Platelet Transfusion Research Articles

Reduced platelet activation in triple-negative essential thrombocythemia compared with JAK2V617F-mutated essential thrombocythemia.

Triple-negative (TN) essential thrombocytopenia (ET) is characterized by the absence of driver mutations while retaining histological and phenotypic characteristics sufficient for an ET diagnosis. Our understanding of TN-ET and its platelet activation remains incomplete. We carried out a large-scale multi-center clinical analysis to analyze the clinical and molecular characteristics, thrombotic complications of TN-ET. We also related the above characteristics to platelet activation to further explore the thrombosis mechanism of TN-ET. A retrospective multicenter study was conducted on 138 TN-ET and 759 ET patients with driver mutations from 1 March 2012 to 1 December 2021. The clinical and molecular characteristics of the TN-ET were summarized. Additionally, platelet activation, apoptosis, and reactive oxygen species (ROS) levels were analyzed in 73 TN-ET patients from this cohort and compared to 41 age- and sex-matched healthy donors. Compared to patients with the JAK2V617F mutation, those with triple-negative mutation were younger (P < 0.001) and exhibited fewer thrombotic events before diagnosis (P < 0.001) and during follow-up (P = 0.039). Patients with triple-negative mutation also presented with significantly reduced CD62P expression in platelets (P = 0.031), slightly reduced calcium concentration in platelets (P = 0.063), increased mitochondrial membrane potential (P = 0.011), reduced phosphatidylserine exposure (P = 0.015), reduced levels of ROS (P = 0.043) and MitoSOX in platelets (P = 0.047). In comparison to JAK2V617F-mutated ET, TN-ET is associated with lower platelet ROS levels, which leads to reduced platelet activation and consequently a lower risk of thrombosis.

Impact of platelet transfusion refractoriness in the first 30 days post-hematopoietic stem cell transplantation on outcomes of patients with myelodysplastic syndrome.

Currently, no study has determined whether platelet transfusion refractoriness (PTR) post-hematopoietic stem cell transplantation (HSCT) before engraftment in patients with myelodysplastic syndrome (MDS) would impacts clinical outcomes. We performed a MDS-specific retrospective analysis to determine whether PTR in one-month post-HSCT in patients with MDS could influence outcomes. Among the 315 patients enrolled, 110 (34.9 %) had PTR from stem cell infusion to one-month post-HSCT. Baseline characteristics of the PTR and non-PTR groups were similar. We found that patients with PTR had a slower and lower rate of platelet engraftment by day 28, as well as a slower recovery of neutrophils. The median days of neutrophil and platelet engraftment were 14 days (9-23) and 17 days (8-28) in the PTR groups versus 13 days (9-23) and 15 days (7-28) in the non-PTR group (P<0.001). By day 28, 84 of 110 patients (76.4%) with PTR achieved platelet engraftment compared with 181 of 205 patients (88.3%) without PTR achieving platelet engraftment (P=0.007). In addition, patients in the PTR group received significantly more red blood cell (median, 17 units vs. 10 units, P<0.001) and platelet transfusions (median, 13 units vs. 7 units, P<0.001). However, the overall survival was similar between the two groups. PTR in one-month post-HSCT, haploidentical donor, and ferritin level>1041ng/ml (median level) were independent adverse factors of platelet engraftment.

Retinopathy of Prematurity in Eight Portuguese Neonatal Intensive Care Units: Incidence, Risk Factors, and Progression-A Prospective Multicenter Study.

