Coagulopathy in Acute Promyelocytic Leukemia: Can We Go Beyond Supportive Care?

Hemorrhage in acute promyelocytic leukemia-fibrinolysis in focus

Coagulopathy continues to be a major challenge in the management of patients with acute promyelocytic leukemia (APL). Novel differentiating agents have led to improved survival in these patients, but perturbations in coagulation continue to have an impact on their prognosis. The most worrisome of coagulation disturbances is bleeding, which is not an uncommon cause of early death in APL. Despite this, there are no consistent predictors of this high risk of fatal hemorrhage in APL. In this context, the fibrinolytic system has been identified as a crucial role player in APL coagulopathy. However, the current guidelines for the management of APL give little regard to tests that measure the fibrinolytic system while giving more importance to close monitoring of conventional coagulation tests and platelet counts to identify the coagulopathy. More recently, viscoelastic tests have come to usefulness in determining global hemostasis and have been widely used for "diagnosing" hyperfibrinolysis in selected clinical settings. In this review, we attempt to describe risk assessment models for diagnosing APL coagulopathy, describe the possible application of viscoelastic tests in this setting, and persuade clinicians to reconsider the use of antifibrinolytics to improve survival of APL patients.

Rotational Thromboelastometry and Clot Waveform Analysis as Point-of-Care Tests for Diagnosis of Disseminated Intravascular Coagulation in Critically Ill Children in Thailand

OBJECTIVES

This study aimed to determine the test performances of rotational thromboelastometry (ROTEM) and activated partial thromboplastin time-based clot waveform analysis (aPTT-CWA) compared with the International Society on Thrombosis and Hemostasis disseminated intravascular coagulation (ISTH-DIC) score for diagnosis of overt disseminated intravascular coagulation (ODIC) in critically ill children. Prognostic indicators of DIC complications were also evaluated.

DESIGN

A prospective cross-sectional observational study was conducted. ROTEM and aPTT-CWA were assessed alongside standard parameters based on the ISTH-DIC score and natural anticoagulants. Both conventional and global hemostatic tests were repeated on days 3-5 for nonovert DIC.

SETTING

PICU of the Department of Pediatrics, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.

SUBJECTS

Infants and children who were admitted to PICU with underlying diseases predisposed to DIC, such as sepsis, malignancy, major surgery, trauma, or severe illness, were included in the study between July 1, 2021, and November 30, 2022.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Sixty-four children were enrolled in this study. The prevalence of ODIC was 20.3%. Regarding ROTEM parameters, using EXTEM clot formation time (CFT) cutoff of greater than 102 seconds provided sensitivity and specificity of 90.9% and 80.9%, respectively, for diagnosing ODIC, with the area under the curve (AUC) of 0.86. In the case of aPTT-CWA performance, no biphasic waveform was observed, whereas both maximum coagulation acceleration (Min2) of less than 0.35%/s 2 and maximum coagulation deceleration of less than 0.25%/s 2 demonstrated identical sensitivities of 76.9% and specificities of 79.6%. Combining two global hemostatic tests significantly improved the diagnostic performance (INTEM CFT + EXTEM CFT + Min2 AUC 0.92 [95% CI, 0.80-1.00] vs. EXTEM CFT AUC 0.86 [95% CI, 0.75-0.96], p = 0.034). Bleeding was the most common consequence. In multivariable logistic regression analysis, Min2 of less than 0.36%/s 2 was an independent risk factor for bleeding complications, with an adjusted odds ratio of 15.08 (95% CI, 1.08-211.15, p = 0.044).

CONCLUSIONS

ROTEM and aPTT-CWA were valuable diagnostic tools in critically ill children who might require point-of-care tests. Min2 showed significant clinical implications for predicting bleeding events in this population.

Central venous catheters do not increase the hemorrhagic risk in acute promyelocytic leukemia patients during induction therapy

