Essential thrombocythemia treatment algorithm 2018

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.

Role of necroptosis and immune infiltration in essential thrombocytosis

BACKGROUND

Necroptosis, a recently identified form of programmed cell death involved in the pathogenesis of a variety of tumor and non-tumor diseases. Nevertheless, the function of necroptosis in essential thrombocytosis (ET) remains unclear, which is a classic myeloproliferative tumor.

MATERIALS AND METHODS

The role of necroptosis in ET was determined via bioinformatics combined with qRT-PCR analysis of clinical samples. GSE57793 and GSE26049 datasets were recruited to identify necroptosis differentially expressed genes based on differential gene identification, necroptosis gene sets and data machine learning. Enrichment analysis (GSEA) was used to evaluate the gene enrichment signaling pathway of ET, immune infiltration analysis was used to explore the abundance of immune cell infiltration in ET, and the correlation between necroptosis differential genes and immune cell infiltration was studied.

RESULTS

Five necroptosis genes were recognized to be remarkably enriched in the necroptosis pathway, including CHMP1B, FTH1, HSP90AB1, IL1A, and RBCK1. The imbalance of invasion of Th1/Th17 cells was identified in ET, and the differential necroptosis gene was positively correlated with the infiltration of multiple immune cells. There is significant necroptosis in ET, which is enriched in the necrotizing apoptotic pathway, and is associated with immune infiltration.

CONCLUSIONS

Necroptosis might drive the progression of ET via stimulating immune infiltration and immune responses. The findings bring new insights into the treatment mechanism and treatment strategy of ET in the future.

The Role of Platelet Dysfunctions in the Pathogenesis of the Hemostatic-Coagulant System Imbalances

Platelet dysfunction plays a critical role in the pathogenesis of various disorders affecting the hemostatic-coagulant system. This review aims to explore the mechanisms by which platelet dysfunctions contribute to the disruption of hemostasis, leading to an increased risk of both thrombosis and bleeding. Platelets, traditionally known for their role in clot formation, can exhibit altered functionality under pathological conditions such as cardiovascular diseases, metabolic disorders, and autoimmune diseases, impacting their interaction with coagulation factors and vascular endothelium. The review discusses the molecular and cellular mechanisms underlying platelet dysfunction, including aberrations in platelet activation, aggregation, and secretion. It also highlights the interplay between platelets and other components of the coagulation cascade, such as fibrinogen and clotting factors, in maintaining vascular integrity. Moreover, the review examines clinical implications, including how platelet dysfunction can be a contributing factor in conditions like deep vein thrombosis, stroke, and disseminated intravascular coagulation (DIC). Finally, current therapeutic approaches targeting platelet dysfunctions, including antiplatelet agents and emerging therapies, are reviewed to provide insights into potential strategies for managing fluid-coagulation system imbalances. This review underscores the importance of a comprehensive understanding of platelet dysfunction to improve diagnosis and treatment of hemostatic disorders.

Relation of JAK2 V617F allele burden and coronary calcium score in patients with essential thrombocythemia

BACKGROUND

JAK2 V617F (JAK2) mutation is associated with clonal hemopoiesis in myeloproliferative neoplasms as well as with faster progression of cardiovascular diseases. Little is known about the relationship between allele burden and the degree of atherosclerotic alteration of coronary vasculature. We previously reported that carotid artery stiffness progressed faster in patients with JAK2 positive essential thromocythemia (ET) patients. After a four-year follow-up we investigated whether mutation burden of a JAK2 allele correlates with a higher coronary calcium score.

PATIENTS AND METHODS

Thirty-six patients with JAK2 positive ET and 38 healthy matched control subjects were examined twice within four years. At each visit clinical baseline characteristics and laboratory testing were performed, JAK2 mutation burden was determined, and coronary calcium was measured.

RESULTS

JAK2 allele burden decreased in 19 patients, did not change in 5 patients, and increased in 4 patients. The coronary calcium Agatston score increased slightly in both groups. Overall, there was no correlation between JAK2 allele burden and calcium burden of coronary arteries. However, in patients with the JAK2 mutation burden increase, the coronary calcium score increased as well.