Retinopathy of prematurity (ROP) is a retinal neovascular disease affecting preterm infants. Identifying risk factors for its development and progression is critical for effective screening and prevention. This study aimed to analyze the incidence of ROP and identify key risk factors for its development and progression. We conducted a prospective, observational cohort study on 455 neonates (gestational age [GA] < 32 weeks or birth weight < 1500 g) across eight Portuguese NICUs. ROP incidence was 37.8%, with 4.6% requiring treatment. Multivariate analysis identified low GA and the number of red blood cell (RBC) transfusions as significant factors for ROP development and progression. After adjusting for these variables, platelet transfusions, high maximum fraction of inspired oxygen (FiO2) in the second week, and surfactant use remained significantly associated with ROP development, while early and late sepsis, maternal chronic hypertension, and delayed enteral nutrition were associated with progression to ROP requiring treatment. These findings underscore the importance of addressing low GAs and adult RBC transfusions in ROP risk management and suggest that maximum FiO2, platelet transfusions, and sepsis also play crucial roles. Larger studies are needed to validate these results and explore preventive interventions, particularly regarding the impact of multiple adult RBC transfusions on fetal hemoglobin percentages.

Storage properties of platelet concentrates from umbilical cord blood prepared using three different methods.

Thrombocytopenia, common in preterm newborns, may increase bleeding risk and is often treated with transfusions. Recent studies reveal that transfusing platelets at a high threshold worsens outcomes, possibly due to a "developmental mismatch" between adult-derived platelets and neonatal hemostatic system. Cord blood-derived platelet concentrates (CBPCs) could be an alternative for newborns. Our study aims to produce and evaluate the quality parameters of CBPCs during storage. Cord blood was collected from placentas after near-term and full-term pregnancies. Several production methods were attempted to obtain CBPCs, varying centrifugation settings, filtration, and dilution procedures. Adult-derived platelet concentrates (PCs) processed with the same methods, and standard PCs from five buffy-coats were used as controls. Storage tests were performed on days 2, 4-5, 7 from the collection. CBPCs parameters were compared with adult-derived PCs, and no significant differences were found for mean platelet volume (MPV), swirling, morphology, glucose, lactate, pCO2, and pO2. pH and bicarbonate were lower in CBPCs. Some significant differences between methods in CD62P expression and JC-1 ratio were observed. Compared with standard PCs, CBPCs showed lower platelet concentration, pH, and JC-1. Additionally, both in CBPCs as well as in control PCs, the apoptosis marker phosphatidylserine was elevated. CBPCs were of comparable quality to control PCs during storage. However, apoptosis markers in both groups were elevated, suggesting processing and storage of low volumes of PCs require further optimization. Also, filtration of low volumes leads to significant platelet loss, an issue that requires remedy.

Quantitative and functional changes in platelets and fibrinogen following cardiopulmonary by-pass in children

IntroductionCardiopulmonary bypass (CPB) causes coagulopathy, increasing the risk of postoperative bleeding and mortality. The underlying causes of post-CPB coagulopathy and the factors associated with its occurrence are not yet fully understood. This study assesses platelet and fibrinogen concentration and function following CPB in children with congenital heart diseases (CHD).MethodsWe analyzed prospective data from 104 patients aged 0–16 years who underwent CPB surgery for CHD. Blood samples were collected before surgery and within 30 min of CPB completion. In addition to usual coagulation tests, functional analyses were performed using point of care systems with thromboelastometry and impedance aggregometry.ResultsPlatelet count, fibrinogen concentration, and platelet and fibrinogen activities significantly decreased after CPB. The duration of CPB was directly associated with a reduction in platelet count and fibrinogen level (r = −0.38, p &amp;lt; 0.001; r = −0.21, p = 0.03, respectively), but not with their measured activity. Postoperative percentages of baseline values for platelet count (58.36% [43.34–74.44] vs. 37.44% [29.81–54.17], p &amp;lt; 0.001) and fibrinogen concentration (73.68% [66.67–82.35] vs. 65.22% [57.89–70.83], p &amp;lt; 0.001) were significantly higher in patients who did not experience hypothermia during surgery. Age was inversely associated with the decrease in platelet count (r = 0.63, p &amp;lt; 0.001), TRAPTEM AUC (r = 0.43, p &amp;lt; 0.001), fibrinogen concentration (r = 0.44, p &amp;lt; 0.001) and FIBTEM MCF (r = 0.57, p &amp;lt; 0.001).ConclusionPost-CPB coagulopathy is multifactorial and not solely attributed to hemodilution. It also involves functional changes in coagulation cascade components, which can be demonstrated by thromboelastometry and impedance aggregometry. Young children, patients requiring prolonged CPB surgery, or those experiencing hypothermia are particularly affected.

