Antifibrinolytics (lysine analogues) for the prevention of bleeding in people with haematological disorders

Safety assessment of tranexamic acid: real-world adverse event analysis from the FAERS database

Background

In recent years, with the continuous expansion of the application scope of Tranexamic acid (TXA), its usage has surged. Despite numerous studies demonstrating its powerful efficacy, concerns regarding its adverse reactions persist, necessitating comprehensive safety assessment. This study analyzed real-world data from the U.S. Food and Drug Administration to investigate TXA-related adverse events, aiming to elucidate its safety and optimize patient treatment.

Methods

The adverse drug event data concerning TXA from 2004 Q1 to 2023 Q3 were collected. Following data standardization, a variety of signal quantification techniques, including the reporting odds ratios, proportional reporting ratios, Bayesian confidence propagation neural network, and empirical Bayes geometric mean were used for analysis.

Results

After analyzing 16,692,026 adverse event reports, a total of 1,574 cases of adverse events related to TXA were identified, spanning 23 system organ classes and 307 preferred terms. In addition to the common thrombosis-related Vascular disorders (n = 386) and Cardiac disorders (n = 377), adverse reactions in the Nervous system disorders category were also observed (n = 785), including Myoclonus (n = 70), Status epilepticus (n = 43), and Myoclonic epilepsy (n = 17). Furthermore, this study uncovered adverse effects such as Renal cortical necrosis, Hepatic cyst rupture, and Vascular stent stenosis, which were not previously mentioned in the instructions. Although these occurred infrequently, they exhibited high signal strength. Both Retinal artery occlusion and Vascular stent thrombosis disorder were frequent and exhibited high signal strength as well. It is worth noting that 78 cases of adverse reactions were caused by confusion between incorrect product administration.

Conclusion

Our research suggests that TXA has some adverse reactions that are being overlooked. As a cornerstone medication in hemorrhage treatment, it's crucial to monitor, identify, and address these adverse reactions effectively.

Tranexamic acid for percutaneous nephrolithotomy

BACKGROUND

Percutaneous nephrolithotomy (PCNL) is the gold standard for the treatment of large kidney stones but comes with an increased risk of bleeding compared to other treatments, such as ureteroscopy and shock wave lithotripsy. Tranexamic acid (TXA) is an antifibrinolytic agent that has been used to reduce bleeding complications in other settings.

OBJECTIVES

To assess the effects of TXA in individuals with kidney stones undergoing PCNL.

SEARCH METHODS

We performed a comprehensive literature search of the Cochrane Library, PubMed (including MEDLINE), Embase, Scopus, Global Index Medicus, trials registries, other sources of the grey literature, and conference proceedings. We applied no restrictions on the language of publication nor publication status. The latest search date was 11 May 2023.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared treatment with PCNL with administration of TXA to placebo (or no TXA) for patients ≥ 18 years old.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies and abstracted data. Primary outcomes were: blood transfusion, stone-free rate (SFR), and thromboembolic events (TEEs). Secondary outcomes were: adverse events (AEs), secondary interventions, major surgical complications, minor surgical complications, unplanned hospitalizations or readmissions, and hospital length of stay (LOS). We performed statistical analyzes using a random-effects model. We rated the certainty of evidence (CoE) according to the GRADE approach using a minimally contextualized approach with predefined thresholds for minimally clinically important differences (MCIDs).

MAIN RESULTS

We analyzed 10 RCTs assessing the effect of systemic TXA in PCNL versus placebo (or no TXA) with 1883 randomized participants. Eight studies were published as full text. One was published in abstract proceedings, but it was separated into two separate studies for the purpose of our analyzes. Average stone surface area ranged 3.45 to 6.62 cm2. We also found a single RCT published in full text assessing the effects of topical TXA in PCNL versus placebo (or no TXA) with 400 randomized participants, the results of which are further described in the review. Here we focus only on the results of TXA used systemically. Blood transfusion - Based on a representative baseline risk of 5.7% for blood transfusions taken from a large presentative observational studies, systemic TXA may reduce blood transfusions (risk ratio (RR) 0.45, 95% confidence interval (CI) 0.27 to 0.76; I2 = 28%; 9 studies, 1353 participants; low CoE). We assumed an MCID of ≥ 2%. Based on 57 participants per 1000 with placebo (or no TXA) being transfused, this corresponds to 31 fewer (from 42 fewer to 14 fewer) participants being transfused per 1000. Stone-free rate - Based on a representative baseline risk of 75.7% for SFR, systemic TXA may increase SFRs (RR 1.11, 95% CI 0.98 to 1.27; I2 = 62%; 4 studies, 603 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 757 participants per 1000 being stone free with placebo (or no TXA), this corresponds to 83 more (from 15 fewer to 204 more) stone-free participants per 1000. Thromboembolic events - There is probably no difference in TEEs (risk difference (RD) 0.00, 95% CI -0.01 to 0.01; I2 = 0%; 6 studies, 841 participants; moderate CoE). We assumed an MCID of ≥ 2%. Since there were no thromboembolic events in intervention and/or control groups in 5 out of6 studies, we opted to assess a risk difference with systemic TXA for this outcome. Adverse events - Systemic TXA may increase AEs (RR 5.22, 95% CI 0.52 to 52.72; I2 = 75%; 4 studies, 602 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 23 participants per 1000 with placebo (or no TXA) having an adverse event, this corresponds to 98 more (from 11 fewer to 1000 more) participants with adverse events per 1000. Secondary interventions - Systemic TXA may have little to no effect on secondary interventions (RR 1.15, 95% CI 0.84 to 1.57; I2 = 0%; 2 studies, 319 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 278 participants per 1000 with placebo (or no TXA) having a secondary intervention, this corresponds to 42 more (from 44 fewer to 158 more) participants with secondary interventions per 1000. Major surgical complications - Based on a representative baseline risk for major surgical complications of 4.1%, systemic TXA may reduce major surgical complications (RR 0.36, 95% CI 0.21 to 0.62; I2 = 0%; 5 studies, 733 participants; moderate CoE). We assumed an MCID of ≥ 2%. Based on 41 participants per 1000 with placebo (or no TXA) having a major surgical complication, this corresponds to 26 fewer (from 32 fewer to 16 fewer) participants with major surgical complications per 1000. Minor surgical complications - Systemic TXA may reduce minor surgical complications (RR 0.71, 95% CI 0.45 to 1.10; I2 = 76%; 5 studies, 733 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 396 participants per 1000 with placebo (or no TXA) having a minor surgical complication, this corresponds to 115 fewer (from 218 fewer to 40 more) participants with minor surgical complications per 1000. Unplanned hospitalizations or readmissions - We are very uncertain how unplanned hospitalizations or readmissions are affected (RR 1.55, 95% CI 0.45 to 5.31; I2 = not applicable; 1 study, 189 participants; very low CoE). We assumed an MCID of ≥ 2%. Hospital length of stay - Systemic TXA may reduce hospital LOS (mean difference 0.52 days lower, 95% CI 0.93 lower to 0.11 lower; I2 = 98%; 7 studies, 1151 participants; low CoE). We assumed an MCID of ≥ 0.5 days.