CONCLUSIONS

The average JAK2 allele burden decreased in our patients with high-risk ET during the four-year period. However, in the small subgroup whose JAK2 mutation burden increased the Agatston coronary calcium score increased as well. This finding, which should be interpreted with caution and validated in a larger group, is in line with emerging evidence that JAK2 mutation accelerates atherosclerosis and can be regarded as a non-classical risk factor for cardiovascular disease.

Revisiting the association between pretreatment thrombocytosis and cancer survival outcomes: an umbrella review of meta-analyses

BACKGROUND

Although associations have been reported linking pretreatment thrombocytosis to cancer survival outcomes, the validity and strength of existing observational evidence have been contested. This study aimed to conduct an umbrella review to comprehensively appraise the strength, validity and credibility of these reported associations.

METHODS

We searched Medline, Embase and Cochrane Database of Systematic Reviews from inception to 8 April 2023 to retrieve meta-analyses of observational studies. Meta-analyses were re-performed using a random-effect model and the strength of evidence was graded as convincing, highly suggestive, suggestive and weak according to seven pre-defined quantitative criteria reflecting statistical significance, amount of data, heterogeneity, and evidence of bias. The quality of review was appraised using the AMSTAR2 checklist. The umbrella review was reported adhering to the PRISMA guideline and was registered on PROSPERO (CRD42023455391).

RESULTS

A total of 21 unique meta-analyses investigating ten cancer subtypes were included. All meta-analyses reported inferior survival outcome in cancer patients with pretreatment thrombocytosis, and 18 of them (85.7%) yielded statistically significant results (P < 0.05). Consistent effects were observed across meta-analyses that adopted different cut-off values (i.e. platelet count > 300 or 400 × 109 /L) to define thrombocytosis. Although evidence appraisal did not identify convincing evidence (Class I), the associations of thrombocytosis with inferior overall survival of lung, gastric, colorectal cancer and malignant mesothelioma were classified as highly suggestive evidence (Class II). According to AMSTAR2 ratings, no meta-analysis was identified with high or moderate quality.

CONCLUSIONS

Our findings consolidated the association between pretreatment thrombocytosis and poor survival outcomes in various cancers. Nonetheless, the absence of convincing associations indicates a need for further large-scale, high-quality evidence to confirm whether platelets can serve as a prognostic predictor or a therapeutic target.

Determination of Platelet Estimate Factor of Sysmex DI-60 Digital Morphology Analyzer for Platelet Count Estimation

CONTEXT.—

In the Sysmex DI-60 digital morphology system, a platelet estimate factor (PEF) is used to calculate the estimated platelet count (PLT).

OBJECTIVE.—

To determine the most accurate PEF by analyzing various specimens, including those with abnormal flag alerts, using both impedance (PLT-I) and optical fluorescent (PLT-F) PLT methods. A validation study was then conducted using random specimens to evaluate the accuracy of the PEF.

DESIGN.—

This study included 120 blood specimens without flag alerts, and 120 blood specimens with flag alerts related to platelet abnormalities to determine the PEF. Each group was equally divided into thrombocytopenia, normal count, and thrombocytosis specimens. The PEF values obtained from the PLT-I and PLT-F methods were analyzed. An additional 120 specimens were used to compare the estimated PLT from PEF with the PLT-F count. Unadjusted PEF disregarded platelet ranges and flag alerts, whereas adjusted PEF incorporated them.

RESULTS.—

The mean PEF values ranged within 9.95 to 12.99 for PLT-I-obtained values (PEF-I) and within 10.32 to 11.69 for PLT-F-obtained values (PEF-F) across different PLT ranges. The mean PEF values were significantly higher in specimens with flags compared with those without flags. The values were 12.43 compared with 10.19 for PEF-I and 11.45 compared with 10.4 for PEF-F. A significant difference was found between PEF-I and PEF-F in flagged specimens, with respective values of 12.43 and 11.45. There was excellent agreement between estimated PLTs using adjusted PEF and PLT-F. However, proportional biases were observed between estimated PLT using unadjusted PEF and PLT-F.

