Early mortality in acute myeloid leukemia with KMT2A rearrangement is associated with high risk of bleeding and disseminated intravascular coagulation.

BACKGROUND: Acute myeloid leukemia (AML) with rearrangement of lysine methyltransferase 2a gene (KMT2Ar) is characterized by chemotherapy resistance and high rates of relapse. However, additional causes of treatment failure or early mortality have not been well-defined in this entity. METHODS: In a retrospective analysis, causes and rates of early mortality following induction treatment were compared between a cohort of adults with KMT2Ar AML (N = 172) and an age-matched cohort of patients with normal karyotype AML (N = 522). RESULTS: The 60-day mortality in patients with KMT2Ar AML was 15% compared with 7% with normal karyotype (p = .04). We found a significantly higher occurrence of major bleeding events (p = .005) and total bleeding events (p = .001) in KMT2Ar AML compared with diploid AML. Among evaluable patients with KMT2Ar AML, 93% exhibited overt disseminated intravascular coagulopathy compared with 54% of patients with a normal karyotype before death (p = .03). In a multivariate analysis, KMT2Ar and a monocytic phenotypic were the only independent predictors of any bleeding event in patients who died within 60 days (odds ratio, 3.5; 95% CI, 1.4-10.4; p = .03; odds ratio, 3.2; 95% CI, 1-1-9.4; p = .04, respectively). CONCLUSION: In conclusion, early recognition and aggressive management of disseminated intravascular coagulopathy and coagulopathy are important considerations that could mitigate the risk of death during induction treatment in KMT2Ar AML. PLAIN LANGUAGE SUMMARY: Acute myeloid leukemia (AML) with rearrangement of KMT2A is characterized by chemotherapy resistance and high rates of relapse. However, additional causes of treatment failure or early mortality have not been well-defined in this entity. In this article, that KMT2A-rearranged AML is demonstrably associated with higher early mortality and an increased risk of bleeding and coagulopathy, specifically, disseminated intravascular coagulation, compared with normal karyotype AML. These findings emphasize the importance of monitoring and mitigating coagulopathy in KMT2A-rearranged leukemia similar to what is done in acute promyelocytic leukemia.

The Intricate Role of Non-Coding RNAs in Sepsis-Associated Disseminated Intravascular Coagulation.

Disseminated Intravascular Coagulation (DIC) is a type of tissue and organ dysregulation in sepsis, due mainly to the effect of the inflammation on the coagulation system. Unfortunately, the underlying molecular mechanisms that lead to this disorder are not fully understood. Moreover, current biomarkers for DIC, including biological and clinical parameters, generally provide a poor diagnosis and prognosis. In recent years, non-coding RNAs have been studied as promising and robust biomarkers for a variety of diseases. Thus, their potential in the diagnosis and prognosis of DIC should be further studied. Specifically, the relationship between the coagulation cascade and non-coding RNAs should be established. In this review, microRNAs, long non-coding RNAs, and circular RNAs are studied in relation to DIC. Specifically, the axis between these non-coding RNAs and the corresponding affected pathway has been identified, including inflammation, alteration of the coagulation cascade, and endothelial damage. The main affected pathway identified is PI3K/AKT/mTOR axis, where several ncRNAs participate in its regulation, including miR-122-5p which is sponged by circ_0005963, ciRS-122, and circPTN, and miR-19a-3p which is modulated by circ_0000096 and circ_0063425. Additionally, both miR-223 and miR-24 were found to affect the PI3K/AKT pathway and were regulated by lncGAS5 and lncKCNQ1OT1, respectively. Thus, this work provides a useful pipeline of inter-connected ncRNAs that future research on their impact on DIC can further explore.

Severe COVID-19 is associated with hyperactivation of the alternative complement pathway.

BACKGROUND: Severe coronavirus disease 2019 (COVID-19) is characterized by impaired type I interferon activity and a state of hyperinflammation leading to acute respiratory distress syndrome. The complement system has recently emerged as a key player in triggering and maintaining the inflammatory state, but the role of this molecular cascade in severe COVID-19 is still poorly characterized. OBJECTIVE: We aimed at assessing the contribution of complement pathways at both the protein and transcriptomic levels. METHODS: To this end, we systematically assessed the RNA levels of 28 complement genes in the circulating whole blood of patients with COVID-19 and healthy controls, including genes of the alternative pathway, for which data remain scarce. RESULTS: We found differential expression of genes involved in the complement system, yet with various expression patterns: whereas patients displaying moderate disease had elevated expression of classical pathway genes, severe disease was associated with increased lectin and alternative pathway activation, which correlated with inflammation and coagulopathy markers. Additionally, properdin, a pivotal positive regulator of the alternative pathway, showed high RNA expression but was found at low protein concentrations in patients with a severe and critical disease, suggesting its deposition at the sites of complement activation. Notably, low properdin levels were significantly associated with the use of mechanical ventilation (area under the curve = 0.82; P = .002). CONCLUSION: This study sheds light on the role of the alternative pathway in severe COVID-19 and provides additional rationale for the testing of drugs inhibiting the alternative pathway of the complement system.

