additive solutions (PAS). The main advantages of this approach are: a reduction of immune and non-immune transfusion reactions risk, an improvement of pathogen inactivation quality and enhancing a clinical effect of PC transfusions after storage. Numerous different PAS and methodologies of their application are suggested to date. In this review we have described and classified recent data on different PAS and the benefits of their clinical application.

Chemotherapy induced thrombocytopenia treated by four types of platelets concentrates

Introduction: Serious adverse event of anticancer chemotherapy is glanulocytopenia and thrombocytopenia which can decrease efficiency of final therapy results. After many years, platelet concentrates transfusion (PCT) is still researching problem without sure standpoint. The aim: To determine whether there is a difference in the clinical efficiency in the use of 4 types of platelet applied for transfusion; - to ascertain whether platelet count increase expressed as corrected count increment (CCI), is a better parameter for the evaluation of platelet transfusion efficiency than the bleeding time (Bt), as the only readily assessable in vivo platelet function related parameter. Subjects and methods: This paper is a part of academic (noncommercial) IV phase observational nointervetion study. Investigation included 78 patients diagnosed with malignant lymphoma and metastatic solid tumors, transfused by platelet concentrates. Patients were devided into 4 groups, based on the type of platelet concentrates used for transfusion. Results: Patients, were transfused with total number of 647 PC units (235 units were non-leukodepleted and 412 units were leukodepleted). Mean number of PC transfusions per patient was 8.3 PC units, and 4.8 PC unit per one transfusion episode. Before PCT: platelets values were: 18.1 x109/L ±13.1, Bt 8.4±6.1min, and after PCT were 28.2 x109/L ±22.1, 4.7±4.4 min respectively ((p<0.01). Mean CCI value was 13.8±30.4. CCI was corrected in 196/129 PCT and Bt in 122/129 PCT. After supportive therapy using PCs Bt was corrected and became similar in all 4 groups. Discussion: Clinical output is the most important parameter for treatment decision because many patients can tolerate prolonged periods of profound thrombocytopenia without serious bleeding problems. Conclusion: In all 4 investigated groups of patients bleeding time was a far better parameter compared with CCI for the PC therapy efficiency. Authors suggest to be careful and follow clinical and laboratory results personalized to single patient. There is a need to develope better therapies and guidelines so the practice of platelet therapy can be expected to improve in the future.

Development of Anti-e after Platelet Concentrate Transfusion

Platelet concentrates (PC) is prepared from donated whole blood units by centrifugation and subsequent pooling of 4-6 units Advancing Transfusion and Cellular Therapies Worldwide Advancing Transfusion and Cellular Therapies Worldwide. Thus, PC may contain a small amount of donor RBC. We report a case of a 60 year-old male patient with past medical history of coronary artery disease, who presented to our emergency department with shortness of breath. Previous medical history indicated a recent admission, one month prior, to another local hospital for shock and respiratory failure. Type and screen (T/S) done at that time reveal an O+ blood type with negative antibody screen. During that admission, the patient received only 5 doses of PC (2-group O+, 2-group O-, and 1-group A-). He denied any other recent blood product transfusions at any other facility. Our current T/S, and before any transfusions, showed a positive antibody screen. A panel for antibody identification was performed. The antibody reacted with 9 out of 10 reagent cells. The reactivity was predominately at room temperature and 37°C phases indicating an IgM class antibody. Some reactivity was also seen at AHG (anti-human globulin) phase indicating an IgG class antibody. The auto control was negative. Testing additional cells revealed an anti-e specificity. Patient’s “e” antigen typing was performed and found to be negative indicating that this is a true allo-antibody. Since anti-e antibody predominantly exists as an IgG immunoglobulin class antibody, the presence of IgM class reactivity suggests that this may be a newly developed antibody. This case illustrates that antibodies to RBC antigens can develop after platelet transfusion.

Transfusion plaquettaire et iso-immunisation anti-Rh1 : intérêt de la séroprévention

Rhesus (Rh) antigens are not expressed on platelets but residual red cells carry the risk of anti-D iso-immunization in transfusion recipients of platelet concentrates (PC). The main theoretical risk associated with this reaction relates to female subjects due to potential obstetrical situations of maternal-foetal Rh incompatibility. Isogroup PC transfusion in this system is therefore advised. However, logistical constraints impose frequent Rh-incompatible transfusions that require the recommendation of anti-Rh immunoglobulin in a girl of childbearing age in this situation. This recommendation, already restricted to a group of patients deserves to be questioned over a decade after being issued. Data from published reports are difficult to interpret because of the heterogeneity of the few series (CP type, immune status, timing of biological tests) but the current techniques for preparing products and most common use of CP apheresis limited the risk of immunization. Moreover, platelet transfusions are particularly relevant to immunocompromised populations which, to what extent (heavy chemotherapy and/or hematopoietic stem cells recipients) seems to be protected from this risk. It is noteworthy that the clinical consequences that may be expected from such immunization are not reported. Although some authors emphasize significant isoimmunization rates (maximum 19%), the heterogeneous conditions and the lack of evidence of clinical consequence suggest evaluating the recommendations or revising them towards more targeted indications of seroprophylaxis.