CONCLUSIONS.—

Adjustment of PEF values according to specific platelet ranges and flag alert presence was shown to enhance the accuracy of PLT estimation using the Sysmex DI-60 system.

Impact of Hydroxyurea to Treat Haematological Disorders on Male Fertility: Two Case Reports and a Systematic Review

PURPOSE

Hydroxyurea (HU) is a cytoreductive agent used as standard treatment option for sickle cell anaemia/disease (SCD), essential thrombocythemia (ET), and polycythaemia vera (PV). Despite its overall good safety profile, its use also in relatively young patients raises an interest on its potential impact on spermatogenesis. To perform a systematic review of all published articles investigating fertility in male patients affected by SCD, ET, and PV and treated with HU. Two paradigmatic case reports of patients affected by PV and ET, respectively, have been also reported.

MATERIALS AND METHODS

PubMed, EMBASE, and Cochrane databases were queried for all the published studies indexed up to November 15th, 2022. A combination of the following keywords was used: "hydroxyurea," "fertility," "male," "sperm," "sickle cell anaemia," "sickle cell disease," "essential thrombocythemia," "polycythaemia vera."

RESULTS

Of 48 articles identified, 8 studies, involving 161 patients, were eligible for inclusion. Overall, the number of spermatogonia per round cross section of seminiferous tubule were decreased in patients with SCD compared to healthy males. HU treatment was always associated with a worsening of semen parameters, even up to azoospermia. Notably, treatment discontinuation was associated with an improvement of semen parameters and a trend toward normalization in the case of PV and ET, with a less clear amelioration in men with SCD. In both our patients with either PV or ET, HU discontinuation was associated with a significant improvement of spermatogenesis with successful spontaneous pregnancies.

CONCLUSIONS

Published evidence do not consistently report normalization of spermatogenesis after HU discontinuation in SCD cases. Conversely, the literature almost consistently reported an improvement of semen parameters at the discontinuation of HU therapy in PV and ET cases. Our real-life two cases confirmed those findings. The willing of fatherhood and the need for effective fertility treatment warrant further research to improve work-up management in men with hematological disorders.

ROP-ET: a prospective phase III trial investigating the efficacy and safety of ropeginterferon alfa-2b in essential thrombocythemia patients with limited treatment options

Interferon-based therapies, such as ropeginterferon alfa-2b have emerged as promising disease-modifying agents for myeloproliferative neoplasms (MPNs), including essential thrombocythemia (ET). Current ET treatments aim to normalize hematological parameters and reduce the thrombotic risk, but they do not modify the natural history of the disease and hence, have no impact on disease progression. Ropeginterferon alfa-2b (trade name BESREMi®), a novel, monopegylated interferon alfa-2b with an extended administration interval, has demonstrated a robust and sustained efficacy in polycythemia vera (PV) patients. Given the similarities in disease pathophysiology and treatment goals, ropeginterferon alfa-2b holds promise as a treatment option for ET. The ROP-ET trial is a prospective, multicenter, single-arm phase III study that includes patients with ET who are intolerant or resistant to, and/or are ineligible for current therapies, such as hydroxyurea (HU), anagrelide (ANA), busulfan (BUS) and pipobroman, leaving these patients with limited treatment options. The primary endpoint is a composite response of hematologic parameters and disease-related symptoms, according to modified European LeukemiaNet (ELN) criteria. Secondary endpoints include improvements in symptoms and quality of life, molecular response and the safety profile of ropeginterferon alfa-2b. Over a 3-year period the trial assesses longer term outcomes, particularly the effects on allele burden and clinical outcomes, such as disease-related symptoms, vascular events and disease progression. No prospective clinical trial data exist for ropeginterferon alfa-2b in the planned ET study population and this study will provide new findings that may contribute to advancing the treatment landscape for ET patients with limited alternatives. TRIAL REGISTRATION: EU Clinical Trials Register; EudraCT, 2023-505160-12-00; Registered on October 30, 2023.

