Thrombosis in myeloproliferative neoplasms during cytoreductive and antithrombotic drug treatment

Impact of treatment for adolescent and young adults with essential thrombocythemia and polycythemia vera

Essential thrombocythemia (ET) and polycythemia vera (PV) are rare in adolescent and young adult (AYA). These conditions, similar to those in older patients, are linked with thrombotic complications and the potential progression to secondary myelofibrosis (sMF). This retrospective study of ET and PV patients diagnosed before age 25 evaluated complication rates and impact of cytoreductive drugs on outcomes. Among 348 patients (278 ET, 70 PV) with a median age of 20 years, the of thrombotic events was 1.9 per 100 patient-years. Risk factors for thrombosis included elevated white blood cell count (>11 × 109/L) (HR: 2.7, p = 0.012) and absence of splenomegaly at diagnosis (HR: 5.7, p = 0.026), while cytoreductive drugs did not reduce this risk. The incidence of sMF was 0.7 per 100 patient-years. CALR mutation (HR: 6.0, p < 0.001) and a history of thrombosis (HR: 3.8, p = 0.015) were associated with sMF risk. Interferon as a first-line treatment significantly improved myelofibrosis-free survival compared to other treatments or the absence of cytoreduction (p = 0.046). Although cytoreduction did not affect thrombotic event, early interferon use reduced sMF risk. These findings support interferon use to mitigate sMF risk in AYA ET and PV patients.

Molecular predictors of venous and arterial thrombotic events in patients with myelofibrosis

While patients with myelofibrosis (MF) face an elevated risk of thrombosis, no validated scoring system currently exists to effectively assess this specific risk. This study aimed to explore distinct molecular risk factors for arterial (ATE) and venous (VTE) thrombosis in a cohort of 141 MF patients. Mutation analysis was performed by next-generation sequencing for a panel of 30 target myeloid genes as previously described: 137 driver and 164 non-driver mutations were detected. JAK2-V617F was identified in 77 (55%) patients, CALR in 45 (32%) patients, and seven (5%) patients carried an MPL variant. Patients #58 and #60 harbored JAK2-V617F and MPL; and patient #67 was positive for all three driver genes. The JAK2-V617F variant allele frequency (VAF) was assessed in 66/80 patients, revealing a median of 34.0% (range, 5.0-96.0). ASXL1 (n = 34 patients) were the most common non-driver mutations, followed by TET2 (n = 26), U2AF1 (n = 12), and DNMT3A (n = 11). During a median follow up of 4.8 years, 24 (17%) patients experienced VTE, 15 (11%) ATE, and two patients experienced both. Among the 24 patients with VTE, 12 (50%) experienced splanchnic vein thrombosis. The JAK2-V617F mutation was associated with VTE (OR 2.6, 95% CI 1.01-7.16), while the DNMT3A mutation was an independent predictor of ATE (OR 5.40, 95% CI 1.30-22.42). High JAK2-V617F VAF (> 50%) was not related with an increased thrombotic risk. Results of this study demonstrate the significance of DNMT3A mutations as an independent molecular risk factor for ATE, highlighting the potential to include these somatic non-driver mutations in future thrombosis risk scores.

How I approach the treatment of thrombotic complications in patients with myeloproliferative neoplasms

ABSTRACT

Arterial and venous thromboses are the most significant complications in patients with myeloproliferative neoplasms (MPNs), with the primary treatment goal being thrombotic risk reduction. In MPN with no history of thrombosis, primary prevention mainly involves the use of aspirin, and cytoreduction is added in high-risk patients. However, thrombotic complications can unveil an MPN in ∼20% of cases, necessitating the initiation of both antithrombotic therapy for the thrombosis and cytoreductive treatment for the MPN. The duration of anticoagulant therapy after an initial venous thromboembolic event is subject to discussion. Furthermore, the occurrence of a thrombotic complication in patients with a known diagnosis of MPN prompts a reconsideration of both antithrombotic and hematologic management. This review uses case-based discussions to explore the management of thrombotic complications in patients with MPN. It addresses the nature and duration of antithrombotic treatments, as well as the approach to cytoreduction. Special attention is given to the place of direct oral anticoagulants and to the management of patients with MPN with splanchnic vein thrombosis, which is disproportionately common in this group.