In acute promyelocytic leukemia (APL), hemorrhage, particularly intracranial hemorrhage, is the most common cause of early death. A central venous catheter (CVC) may provide a greater guarantee of safety and comfort to APL patients. However, CVCs have seldom been attempted in APL patients during induction therapy because of concerns about increasing the risk of hemorrhagic complications after this invasive procedure. To evaluate the hemorrhagic risk after CVC placement in APL patients during induction therapy, we retrospectively analyzed 95 newly diagnosed patients with APL from January 2010 to December 2022. Among these patients, 39 patients in the CVC group and 56 patients in the non-CVC group were included. Laboratory and clinical parameters of the two groups were collected and compared. There were no significant differences in median platelet, fibrinogen (Fbg), D-dimer, prothrombin time (PT), white blood count (WBC) and hemoglobin (Hb) between the CVC and non-CVC groups on the first day of the visit (day 0) and the following days (day 4, day 7, day 11, day 14, day 18 and day 21) (p = 0.382, p = 0.805, p = 0.456, p = 0.902, p = 0.901 and p = 0.097, respectively). The consumption of transfused platelets and Fbg was not significantly different between the CVC group and non-CVC group (5.0 vs. 4.5 units, p = 0.34, and 6.8 vs. 6.0, p = 0.36, respectively). The last day of platelet and Fbg transfusion was also not significantly different (21 vs. 19, p = 0.238 and 7.5 vs. 8.5, p = 0.684, respectively). The incidences of total hemorrhagic events and hemorrhagic death were lower in the CVC group than in the non-CVC group (17.9% vs. 37.5%, p = 0.04 and 0% vs. 16.1%, p = 0.01, respectively). The 30-day survival rate was not significantly different (92.3% vs. 82.1%, respectively, p = 0.145) for the CVC group compared with the non-CVC group. Our study suggested that CVCs did not increase the hemorrhagic risk in APL patients during induction therapy and that a CVC should be considered in this type of clinical situation.

Coagulation and platelet biology at the intersection of health and disease: illustrated capsules of the 11th Symposium on Hemostasis at the University of North Carolina

The University of North Carolina Symposia on Hemostasis began in 2002, with The First Symposium on Hemostasis with a Special Focus on FVIIa and Tissue Factor. They have occurred biannually since and have maintained the primary goal of establishing a forum for the sharing of outstanding advances made in the basic sciences of hemostasis. The 2024 11th Symposium on Hemostasis will bring together leading scientists from around the globe to present and discuss the latest research related to coagulation factors and platelet biology. In keeping with the tradition of the conference, we expect novel cross-disciplinary collaborations to result from bringing together fundamental scientists and physician-scientists from different backgrounds and perspectives. The aim of these collaborations is to springboard the next generation of important advances in the field. This year's program was designed to discuss Coagulation and Platelet Biology at the Intersection of Health and Disease. The goal is to develop a better understanding of the pathophysiologic mechanisms leading to hemostatic and thrombotic disorders as this understanding is critical for the continued development of safe and efficacious therapeutics. Included in this review article are illustrated capsules provided by our speakers that highlight the main conclusions of the invited talks.

Thrombosis in Myeloid Malignancies: From CHIP to AML

The development of myeloid malignancies is a multi-step process starting from pre-malignant stages. Large-scale studies on clonal hematopoiesis of indeterminate potential (CHIP) identified this condition as a risk factor for developing hematologic malignancies, in particular myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). In parallel, CHIP was found to confer an enhanced thrombotic risk, in particular for cardiovascular diseases. In a similar fashion, in recent years, alongside their life-threatening features, increasing attention has been drawn toward thrombotic complications in myeloid malignancies. Thus, the purpose of this review is to gather a growing body of evidence on incidence, pathogenesis and clinical impact of thrombosis in myeloid malignancies at every step of malignant progression, from CHIP to AML.

How to avoid early mortality in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL), a phenotypically and genotypically unique subtype of acute myeloid leukemia, has seen unprecedented advances in its management since the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide. However, the phenomenal pharmacologic conversion of this once highly fatal disease to one with a long-term survival exceeding 90% among patients who survive induction remains impaired by the significant incidence of early death (ED) reaching 30% in some real-world studies. The key driver for ED in APL is catastrophic hemorrhage with a proclivity for cranial sites. Most EDs in APL are currently considered preventable. Here, we discuss the concept of early death in APL and its characteristics. Importantly, we outline implementable strategies to reduce the incidence of ED. Early recognition of APL underpins these preventive measures as significant delays in the diagnosis increase the likelihood of ED. While early administration of ATRA is often taught to all hematology trainees, this lifesaving intervention is only possible if providers, including those in emergency departments and urgent/immediate care settings, are trained to have a high index of suspicion and competence to recognize the morphologic and clinical characteristics of the disease. Other proposed strategies tackle the complications that can be present at diagnosis or arise during induction therapy and address the issues of expert consultation and protocol adherence in the management of these patients. While some of these measures appear intuitive and others aspirational, widespread adoption could bring about an era of cure for almost every patient with APL.