A Translational Investigation of IFN-α and STAT1 Signaling in Endothelial Cells during Septic Shock Provides Therapeutic Perspectives.

Septic shock and disseminated intravascular coagulation (DIC) are known to be characterized by an endothelial cell dysfunction. The molecular mechanisms underlying this relationship are, however, poorly understood. In this work, we aimed to investigate human circulating IFN-α in patients with septic shock-induced DIC and tested the potential role of endothelial Stat1 (signal transducer and activator of transcription 1) as a therapeutic target in a mouse model of sepsis. For this, circulating type I, type II, and type III IFNs and procoagulant microvesicles were quantified in a prospective cohort of patients with septic shock. Next, we used a septic shock model induced by cecal ligation and puncture in wild-type mice, in Ifnar1 (type I IFN receptor subunit 1)-knockout mice, and in Stat1 conditional knockout mice. In human samples, we observed higher concentrations of circulating IFN-α and IFN-α1 in patients with DIC compared with patients without DIC, whereas concentrations of IFN-ß, IFN-γ, IFN-λ1, IFN-λ2, and IFN-λ3 were not different. IFN-α concentration was positively correlated with CD105 microvesicle concentrations, reflecting endothelial injury. In Ifnar1-/- mice, cecal ligation and puncture did not induce septic shock and was characterized by lesser endothelial cell injury, with lower aortic inflammatory cytokine expression, endothelial inflammatory-related gene expression, and fibrinolysis. In mice in which Stat1 was specifically ablated in endothelial cells, a marked protection against sepsis was also observed, suggesting the relevance of an endothelium-targeted strategy. Our work highlights the key roles of type I IFNs as pathogenic players in septic shock-induced DIC and the potential pertinence of endothelial STAT1 as a therapeutic target.

Clotting disorder in severe acute respiratory syndrome coronavirus 2.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel human respiratory viral infection that has rapidly progressed into a pandemic, causing significant morbidity and mortality. Blood clotting disorders and acute respiratory failure have surfaced as the major complications among the severe cases of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection. Remarkably, more than 70% of deaths related to COVID-19 are attributed to clotting-associated complications such as pulmonary embolism, strokes and multi-organ failure. These vascular complications have been confirmed by autopsy. This study summarizes the current understanding and explains the possible mechanisms of the blood clotting disorder, emphasizing the role of (1) hypoxia-related activation of coagulation factors like tissue factor, a significant player in triggering coagulation cascade, (2) cytokine storm and activation of neutrophils and the release of neutrophil extracellular traps and (3) immobility and ICU related risk factors.

Thrombocytopenia-Associated Multiple Organ Failure.

Thrombocytopenia-associated multiple organ failure is a clinical phenotype encompassing a spectrum of syndromes associated with disseminated microvascular thromboses. Autopsies performed in patients that died with thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, or disseminated intravascular coagulation reveal specific findings that can differentiate these 3 entities. Significant advancements have been made in our understanding of the pathologic mechanisms of these syndromes. Von Willebrand factor and ADAMTS-13 play a central role in thrombotic thrombocytopenic purpura. Shiga toxins and the complement pathway drive the hemolytic uremic syndrome pathology. Tissue factor activity is vital in the development of disseminated intravascular coagulation.

Clinical Outcomes of Recombinant Human-soluble Thrombomodulin Treatment for Disseminated Intravascular Coagulation in Solid Tumors.

Disseminated intravascular coagulation (DIC) that occurs during cancer therapy prevents continuation of therapy, contributing to a worse prognosis. While recombinant human-soluble thrombomodulin (rhTM), a new DIC drug, has occasionally shown its efficacy in DIC associated with infection and blood cancer, its efficacy in patients with solid tumors has been unproven. This review presents the results on the efficacy and safety of rhTM as a DIC drug in patients with solid tumors that have been confirmed by the clinical data of three previous reports. The number of cases in each study was 101, 123 and 40. The respective DIC resolution rate was 34.0%, 35.2% and 32.5%, and the 28-day survival rate was 55.4%, 52.0% and 40.0%. Although comparison with other anti-DIC therapies is required, rhTM therapy is considered one of the treatment options of DIC in patients with solid tumors.