AUTHORS' CONCLUSIONS

Based on 10 RCTs with substantial methodological limitations that lowered all CoE of effect, we found that systemic TXA in PCNL may reduce blood transfusions, major and minor surgical complications, and hospital LOS, as well as improve SFRs; however, it may increase AEs. We are uncertain about the effects of systemic TXA on other outcomes. Findings of this review should assist urologists and their patients in making informed decisions about the use of TXA in the setting of PCNL.

Principles of minimize bleeding and the transfusion of blood and its components in operated patients - surgical aspects

One of the target of perioperative tratment in surgery is decreasing intraoperative bleeding, which increases the number of perioperative procedures, mortality and treatment costs, and also causes the risk of transfusion of blood and its components. Trying to minimize the blood loss(mainly during the operation) as well as the need to transfuse blood and its components (broadly understood perioperative period) should be standard treatment for a patient undergoing a procedure. In the case of this method, the following steps should be taken: 1) in the preoperative period: identyfication of risk groups as quickly as possible, detecting and treating anemia, applying prehabilitation, modyfying anticoagulant treatment, considering donating one's own blood in some patients and in selected cases erythropoietin preparations; 2) in the perioperative period: aim for normothermia, normovolemia and normoglycemia, use of surgical methods that reduce bleeding, such as minimally invasive surgery, high-energy coagulation, local hemostatics, prevention of surgical site infection, proper transfusion of blood and its components if it occurs; 3) in the postoperative period: monitor the condition of patients, primarily for the detection of bleeding, rapid reoperation if required, suplementation (oral administration preferred) nutrition with microelements (iron) and vitamins, updating its general condition. All these activities, comprehensively and in surgical cooperation with the anesthesiologist, should reduce the blood loss and transfusion of blood and its components.

Idiopathic Aplastic anemia: Indian Perspective

Aplastic anemia (AA) is a rare immunologically mediated bone marrow failure syndrome, characterized by progressive loss of hematopoietic stem cells resulting in peripheral pancytopenia. Elaborative investigation including molecular tests is required to exclude inherited bone marrow failure syndrome (IMBFS) as the treatment and prognosis vary dramatically between them. Haematopoietic stem cell transplant with a fully matched sibling donor (MSD-HSCT) is still the only curative treatment. Management of AA is a real-time challenge in India, because of the delay in the diagnosis, lack of proper supportive care, limited availability of the expertise centre, and the patient's affordability. Recently, results with intensified immunosuppressive therapy that includes anti-thymocyte globulin with cyclosporine-A (CsA) and eltrombopag, are enough encouraging to consider it as treatment of choice in patients lacking MSD or who are not fit for HSCT. However, limitations in resource constraints settings including the cost of therapy limit its full utilization. Relapse of the disease or evolution to myelodysplasia or paroxysmal nocturnal haemoglobinuria (PNH) in a proportion of patients is another challenge with immunosuppressants. The majority of the AA patients still receive CsA with or without androgens in India, mostly because of increased cost and limited availability of HSCT and ATG. The use of the unrelated or alternative donor is still upcoming in India, with unavailable data in terms of response and survival. Therefore, there is an utmost need for novel agents for the better management of AA having a balanced efficacy and toxicity profile to improve the survival and quality of life.

Hyperhomocysteinemia and Accelerated Aging: The Pathogenic Role of Increased Homocysteine in Atherosclerosis, Osteoporosis, and Neurodegeneration

Cardiovascular diseases and osteoporosis, seemingly unrelated disorders that occur with advanced age, share major pathogenetic mechanisms contributing to accelerated atherosclerosis and bone loss. Hyperhomocysteinemia (hHcy) is among these mechanisms that can cause both vascular and bone disease. In its more severe form, hHcy can present early in life as homocystinuria, an inborn error of metabolic pathways of the sulfur-containing amino acid methionine. In its milder forms, hHcy may go undiagnosed and untreated into adulthood. As such, hHcy may serve as a potential therapeutic target for cardiovascular disease, osteoporosis, thrombophilia, and neurodegeneration, collectively representing accelerated aging. Multiple trials to lower cardiovascular risk and improve bone density with homocysteine-lowering agents, yet none has proven to be clinically meaningful. To understand this unmet clinical need, this review will provide mechanistic insight into the pathogenesis of vascular and bone disease in hHcy, using homocystinuria as a model for accelerated atherosclerosis and bone density loss, a model for accelerated aging.

Tranexamic Acid in Non-Traumatic Intracerebral Haemorrhage (TANICH II): Introducing the Potential Role of 3 g Tranexamic Acid in Haematoma Reduction

Background

Intracerebral haemorrhage (ICH) can be devastating, particularly if haematoma expansion occurs. The efficacy of tranexamic acid (TXA), an anti-fibrinolytic agent, in reducing haematoma expansion is now being studied worldwide. However, the optimal dosage of TXA has yet to be determined. This study was designed to further establish the potential of different doses of TXA.

Methods

A double-blinded, randomised, placebo-controlled study was carried out among adults with non-traumatic ICH. Eligible study subjects were randomly assigned to receive placebo, 2-g TXA treatment or 3-g TXA treatment. Haematoma volumes before and after intervention were measured using the planimetric method.