Arteriovenous thrombosis, a complication of induction therapy with all-trans retinoic acid for acute promyelocytic leukemia: A case report

We report a case of arterial and venous thrombosis during induction therapy. This case emphasizes considering some degree of caution for thrombotic events in APL patients which was represented in our case as abdominal pain. Rapid initiation of anticoagulation and preventive measures is suggested for better management of the condition.

The Coagulopathy of Acute Promyelocytic Leukemia: An Updated Review of Pathophysiology, Risk Stratification, and Clinical Management

Acute promyelocytic leukemia (APL) has a well-established mechanism and a long-term prognosis that exceeds that of any other acute leukemia. These improving outcomes are due, in part, to all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), two targeted and highly active agents in this disease. However, there remains a considerable morbidity and mortality risk in APL secondary to clinically significant hemorrhagic and/or thrombotic events. Prevention and treatment of these coagulopathic complications remain significant impediments to further progress in optimizing outcomes for patients with APL. Moreover, the relative rarity of APL hinders adequately powered randomized controlled trials for evaluating APL coagulopathy management strategies. This review draws from peer-reviewed works falling between initial descriptions of APL in 1957 and work published prior to January 2023 and provides an updated overview of the pathophysiology of hemorrhagic and thrombotic complications in APL, outlines risk stratification parameters, and compiles current clinical best practices. An improved understanding of the pathophysiologic mechanisms driving hemorrhage and thrombosis along with the completion of well-designed trials of management strategies will assist clinicians in developing interventions that mitigate these devastating complications in an otherwise largely curable disease.

Value of the FDP/FIB ratio in predicting early severe bleeding events in patients with newly diagnosed acute promyelocytic leukemia

Severe bleeding is the leading cause of early death in patients with newly diagnosed acute promyelocytic leukemia (APL). However, there are no means for hemorrhagic risk stratification in APL. This study aimed to identify optimized predictors of severe bleeding events related to APL. A total of 109 consecutive patients with newly diagnosed APL from January 2015 to April 2022 were retrospectively investigated. A systematic review of computer-based patient medical records was conducted to obtain clinical date, including baseline characteristics, routine blood examination findings, coagulation and fibrinolysis indexes, and bleeding events. Among the 109 patients, 89 were classified into the no-severe bleeding group, while 20 had severe bleeding. Compared with the patients with no severe bleeding, the patients with severe bleeding had significantly higher circulating leukemic cell percentages, disseminated intravascular coagulation (DIC) scores, D-dimer (D-D) levels, and fibrin degradation product (FDP) levels. They also had lower fibrinogen (FIB) levels and a longer prothrombin time. Multivariate analysis revealed that the circulating leukemic cell percentage (OR = 1.040, CI = 1.008-1.072, P = 0.012), FIB level (OR = 0.101, CI = 0.011-0.896, P = 0.040), and FDP level (OR = 1.012, CI = 1.000-1.024, P = 0.047) were independent risk factors for severe bleeding. FDP/FIB, D-D/FIB, and seven meaningful indicators in the single-factor analysis were included in the receiver operating characteristic (ROC) curve analysis. The results showed that FDP/FIB was the best indicator for predicting severe bleeding related to newly diagnosed APL. The area under the ROC curve of FDP/FIB was 0.915, and the best cutoff value was 61.77, with 100% sensitivity and 74.2% specificity. Statistical analysis showed a higher incidence of severe bleeding and higher DIC scores when FDP/FIB was >61.77 in APL patients. FDP/FIB has obvious advantages in predicting the degree of bleeding associated with primary promyelocytic leukemia; the greater the FDP/FIB value, the more severe the bleeding. The risk of severe bleeding was the highest when FDP/FIB > 61.77.

[Devil with angel wings - when vitamin A saves lives]

ANAMNESIS AND CLINICAL EXAMINATION

A 40-year-old male patient presented to our emergency department with a new onset of hemorrhagic diathesis. Clinically, there were marked bleeding stigmata with extensive ecchymosis in the thigh area and oral mucosal hemorrhage with otherwise general well-being.

DIAGNOSTICS

The coagulation diagnostics performed were consistent with the picture of disseminated intravascular consumption coagulopathy. Microscopic blood count also revealed 74% morphologically atypical promyelocytes.