Implementation of a new platelet pooling system for platelet concentrates led to a higher corrected count increment after transfusion: a comparative observational study of platelet concentrates before and after implementation

To study the effect of extended storage of platelet concentrates (PCs) and the implementation of a new platelet pooling system for PCs on corrected count increment (CCI) after transfusion. Due to new developments and changes in processes or procedures, one should remain alert for the effects of these changes. Besides in vitro studies and validation, in vivo studies are also important, as it has been shown that in vitro results do not always predict in vivo outcomes. After introduction of extended storage of PCs for 5-7 days prepared from five buffy coats and plasma, transfusion monitoring for transfusions of PCs in haemato-oncological patients was set up. After 9 months, a new pooling system for PCs was implemented, Composelect instead of Optipure PLT, and transfusion monitoring was continued for another 8 months. The CCI was used as primary outcome. In total, 93 patients were included and transfused with PCs prepared in the Optipure PLT system (262 transfusions) or in the Composelect system (127 transfusions). Extended storage of PCs for 7 days had no significant effect on CCI. Although the implementation of the Composelect system did not influence the CCI1 h (13.8 ± 6.0 vs. 13.0 ± 5.8; n.s.), it seemed to have a positive effect on CCI24 h (7.0 ± 4.9 vs. 4.7 ± 4.5; P < 0.05). Although the influence of confounders could not be excluded, it seemed that implementation of the Composelect system for PCs led to an improved CCI24 h and that extended storage of PCs did not influence the CCI.

Hemostatic Function and Transfusion Efficacy of Apheresis Platelet Concentrates Treated with Gamma Irradiation in Use for Thrombocytopenic Patients

Background: During the transfusion of blood components, the transfer of allogeneic donor white blood cells (WBCs) can mediate transfusion-associated graft-versus-host disease (TA-GVHD). To minimize the reaction, exposure of blood products to gamma irradiation is currently the standard of care. The aim of our study was to evaluate and compare hemostatic function, transfusion efficacy, and safety of gamma-irradiated single-donor apheresis platelet concentrates (PCs) and of conventional non-irradiated PCs in patients with chemotherapy-induced thrombocytopenia. Methods: 20 double-dose single-donor leukoreduced PCs were split in two identical units; one was gamma-irradiated with 25 Gy (study arm A) and the other remains non-irradiated (study arm B). Both units were stored under equal conditions. Hematologic patients were randomly assigned to receive gamma-irradiated or conventional non-irradiated PCs. Hemostatic function was evaluated by thrombelastography (TEG). TEG measurements were taken pre transfusion and 1 and 24 h post transfusion. TEG profiles were measured, noting the time to initiate clotting (R), the angle of clot formation (α), and the maximum amplitude (clot strength (MA)). Whole blood samples were collected from these thrombocytopenic patients at 1 and 24 h for PLT count increments (CIs) and corrected count increments (CCIs) with assessments of transfusion efficacy. Time to next PLT transfusion, transfusion requirement of RBCs, active bleeding, and adverse events (AEs), were analyzed. Results: No differences could be found in hemostatic function parameters (MA, R, and α) between study arms A and B (all p values > 0.096) pre transfusion as well as 1 and 24 h post transfusion. No differences between study arms A and B were observed for mean (± standard deviation (SD)) 1-hour CCI (12.83 ± 6.33 vs. 11.59 ± 5.97) and 24-hour CCI (6.56 ± 4.10 vs. 5.76 ± 4.05). Mean 1-hour CI and 24-hour CI were not significantly different in both study arms (p = 0.254 and p = 0.242 respectively). Median time to the next PC transfusion after study PC was not significantly different between groups: (2.4 vs. 2.2 days, p = 0.767). No differences could be found in transfusion requirement of red blood cells (p = 0.744) between both study arms. There were also no regarding bleeding, adverse events, and acute transfusion reaction(s). Conclusions: This study confirms safety of gamma-irradiated PCs for treatment thrombocytopenia. Hemostatic function, transfusion efficacy, bleeding, and safety of single-donor apheresis PCs treated with gamma irradiation versus untreated control PCs are comparable.

Costs and benefits of PAS platelets: A mix of science, quality, and value

Costs and benefits of <scp>PAS</scp> platelets: A mix of science, quality, and value

Impact of immunoreactive substances contained in apheresis platelet concentrate on postoperative respiratory function in surgical patients receiving platelet transfusion: a prospective cohort study

To construct an alternative policy for the donor selection of platelet concentrate (PC), a clinical study exploring the features of lung injury following PC administration is needed. Although a male-donor-only policy for plasma products appears to have efficiently reduced transfusion-related acute lung injury (TRALI), this policy may not be applied to PC because of supply shortages. We prospectively examined pulmonary function after the transfusion of PC in informed surgical patients treated at a tertiary university hospital in Japan. The contributions of immunoreactive substances contained in the PC to respiratory function after PC transfusion was then statistically examined. Eighty-six patients (56 men, 30 women) were enrolled in the analysis. Fifty-four cases experienced respiratory failure (PaO2 /FiO2 <300 mmHg) after transfusion. Five cases were diagnosed as possible TRALI based on permeability pulmonary oedema, while 23 cases were diagnosed as transfusion-associated circulatory overload (TACO) based on chest radiograph findings. A multivariate logistic regression analysis identified the presence of anti-granulocyte antibody as a significant predictor of possible TRALI [P = 0.023; odds ratio (OR), 13.0; 95% confidence interval (CI), 1.4-118.3]. Meanwhile, anti-leukocyte antibody class II was identified as a significant independent predictor of TACO (P = 0.010; OR, 18.4; 95% CI, 2.0-170.1). Our data suggest that antibodies contained in PC may contribute to the deterioration of respiratory function after PC transfusion, although the diagnoses of TACO and TRALI may have overlapped among the patients with pulmonary distress in this cohort.