Results

A total of 60 subjects with 20 subjects in each treatment group were recruited for this study. Among the 60 subjects, the majority were male (n = 36, 60%), had known cases of hypertension (n = 43, 71.7%) and presented with full Glasgow coma scale (GCS) (n = 41, 68.3%). The results showed that there was no statistically significant difference (P = 0.315) in the mean changes of haematoma volume when compared with three study groups using ANCOVA, although the 3-g TXA group was the only group that showed haematoma volume reduction (mean reduction of 0.2 cm³) instead of expansion as in placebo (mean expansion 1.8 cm³) and 2-g TXA (mean expansion 0.3 cm³) groups. Good recovery was observed in all study groups, with only three subjects being moderately disabled. No adverse effects were reported in any of the study groups.

Conclusion

To the best of our knowledge, this is the first clinical study using 3 g of TXA in the management of non-traumatic ICH. From our study, 3 g of TXA may potentially be helpful in reducing haematoma volume. Nonetheless, a larger-scale randomised controlled trial should be carried out to further establish the role of 3 g of TXA in non-traumatic ICH.

Absence of hyperfibrinolysis may explain lack of efficacy of tranexamic acid in hypoproliferative thrombocytopenia

The American Trial Using Tranexamic Acid (TXA) in Thrombocytopenia (A-TREAT, NCT02578901) demonstrated no superiority of TXA over placebo in preventing World Health Organization (WHO) grade 2 or higher bleeding in patients with severe thrombocytopenia requiring supportive platelet transfusion following myeloablative therapy for hematologic disorders. In this ancillary study, we sought to determine whether this clinical outcome could be explained on the basis of correlative assays of fibrinolysis. Plasma was collected from A-TREAT participants (n = 115) before the initiation of study drug (baseline) and when TXA was at steady-state trough concentration (follow-up). Global fibrinolysis was measured by 3 assays: euglobulin clot lysis time (ECLT), plasmin generation (PG), and tissue-type plasminogen activator (tPA)-challenged clot lysis time (tPA-CLT). TXA was quantified in follow-up samples by tandem mass spectrometry. Baseline samples did not demonstrate fibrinolytic activation by ECLT or tPA-CLT. Furthermore, neither ECLT nor levels of plasminogen activator inhibitor-1, tPA, plasminogen, alpha2-antiplasmin, or plasmin-antiplasmin complexes were associated with a greater risk of WHO grade 2+ bleeding. TXA trough concentrations were highly variable (range, 0.7-10 μg/mL) and did not correlate with bleeding severity, despite the fact that plasma TXA levels correlated strongly with pharmacodynamic assessments by PG (Spearman r, -0.78) and tPA-CLT (r, 0.74). We conclude that (1) no evidence of fibrinolytic activation was observed in these patients with thrombocytopenia, (2) trough TXA concentrations varied significantly between patients receiving the same dosing schedule, and (3) tPA-CLT and PG correlated well with TXA drug levels.

Promotion of Platelet Production by Co-Transplantation of Mesenchymal Stem Cells in Bone Marrow Transplantation

BACKGROUND

Therapeutic strategies that can promote platelet production are in demand to enhance clinical outcomes of bone marrow transplantation (BMT). Our research group has studied human tonsil-derived mesenchymal stem cells (T-MSCs) and their effectiveness in promoting bone marrow (BM) engraftment. Here, we analyzed the effects of T-MSCs on platelet production and hemostasis.

METHODS

Donor BM cells (BMCs) were isolated from C57BL/6 mice and transplanted with or without T-MSCs to BALB/c recipient mice. Mice were sacrificed and blood cells were counted using an Auto Hematology Analyzer. Femur sections were stained with CD41 antibody to analyze megakaryocytes in the BM. Growth factor secretion from MSCs was analyzed using the Quantibody Array. Effects of T-MSC conditioned medium (CM) on megakaryopoiesis were investigated using the MegaCult assay. In a mouse model of BMT, T-MSC CM was injected with or without anti-placental growth factor (α-PlGF) blocking antibody, and blood cell numbers and coagulation were analyzed.

RESULTS

T-MSC co-transplantation increased percent survival of BMT mice. Platelet numbers were significantly lower in the BMC-only group, whereas T-MSC co-transplantation restored circulating platelets to levels similar to those of the control group. Significantly reduced numbers of CD41 + megakaryocytes in Bu-Cy and BMC groups were increased by T-MSC co-transplantation. PlGF secretion from T-MSCs were detected and enhanced megakaryopoiesis, platelet production, and coagulation by T-MCS CM were disrupted in the presence of the α-PlGF blocking antibody.

CONCLUSION

We demonstrated the effectiveness of T-MSC co-transplantation in promoting platelet production and coagulation after BMT. These findings highlight the potential therapeutic relevance of T-MSCs for preventing thrombocytopenia after BMT.

Zastosowanie fibryny w inżynierii tkankowej. Osiągnięcia i perspektywy

W ostatnich latach istotnym obszarem zastosowania fibryny stała się inżynieria tkankowa, w której wykorzystuje się naturalne właściwości biostatyczne i bioaktywne fibryny, a także możliwość pułapkowania i wiązania w jej strukturze czynników wzrostu. Fibryna jest najczęściej stosowana w postaci żeli i dysków. Jednak każda postać wskutek pochłaniania wody docelowo przyjmuje postać żelu. Białko to w warunkach in vivo spełnia rolę rusztowania dla komórek, a także może być aplikowane w miejsca trudno dostępne – może wypełniać ubytki tkanek i podtrzymywać tkanki okalające, zapobiegając ich zapadaniu się. Ponadto fibryna hamuje krwawienie i inicjuje proces odnowy, jak również pełni rolę stymulatora wzrostu komórek. Przez modyfikacje struktury fibryny cząsteczkami adhezyjnymi, można przyspieszyć odbudowę prawidłowej struktury tkanek. Jej właściwości strukturalne mogą być także wykorzystywane jako rezerwuar czynników wzrostu i system ich przedłużonego uwalniania. Fibryna jest materiałem biodegradowalnym, umożliwiając skorelowanie ubytku matrycy fibrynowej z odbudową tkanek własnych pacjenta. Wprowadzenie metod druku 3D i elektroprzędzenia umożliwia formulację dopasowanych do uszkodzeń kształtek oraz włóknin bez utraty bioaktywnych funkcji fibryny. Metody te umożliwiają także poprawę właściwości mechanicznych przez otrzymywanie m.in. włóknin fibryny z innymi polimerami, co jest szczególnie uzasadnione w przypadku materiałów stosowanych w odbudowie takich struktur jak ścięgna czy kości. Biotechnologiczna synteza fibrynogenu może w przyszłości uniezależnić pozyskiwanie go z krwi i zwiększyć popularność wyrobów medycznych otrzymywanych z fibryny.