DIAGNOSIS, THERAPY, AND CLINICAL COURSE

Bone marrow investigation confirmed the diagnosis of a microgranular variant of acute promyelocytic leukemia. In addition to coagulation optimization, therapy with all-trans retinoic acid (ATRA) was initiated immediately. Subsequently, arsenic trioxide (ATO) and the anthracycline idarubicin were added. No severe complications occurred in the following course of treatment. Moreover, the patient is currently in complete remission regarding acute promyelocytes leukemia.

CONCLUSIONS

Acute promyelocytic leukemia accounts for approximately 10-15% of all acute myeloid leukemias. Often, association with marked coagulation abnormalities due to disseminated intravascular consumption coagulopathy, which is present at diagnosis, APL becomes fatal if untreated. Rapid therapy initiation with ATRA and coagulation optimization, initiated as soon as the diagnosis is suspected, are crucial for prognosis.

Multi-omics and machine learning reveal context-specific gene regulatory activities of PML::RARA in acute promyelocytic leukemia

The PML::RARA fusion protein is the hallmark driver of Acute Promyelocytic Leukemia (APL) and disrupts retinoic acid signaling, leading to wide-scale gene expression changes and uncontrolled proliferation of myeloid precursor cells. While known to be recruited to binding sites across the genome, its impact on gene regulation and expression is under-explored. Using integrated multi-omics datasets, we characterize the influence of PML::RARA binding on gene expression and regulation in an inducible PML::RARA cell line model and APL patient ex vivo samples. We find that genes whose regulatory elements recruit PML::RARA are not uniformly transcriptionally repressed, as commonly suggested, but also may be upregulated or remain unchanged. We develop a computational machine learning implementation called Regulatory Element Behavior Extraction Learning to deconvolute the complex, local transcription factor binding site environment at PML::RARA bound positions to reveal distinct signatures that modulate how PML::RARA directs the transcriptional response.

Acute promyelocytic leukemia with FIP1L1::RARA fusion gene: The clinical utility of transcriptome sequencing and bioinformatic analyses

Background

Acute promyelocytic leukemia (APL) is typically characterized by the presence of coagulopathy and the PML::RARA fusion gene. The FIP1L1::RARA has been reported as a novel fusion gene, but studies on its pathogenesis are limited.

Objectives

A FIP1L1::RARA fusion in a child finally diagnosed as APL was reported. RNA sequencing (RNA-seq) of six patients (three cases of acute lymphoblastic leukemia (ALL), one case of myelodysplastic syndrome (MDS), one case of acute megakaryoblastic leukemia (M7), and one case of APL with FIP1L1::RARA) were performed.

Methods

Transcriptome analysis of six patients was performed by RNA-seq. The heat map was used for showing the RNA expression profile, the volcano plot for identifying differential expression genes (DEGs), and the KEGG Orthology-Based Annotation System (KOBAS) online biological information database for KEGG pathway enrichment analysis.

Results

Obvious differences between APL with FIP1L1::RARA and hematologic malignancies were identified. 1060 common differentially expressed genes (co-DEGs) were detected between APL with FIP1L1::RARA vs ALL and APL with FIP1L1::RARA vs myeloid neoplasms (MDS, M7), the up-regulated genes were mainly mapped into platelet activation, cancer, AMPK signaling pathway, PI3K-Akt signaling pathway, and MAPK signaling pathway. The down-regulated genes were significantly associated with TNF signaling pathway, Rap1 signaling pathway, Age-RAGE signaling pathway, and apoptosis.

Conclusion

A FIP1L1::RARA fusion in a child finally diagnosed as APL was reported. RNA-seq may provide a new diagnostic method when RARA rearrangements fail to be identified by conventional methods. In the analysis of co-DEGs between case vs ALL and case vs myeloid neoplasms, the up-regulated and down-regulated genes were enriched in different signaling pathways. Further experimental studies are needed to identify pathogenesis and treatment for APL with FIP1L1::RARA.