Research trends in essential thrombocythemia from 2001 to 2024: a bibliometric analysis

OBJECTIVE

This study aims to conduct a comprehensive bibliometric analysis of ET research, focusing on contributions from authors, institutions, and countries or regions, while mapping collaboration networks. Furthermore, it identifies development trends to provide insights for future research.

METHODS

A bibliometric analysis of ET-related publications (2001-2024) was conducted using data from the Web of Science Core Collection, focusing on publication trends, co-authorship networks, co-citation relationships, and citation bursts.

RESULTS

A total of 4,297 studies published in 778 journals were included in the analysis. ET research has grown rapidly, with major contributions from researchers in the United States and Europe, particularly through extensive collaborations. Leading figures such as Ayalew Tefferi and Alessandro M. Vannucchi have driven advances in ET classification, molecular mechanisms, and targeted therapies. The discovery of driver mutations, such as JAK2, has revolutionized the diagnostic and therapeutic approaches to ET. Research focus has shifted from clinical morphological diagnosis to molecular diagnostics, with the field now entering the era of targeted therapies. However, the heterogeneity of ET, the limitations of targeted therapies, particularly the lack of management experience and data for high-risk and special populations, as well as the incomplete understanding of the role of inflammation in the disease mechanism, continue to hinder both clinical and scientific progress in ET research.

CONCLUSIONS

Bibliometric analysis demonstrates significant advances in ET research, particularly in molecular pathology and targeted therapies. Future research should address ET heterogeneity, optimize management of high-risk and special populations, overcome the limitations of targeted therapies, and further elucidate the role of inflammation to achieve individualized precision therapy.

Real-world data on direct oral anticoagulants in BCR::ABL1-negative myeloproliferative neoplasms (MPNs): a multicenter retrospective study on behalf of scientific subcommittee on MPNs for Turkish society of hematology

BCR::ABL1-negative myeloproliferative neoplasms (MPNs) pose a substantial risk of thrombosis, leading to significant morbidity and mortality. Anticoagulant therapy, historically based on vitamin K antagonists (VKAs), has limitations in preventing recurrent thrombotic events and managing bleeding complications. Direct oral anticoagulants (DOACs) offer a potential alternative with improved pharmacokinetics and compliance. However, evidence on DOAC efficacy and safety in MPNs remains limited, necessitating further investigation. In this multicenter retrospective study in Türkiye, we assessed real-world usage patterns and outcomes of DOACs in MPN patients. Data from 220 patients with PV, ET, or PMF receiving DOACs or VKAs for thrombosis or nonvalvular atrial fibrillation (NVAF) were collected from medical records. Thrombotic events and bleeding episodes were documented based on ISTH criteria. DOACs were used in 126 patients as first-line anticoagulant therapy or following VKAs. Ninety-four patients were on VKAs, of which 83 as a first-line treatment. There were eight thromboses (6.3%) seen in 126 DOAC patients, and similarly, seven episodes (9.4%) of thrombosis were observed in 94 patients using VKA. Major bleeding occurred in seven patients (5.6%) on DOAC and 3 (3.2%) in VKA. Thrombotic and bleeding risks were comparable between DOACs and VKAs (p = 0.708 and p = 0.158, respectively). The incidence rate of thrombosis in the VKA group is 1.1% and in the DOAC group is 1.9%. The incidence of major bleeding in the VKA group is 0.6% and 1.6% in the DOAC group. To the best of our knowledge, our study included the largest number of MPN patients to date, comparing DOACs with VKA in terms of both efficacy and safety, which suggests DOACs as promising alternatives to VKAs for managing thrombotic risk in MPNs with manageable toxicity. Despite the limitations of retrospective studies, DOACs' benefits in terms of efficacy and compliance warrant further investigation through prospective trials. Individualized treatment decisions should consider patient-specific factors, emphasizing collaborative efforts between specialists to optimize DOAC therapy in patients with MPNs. Comparable efficacy and safety between DOACs and VKAs were observed in MPN patients.