Safety of intramuscular tixagevimab-cilgavimab (Evusheld®) administration in patients at risk of iatrogenic haematoma due to haematological disorders.

Traditionally, intramuscular (IM) injections have been avoided in patients with haematological diseases due to the risk of iatrogenic haematoma. Tixagevimab-cilgavimab (Evusheld®) is a novel monoclonal antibody combination used as preexposure prophylaxis against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), for those at highest risk of severe infections. It is delivered as two separate IM injections (1.5 mL each). Patients with haematological disease are at higher risk for severe SARS-CoV-2 infections, which may be partially abrogated by the prophylactic inoculation of tixagevimab-cilgavimab. A combined retrospective and prospective study of patients under the haematology service at a large metropolitan hospital receiving tixagevimab-cilgavimab was conducted. Tixagevimab-cilgavimab was administered IM to all patients, with platelet and factor replacement provided according to local protocols. Patients completed a numerical pain score daily for seven days following the injection, with scores ≥4/10 prompting an ultrasound to identify iatrogenic gluteal haematomas. The study recruited 131 patients; 66 patients were thrombocytopenic, including 10 patients with a platelet count <30 × 109/L. Fourteen patients (10.7%) received a single platelet transfusion prior to tixagevimab-cilgavimab administration, while two patients received fresh frozen plasma. No gluteal haematomas were identified, and only two patients reported an initial pain score of ≥4/10. The intramuscular administration of tixagevimab-cilgavimab in patients with haematological diseases was well tolerated and was not associated with iatrogenic haematoma.

Post-thaw CD34+ cell recovery likely degraded under extreme graft platelet concentrations.

Impaired post-thaw CD34 cell (postCD34) viability in autologous haematopoietic stem cell transplant (ASCT) could indicate delayed engraftment where multiple factors might complicate the relationship. Despite of a couple of unconfirmed reports of a negative correlation of platelet concentration with postCD34 viability, how platelets might be involved in the relationship is largely unknown. Therefore, this question was addressed in this retrospective study of 82 ASCT patients with a total of 150 collections of peripheral blood stem cells in New Zealand. A significant negative correction between platelet concentration and postCD34 recovery (r = -0.18, p = 0.028) was observed overall, but upon further analysis only confirmed in the subset with graft platelets 1500-2000 ×109/L. Importantly, the postCD34 recovery was clearly reduced in the subgroups with either the lowest or the highest platelet concentration. The lowest subgroup was enriched with collections from patients with Hodgkin or non-Hodgkin lymphoma, whereas the highest subgroup from patients with multiple myeloma, both with clearly male preponderance. We hypothesized that graft platelet concentrations probably indicated CD34 cell state (e.g. cell cycle and cell adhesion highly related to platelet functions) that sustained when platelet concentrations were within a niche range but went out of kilter otherwise.

Clinical characteristics, treatment, and outcomes of nivolumab induced immune thrombocytopenia.

Immune thrombocytopenia (ITP) represents an uncommon hematological side effect associated with nivolumab, and its distinct clinical attributes remain poorly defined. This research aimed to explore the clinical manifestations and outcomes of ITP induced by nivolumab. Reports on nivolumab induced ITP up to April 30, 2024, were collected for retrospective analysis. The study involved 34 patients with a median age of 67 years (range 32, 82). The onset of ITP varied from 10 to 100 days post initial dosage, with a median onset at 70 days. The majority of patients exhibited no symptoms, with only 23.5% experiencing clinically significant bleeding and 11.8% facing non-clinically significant bleeding. The median platelet count was 12 × 109/L (range 0, 115), with 67.6% of patients having platelet levels below 25 × 109/L. Bone marrow biopsy revealed mainly elevated megakaryocytes. Platelet-associated IgG levels were elevated with a median of 210 ng/107 cells (range 73, 1130). Subsequent interventions, which included cessation of nivolumab, administration of systemic corticosteroids, intravenous immunoglobulin therapy, a thrombopoietin receptor agonist, platelet transfusion, and rituximab treatment, resulted in 82.4% of subjects achieving normalized platelet counts, whereas 5.9% passed away due to ITP. ITP is a rare life-threatening immune-related adverse event and necessitates close monitoring. Systemic steroids are the primary treatment for ITP, while intravenous immunoglobulin, thrombopoietin receptor agonist and rituximab are other options.