Effects of platelet concentrate storage time reduction in patients after blood stem cell transplantation

To evaluate the clinical effect of platelet concentrate (PC) transfusions after PC storage time reduction to 4days. This was a single-centre cohort study comparing two 3-month periods of time, before and after the reduction of PC storage time from 5 to 4days. Seventy-seven consecutive patients with PC transfusions were enrolled after blood stem cell transplantation. Corrected platelet count increment (CCI) on the morning after transfusion, time to next platelet transfusion, need for red blood cell (RBC) transfusion and clinical bleeding symptoms were compared. Platelet concentrate storage time was reduced between period 1 (storage for up to 5days, median storage time 78h, range 11-136h) and period 2 (storage for up to 4days, median storage time 53h, range 11-112h). Patients were comparable for age, weight, body surface area, underlying disorder, type of transplantation and transfused platelet dose. The CCI increased from a median of 4 (range 0-20) to 8 (0-68)×10(9) /l per 10(11) platelets/m(2) (P<0·0001). Time to next PC transfusion increased from 1·1 to 2·0days (P<0·0001). Any bleeding symptom was noted in 20 of 36 patients (56%) vs. 9/41 patients (22%, P<0·01). Nose bleeds, haematuria and bleeding at more than one site were significantly reduced. Frequency of RBC transfusion within 5days after PC transfusion was reduced from 74 to 58% (P<0·0001). Platelet concentrate storage time shortening was associated with highly significant CCI increase, reduced RC needs and lower patient numbers with bleeding events.

Preoperative hemostasis and its association with bleeding and blood component transfusion requirements in cardiopulmonary bypass surgery

Variables of hemostasis before surgery might indicate an elevated risk of bleeding. We determined hemostasis tests and standardized bleeding history and their association with bleeding and transfusion requirements in cardiopulmonary bypass (CPB) surgery. In a prospective trial, variables from 104 patients were associated with postsurgical bleeding and with red blood cells (RBCs) and platelet concentrate (PC) transfusions. Variables included standardized bleeding history, prothrombin time (PT), fibrinogen, fibrin monomers, Factor VIII, von Willebrand factor (VWF), multiple electrode aggregation (MEA), and the day of aspirin or thienopyridine withdrawal before operation. Multiple linear regression revealed bleeding history score, ADP-induced MEA, CPB time, and hemoglobin (Hb) independently associated with postoperative bleeding and bleeding history, arachidonic acid (AA)-induced MEA, CPB time, and PT associated with RBC transfusions. The logistic regression model for the outcome of bleeding within 24 hours after operation indicated ADP-induced MEA, the day of aspirin withdrawal before operation, and CPB time as predictors. AA-induced MEA, CPB time, Hb, and PT were predictors of RBCs transfusion. ADP-induced MEA, the day of aspirin withdrawal, PT, and VWF were associated with PC transfusion. A standardized bleeding history may help to identify patients undergoing CPB surgery whose risk of bleeding is elevated. ADP-induced MEA appears to predict postoperative bleeding and PC transfusion requirements, while AA-induced MEA and preoperative Hb indicate the need for RBCs. The time of aspirin withdrawal before surgery influences perioperative blood loss and PC transfusion.

Lysophosphatidylcholines: Bioactive Lipids Generated During Storage of Blood Components

Transfusion-related acute lung injury (TRALI) is suggested to be a "two hit" event, resulting from priming and activation of pulmonary neutrophils. It is known that neutrophil activation may result from infusion of lysophosphatidylcholines (LysoPCs) accumulated during storage of blood components. The aim of our study was to verify whether the LysoPCs are released into the storage medium of blood components. We measured the LysoPCs concentration in the supernatants from stored apheresis platelet concentrates (PLTs), packed non-leukoreduced red blood cell concentrates (RBCs), leukoreduced red blood cell concentrates (L-RBCs), fresh frozen plasma (FFP) and donor plasma (control). Lipids were separated on high-performance thin-layer chromatography, detected by primulin spray and quantified by photodensitometric scanning. The LysoPCs concentration in donor plasma was similar to that in FFP. During storage the LysoPCs content in PLTs increased almost two-fold as compared to the fresh isolated platelets. In RBCs and L-RBCs the LysoPC level was very low or below detection limit and did not increase throughout the storage period. According to our observations bioactive LysoPCs may be considered a neutrophil-activating factor only following PLT transfusions but not RBCs transfusions.