Molecular and Clinical Risk Factors Associated with Thrombosis and Bleeding in Myelofibrosis Patients

BACKGROUND

 The risk of thrombosis and bleeding in myelofibrosis (MF) has been historically underappreciated. We sought to investigate potential molecular and clinical risk factors for venous (VTE) and arterial (ATE) thrombotic events as well as bleeding episodes.

METHODS

 Data from 246 consecutive MF patients were analyzed. Driver mutations were tested in 191 patients.

RESULTS

 In total, 181 mutations were found in 177 MF patients: 118 (61.8%) patients showed JAK2-V617F, 50 patients (26.2%) showed CALR, and 6 patients (3.1%) showed MPL mutations. Two patients were JAK2-V617F and MPL positive and one patient was positive for all three genes. Fourteen (7.3%) patients were triple negative. The JAK2-V617F allele burden was assessed in 63 JAK2-V617F-mutated patients, revealing a median of 35.6% (range: 5.0-96.0). At the time of MF diagnosis and during follow-up, 84 thrombotic events (52 VTEs and 32 ATEs) were observed, corresponding to 6.6% of patients per year. A significant association was found between JAK2-V617F mutation (OR: 2.5, 95% CI: 1.1-5.6) and prior VTE (OR: 7.6, 95% CI: 2.1-27.1) with an increased risk of VTE. Patients with prefibrotic MF had a higher rate of ATE than patients with overt MF. Hemorrhagic events occurred in 34 (13.8%) patients, corresponding to 3.8% of patients per year. Fibrosis grade 3 was associated with bleeding risk (OR: 3.4, 95% CI: 1.2-9.2, p = 0.02).

CONCLUSIONS

 The presence of the JAK2-V617F mutation, regardless of allele burden, and prior thrombosis were strongly associated with an increased risk of VTE. Patients with prefibrotic MF might be considered at high risk for developing ATE.

Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratio as novel prognostic biomarkers in BCR-ABL negative myeloproliferative neoplasms

Higher neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been associated with increased risk of thrombosis, cardiovascular mortality, but their role in myeloproliferative neoplasms (MPN) remains unclear. We analyzed NLR and PLR as prognostic markers for thrombosis and overall survival (OS) in the study that included 461 consecutive MPN patients who were diagnosed from 2018 to 2022 at University center. Twenty age-matched patients without hematological disorder were used as controls. NLR and PLR were significantly increased in whole MPN group compared to controls. NLR was highest in PV > PMF > ET (p < 0.001) while PLR was highest in ET > PMF > PV (p < 0.001). Thrombosis occurrence during follow-up correlated with NLR, NLR ≥ 4.5, presence of ≥ 2 CV factors and previous thrombosis. Arterial thrombosis was associated with previous thrombosis, NLR and NLR ≥ 4.5. Similarly in venous thrombosis previous thrombosis was risk factor, together with NLR, NLR ≥ 4.5, PLR, but also secondary malignancy and female gender. In multivariate Cox model, most important factors for thrombosis development during follow-up were previous thrombosis, NLR ≥ 4.5 and PLR ≥ 500; for arterial thrombosis, NLR ≥ 4.5 and previous thrombosis; for venous thrombosis PLR ≥ 500 and previous thrombosis. Patients with pre-PMF had significantly higher NLR than ET patients. In multivariate Cox regression model, most important factors associated with survival were NLR ≥ 4.5 and PLR ≥ 500. This study highlights strong prognostic correlation of NLR ≥ 4.5 and PLR ≥ 500 with development of thrombosis and OS in MPN. Besides previous thrombosis, most important factor associated with development of arterial thrombosis is NLR ≥ 4.5 and for venous PLR ≥ 500. Our results revealed that NLR ≥ 4.5 could be used as additional marker to distinguish ET from prePMF.