A Novel Intraoperative Transient Variant of Immune Thrombocytopenia

Immune thrombocytopenia, also known as immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by a very low number of platelets and associated excessive bleeding. Primary ITP is a diagnosis of exclusion and secondary causes of ITP including lymphoproliferative disorders, medications, and certain infections must be ruled out during workup. This is the first report to highlight intraoperative ITP or an ITP-like novel variant in the perioperative setting leading to increased bleeding. The patient's extensive workup failed to reveal any secondary causative factors. The clinical presentation of ITP was transient. She received tranexamic acid (TXA), intravenous steroids, and intravenous immunoglobulins (IVIG) and recovered without complication. This case report explores a potentially underreported cause for intraoperative and postoperative hemorrhage in surgical patients.

Challenges and Advances in Managing Thrombocytopenic Cancer Patients

Cancer patients have varying incidence, depth and duration of thrombocytopenia. The mainstay of managing severe chemotherapy-induced thrombocytopenia (CIT) in cancer is the use of platelet transfusions. While prophylactic platelet transfusions reduce the bleeding rate, multiple unmet needs remain, such as high residual rates of bleeding, and anticancer treatment dose reductions/delays. Accordingly, the following promising results in other settings, antifibrinolytic drugs have been evaluated for prevention and treatment of bleeding in patients with hematological malignancies and solid tumors. In addition, Thrombopoeitin receptor agonists have been studied for two major implications in cancer: treatment of severe thrombocytopenia associated with myelodysplastic syndrome and acute myeloid leukemia; primary and secondary prevention of CIT in solid tumors in order to maintain dose density and intensity of anti-cancer treatment. Furthermore, thrombocytopenic cancer patients are often prescribed antithrombotic medication for indications arising prior or post cancer diagnosis. Balancing the bleeding and thrombotic risks in such patients represents a unique clinical challenge. This review focuses upon non-transfusion-based approaches to managing thrombocytopenia and the associated bleeding risk in cancer, and also addresses the management of antithrombotic therapy in thrombocytopenic cancer patients.

Platelet transfusion and tranexamic acid to prevent bleeding in outpatients with a hematological disease: A Dutch nationwide survey

OBJECTIVES

There is scarce evidence about the effectiveness of anti-bleeding measures in hematological outpatients experiencing persistent severe thrombocytopenia. We aim to describe clinical practice and clinicians' considerations on the administration of prophylactic platelet transfusions and tranexamic acid (TXA) to outpatients with acute leukemia, myelodysplastic syndrome (MDS), or aplastic anemia (AA) in the Netherlands.

METHODS

We conducted an online survey among members of the Dutch Society for Hematology.

RESULTS

The survey was filled out by 73 respondents. Prophylactic platelet transfusions are widely used in acute leukemia and MDS outpatients receiving disease-modifying treatments (87%-98% of respondents). TXA is predominantly prescribed in case of bleeding (tendency) (71%-88% of respondents). Conditions potentially increasing bleeding risks highly variably influence clinicians' decision making on anti-bleeding regimens, which includes a wide range in adhered platelet thresholds.

CONCLUSION

Considering that both the contribution of prophylactic platelet transfusions as well as TXA to limiting bleeding is insufficiently evidence-based, there is an urgent need for trials on optimal anti-bleeding strategies in this outpatient population, which should encompass efficacy, logistic, financial, and quality-of-life aspects.

Management of hemostatic complications in acute leukemia: Guidance from the SSC of the ISTH

Patients with acute leukemia frequently develop thrombocytopenia and hemostatic complications caused by coagulopathy. Coagulopathy complicates the management of these patients and can lead to significant morbidity and mortality. This guidance document aims to review and provide guidance on the management of hemostatic complications in adult patients with acute leukemia, addressing four main issues, including platelet transfusion, disseminated intravascular coagulation, L-asparaginase-related hypofibrinogenemia, and the use of antifibrinolytic agents.

Tranexamic Acid in a Case Report of Life-threatening Nontraumatic Hemorrhage in Immune Thrombocytopenic Purpura

Introduction

Immune thrombocytopenic purpura (ITP) is an autoimmune-mediated disorder in which the body produces antibodies that destroy platelets, causing an increased risk of bleeding and bruising. Tranexamic acid (TXA) is a medication that prevents clot breakdown and is used to treat uncontrolled bleeding.

Case Report

We present the case of an 11-year-old female with significant epistaxis and hypotension in the emergency department. Traditional therapies were initiated; however, the patient continued to have bleeding and remained hypotensive, so intravenous TXA was given. The patient’s bleeding then resolved.

Conclusion

TXA may be a safe and effective adjunct to traditional therapies for the treatment of life-threatening hemorrhage in ITP patients.

Development of Optimized Tissue-Factor-Targeted Peptide Amphiphile Nanofibers to Slow Noncompressible Torso Hemorrhage

Noncompressible torso hemorrhage accounts for a significant portion of preventable trauma deaths. We report here on the development of injectable, targeted supramolecular nanotherapeutics based on peptide amphiphile (PA) molecules that are designed to target tissue factor (TF) and, therefore, selectively localize to sites of injury to slow hemorrhage. Eight TF-targeting sequences were identified, synthesized into PA molecules, coassembled with nontargeted backbone PA at various weight percentages, and characterized via circular dichroism spectroscopy, transmission electron microscopy, and X-ray scattering. Following intravenous injection in a rat liver hemorrhage model, two of these PA nanofiber coassemblies exhibited the most specific localization to the site of injury compared to controls (p < 0.05), as quantified using immunofluorescence imaging of injured liver and uninjured organs. To determine if the nanofibers were targeting TF in vivo, a mouse saphenous vein laser injury model was performed and showed that TF-targeted nanofibers colocalized with fibrin, demonstrating increased levels of nanofiber at TF-rich sites. Thromboelastograms obtained using samples of heparinized rat whole blood containing TF demonstrated that no clots were formed in the absence of TF-targeted nanofibers. Lastly, both PA nanofiber coassemblies decreased blood loss in comparison to sham and backbone nanofiber controls by 35-59% (p < 0.05). These data demonstrate an optimal TF-targeted nanofiber that localizes selectively to sites of injury and TF exposure, and, interestingly, reduces blood loss. This research represents a promising initial phase in the development of a TF-targeted injectable therapeutic to reduce preventable deaths from hemorrhage.