A Phase 1b PK/PD Study to Demonstrate Antigen Elimination with RLYB212, a Monoclonal Anti-HPA-1a Antibody for FNAIT Prevention.

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare bleeding disorder of the fetus/newborn caused by development of maternal alloantibodies against fetal human platelet antigens (HPAs), predominantly HPA-1a. Currently there are no treatments available to prevent maternal alloimmunization to HPAs or FNAIT. This proof-of-concept study (EudraCT Number: 2021-005380-49) was designed to assess the ability of subcutaneous (SC) RLYB212, a monoclonal anti-HPA-1a antibody, to eliminate HPA-1a-positive platelets in an antigen challenge model of a 30 mL fetal-maternal hemorrhage. Subjects were randomized to receive a single SC dose of RLYB212 or placebo on day 1 in a single-blinded manner, followed by transfusion of 10 × 109 HPA-1a-positive platelets on day 8. Four subjects received 0.09 mg SC RLYB212, five received 0.29 mg SC RLYB212, and two received placebo. RLYB212 achieved rapid elimination of HPA-1a-positive platelets in a concentration-dependent manner, with concentrations as low as 3.57 ng/mL meeting the prespecified proof-of-concept criterion of ≥90% reduction in platelet elimination half-life versus placebo. Following HPA-1a-positive platelet transfusion, a rapid decline was observed in the concentration of RLYB212 over a period of 2 to 24 hours, corresponding to the time needed for RLYB212 to bind to ∼10% of HPA-1a on cell surfaces. RLYB212 was well tolerated with no reports of drug-related adverse events. The data from this study are consistent with preclinical efficacy data and support the potential use of RLYB212 as a prophylactic treatment for FNAIT that prevents maternal HPA-1a alloimmunization during at-risk pregnancies.

Nomogram for the Therapeutic Efficacy of Apheresis Platelet Transfusion in Hematologic Patients

Nomogram for the Therapeutic Efficacy of Apheresis Platelet Transfusion in Hematologic Patients

Adhesive and cohesive fracture of blood clots: Experiments and modeling

Blood clots represent living materials composed of a polymer network and an abundance of cells. They might fracture within the bulk material of the clot (cohesive fracture), at the interface between the clot and the surrounding tissue (adhesive fracture), or through a combination of both modes (hybrid fracture). The clot fracture within vascular systems and injury sites could lead to life-threatening conditions. Despite the significance, understanding and modeling the fracture behaviors of blood clots, including their dependence on mechanical loading and cellular components, remain in a nascent stage. In this study, we employ an integrated experimental-computational approach to comprehensively investigate the fracture behaviors of bovine blood clots. We explore various mechanical factors, substrates, and cellular components such as red blood cells (RBCs) and platelets. Our findings reveal that among various tissue substrates, blood clots exhibit the highest interfacial adhesion energy with muscle, and the lowest to the inner arterial lining, consistent with their biological function. Both interfacial adhesion energy and bulk fracture energy are rate-dependent, although they exhibit different dependencies. Also, RBCs and platelets have different effects on clot fracture. An increase in RBC content tends to toughen both adhesion and fracture of blood clots. However, an increase in platelet content enhances interfacial adhesion energy but lowers the bulk fracture energy. The platelet content also governs the shift from adhesive fracture to hybrid fracture. To model clot fracture, we developed two finite element models incorporating a coupled cohesive-zone and Mullins-effect approach to simulate pure shear fracture and peeling of blood clots. These models, validated through experimental data, elucidate the interplay between intrinsic fracture toughness, interfacial strength, and bulk energy dissipation during clot fracture. This study significantly advances our understanding of clot mechanics, providing valuable insights into the mechanics of similar living materials and the management of clot-related disorders such as hemorrhage and thrombosis.