Essential thrombocythaemia: A contemporary approach with new drugs on the horizon

Essential thrombocythaemia (ET) is a myeloproliferative neoplasm characterized by an increased risk of vascular complications and a tendency to progress to myelofibrosis and acute leukaemia. ET patients have traditionally been stratified into two thrombosis risk categories based on age older than 60 years and a history of thrombosis. More recently, the revised IPSET-thrombosis scoring system, which accounts for the increased risk linked to the JAK2 mutation, has been incorporated into most expert recommendations. However, there is increasing evidence that the term ET encompasses different genomic entities, each with a distinct clinical course and prognosis. Moreover, the effectiveness and toxicity of cytoreductive and anti-platelet treatments differ depending on the molecular genotype. While anti-platelets and conventional cytoreductive agents, mainly hydroxycarbamide (hydroxyurea), anagrelide and pegylated interferon, remain the cornerstone of treatment, recent research has shed light on the effectiveness of novel therapies that may help improve outcomes. This comprehensive review focuses on the evolving landscape of treatment strategies in ET, with an emphasis on the role of molecular profiling in guiding therapeutic decisions. Besides evidence-based management according to revised IPSET-thrombosis stratification, we also provide specific observations for those patients with CALR-, MPL-mutated and triple-negative ET, as well as cases with high-risk mutations.

Outcomes of Patients with Preoperative Thrombocytosis After Hip Fracture Surgery

INTRODUCTION

Low platelet counts have clinically relevant effects on patient outcomes after hip fracture surgery; however, the relationship between abnormally high platelet counts and postoperative outcomes in this population is unknown.

METHODS

The ACS-NSQIP database was queried for patients who underwent hip fracture surgery between 2015 and 2019. Outcomes were compared between patients with normal platelet counts (150,000 to 450,000/μL) and thrombocytosis (>450,000/μL).

RESULTS

Eighty-six thousand three hundred eleven hip fracture patients were identified, of which 1067 (1.2%) had preoperative thrombocytosis. Compared with patients with normal platelet counts, patients with preoperative thrombocytosis had increased rates of 30-day mortality (6.4% vs 4.5%, P = 0.004; OR 1.15 [95% CI 0.88 to 1.50], P = 0.322) as well as increased rates and odds of readmission (11.4% vs 7.8%, P < 0.001; OR 1.35 [95% CI 1.10 to 1.65], P = 0.004) and venous thromboembolic events (3.2% vs 1.7%, P < 0.001; OR 1.88 [95% CI 1.31 to 2.71], P < 0.001).

CONCLUSIONS

Hip fracture patients with preoperative thrombocytosis had increased rates of early mortality as well as increased odds of venous thromboembolic events and readmission. A patient with thrombocytosis may benefit from close postoperative surveillance and careful follow-up. Future prospective studies are needed to verify causation and investigate how to mitigate adverse outcomes in hip fracture patients with preoperative thrombocytosis.

Hemorrhagic Coagulation Disorders and Ischemic Stroke: How to Reconcile Both?

Coagulation and fibrinolytic system disorders are conditions in which the blood's ability to clot is impaired, resulting in an increased risk of thrombosis or bleeding. Although these disorders are the expression of two opposing tendencies, they can often be associated with or be a consequence of each other, contributing to making the prognosis of acute cerebrovascular events more difficult. It is important to recognize those conditions that are characterized by dual alterations in the coagulation and fibrinolytic systems to reduce the prognostic impact of clinical conditions with difficult treatment and often unfortunate outcomes. Management of these individuals can be challenging, as clinicians must balance the need to prevent bleeding episodes with the potential risk of clot formation. Treatment decisions should be made on an individual basis, considering the specific bleeding disorder, its severity, and the patient's general medical condition. This review aims to deal with all those forms in which coagulation and fibrinolysis represent two sides of the same media in the correct management of patients with acute neurological syndrome. Precision medicine, personalized treatment, advanced anticoagulant strategies, and innovations in bleeding control represent future directions in the management of these complex pathologies in which stroke can be the evolution of two different acute events or be the first manifestation of an occult or unknown underlying pathology.