Disseminated intravascular coagulation and melanoma: a novel case occurring in metastatic melanoma with BRAF and NRAS mutations and systematic review.

Disseminated intravascular coagulation is a complex and potentially lethal complication of malignancy, in which the fundamental abnormality is excessive activation of the coagulation system. It is a rare complication of melanoma which can be difficult to diagnose in some circumstances, leading to delay in treatment. Herein, we describe the first case of disseminated intravascular coagulation occurring in BRAF and NRAS-mutant metastatic melanoma, and systematically review the literature regarding disseminated intravascular coagulation in melanoma. This review summarizes the reported cases of disseminated intravascular coagulation in melanoma and those secondary to the novel treatment of melanoma, and explores the pathophysiology of disseminated intravascular coagulation in melanoma, highlighting the key role of expression of markers of coagulation and fibrinolysis in disseminated intravascular coagulation, as well as more widely in melanoma. Current limitations in the literature are also identified and discussed, particularly with respect to improving the management of this lethal complication. Disseminated intravascular coagulation is a rare complication of melanoma that typically portends poor prognosis.

Acute haemolysis, DIC and renal failure after transfusion of uncross-matched blood during trauma resuscitation: illustrative case and literature review.

AIMS/OBJECTIVES: The aims of this study were to report a patient with acute haemolytic transfusion reaction (HTR) after transfusing uncross-matched red blood cell (RBC) units and to identify the frequency of this complication. BACKGROUND: Uncross-matched RBC units are commonly transfused in emergencies, but the frequency of acute HTR is unknown. METHODS: We describe a male stabbing victim who received three units of uncross-matched RBC units complicated by acute intravascular HTR, disseminated intravascular coagulation (DIC) and renal failure. We identified 14 studies evaluating the frequency of acute HTR post-emergency transfusion of uncross-matched RBC units. RESULTS: Acute HTR was shown by haemoglobinuria, free-plasma haemoglobin and methemalbumin, with anti-K and anti-Fya eluted from recipient red cells; acute DIC featured severe hypofibrinogenemia, thrombocytopenia, elevated fibrin D-dimer and multiple bilateral renal infarcts. Two of the three transfused units reacted with pre-existing RBC alloantibodies [anti-K (titre, 128), anti-Fya (titre, 512)], explained by transfusion 25 years earlier. Our literature review found the frequency of acute HTR following emergency transfusion of uncross-matched RBC units to be 2/3998 [0·06% (95% CI, 0·01-0·21%)]. CONCLUSIONS: Although emergency transfusion of uncross-matched blood is commonly practiced at trauma centres worldwide, with low risk of acute HTR (<1/1000), our well-documented patient case demonstrates the potential for acute HTR with severe complications.

Tie2 protects the vasculature against thrombus formation in systemic inflammation.

Disordered coagulation contributes to death in sepsis and lacks effective treatments. Existing markers of disseminated intravascular coagulation (DIC) reflect its sequelae rather than its causes, delaying diagnosis and treatment. Here we show that disruption of the endothelial Tie2 axis is a sentinel event in septic DIC. Proteomics in septic DIC patients revealed a network involving inflammation and coagulation with the Tie2 antagonist, angiopoietin-2 (Angpt-2), occupying a central node. Angpt-2 was strongly associated with traditional DIC markers including platelet counts, yet more accurately predicted mortality in 2 large independent cohorts (combined N = 1,077). In endotoxemic mice, reduced Tie2 signaling preceded signs of overt DIC. During this early phase, intravital imaging of microvascular injury revealed excessive fibrin accumulation, a pattern remarkably mimicked by Tie2 deficiency even without inflammation. Conversely, Tie2 activation normalized prothrombotic responses by inhibiting endothelial tissue factor and phosphatidylserine exposure. Critically, Tie2 activation had no adverse effects on bleeding. These results mechanistically implicate Tie2 signaling as a central regulator of microvascular thrombus formation in septic DIC and indicate that circulating markers of the Tie2 axis could facilitate earlier diagnosis. Finally, interventions targeting Tie2 may normalize coagulation in inflammatory states while averting the bleeding risks of current DIC therapies.