Plasma proteomes of acute myeloid leukemia patients treated with transfusions reveal signatures of inflammation and hemostatic dysregulation

BackgroundBone marrow aplasia is a common feature in acute myeloid leukemia (AML) patients during their remission induction treatment, and is associated with potential complications such as bleeding, infection and anemia. Frequent platelet and red cell transfusions are administered to prevent and treat these complications. However, platelet counts are poorly associated with bleeding events in this population. Therefore, plasma protein levels could add valuable insights to improve our understanding of the patient's health state. In this study, we aimed to delineate the plasma proteome, including inflammatory pathways, hemostatic and immune components, of AML patients during treatment with intensive transfusion support.MethodsWe employed unbiased mass spectrometry (MS)-based proteomics on longitudinal plasma samples from 10 AML patients during intensive-transfusion treatment phase with healthy individuals as baseline control.ResultsA total of 450 proteins were quantified in plasma samples from AML patients and healthy controls. Alteration in proteins levels were mainly observed for proteins involved in inflammation (e.g. SAA1 and CRP), and complement (e.g. C9 and MASP2) when comparing AML versus healthy individuals. Correlation analysis revealed additional affected protein dynamics, including proteins associated with coagulation cascade, endopeptidase inhibitors activity and lipoprotein remodeling.ConclusionThe plasma proteome from AML patients during intensive treatment shows a disbalance in inflammation, endopeptidase inhibitors activity, lipoprotein remodeling, coagulation and complement. These effects and potential associations with bleeding risk will be further studied in a bigger cohort.

Platelet transfusion.

Platelet transfusions, used as prophylaxis or treatment for bleeding, are potentially life-saving. In many countries, demand for platelet transfusion is rising. Platelets are a limited and costly resource, and it is vital that they are used appropriately. This study will explore the evidence behind platelet transfusions in different contexts, in particular recent and important research in this area. Recent randomized clinical trials demonstrate the efficacy of platelet transfusions in some contexts but potential detrimental effects in others. Platelet transfusions also carry risk of transfusion reactions, bacterial contamination and platelet transfusion refractoriness. Observational and clinical studies, which highlight approaches to mitigate these risks, will be discussed. There is growing interest in cold-stored or cryopreserved platelet units, which may improve platelet function and availability. Clinical trials also highlight the efficacy of other supportive measures such as tranexamic acid or thrombopoietin receptor agonists in patients with bleeding. Although platelet transfusions are beneficial in many patients, there remain many settings in which the optimal use of platelet transfusions is unclear, and some situations in which they may have detrimental effects. Future clinical trials are needed to determine optimal use of platelet transfusions in different patient populations.

Neuroprotective effects of intranasal extracellular vesicles from human platelet concentrates supernatants in traumatic brain injury and Parkinson’s disease models