Asymptomatic Essential Thrombocytosis Presenting with Extrahepatic Portal Vein Thrombosis: A Case Report

BACKGROUND Essential thrombocytosis (ET) is a myeloproliferative neoplasm variant that leads to excessive platelet production in the bone marrow. Janus kinase 2 (JAK2) mutation is observed in 60% of ET cases. The risk of thrombosis increases with the presence of this mutation. ET can cause systemic thrombosis, including extra-portal vein thrombosis (EHPVT). In patients with ET-induced EHPVT, varied symptoms generally occur. However, our case was asymptomatic. This condition is relatively rare. CASE REPORT A 49-year-old woman presented to our hospital for a detailed clinical examination 1 month after a health examination, and blood tests revealed microcytic anemia and thrombocytosis. The patient had no current concerns and had no relevant medical or alcohol consumption history. Esophagogastroduodenoscopy demonstrated esophageal varices, with portal hypertension suspected as the underlying cause. Contrast-enhanced computed tomography scans revealed a thrombus in the portal vein, but liver cirrhosis and a tumor were ruled out. JAK2 mutation was positive, which led to myeloproliferative neoplasms being considered as the differential diagnosis. Bone marrow biopsy demonstrated many mature megakaryocytes with large and irregular nuclei and platelet aggregation in the field of view, leading to the diagnosis of ET. CONCLUSIONS This case study describes a patient with EHPVT caused by JAK2-positive ET. This case report emphasizes that physicians should consider myeloproliferative neoplasms as part of their differential diagnosis when presented with EHPVT.

Essential Thrombocythemia and Ischemic Stroke: A Case Series of Five JAK2-Positive Patients

Background and Objectives: Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm characterized by elevated platelet counts and an increased risk of thrombotic events, including ischemic strokes. Materials and Methods: We conducted a retrospective analysis of data from consecutive ischemic stroke patients with ET between March 2014 and February 2023. Results: This case series describes the clinical presentation, radiological features, and management of five patients with ET-associated ischemic strokes, all harboring the JAK2 mutation. The diverse radiological findings suggest that both large and small vessel diseases may be influenced by the prothrombotic state induced by ET. A significant elevation in platelet count was observed to correlate with the emergence of new acute infarctions in some cases. Conclusions: The study highlights combined use of antiplatelet and cytoreductive therapy in preventing secondary stroke events in patients with ET and JAK2 mutations. The heterogeneity of stroke patterns in this population necessitates a comprehensive understanding of the underlying pathophysiological mechanisms and tailored therapeutic approaches.

A case of MDS/MPN overlap syndrome with ring sideroblasts and thrombocytosis: Tackling the quandary of thrombosis versus hemorrhage

Key Clinical Message

No formal treatment guidelines for MDS/MPN-RS-T exist. With salient features such as anemia and thrombocytosis, management is individualized and aims to address anemia, thrombosis, and in some cases acquired von Willebrand's disease.

Abstract

Myelodysplastic/myeloproliferative overlap syndrome with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) is a rare myeloid neoplasm showing myelodysplastic and myeloproliferative features. With extremely raised platelets, possibility of acquired von Willebrand and risk of hemorrhage is increased. With this quandary in mind, a descriptive case and a brief discussion of available treatments ensues.

Hematologic Disorders and the Nervous System

OBJECTIVE

This article discusses the epidemiology, diagnosis, treatment, and prevention of neurologic complications of red blood cell, platelet, and plasma cell disorders.

LATEST DEVELOPMENTS

Cerebrovascular complications can occur in patients with blood cell and platelet disorders. Treatment strategies to prevent stroke are available for patients with sickle cell disease, polycythemia vera, and essential thrombocythemia. A diagnosis of thrombotic thrombocytopenic purpura should be considered in patients with neurologic symptoms, hemolytic anemia, thrombocytopenia, mild renal insufficiency, and fever. Plasma cell disorders can be associated with peripheral neuropathy, and classification of the monoclonal protein type and neuropathy aid in diagnosis. Patients with POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes) syndrome can present with arterial and venous neurologic events.

ESSENTIAL POINTS

This article discusses the neurologic complications of blood cell disorders and the most recent advances in prevention and treatment.