Dramatic response of acute disseminated intravascular coagulation to erlotinib in a patient with lung adenocarcinoma with activating EGFR mutation.

Disseminated intravascular coagulation (DIC) is a commonly encountered clinical situation characterized by thrombotic occlusion or bleeding in patients with lung cancer. DIC in patients with cancer is usually asymptomatic, taking a chronic form as a compensatory mechanism. Although acute DIC in patients with lung cancer is rarely reported, it can be fatal. We herein describe a patient with lung adenocarcinoma with an activating mutation of the epidermal growth factor receptor (EGFR) gene who developed acute DIC after minor surgical excision. The patient's condition dramatically improved immediately after administration of erlotinib. This report alerts physicians to the occurrence of acute DIC and serves as a reference in treating EGFR mutation-positive lung cancer in patients with DIC.

Predictors of thrombohemorrhagic early death in children and adolescents with t(15;17)-positive acute promyelocytic leukemia treated with ATRA and chemotherapy.

Clinical trials on childhood acute promyelocytic leukemia (APL) report early death (ED) rates of 3-8%, but predictors of thrombohemorrhagic (TH)-ED are not well understood. In a retrospective study, we aimed to determine the incidence and predictors of TH-ED in childhood APL. Data were analyzed from children and adolescents with t(15;17)-positive APL (n = 683) who started treatment with all-trans retinoic acid (ATRA) and chemotherapy in different international studies. Demographic data; initial white blood cell (WBC), peripheral blood (PB) blast, and platelet counts; hemoglobin value; coagulation parameters; morphologic variant (M3 or M3v); and induction details were analyzed. Early death was defined as death occurring within 30 days of presentation. The incidence of ED was 4.7% (32 of 683 patients). Predictors of TH-ED were identified by univariable and multivariable Cox proportional hazard regression analyses (n = 25). In univariable analysis, high WBC (>10 × 109/L) (P < 0.001) and high PB blast (>30 × 109/L) (P < 0.001), M3v (P < 0.01), and black ethnicity (P < 0.001) were independent predictors of TH-ED. In multivariable analysis, high WBC count (P < 0.01) and obesity (i.e., body mass index ≥95th percentile for age) (P = 0.03) were predictors of TH-ED. Initial high WBC counts and obesity are likely predictors of TH-ED in childhood APL. The efficacy of novel drugs for APL-associated coagulopathy or of frontline arsenic trioxide and ATRA combination regimens in reducing ED rates in childhood APL remains to be established.

Cellular microparticles and pathophysiology of traumatic brain injury.

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. The finding that cellular microparticles (MPs) generated by injured cells profoundly impact on pathological courses of TBI has paved the way for new diagnostic and therapeutic strategies. MPs are subcellular fragments or organelles that serve as carriers of lipids, adhesive receptors, cytokines, nucleic acids, and tissue-degrading enzymes that are unique to the parental cells. Their sub-micron sizes allow MPs to travel to areas that parental cells are unable to reach to exercise diverse biological functions. In this review, we summarize recent developments in identifying a casual role of MPs in the pathologies of TBI and suggest that MPs serve as a new class of therapeutic targets for the prevention and treatment of TBI and associated systemic complications.

DAMP and DIC: The role of extracellular DNA and DNA-binding proteins in the pathogenesis of DIC.

Disseminated intravascular coagulation (DIC) is a heterogeneous group of disorders, which manifest as a spectrum of haemorrhage and thrombosis complicating many primary conditions including sepsis, trauma and malignancies. The pathophysiology of this condition is complex. In the recent years there is growing evidence that damage associated molecular patterns (DAMPs) play a crucial role in the pathogenesis of DIC. Upon cell-death and/or cell activation of hematopoietic and parenchymal cells extracellular cell-free DNA as well as DNA binding proteins (e.g. histones and high mobility group box 1 protein [HMGB1]) are released into circulation. This release is a highly regulated process mediated among others by serine proteases, such as factor VII-activating protease (FSAP) and DNase1. Circulating cell-free DNA has been demonstrated to influence primary and secondary hemostasis by inducing platelet aggregation, promoting coagulation activation, inhibition of fibrinolysis and directly interfering with clot stability. In this respect cell-free DNA in tissue as well as released into the circulation after neutrophil activation in the form of neutrophil extracellular traps (NETs) has been shown to be cytotoxic and highly procoagulant. DNA-binding proteins such as histones and HMGB1 are also strongly procoagulant and are involved in the pathogenesis of DIC. The present review gives an overview on how extracellular DNA is released into circulation and the structure of circulating DNA. In addition it summarizes the effect of extracellular DNA and DNA-binding proteins on platelet activation, plasmatic coagulation as well as fibrinolysis.