Thrombosis in myeloproliferative neoplasms: a viewpoint on its impact on myelofibrosis, mortality, and solid tumors

This viewpoint summarizes findings from analyses of large personal patient databases of myeloproliferative neoplasms (MPNs) to assess the impact of thrombosis on mortality, disease progression, and second cancers (SC). Despite advances, the current incidence of arterial and venous thrombosis remains a challenge. These events appear to signal a more aggressive disease course, as evidenced by their association with myelofibrosis progression and mortality using multistate models and time-dependent multivariable analysis. Inflammatory biomarkers, such as the neutrophil-to-lymphocyte ratio (NLR), are associated with the aggressiveness of polycythemia vera (PV) and essential thrombocythemia (ET), linking thrombosis to SC risk. This suggests a common inflammatory pathway likely influencing cardiovascular disease and cancer incidence. Notably, this is observed more frequently in younger patients, likely due to prolonged exposure to MPN and environmental inflammatory triggers. These data underscore the need for new studies to validate these associations, delineate the sequence of events, and identify therapeutic targets to mitigate thrombotic events and potentially improve overall patient outcomes in MPN.

Myeloproliferative Neoplasms and Cardiovascular Disease: A Review

OPINION STATEMENT

Myeloproliferative neoplasms (MPN) are a heterogenous group of disorders of clonal hematopoiesis characterized by constitutive activation of the JAK/STAT signaling pathway leading to proliferation of blood cells. Cardiovascular disease (CVD) contributes significantly to the morbidity and mortality of patients with MPN. Particularly well-known CVD complications of MPNs are arterial and venous thrombotic events. However, MPNs are also associated with other forms of CVD including atrial fibrillation, heart failure, and pulmonary hypertension. Recent studies have characterized outcomes of patients with MPN and CVD, including acute myocardial infarction (AMI), heart failure, atrial fibrillation, and pulmonary hypertension. Additionally, optimal cardiovascular disease prevention strategies in patients with MPN are not yet clear. Further investigation is warranted to improve CVD outcomes in patients with MPN. Clinicians should be aware of cardiovascular complications of MPN, including thrombotic as well as non-thrombotic complications (heart failure, arrhythmias, pulmonary hypertension).

Epidemiology and disease characteristics of myelofibrosis: a comparative analysis between Italy and global perspectives

Myelofibrosis (MF) is a clonal disorder of hematopoietic stem cells characterized by altered bone marrow function and fibrosis. The aim of this narrative review is to report on the most recent epidemiologic data and to discuss features of MF and current strategies for the management of this condition in clinical practice. MF features covered by our review will include: characteristics of patients with MF; myeloproliferative and myelodepletive phenotypes; MF-associated thrombosis and bleeding; risk of infections; prefibrotic and overt PMF; secondary MF. Finally, we will discuss a few aspects of MF management in clinical practice and suggest strategies for its optimization and standardization. The focus of our paper is on Italy, but relevant data from other countries will also be reviewed.

Myeloproliferative neoplasms in the adolescent and young adult population: A comprehensive review of the literature

Myeloproliferative neoplasms (MPN) are characterized by a clonal proliferation of myeloid lineage cells within the bone marrow. The classical BCR-ABL negative MPNs are comprised of polycythaemia vera, essential thrombocythaemia and primary myelofibrosis. Historically, the majority of MPNs are diagnosed in adults older than 60 years of age; however, in recent years, there has been recognition of MPNs in the adolescent and young adult (AYA) population. AYAs with MPN, typically defined as between the ages of 15 and 39 years old, may comprise up to 20% of patients diagnosed with MPN. They demonstrate unique patterns of driver mutations and thrombotic events and remain at risk for progression to more aggressive disease states. Given the likely long length of time they will live with their disease, there is a significant unmet need in identifying well-tolerated and effective treatment options for these patients, particularly with the advent of disease modification. In this review, we provide a comprehensive overview of the clinical features, disease course and management of AYA patients with MPN and, in doing so, highlight key characteristics that distinguish them from their older counterparts.