BackgroundThe burgeoning field of regenerative medicine has significantly advanced with recent findings on biotherapies using human platelet lysates (HPLs), derived from clinical-grade platelet concentrates (PCs), for treating brain disorders. These developments have opened new translational research avenues to explore the neuroprotective effects of platelet-extracellular vesicles (PEVs). Their potential in managing neurodegenerative conditions like traumatic brain injury (TBI) and Parkinson’s disease (PD) warrants further exploration. We aimed here to characterize the composition of a PEV preparation isolated from platelet concentrate (PC) supernatant, and determine its neuroprotective potential and neurorestorative effects in cellular and animal models of TBI and PD.MethodsWe isolated PEVs from the supernatant of clinical-grade PC collected from healthy blood donors utilizing high-speed centrifugation. PEVs were characterized by biophysical, biochemical, microscopic, and LC–MS/MS proteomics methods to unveil biological functions. Their functionality was assessed in vitro using SH-SY5Y neuronal cells, LUHMES dopaminergic neurons, and BV-2 microglial cells, and in vivo by intranasal administration in a controlled cortical impact (CCI)-TBI model using 8-weeks-old male C57/BL6 mice, and in a PD model induced by MPTP in 5-month-old male C57/BL6 mice.ResultsPEVs varied in size from 50 to 350 nm, predominantly around 200 nm, with concentrations ranging between 1010 and 1011/mL. They expressed specific platelet membrane markers, exhibited a lipid bilayer by cryo-electron microscopy and, importantly, showed low expression of pro-coagulant phosphatidylserine. LC–MS/MS indicated a rich composition of trophic factors, including neurotrophins, anti-inflammatory agents, neurotransmitters, and antioxidants, unveiling their multifaceted biological functions. PEVs aided in the restoration of neuronal functions in SH-SY5Y cells and demonstrated remarkable neuroprotective capabilities against erastin-induced ferroptosis in dopaminergic neurons. In microglial cells, they promoted anti-inflammatory responses, particularly under inflammatory conditions. In vivo, intranasally delivered PEVs showed strong anti-inflammatory effects in a TBI mouse model and conserved tyrosine hydroxylase expression of dopaminergic neurons of the substantia nigra in a PD model, leading to improved motor function.ConclusionsThe potential of PEV-based therapies in neuroprotection opens new therapeutic avenues for neurodegenerative disorders. The study advocates for clinical trials to establish the efficacy of PEV-based biotherapies in neuroregenerative medicine.Graphical

Early prediction of platelet recovery with immature platelet fraction in patients receiving hematopoietic stem cell transplantation.

Hematopoietic stem cell transplantation (HSCT) is pivotal in treating hematologic disorders, yet it poses the risk of post-transplantation pancytopenia. Prophylactic platelet transfusions are often administered to mitigate this risk. Utilizing practical markers, such as immature platelet fraction (IPF), to predict hematopoietic recovery in advance could reduce unnecessary prophylactic transfusions. Our prospective study, involving 53 HSCT patients at Taipei Veterans General Hospital between September 2022 and May 2023, utilized the Sysmex XN analyzer to assess peripheral blood cell parameters. We investigated whether IPF could predict platelet recovery early, determined the optimal cut-off value, and compared platelet usage. Neutrophil and platelet engraftment occurred 10 (median; range: 10-12) and 15 (median; range: 15-18) days post-HSCT. Notably, 71.7% of patients exhibited an IPF increase exceeding 2% before platelet recovery. The optimal cut-off IPF on day 10 for predicting platelet recovery within five days was 2.15% (specificity 0.89, sensitivity 0.65). On average, patients received 3.89 units of post-transplantation platelet transfusion. Our results indicate that IPF serves as a predictive marker for platelet engraftment, peaking before the increase in platelet count. This insight aids clinicians in assessing the need for prophylactic platelet transfusions. Integrating reference IPF values alongside platelet counts enhances the accuracy of evaluating a patient's hematopoietic recovery status. Anticipating the timing of platelet recovery optimizes blood product usage and mitigates transfusion reaction risks.

Manufacture and Initial Characterisation of RAPIDTM Biodynamic Haematogel, an Autologous Platelet and Leukocyte-Rich Plasma Gel for Diabetic Foot Ulcers.