The many roles of tranexamic acid: An overview of the clinical indications for TXA in medical and surgical patients

Clinically significant bleeding can occur as a consequence of surgery, trauma, obstetric complications, anticoagulation, and a wide variety of disorders of hemostasis. As the causes of bleeding are diverse and not always immediately apparent, the availability of a safe, effective, and non-specific hemostatic agent is vital in a wide range of clinical settings, with antifibrinolytic agents often utilized for this purpose. Tranexamic acid (TXA) is one of the most commonly used and widely researched antifibrinolytic agents; its role in postpartum hemorrhage, menorrhagia, trauma-associated hemorrhage, and surgical bleeding has been well defined. However, the utility of TXA goes beyond these common indications, with accumulating data suggesting its ability to reduce bleeding and improve clinical outcomes in the face of many different hemostatic challenges, without a clear increase in thrombotic risk. Herein, we review the literature and provide practical suggestions for clinical use of TXA across a broad spectrum of bleeding disorders.

Fibrinolysis Inhibitors: Potential Drugs for the Treatment and Prevention of Bleeding

Hyperfibrinolytic situations can lead to life-threatening bleeding, especially during cardiac surgery. The approved antifibrinolytic agents such as tranexamic acid, ε-aminocaproic acid, 4-aminomethylbenzoic acid, and aprotinin were developed in the 1960s without the structural insight of their respective targets. Crystal structures of the main antifibrinolytic targets, the lysine binding sites on plasminogen's kringle domains, and plasmin's serine protease domain greatly contributed to the structure-based drug design of novel inhibitor classes. Two series of ligands targeting the lysine binding sites have been recently described, which are more potent than the most-widely used antifibrinolytic agent, tranexamic acid. Furthermore, four types of promising active site inhibitors of plasmin have been developed: tranexamic acid conjugates targeting the S1 pocket and primed sites, substrate-analogue linear homopiperidylalanine-containing 4-amidinobenzylamide derivatives, macrocyclic inhibitors addressing nonprimed binding regions, and bicyclic 14-mer SFTI-1 analogues blocking both, primed and nonprimed binding sites of plasmin. Furthermore, several allosteric plasmin inhibitors based on heparin mimetics have been developed.

The TREATT Trial (TRial to EvaluAte Tranexamic acid therapy in Thrombocytopenia): safety and efficacy of tranexamic acid in patients with haematological malignancies with severe thrombocytopenia: study protocol for a double-blind randomised controlled trial

Background

Patients with haematological malignancies often develop thrombocytopenia as a consequence of either their disease or its treatment. Platelet transfusions are commonly given to raise a low platelet count and reduce the risk of clinical bleeding (prophylaxis) or stop active bleeding (therapy). Recent studies have shown that many patients continue to experience bleeding despite the use of prophylactic platelet transfusions. Tranexamic acid is an anti-fibrinolytic, which reduces the breakdown of clots formed in response to bleeding. Anti-fibrinolytics have been shown to prevent bleeding, decrease blood loss and use of red cell transfusions in elective and emergency surgery, and are used widely in these settings. The aim of this trial is to test whether giving tranexamic acid to patients receiving treatment for haematological malignancies reduces the risk of bleeding or death and the need for platelet transfusions.

Methods

This is a multinational randomised, double-blind, placebo-controlled, parallel, superiority trial. Patients will be randomly assigned to receive tranexamic acid (given intravenously or orally) or a matching placebo in a 1:1 ratio, stratified by site. Patients with haematological malignancies receiving intensive chemotherapy or stem cell transplantation (or both) who are at least 18 years of age and expected to become severely thrombocytopenic for at least 5 days will be eligible for this trial. The primary outcome of the trial is the proportion of patients who died or had bleeding of World Health Organization grade 2 or above during the first 30 days of the trial. We will measure the rates of bleeding daily by using a short, structured assessment of bleeding, and we will record the number of transfusions given to patients. We will assess the risk of arterial and venous thrombosis for 120 days from the start of trial treatment.

Discussion

This trial will assess the safety and efficacy of using prophylactic tranexamic acid during a period of intensive chemotherapy and associated thrombocytopenia in people with haematological disorders.

Trial registration

This study was prospectively registered on Current Controlled Trials on 25 March 2015 (ISRCTN73545489) and is also registered on ClinicalTrials.gov (NCT03136445).

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3663-2) contains supplementary material, which is available to authorized users.

Successful management of refractory bleeding in liver failure with tranexamic acid: Case report and literature review

A 50-year-old woman with advanced cirrhosis presented with spontaneous subdural hematoma. She had a worsening clinical course following craniotomy despite administration of multiple blood products. With elevation in D-dimer, persistently low fibrinogen and poor response to factor/fibrinogen replacement therapies, we had a suspicion for uncontrolled fibrinolysis. A literature review was conducted on treatment of hyperfibrinolysis in cirrhosis, finding 4 reports in which antifibrinolytics were used to control bleeding with different outcomes. The dose of tranexamic acid used in our patient was employed from previous experience in trauma patients. We transitioned from intravenous to oral administration based on expected pharmacokinetics. Our patient had a successful outcome with resolution of bleeding.

Prophylactic platelet transfusions prior to surgery for people with a low platelet count

BACKGROUND

People with thrombocytopenia often require a surgical procedure. A low platelet count is a relative contraindication to surgery due to the risk of bleeding. Platelet transfusions are used in clinical practice to prevent and treat bleeding in people with thrombocytopenia. Current practice in many countries is to correct thrombocytopenia with platelet transfusions prior to surgery. Alternatives to platelet transfusion are also used prior surgery.

OBJECTIVES

To determine the clinical effectiveness and safety of prophylactic platelet transfusions prior to surgery for people with a low platelet count.