Optimization of cardiovascular risk factor management in patients with BCR::ABL1 negative chronic myeloproliferative neoplasms, current knowledge, and perspectives

The exact prognostic role of cardiovascular (CV) risk factors in patients with BCR::ABL1 negative chronic myeloproliferative neoplasms (MPNs) remains unknown as it is often masked by other MPN-related features that bear strong prognostic impact on thrombotic risk. Therefore, current MPN treatment is not primarily guided by presence of CV risk factors. Treatment of CV risk factors in MPN patients usually mirrors that from the general population, despite the fact that CV risk factors in MPNs have their own specificities. Moreover, the optimal target levels for different metabolic deflections in MPNs (i.e., low-density lipoprotein, serum uric acid, or glycated hemoglobin levels) have not been defined. In the current review, we separately discuss the most important aspects of every individual CV risk factor (arterial hypertension, hyperlipidemia, chronic kidney disease, smoking, diabetes mellitus, hyperuricemia, and obesity and cachexia) in MPNs, summarize recent advances in the field, and propose future directions and research areas which may be needed to appropriately manage CV risk factors in MPNs.

Cancer-associated splanchnic vein thrombosis: Clinical implications and management considerations

Splanchnic vein thrombosis (SVT), a thrombosis which involves the portal, mesenteric, and splenic veins, and the Budd-Chiari syndrome, represents an uncommon type of venous thromboembolism (VTE). Like with deep vein thrombosis of the lower extremities and pulmonary embolism, ample evidence suggests a significant association between SVT and cancer, particularly intra-abdominal solid malignancies (e.g. hepatobiliary and pancreatic cancers) and myeloproliferative neoplasms (MPN). Clinical symptoms of SVT in cancer patients can be ambiguous, and frequently attributed to the primary cancer itself. Alternatively, SVT may be asymptomatic and detected incidentally during cancer staging or follow-up evaluations. SVT can also precede the diagnosis of cancer and has been associated with poorer outcomes in patients with liver or pancreatic cancers. Therefore, an unprovoked SVT warrants a thorough evaluation for an underlying malignancy or MPN. Cancer-associated SVT carries a high risk of VTE extension, recurrence and bleeding. Extended anticoagulant treatment is often required in the absence of a high bleeding risk. Guidelines suggest treatment with either low molecular weight heparin (LMWH) or direct oral anticoagulants (DOACs), although available data on the safety and effectiveness of DOACs in these patients is limited. This comprehensive review outlines the epidemiology, pathogenesis, risk factors, and diagnosis of cancer-associated SVT and underscores the importance of comprehensive patient evaluation and evidence-based management.

Multiomic profiling reveals metabolic alterations mediating aberrant platelet activity and inflammation in myeloproliferative neoplasms

Platelets from patients with myeloproliferative neoplasms (MPNs) exhibit a hyperreactive phenotype. Here, we found elevated P-selectin exposure and platelet-leukocyte aggregates indicating activation of platelets from essential thrombocythemia (ET) patients. Single-cell RNA-seq analysis of primary samples revealed significant enrichment of transcripts related to platelet activation, mTOR, and oxidative phosphorylation in ET patient platelets. These observations were validated via proteomic profiling. Platelet metabolomics revealed distinct metabolic phenotypes consisting of elevated ATP generation accompanied by increases in the levels of multiple intermediates of the tricarboxylic acid cycle, but lower α-ketoglutarate (α-KG) in MPN patients. Inhibition of PI3K/AKT/mTOR signaling significantly reduced metabolic responses and hyperreactivity in MPN patient platelets, while α-KG supplementation markedly reduced oxygen consumption and ATP generation. Ex vivo incubation of platelets from both MPN patients and Jak2 V617F-knockin mice with α-KG supplementation significantly reduced platelet activation responses. Oral α-KG supplementation of Jak2 V617F mice decreased splenomegaly and reduced hematocrit, monocyte, and platelet counts. Finally, α-KG treatment significantly decreased proinflammatory cytokine secretion from MPN CD14+ monocytes. Our results reveal a previously unrecognized metabolic disorder in conjunction with aberrant PI3K/AKT/mTOR signaling that contributes to platelet hyperreactivity in MPN patients.