This observational study reports the process for the manufacture of RAPIDTM Biodynamic Haematogel and explores the properties of the platelet and leukocyte-rich plasma gels formed. Gels were manufactured from 60 mL of human blood using the protocol of Biotherapy Services. Platelet and leukocyte content, time-to-gel, gel weight and the temporal profile of liquid exudation from the gels were measured, along with the content of growth factors VEGF and PDGF in the releasate. The effect of the releasate on human keratinocyte (HaCat) cell proliferation was also determined. The platelet and leukocyte concentrations in donor blood were 1.60-8.10 × 108 and 1.00 × 106-2.00 × 107 cells/mL, which were concentrated 2.67- and 1.12-fold, respectively, during processing. Structurally weak gels were formed which exuded a clear liquid releasate (77.4% w/w of gel weight over 60 min) that contained 278 pg/mL VEGF and 1319 pg/mL PDGF. The releasate produced concentration-dependent proliferation of HaCat cells: 5-15% releasate produced a 2.7-8.9-fold increase in growth over 48 h. In conclusion, we have described the point-of-care manufacturing protocol and characterised the gel properties of RAPIDTM Biodynamic Haematogel. This is an essential first step towards identifying, understanding and controlling critical processing parameters that impact on this medicinal product's quality.

Thromboelastography-guided Intraoperative Platelet Transfusion in Pediatric Heart Surgery

BackgroundPostoperative bleeding is associated with significant resource use and is an important contributor to other major adverse events in pediatric patients undergoing complex cardiac surgical procedures. Thromboelastography (TEG; TEG 6S, Haemonetics) can guide perioperative blood product transfusions to reduce the risk of postoperative bleeding. This study validated the use of a previously developed TEG 6S maximum amplitude (TEG-MA)–based platelet transfusion calculator used during cardiac surgical procedures to minimize the risk of postoperative bleeding. MethodsIn this single-center retrospective study of pediatric patients (aged ≤18 years) who underwent cardiac surgical procedures requiring cardiopulmonary bypass at Boston Children’s Hospital (Boston, MA) (N = 1000), the volume of platelet transfusion administered at surgical team discretion was compared with the platelet calculator–recommended platelet transfusion volume by using linear regression analysis. Associations between the adequacy of perioperative platelet transfusion and postoperative bleeding or thrombotic complications within the first 24 hours postoperatively (bleeding) and until hospital discharge (thrombosis) were evaluated by logistic regression analysis. ResultsLower TEG-MA (≤45 mm) measurements after transfusion were associated with a higher risk for postoperative bleeding (odds ratio, 4.4; 95% CI, 2.6-7.4; P < .01 [significant P value <.05]). The platelet transfusion calculator–recommended platelet transfusion volume (on the basis of TEG-MA measured at the time of rewarming) demonstrated moderate correlation with the measured TEG-MA value after platelet transfusion (Pearson r = 0.7). Intraoperative volumes of platelet transfusion that failed to increase a postoperative TEG-MA of at least 45 mm significantly increased the risk for postoperative bleeding in the first 24 hours after surgical procedures (odds ratio, 3.2; 95% CI, 1.9-5.4; P < .01 [significant P value <.05]). The posttransfusion TEG-MA was not independently associated with thrombosis. ConclusionsCustomizing perioperative platelet transfusion therapy by using quantitative diagnostic tests can help reduce postoperative bleeding complications.

Platelet transfusions in adult ICU patients with thrombocytopenia: A sub-study of the PLOT-ICU inception cohort study.

Platelet transfusions are frequently used in the intensive care unit (ICU), but current practices including used product types, volumes, doses and effects are unknown. Sub-study of the inception cohort study 'Thrombocytopenia and Platelet Transfusions in the ICU (PLOT-ICU)', including acutely admitted, adult ICU patients with thrombocytopenia (platelet count <150 × 109/L). The primary outcome was the number of patients receiving platelet transfusion in ICU by product type. Secondary outcomes included platelet transfusion details, platelet increments, bleeding, other transfusions and mortality. Amongst 504 patients with thrombocytopenia from 43 hospitals in 10 countries in Europe and the United States, 20.8% received 565 platelet transfusions; 61.0% received pooled products, 21.9% received apheresis products and 17.1% received both with a median of 2 (interquartile range 1-4) days from admission to first transfusion. The median volume per transfusion was 253 mL (180-308 mL) and pooled products accounted for 59.1% of transfusions, however, this varied across countries. Most centres (73.8%) used fixed dosing (medians ranging from 2.0 to 3.5 × 1011 platelets/transfusion) whilst some (mainly in France) used weight-based dosing (ranging from 0.5 to 0.7 × 1011 platelets per 10 kg body weight). The median platelet count increment for a single prophylactic platelet transfusion was 2 (-1 to 8) × 109/L. Outcomes of patients with thrombocytopenia who did and did not receive platelet transfusions varied. Among acutely admitted, adult ICU patients with thrombocytopenia, 20.8% received platelet transfusions in ICU of whom most received pooled products, but considerable variation was observed in product type, volumes and doses across countries. Prophylactic platelet transfusions were associated with limited increases in platelet counts.