SEARCH METHODS

We searched the following major data bases: Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), PubMed (e-publications only), Ovid MEDLINE, Ovid Embase, the Transfusion Evidence Library and ongoing trial databases to 11 December 2017.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs), as well as non-RCTs and controlled before-and-after studies (CBAs), that met Cochrane EPOC (Effective Practice and Organisation of Care) criteria, that involved the transfusion of platelets prior to surgery (any dose, at any time, single or multiple) in people with low platelet counts. We excluded studies on people with a low platelet count who were actively bleeding.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane for data collection. We were only able to combine data for two outcomes and we presented the rest of the findings in a narrative form.

MAIN RESULTS

We identified five RCTs, all conducted in adults; there were no eligible non-randomised studies. Three completed trials enrolled 180 adults and two ongoing trials aim to include 627 participants. The completed trials were conducted between 2005 and 2009. The two ongoing trials are scheduled to complete recruitment by October 2019. One trial compared prophylactic platelet transfusions to no transfusion in people with thrombocytopenia in an intensive care unit (ICU). Two small trials, 108 participants, compared prophylactic platelet transfusions to other alternative treatments in people with liver disease. One trial compared desmopressin to fresh frozen plasma or one unit of platelet transfusion or both prior to surgery. The second trial compared platelet transfusion prior to surgery with two types of thrombopoietin mimetics: romiplostim and eltrombopag. None of the included trials were free from methodological bias. No included trials compared different platelet count thresholds for administering a prophylactic platelet transfusion prior to surgery. None of the included trials reported on all the review outcomes and the overall quality per reported outcome was very low.None of the three completed trials reported: all-cause mortality at 90 days post surgery; mortality secondary to bleeding, thromboembolism or infection; number of red cell or platelet transfusions per participant; length of hospital stay; or quality of life.None of the trials included children or people who needed major surgery or emergency surgical procedures.Platelet transfusion versus no platelet transfusion (1 trial, 72 participants)We were very uncertain whether giving a platelet transfusion prior to surgery had any effect on all-cause mortality within 30 days (1 trial, 72 participants; risk ratio (RR) 0.78, 95% confidence interval (CI) 0.41 to 1.45; very-low quality evidence). We were very uncertain whether giving a platelet transfusion prior to surgery had any effect on the risk of major (1 trial, 64 participants; RR 1.60, 95% CI 0.29 to 8.92; very low-quality evidence), or minor bleeding (1 trial, 64 participants; RR 1.29, 95% CI 0.90 to 1.85; very-low quality evidence). No serious adverse events occurred in either study arm (1 trial, 72 participants, very low-quality evidence).Platelet transfusion versus alternative to platelet transfusion (2 trials, 108 participants)We were very uncertain whether giving a platelet transfusion prior to surgery compared to an alternative has any effect on the risk of major (2 trials, 108 participants; no events; very low-quality evidence), or minor bleeding (desmopressin: 1 trial, 36 participants; RR 0.89, 95% CI 0.06 to 13.23; very-low quality evidence: thrombopoietin mimetics: 1 trial, 65 participants; no events; very-low quality evidence). We were very uncertain whether there was a difference in transfusion-related adverse effects between the platelet transfused group and the alternative treatment group (desmopressin: 1 trial, 36 participants; RR 2.70, 95% CI 0.12 to 62.17; very-low quality evidence).

AUTHORS' CONCLUSIONS

Findings of this review were based on three small trials involving minor surgery in adults with thrombocytopenia. We found insufficient evidence to recommend the administration of preprocedure prophylactic platelet transfusions in this situation with a lack of evidence that transfusion resulted in a reduction in postoperative bleeding or all-cause mortality. The small number of trials meeting the inclusion criteria and the limitation in reported outcomes across the trials precluded meta-analysis for most outcomes. Further adequately powered trials, in people of all ages, of prophylactic platelet transfusions compared with no transfusion, other alternative treatments, and considering different platelet thresholds prior to planned and emergency surgical procedures are required. Future trials should include major surgery and report on bleeding, adverse effects, mortality (as a long-term outcome) after surgery, duration of hospital stay and quality of life measures.

Perioperative management of the bleeding patient

Perioperative bleeding remains a major complication during and after surgery, resulting in increased morbidity and mortality. The principal causes of non-vascular sources of haemostatic perioperative bleeding are a preexisting undetected bleeding disorder, the nature of the operation itself, or acquired coagulation abnormalities secondary to haemorrhage, haemodilution, or haemostatic factor consumption. In the bleeding patient, standard therapeutic approaches include allogeneic blood product administration, concomitant pharmacologic agents, and increasing application of purified and recombinant haemostatic factors. Multiple haemostatic changes occur perioperatively after trauma and complex surgical procedures including cardiac surgery and liver transplantation. Novel strategies for both prophylaxis and therapy of perioperative bleeding include tranexamic acid, desmopressin, fibrinogen and prothrombin complex concentrates. Point-of-care patient testing using thromboelastography, rotational thromboelastometry, and platelet function assays has allowed for more detailed assessment of specific targeted therapy for haemostasis. Strategic multimodal management is needed to improve management, reduce allogeneic blood product administration, and minimize associated risks related to transfusion.

Abnormal Uterine Bleeding in Young Women with Blood Disorders

Abnormal uterine bleeding is common in adolescents and is thought to affect 9% to 14% of women in their reproductive years. Certain unique aspects of underlying inherited or acquired blood disorders exacerbate the "expected" hormonal imbalance at this age, thereby increasing the morbidity of the underlying problem. A multifactorial etiology demands a collaborative approach between hematologists and gynecologists or adolescent medicine physicians to effectively manage abnormal uterine bleeding in young women with blood disorders.

Complications and management of coagulation disorders in leukemia patients

Patients with leukemia are predisposed to various coagulation abnormalities. Thrombosis and bleeding continue to be a major cause of morbidity and mortality in leukemias. The pathophysiology of these disorders is unique, and not only the disease but also the treatment and other factors play a role. There has been an increase in the understanding of these disorders in leukemias. However, it is still difficult to predict when and which patients will have these complications. The evidence for the management of coagulation abnormalities in leukemias is still evolving and not as established as in solid malignancies. The management of these disorders is complex, and making clinical decisions is often challenging. In the era of specialization, where there are different hematologists looking after benign- and malignant-hematology patients, opinions of thrombosis experts are often sought by leukemia specialists. This review aims to bridge the gap in the knowledge of these disorders between these specialists.