Distinct clinico-molecular arterial and venous thrombosis scores for myeloproliferative neoplasms risk stratification

Current recommended risk scores to predict thrombotic events associated with myeloproliferative neoplasms (MPN) do not discriminate between arterial and venous thrombosis despite their different physiopathology. To define novel stratification systems, we delineated a comprehensive landscape of MPN associated thrombosis across a large long-term follow-up MPN cohort. Prior arterial thrombosis, age >60 years, cardiovascular risk factors and presence of TET2 or DNMT3A mutations were independently associated with arterial thrombosis in multivariable analysis. ARTS, an ARterial Thrombosis Score, based on these four factors, defined low- (0.37% patients-year) and high-risk (1.19% patients-year) patients. ARTS performance was superior to the two-tiered conventional risk stratification in our training cohort, across all MPN subtypes, as well as in two external validation cohorts. Prior venous thrombosis and presence of a JAK2V617F mutation with a variant allelic frequency ≥50% were independently associated with venous thrombosis. The discrimination potential of VETS, a VEnous Thrombosis Score based on these two factors, was poor, similar to the two-tiered conventional risk stratification. Our study pinpoints arterial and venous thrombosis clinico-molecular differences and proposes an arterial risk score for more accurate patients' stratification. Further improvement of venous risk scores, accounting for additional factors and considering venous thrombosis as a heterogeneous entity is warranted.

Clonal hematopoiesis of indeterminate potential: implications for the cardiologists

Myeloproliferative neoplasms, including polycythemia vera, essential thrombocythemia, and myelofibrosis, are characterized by somatic gene mutations in bone marrow stem cells, which trigger an inflammatory response influencing the development of associated cardiovascular complications. In recent years, the same mutations were found in individuals with cardiovascular diseases even in the absence of hematological alterations. These genetic events allow the identification of a new entity called 'clonal hematopoiesis of indeterminate potential' (CHIP), as it was uncertain whether it could evolve toward hematological malignancies. CHIP is age-related and, remarkably, myocardial infarction, stroke, and heart failure were frequently reported in these individuals and attributed to systemic chronic inflammation driven by the genetic mutation. We reviewed the connection between clonal hematopoiesis, inflammation, and cardiovascular diseases, with a practical approach to improve clinical practice and highlight the current unmet needs in this area of knowledge.

Whole blood transcriptional profiling reveals highly deregulated atherosclerosis genes in Philadelphia-chromosome negative myeloproliferative neoplasms

BACKGROUND

The Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) are associated with a huge comorbidity burden, including an increased risk of cardiovascular diseases. Recently, chronic inflammation has been suggested to be the driving force for clonal evolution and disease progression in MPN but also potentially having an impact upon the development of accelerated (premature) atherosclerosis.

OBJECTIVES

Since chronic inflammation, atherosclerosis, and atherothrombosis are prevalent in MPNs and we have previously shown oxidative stress genes to be markedly upregulated in MPNs, we hypothesized that genes linked to development of atherosclerosis might be highly deregulated as well.

METHODS

Using whole blood gene expression profiling in patients with essential thrombocythemia (ET; n = 19), polycythemia vera (PV; n = 41), or primary myelofibrosis (PMF; n = 9), we herein for the first time report aberrant expression of several atherosclerosis genes.

RESULTS

Of 84 atherosclerosis genes, 45, 56, and 46 genes were deregulated in patients with ET, PV, or PMF, respectively. Furthermore, BCL2L1, MMP1, PDGFA, PTGS1, and THBS4 were progressively significantly upregulated and BCL2 progressively significantly downregulated from ET over PV to PMF (all FDR <0.05).

CONCLUSIONS

We have for the first time shown massive deregulation of atherosclerosis genes in MPNs, likely reflecting the inflammatory state in MPNs in association with in vivo activation of leukocytes, platelets, and endothelial cells being deeply involved in the atherosclerotic process.