Prevalence and Therapeutic Implications of Clonal Hematopoiesis of Indeterminate Potential in Young Patients With Stroke

BACKGROUND

Undetermined stroke etiology hampers optimal secondary prevention in a large proportion of young patients. We explored whether genetic screening for clonal hematopoiesis of indetermined potential (CHIP), a novel risk factor for stroke, could identify patients with myeloid precursor lesions or covert myeloid neoplasm requiring specific treatment.

METHODS

We performed targeted sequencing on 56 genes recurrently mutated in hematologic neoplasms in a prospective cohort of patients with acute brain ischemia between 18 and 60 years. CHIP prevalence was compared with age-matched healthy controls from the Nijmegen Biomedical Study (n=1604) and the UK Biobank (n=101 678). Patients with suspicion of high-risk CHIP or myeloid neoplasm were invited for further hematologic evaluation.

RESULTS

We included 248 consecutive patients (39% women) of whom 176 (71%) had cryptogenic stroke etiology. Fifty-one (21%) patients had CHIP, 3-fold more than in the general population (7.7% versus 2.6% for the Nijmegen Biomedical Study and 11.9% versus 4.1% for UK Biobank; P<0.001 for both). Patients with CHIP were older (median [interquartile range], 53 [50-59] versus 51 [41-56] years; P<0.001), had higher carotid intima-media thickness (0.68 [0.58-0.80] versus 0.59 [0.51-0.73] mm; P=0.009), and had higher burden of atherosclerosis (29.4% versus 16.7%; P=0.04). We invited 11 patients (4.4%) for further hematologic assessment, which in 7 led to the diagnosis of high-risk CHIP and in 2 to the new diagnosis of a myeloproliferative neoplasm with indication for cytoreductive therapy.

CONCLUSIONS

Using genetic screening for myeloid disorders in patients with stroke of predominantly undetermined etiology, we found a 3-fold higher CHIP prevalence than in the general population. We identified high-risk CHIP and previously covert myeloproliferative neoplasms as potential stroke etiologies in 4.4% and 1% of patients, respectively. Our findings demonstrate the diagnostic and therapeutic yield of genetic screening in young patients with stroke. Future studies should investigate the role of CHIP for stroke recurrence and optimal secondary prevention.

Leukocytosis and MPNs: Where do we stand?

The Philadelphia-negative myeloproliferative neoplasms (MPNs)-essential thrombocythemia (ET), polycythemia vera (PV) and myelofibrosis (MF), are characterized by a propensity for thrombotic events and variable risks for transformation to MF (for ET and PV) and acute leukemia. Leukocytosis, which serves a minor criterion for the diagnosis of MF, is present in a significant portion of patients with MPNs. The relation and impact of leukocytosis on disease course and outcomes of patients with MPNs has been studied in multiple, large retrospective and prospective studies. Despite this, the association of leukocytosis and thrombosis, fibrosis and leukemic transformation remains unclear. This article details the published investigations regarding the impact of leukocytosis in MPNs and explores the changing role of leukocytosis in disease prognostication as increasing emphasis is placed on molecular and genetic studies.

Hiperpigmentação Mucocutânea Associada à Terapia de Hidroxiureia em Paciente com Trombocitemia Essencial: Relato de Caso

Introdução: A hiperpigmentação mucocutânea é uma condição dermatológica que pode estar relacionada a tratamentos quimioterápicos, a exemplo das terapias com uso de hidroxiureia (HU). A HU é um fármaco citostático de amplo uso nas doenças mieloproliferativas e compõe a principal linha de tratamento da trombocitemia essencial (TE). O presente estudo tem por objetivo relatar um caso raro de hiperpigmentação mucocutânea em um paciente com TE. Relato do caso: Paciente do sexo masculino, 68 anos de idade, 89 kg, com diagnóstico de TE, em uso de HU 2 g/dia. Com três meses de terapia, apresentou lesões hiperpigmentadas de coloração acastanhadas em pele das mãos e mucosa oral (língua). Em decisão partilhada com o médico-assistente, o paciente optou pela continuação do uso do medicamento. Após seis anos de acompanhamento, as lesões mantêm-se estáveis. Conclusão: A hiperpigmentação mucocutânea associada à terapia com HU é um evento benigno secundário ao uso do fármaco e não exige a interrupção de uso, porém, sua retirada, ou redução das doses, geralmente leva à diminuição ou ao desaparecimento das lesões.