Prophylactic platelet transfusions prior to surgery for people with a low platelet count

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To determine the clinical effectiveness and safety of prophylactic platelet transfusions prior to surgery for people with a low platelet count or platelet dysfunction (inherited or acquired).

Metabolomic profile and nucleoside composition of Cordyceps nidus sp. nov. (Cordycipitaceae): A new source of active compounds

Cordyceps sensu lato is a genus of arthropod-pathogenic fungi, which have been used traditionally as medicinal in Asia. Within the genus, Ophiocordyceps sinensis is the most coveted and expensive species in China. Nevertheless, harvesting wild specimens has become a challenge given that natural populations of the fungus are decreasing and because large-scale culture of it has not yet been achieved. The worldwide demand for products derived from cultivable fungal species with medicinal properties has increased recently. In this study, we propose a new species, Cordyceps nidus, which parasitizes underground nests of trapdoor spiders. This species is phylogenetically related to Cordyceps militaris, Cordyceps pruinosa, and a sibling species of Cordyceps caloceroides. It is found in tropical rainforests from Bolivia, Brazil, Colombia and Ecuador. We also investigated the medicinal potential of this fungus based on its biochemical properties when grown on four different culture media. The metabolic profile particularly that of nucleosides, in polar and non-polar extracts was determined by UPLC, and then correlated to their antimicrobial activity and total phenolic content. The metabolome showed a high and significant dependency on the substrate used for fungal growth. The mass intensities of nucleosides and derivative compounds were higher in natural culture media in comparison to artificial culture media. Among these compounds, cordycepin was the predominant, showing the potential use of this species as an alternative to O. sinensis. Furthermore, methanol fractions showed antimicrobial activity against gram-positive bacteria, and less than 3.00 mg of gallic acid equivalents per g of dried extract were obtained when assessing its total phenolic content by modified Folin-Ciocalteu method. The presence of polyphenols opens the possibility of further exploring the antioxidant capacity and the conditions that may enhance this characteristic. The metabolic composition and biochemical activity indicate potential use of C. nidus in pharmaceutical applications.

Alternative agents to prophylactic platelet transfusion for preventing bleeding in people with thrombocytopenia due to chronic bone marrow failure: a meta-analysis and systematic review

BACKGROUND

People with thrombocytopenia due to bone marrow failure are vulnerable to bleeding. Platelet transfusions have limited efficacy in this setting and alternative agents that could replace, or reduce platelet transfusion, and are effective at reducing bleeding are needed.

OBJECTIVES

To compare the relative efficacy of different interventions for patients with thrombocytopenia due to chronic bone marrow failure and to derive a hierarchy of potential alternative treatments to platelet transfusions.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (the Cochrane Library 2016, Issue 3), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1980) and ongoing trial databases to 27 April 2016.

SELECTION CRITERIA

We included randomised controlled trials in people with thrombocytopenia due to chronic bone marrow failure who were allocated to either an alternative to platelet transfusion (artificial platelet substitutes, platelet-poor plasma, fibrinogen concentrate, recombinant activated factor VII (rFVIIa), desmopressin (DDAVP), recombinant factor XIII (rFXIII), recombinant interleukin (rIL)6 or rIL11, or thrombopoietin (TPO) mimetics) or a comparator (placebo, standard of care or platelet transfusion). We excluded people undergoing intensive chemotherapy or stem cell transfusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results, extracted data and assessed trial quality. We estimated summary risk ratios (RR) for dichotomous outcomes. We planned to use summary mean differences (MD) for continuous outcomes. All summary measures are presented with 95% confidence intervals (CI).We could not perform a network meta-analysis because the included studies had important differences in the baseline severity of disease for the participants and in the number of participants undergoing chemotherapy. This raised important concerns about the plausibility of the transitivity assumption in the final dataset and we could not evaluate transitivity statistically because of the small number of trials per comparison. Therefore, we could only perform direct pairwise meta-analyses of included interventions.We employed a random-effects model for all analyses. We assessed statistical heterogeneity using the I2 statistic and its 95% CI. The risk of bias of each study included was assessed using the Cochrane 'Risk of bias' tool. The quality of the evidence was assessed using GRADE methods.

MAIN RESULTS

We identified seven completed trials (472 participants), and four ongoing trials (recruiting 837 participants) which are due to be completed by December 2020. Of the seven completed trials, five trials (456 participants) compared a TPO mimetic versus placebo (four romiplostim trials, and one eltrombopag trial), one trial (eight participants) compared DDAVP with placebo and one trial (eight participants) compared tranexamic acid with placebo. In the DDAVP trial, the only outcome reported was the bleeding time. In the tranexamic acid trial there were methodological flaws and bleeding definitions were subject to significant bias. Consequently, these trials could not be incorporated into the quantitative synthesis. No randomised trial of artificial platelet substitutes, platelet-poor plasma, fibrinogen concentrate, rFVIIa, rFXIII, rIL6 or rIL11 was identified.We assessed all five trials of TPO mimetics included in this review to be at high risk of bias because the trials were funded by the manufacturers of the TPO mimetics and the authors had financial stakes in the sponsoring companies.The GRADE quality of the evidence was very low to moderate across the different outcomes.There was insufficient evidence to detect a difference in the number of participants with at least one bleeding episode between TPO mimetics and placebo (RR 0.86, 95% CI 0.56 to 1.31, four trials, 206 participants, low-quality evidence).There was insufficient evidence to detect a difference in the risk of a life-threatening bleed between those treated with a TPO mimetic and placebo (RR 0.31, 95% CI 0.04 to 2.26, one trial, 39 participants, low-quality evidence).There was insufficient evidence to detect a difference in the risk of all-cause mortality between those treated with a TPO mimetic and placebo (RR 0.74, 95%CI 0.52 to 1.05, five trials, 456 participants, very low-quality evidence).There was a significant reduction in the number of participants receiving any platelet transfusion between those treated with TPO mimetics and placebo (RR 0.76, 95% CI 0.61 to 0.95, four trials, 206 participants, moderate-quality evidence).There was no evidence for a difference in the incidence of transfusion reactions between those treated with TPO mimetics and placebo (pOR 0.06, 95% CI 0.00 to 3.44, one trial, 98 participants, very low-quality evidence).There was no evidence for a difference in thromboembolic events between TPO mimetics and placebo (RR 1.41, 95%CI 0.39 to 5.01, five trials, 456 participants, very-low quality evidence).There was no evidence for a difference in drug reactions between TPO mimetics and placebo (RR 1.12, 95% CI 0.83 to 1.51, five trials, 455 participants, low-quality evidence).No trial reported the number of days of bleeding per participant, platelet transfusion episodes, mean red cell transfusions per participant, red cell transfusion episodes, transfusion-transmitted infections, formation of antiplatelet antibodies or platelet refractoriness.In order to demonstrate a reduction in bleeding events from 26 in 100 to 16 in 100 participants, a study would need to recruit 514 participants (80% power, 5% significance).