Prediction of major bleeding events in 1381 patients with essential thrombocythemia

The goal of therapy in essential thrombocythemia (ET) is reducing thrombotic risk. No algorithm to predict hemorrhage risk exists. The impact ofanti-platelet, cytoreductive and anticoagulation therapies on risk of major bleeding (MB) was evaluated. MB events were retrospectively analyzed in 1381 ET from 10 European centers. There were 0.286 MB events/person-year. Neither the International Thrombosis Prognostic Score for thrombosis in essential thrombocythemia (IPSET-t) nor the revised IPSET-t (r-IPSET-t) was predictive for hemorrhage-free survival at 10 years (p = 0.092 vs p = 0.1). Ageand leukocyte count were MB risk factors, while low hemoglobin was protective. For ET with extreme thrombocytosis (ExtT) and leukocytosis cytoreduction was not protective. MB were more frequent in ET with ExtT who received anticoagulation. Antiplatelet therapy was not, while anticoagulation was a risk factor for MB (HR 3.05, p = 0.016, CI 1.23-7.56), in particular vitamin K antagonists (22.6% of those treated had a MB event, HR 2.96, p = 0.004, CI 1.41-6.22). Survival at 10 years was associated with hemorrhage (OR 2.54, p < 0.001) but not thrombosis (HR 0.95, p = 0.829). Hemorrhage has a higher risk of mortality than thrombosis. Improved risk stratification for MB is necessary. The choice of anticoagulation, cytoreduction and antiplatelet therapies is an important area of research in ET.

Toxicity of targeted anticancer treatments on the liver in myeloproliferative neoplasms

The liver has a central role in metabolism, therefore, it is susceptible to harmful effects of ingested medications (drugs, herbs, and nutritional supplements). Drug-induced liver injury (DILI) comprises a range of unexpected reactions that occur after exposure to various classes of medication. Even though most cases consist of mild, temporary elevations in liver enzyme markers, DILI can also manifest as acute liver failure in some patients and can be associated with mortality. Herein, we briefly review available data on DILI induced by targeted anticancer agents in managing classical myeloproliferative neoplasms: Chronic myeloid leukemia, polycythemia vera, essential thrombocythemia, and myelofibrosis.

Thrombosis Risk Assessment in Myeloproliferative Neoplasm-Is There a Role for Viscoelastic Testing?

Philadelphia chromosome-negative myeloproliferative neoplasms include polycythemia vera, essential thrombocythemia, and myelofibrosis. They are associated with increased thrombotic events, and the primary goal of therapy, in particular those with polycythemia vera and essential thrombocythemia, is the prevention of thrombotic complications typically with antiplatelet therapy and/or cytoreduction. While several patient-, disease-, and genomic-related factors have been identified to influence thrombotic risks, there are no routine laboratory investigations to date that are sufficiently accurate to assess the underlying procoagulant state and predict the thrombotic risks. Conventional coagulation testing only measures time to clot formation and cannot reliably predict bleeding and thrombotic risks. Global coagulation assays such as thromboelastography, thrombin, and fibrin generation may provide a more thorough assessment of hemostatic function. Thromboelastography and thromboelastometry are viscoelastic tests which measure the mechanical properties of the hemostatic process, including the global dynamics of clot formation, stabilization, and dissolution. While viscoelastic testing is gaining traction in the investigations of coagulopathies and goal-directed blood product replacement in trauma and massive transfusion settings, the role of these assays in thrombosis is less well defined. Here, we provide a review of the current evidence of the role of viscoelastic testing in myeloproliferative neoplasm, particularly in the thrombotic risk assessment.

Current evidence on the use of direct oral anticoagulants in patients with myeloproliferative neoplasm: a systematic review

INTRODUCTION

Thromboembolic events in myeloproliferative neoplasms (MPNs) are one of the most important causes of mortality and morbidity, in which vitamin K antagonists (VKAs) have been used mostly. Recently, direct oral anticoagulants (DOACs) are used in venous thromboembolism (VTE) and cancer-associated thrombosis (CAT). With the adoption of data from CAT and VTE, the usage of DOACs in MPNs is increasing.