Prolonged administration of oral phenylbutazone and firocoxib in horses has no impact on selected cytokine and growth factor concentrations in platelet-rich plasma and autologous protein solution.

To determine the effects of prolonged administration of the oral NSAIDs phenylbutazone and firocoxib on concentrations of cytokines and growth factors in platelet-rich plasma (PRP) and autologous protein solution (APS). 6 adult University owned horses. Horses were randomized to receive phenylbutazone (1 g, orally, q 12 h) or firocoxib (57 mg, orally, q 24 h) for 6 days. Blood was obtained and processed for APS (Pro-Stride) and PRP (Restigen) before the administration of NSAIDs and at 7 days (1 day following cessation of NSAIDs). Horses underwent a two-week washout period, during which blood was obtained at 14 days and 21 days. The protocol was repeated with a crossover design. PRP and APS were analyzed for concentrations of platelets, leukocytes, and several cytokines (IL-1β, IL-10, IL-6, IL-8, and tumor necrosis factor-α) and growth factors (PDGF, FGF-2, and TGF-β1) using immunoassays. Plasma was evaluated for drug concentrations. No significant differences existed in concentrations of growth factors and cytokines before or after prolonged administration of NSAIDs. There were significant differences in concentrations of leukocytes and platelets in PRP compared to APS, with higher concentrations of leukocytes at the day 7 time point (T) in APS (phenylbutazone) and in concentrations of platelets in APS at T0 (firocoxib) and in APS at T7 (phenylbutazone). Veterinarians can recommend the administration of these oral NSAIDs prior to obtaining blood for PRP and APS provided a single-day washout period is instituted.

Inpatient outcomes of NSTEMI among patients with immune thrombocytopenia: a propensity matched national study.

Patients with immune thrombocytopenia (ITP) admitted for non-ST elevation myocardial infarction (NSTEMI) present a unique therapeutic challenge due to the increased risk of bleeding with antiplatelet and anticoagulation therapies. There is limited evidence studying hospital mortality and complications in this population. The study included a patient cohort from the 2018-2021 National Inpatient Sample database. Propensity score matched NSTEMI patients with and without ITP using a 1:1 matching ratio. Outcomes analyzed were in-hospital mortality, rates of diagnostic angiogram, percutaneous coronary intervention (PCI), acute kidney injury (AKI), congestive heart failure (CHF), cardiogenic shock, cardiac arrest, mechanical ventilation, tracheal intubation, ventricular tachycardia (VT), ventricular fibrillation (VF), major bleeding, need for blood and platelet transfusion, length of stay (LOS), and total hospitalization charges. A total of 1,699,020 patients met inclusion criteria (660,490 females [39%], predominantly Caucasian 1,198,415 (70.5%); mean [SD] age 67, [3.1], including 2,615 (0.1%) patients with ITP. Following the propensity matching, 1,020 NSTEMI patients with and without ITP were matched. ITP patients had higher rates of inpatient mortality (aOR 1.98, 95% CI 1.11-3.50, p 0.02), cardiogenic shock, AKI, mechanical ventilation, tracheal intubation, red blood cells and platelet transfusions, longer LOS, and higher total hospitalization charges. The rates of diagnostic angiogram, PCI, CHF, VT, VF, and major bleeding were not different between the two groups. Patients with ITP demonstrated higher odds of in-hospital mortality for NSTEMI and need for platelet transfusion with no difference in rates of diagnostic angiogram or PCI.