AUTHORS' CONCLUSIONS

There is insufficient evidence at present for thrombopoietin (TPO) mimetics for the prevention of bleeding for people with thrombocytopenia due to chronic bone marrow failure. There is no randomised controlled trial evidence for artificial platelet substitutes, platelet-poor plasma, fibrinogen concentrate, rFVIIa, rFXIII or rIL6 or rIL11, antifibrinolytics or DDAVP in this setting.

Alternatives, and adjuncts, to prophylactic platelet transfusion for people with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation

BACKGROUND

Platelet transfusions are used in modern clinical practice to prevent and treat bleeding in people with thrombocytopenia. Although considerable advances have been made in platelet transfusion therapy since the mid-1970s, some areas continue to provoke debate especially concerning the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding.

OBJECTIVES

To determine whether agents that can be used as alternatives, or adjuncts, to platelet transfusions for people with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation are safe and effective at preventing bleeding.

SEARCH METHODS

We searched 11 bibliographic databases and four ongoing trials databases including the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 4), MEDLINE (OvidSP, 1946 to 19 May 2016), Embase (OvidSP, 1974 to 19 May 2016), PubMed (e-publications only: searched 19 May 2016), ClinicalTrials.gov, World Health Organization (WHO) ICTRP and the ISRCTN Register (searched 19 May 2016).

SELECTION CRITERIA

We included randomised controlled trials in people with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation who were allocated to either an alternative to platelet transfusion (artificial platelet substitutes, platelet-poor plasma, fibrinogen concentrate, recombinant activated factor VII, desmopressin (DDAVP), or thrombopoietin (TPO) mimetics) or a comparator (placebo, standard care or platelet transfusion). We excluded studies of antifibrinolytic drugs, as they were the focus of another review.

DATA COLLECTION AND ANALYSIS

Two review authors screened all electronically derived citations and abstracts of papers identified by the review search strategy. Two review authors assessed risk of bias in the included studies and extracted data independently.

MAIN RESULTS

We identified 16 eligible trials. Four trials are ongoing and two have been completed but the results have not yet been published (trial completion dates: April 2012 to February 2017). Therefore, the review included 10 trials in eight references with 554 participants. Six trials (336 participants) only included participants with acute myeloid leukaemia undergoing intensive chemotherapy, two trials (38 participants) included participants with lymphoma undergoing intensive chemotherapy and two trials (180 participants) reported participants undergoing allogeneic stem cell transplantation. Men and women were equally well represented in the trials. The age range of participants included in the trials was from 16 years to 81 years. All trials took place in high-income countries. The manufacturers of the agent sponsored eight trials that were under investigation, and two trials did not report their source of funding.No trials assessed artificial platelet substitutes, fibrinogen concentrate, recombinant activated factor VII or desmopressin.Nine trials compared a TPO mimetic to placebo or standard care; seven of these used pegylated recombinant human megakaryocyte growth and differentiation factor (PEG-rHuMGDF) and two used recombinant human thrombopoietin (rhTPO).One trial compared platelet-poor plasma to platelet transfusion.We considered that all the trials included in this review were at high risk of bias and meta-analysis was not possible in seven trials due to problems with the way data were reported.We are very uncertain whether TPO mimetics reduce the number of participants with any bleeding episode (odds ratio (OR) 0.40, 95% confidence interval (CI) 0.10 to 1.62, one trial, 120 participants, very low quality evidence). We are very uncertain whether TPO mimetics reduce the risk of a life-threatening bleed after 30 days (OR 1.46, 95% CI 0.06 to 33.14, three trials, 209 participants, very low quality evidence); or after 90 days (OR 1.00, 95% CI 0.06 to 16.37, one trial, 120 participants, very low quality evidence). We are very uncertain whether TPO mimetics reduce platelet transfusion requirements after 30 days (mean difference -3.00 units, 95% CI -5.39 to -0.61, one trial, 120 participants, very low quality evidence). No deaths occurred in either group after 30 days (one trial, 120 participants, very low quality evidence). We are very uncertain whether TPO mimetics reduce all-cause mortality at 90 days (OR 1.00, 95% CI 0.24 to 4.20, one trial, 120 participants, very low quality evidence). No thromboembolic events occurred for participants treated with TPO mimetics or control at 30 days (two trials, 209 participants, very low quality evidence). We found no trials that looked at: number of days on which bleeding occurred, time from randomisation to first bleed or quality of life.One trial with 18 participants compared platelet-poor plasma transfusion with platelet transfusion. We are very uncertain whether platelet-poor plasma reduces the number of participants with any bleeding episode (OR 16.00, 95% CI 1.32 to 194.62, one trial, 18 participants, very low quality evidence). We are very uncertain whether platelet-poor plasma reduces the number of participants with severe or life-threatening bleeding (OR 4.00, 95% CI 0.56 to 28.40, one trial, 18 participants, very low quality evidence). We found no trials that looked at: number of days on which bleeding occurred, time from randomisation to first bleed, number of platelet transfusions, all-cause mortality, thromboembolic events or quality of life.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine if platelet-poor plasma or TPO mimetics reduce bleeding for participants with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation. To detect a decrease in the proportion of participants with clinically significant bleeding from 12 in 100 to 6 in 100 would require a trial containing at least 708 participants (80% power, 5% significance). The six ongoing trials will provide additional information about the TPO mimetic comparison (424 participants) but this will still be underpowered to demonstrate this level of reduction in bleeding. None of the included or ongoing trials include children. There are no completed or ongoing trials assessing artificial platelet substitutes, fibrinogen concentrate, recombinant activated factor VII or desmopressin in people undergoing intensive chemotherapy or stem cell transplantation for haematological malignancies.