AREAS COVERED

In this paper, we performed a systematic review to the current literature regarding the usage of DOACs in MPNs. Eleven studies involving 944 patients were included. The reasons for initiating DOACs were secondary prophylaxis for thrombosis (arterial or venous) and atrial fibrillation (AF) in 562 and 382 patients, respectively. A total of 84 (8.9%) recurrent thrombotic (arterial or venous) events recorded. Forty-six (8.1%) events occurred in the thrombosis group (arterial or venous) and 38 (9.9%) events occurred in patients with AF.

EXPERT OPINION

Ease of management and patient comfort should be regarded as benefits of DOACs compared to VKAs. However, it would be appropriate to bring an individualized approach until we obtain high-quality data with prospectively designed studies involving more patients and longer follow-up time concerning the use of DOACs in patients with MPNs.

Distinctive Attributes of Indian Patients With Classical BCR::ABL1 Negative Myeloproliferative Neoplasms: Unified Clinical and Laboratory Data

INTRODUCTION

We report one of the largest single center data from a mixed referral setting in India describing baseline characteristics and outcomes of patients with classical BCR::ABL1 negative myeloproliferative neoplasms (MPNs).

MATERIALS AND METHODS

Patients diagnosed from June 2019 to 2022 were included. Workup and treatment was as per current guidelines.

RESULTS

Diagnosis comprised polycythemia vera (PV) in 51(49%), ET in 33(31.7%) and prefibrotic primary myelofibrosis (MF) pre fibrotic myelofibrosis (prePMF) and myelofibrosis in 10(9.6%) patients each. Median age at diagnosis was 52 years for PV and ET, 65.5 for MF and 79 years for prePMF. Diagnosis was incidental in 63(56.7%) and after thrombosis in 8(7.2%) patients. Baseline next generation sequencing (NGS) was available for 63(60.5%) patients. Driver mutations in PV: JAK2 in 80.3%; in ET: JAK2 in 41%, CALR in 26%, MPL in 2.9%; in prePMF JAK2 in 70%, CALR in 20%, MPL in 10%, and in MF: JAK2 in 10%, MPL in 30% and CALR in 40%. Seven novel mutations were detected of which 5 were potentially pathogenic on computational analysis. After median follow up of 30 months, 2 patients had disease transformation and none had new episodes of thrombosis. Ten patients died, most commonly with cardiovascular events(n = 5,50%). Median overall survival was not reached. Mean OS time was 10.19 years(95%CI, 8.6 to 11.74) and mean time to transformation was 12.2 years(95% CI,11.8 to 12.6).

CONCLUSION

Our data indicates comparatively indolent presentation of MPNs in India with younger age and lower risk of thrombosis. Further follow up will enable correlation with molecular data and guide modification of age based risk stratification models.

JAK2V617F mutation and circulating extracellular vesicles in essential thrombocythemia

The clinical course of essential thrombocythemia (ET) is complicated with thrombosis which significantly impacts patients' mortality. Studies have identified JAK2V617F mutation as an independent risk factor for thrombosis. Circulating extracellular vesicles (EVs) were evaluated in several studies regarding myeloproliferative neoplasms and thrombosis as potential biomarkers. The present study investigates the relationship between JAK2V617F mutation and EVs levels in 119 ET patients. Our analyses revealed that JAK2V617F-positive patients are at a significantly increased risk of thrombosis within five years before the ET diagnosis (hazard ratio [95% CI]: 11.9 [1.7-83.7], P = 0.013), and that JAK2V617F mutation is an independent risk factor for thrombosis at ET diagnosis or during the follow-up (hazard ratio [95% CI]: 3.56 [1.47-8.62], P = 0.005). ET patients have higher levels of platelet-EVs, erythrocyte-EVs and procoagulant activity of EVs than the healthy population. Absolute and relative counts of platelet-EVs are increased in the presence of JAK2V617F mutation (P = 0.018, P = 0.024, respectively). In conclusion, our results support the role of JAK2V617F mutation in the pathogenesis of thrombosis in essential thrombocythemia through enhancing platelet activation.