Differential expression of leukocyte receptors in disseminated intravascular coagulation: prognostic value of low protein C receptor expression.

BACKGROUND: The protein C receptor (PROCR), toll-like receptor (TLR) and L-selectin leukocyte receptor play roles in systemic inflammatory response including disseminated intravascular coagulation (DIC). Expression of these receptors, which mediate systemic immune or coagulation responses, is tightly regulated by physiologic or pathologic signals. We investigated whether the expressions of 3 leukocyte receptors (PROCR, TLR4, L-selectin) was related to clinical outcomes in patients suggestive of having DIC. METHODS: RNA was extracted from the peripheral blood buffy coats of patients suggestive of having DIC. After reverse transcription, mRNA expression levels of PROCR, TLR4, and L-selectin were measured using Taqman Gene Expression Assays. The 28-day hospital mortality rate was used as a clinical outcome. RESULTS: The expression level of PROCR mRNA in leukocytes was lower in those with overt-DIC as compared to those without overt-DIC, however, this difference was not statistically significant. As for TLR4 and L-selectin mRNA expression, there were no significant differences observed between those with and without overt-DIC. A Kaplan-Meier survival analysis revealed that patients with low PROCR mRNA expression levels showed significantly lower survival rates than those with high expression levels. On multivariate cox regression analysis, low levels of PROCR mRNA expression were an independent prognostic marker. However, expression levels of TLR4 and L-selectin mRNA were not associated with any prognostic value. CONCLUSION: Considering that the PROCR is an important anticoagulant receptor, low PROCR mRNA expression levels associated with a poor prognosis in patients with DIC represents an exhaustion of the natural anticoagulant system, and reflects the final decompensate stage of DIC. The leukocyte PROCR may contribute to a dampening of florid activation of coagulation reactions in vivo.

Zinc fingers poke zebrafish, cause thrombosis!

In this issue of Blood, Liu et al describe the creation of a null mutation for the antithrombin III gene (at3) in zebrafish by using zinc finger nuclease technology.

miR-96 and miR-330 overexpressed and targeted AQP5 in lipopolysaccharide-induced rat lung damage of disseminated intravascular coagulation.

Disseminated intravascular coagulation (DIC) is a severe clinical condition that can lead to or aggravate the development of multiple organ dysfunction syndrome. Of all types of organ damage, lung damage is the most frequent and most severe. In DIC patients, lung damage is primarily characterized by pulmonary edema. Aquaporin (AQP) 5 is the chief AQP in the lungs and it plays a key role in many processes, including water transport in normal and abnormal lungs. Here we demonstrate that expression of AQP5 and two microRNAs, miR-96 and miR-330, in rat lung of lipopolysaccharide (LPS)-induced DIC. We also show that both miR-96 and miR-330 can regulate the expression of AQP5 by binding with its 3'-untranslated region (UTR) by luciferase activity assay. These results suggest that microRNAs are involved in lung damage in LPS-induced rat DIC and can be a potential target for molecular therapy.

Targeted mutagenesis of zebrafish antithrombin III triggers disseminated intravascular coagulation and thrombosis, revealing insight into function.

Pathologic blood clotting is a leading cause of morbidity and mortality in the developed world, underlying deep vein thrombosis, myocardial infarction, and stroke. Genetic predisposition to thrombosis is still poorly understood, and we hypothesize that there are many additional risk alleles and modifying factors remaining to be discovered. Mammalian models have contributed to our understanding of thrombosis, but are low throughput and costly. We have turned to the zebrafish, a tool for high-throughput genetic analysis. Using zinc finger nucleases, we show that disruption of the zebrafish antithrombin III (at3) locus results in spontaneous venous thrombosis in larvae. Although homozygous mutants survive into early adulthood, they eventually succumb to massive intracardiac thrombosis. Characterization of null fish revealed disseminated intravascular coagulation in larvae secondary to unopposed thrombin activity and fibrinogen consumption, which could be rescued by both human and zebrafish at3 complementary DNAs. Mutation of the human AT3-reactive center loop abolished the ability to rescue, but the heparin-binding site was dispensable. These results demonstrate overall conservation of AT3 function in zebrafish, but reveal developmental variances in the ability to tolerate excessive clot formation. The accessibility of early zebrafish development will provide unique methods for dissection of the underlying mechanisms of thrombosis.