Coagulopathy in Patients with Low/Intermediate Risk Acute Promyelocytic Leukemia treated with First Line Arsenic Trioxide in Combination with All-Trans Retinoic Acid: A Monocentric Experience

No abstract  

Novel Classification of Thrombotic Disorders Based on Molecular Hemostasis and Thrombogenesis Producing Primary and Secondary Phenotypes of Thrombosis

Thrombosis, the common and deadliest disorder among human diseases, develops as a result of the intravascular hemostasis following an intravascular injury, which can be caused by a variety of trauma, non-traumatic insults or clinical illnesses. Thrombosis can occur at any location of the vascular system supplied by blood from the heart to large and smallest arterial and venous systems and may affect the function and anatomy of the organ and tissue. It more commonly occurs in the smaller circulatory system of the vascular tree such as arterioles and capillaries, and venules of the organs, especially in the brain, lungs, heart, pancreas, muscle and kidneys, and sinusoids of the liver. Thrombosis has been referred as the disease of "blood clots", which concept is incompletely defined, but represents many different hemostatic diseases from microthrombosis to fibrin clot disease, macrothrombosis, and combined micro-macrothrombosis. Thrombosis is produced following an intravascular injury via one or more combination of four different mechanisms of thrombogenesis: microthrombogenesis, fibrinogenesis, macrothrombogenesis and micro-macrothrombogenesis initiated by normal physiological hemostasis in vivo. The clinical phenotype expression of thrombosis is determined by: (1) depth of the intravascular wall injury, (2) extent of the injury affecting the vascular tree system, (3) physiological character of the involved vascular system, (4) locality of the vascular injury, and (5) underlying non-hemostatic conditions interacting with hemostasis. Recent acquisition of "two-path unifying theory" of hemostasis and "two-activation theory of the endothelium" has opened a new frontier in science of medicine by identifying the pathophysiological mechanism of different thrombotic disorders and also contributing to the better understanding of many poorly defined human diseases, including different phenotypes of stroke and cardiovascular disease, trauma, sepsis and septic shock, multiorgan dysfunction syndrome, and autoimmune disease, and others. Reviewed are the fundamentals in hemostasis, thrombogenesis and thrombosis based on hemostatic theories, and proposed is a novel classification of thrombotic disorders.

Genetic and Epigenetic Signatures in Acute Promyelocytic Leukemia Treatment and Molecular Remission

Acute myeloid leukemia (AML) is an aggressive, heterogeneous group of malignancies with different clinical behaviors and different responses to therapy. For many types of cancer, finding cancer early makes it easier to treat. Identifying prognostic molecular markers and understanding their biology are the first steps toward developing novel diagnostic tools or therapies for patients with AML. In this study, we defined proteins and genes that can be used in the prognosis of different acute leukemia cases and found possible uses in diagnostics and therapy. We analyzed newly diagnosed acute leukemia cases positive for t (15; 17) (q22; q21) PML-RAR alpha, acute promyelocytic leukemia (APL). The samples of bone marrow cells were collected from patients at the diagnosis stage, as follow-up samples during standard treatment with all-trans retinoic acid, idarubicin, and mitoxantrone, and at the molecular remission. We determined changes in the expression of genes involved in leukemia cell growth, apoptosis, and differentiation. We observed that WT1, CALR, CAV1, and MYC genes’ expression in all APL patients with no relapse history was downregulated after treatment and could be potential markers associated with the pathology, thereby revealing the potential value of this approach for a better characterization of the prediction of APL outcomes.

Effect of Therapeutically Related Drugs on Coagulation-Anticoagulation Balance in Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) usually presents with a series of coagulation-anticoagulation disturbance. Early administration of All-trans retinoic acid (ATRA) can reduce the risk of bleeding, but the potential for thrombosis needs to be addressed in some cases. The role of arsenic agent in correcting coagulation disorder remains to be studied, but oral arsenic agent shows potential advantages in coagulation recovery compared with intravenous agent, and chemotherapy can aggravate the progress of coagulation disease. In addition to early application of ATRA, avoiding invasive procedures and transfusion support can reduce the risk of bleeding. Whether the administration of heparin, thrombomodulin, recombinant factor VIIa or antifibrinolytics reduces the risk of bleeding and thrombosis associated with APL remains to be further explored, and their routine use outside of clinical trials is not recommended. This article reviews the effects of related drugs on coagulation-anticoagulation balance in APL patients.

Prevention of venous thromboembolism in hematologic neoplasms: an expert consensus from SEHH-SETH

Venous thromboembolism (VTE) is a serious complication in hematologic neoplasms, so finding adequate prevention strategies is an urgent requirement. However, prospective studies with large enough cohorts are scarce, limiting the development of evidence-based thromboprophylaxis guidelines. The present position paper is addressed to all hematologists treating patients affected by hematologic neoplasms with the aim to provide clinicians with a useful tool for the prevention of VTE.