A Young Adult With Essential Thrombocythemia Presenting as Myocardial Infarction

Essential thrombocythemia (ET) is a myeloproliferative neoplasm involving the clonal proliferation of platelets. It is Philadelphia negative and is associated with Janus kinase 2 (JAK2), calreticulin (CALR), or myeloproliferative leukemia virus oncogene (MPL) mutations. The resultant platelets have quantitative and qualitative defects, making them more sticky and prone to thromboembolism. However, ET does not only affect platelet survival, it also has a low leukemogenic potential. It's more common in the elderly, 60 years or more, but can be seen in all age groups, including children. Patients with ET have an increased risk of vascular events like hemorrhage and thromboses like cerebrovascular events, myocardial infarction, superficial thrombophlebitis, deep vein thrombosis, and pulmonary embolism. Cardiovascular risk factors like hypertension, diabetes, and smoking can lead to increased thromboembolism and atherosclerosis. The management of ET focuses primarily on the prevention of thrombosis and hemorrhage. It involves cardiovascular risk management and antiplatelet and cytoreductive therapy according to the risk stratification. Low-risk ET patients are treated with low-dose aspirin, and high-risk ET patients are treated with cytoreductive therapy with hydroxyurea. Interferon (IFN) and anagrelide are reserved for young patients or pregnant women. This case report discusses a 40-year-old male, a known smoker presenting with myocardial infarction and left anterior descending artery (LAD) blockage without any prior history. His high platelets and the relative absence of cardiovascular risk factors helped reach the diagnosis, and bone marrow analysis and mutation analysis confirmed the diagnosis. The patient was started on hydroxyurea, which decreased the total platelet count. 

Essential thrombocythemia with non-ST-segment elevation myocardial infarction as the first manifestation: A case report

BACKGROUND

We report a case of essential thrombocythemia (ET) in a 44-year-old male who exhibited non-ST-segment-elevation myocardial infarction (NSTEMI) as the first manifestation without known cardiovascular risk factors (CVRFs). For the first time, we reported a left main trifurcation lesion in NSTEMI caused by ET, including continuous stenosis lesions from the left main to the ostial left anterior descending (LAD) artery and an obvious thrombotic lesion in the ostial and proximal left circumflex (LCX) artery. There was 60% diffuse stenosis in the left main (LM) that extended to the ostial LAD, thrombosis of the ostial LAD and proximal LCX, and 90% stenosis in the proximal LCX. During the operation, thrombus aspiration was performed, but no obvious thrombus was aspirated. Performing the kissing balloon technique (KBT) in the LCX and LM unexpectedly increased the narrowness of the LAD. Then, the single-stent crossover technique, final kissing balloon technique and proximal optimization technique (POT) were performed. On the second day after percutaneous coronary intervention (PCI), the number of platelets (PLTs) still increased significantly to as high as 696 × 10⁹/L. The bone marrow biopsy done later, together with JAK2 (exon 14) V617F mutation, confirms the diagnosis of ET. Hydroxyurea was administered to inhibit bone marrow proliferation to control the number of PLTs.

CASE SUMMARY

A 44-year-old male patient went to a local hospital for treatment for intermittent chest pain occurring over 8 h. The examination at the local hospital revealed elevated cTnI and significantly elevated platelet. Then, he was diagnosed with acute myocardial infarction and transferred to our hospital for emergency interventional treatment by ambulance. During the operation, thrombus aspiration, the single-stent crossover technique, final kissing balloon technique and POT were performed. Dual antiplatelet therapy comprising aspirin and ticagrelor was used after PCI. Evidence of mutated JAK2 V617F and bone marrow biopsy shown the onset of ET. Together with JAK2 (exon 14) V617F mutation, ET was diagnosed according to the World Health Organization (WHO) diagnostic criteria, and the patient was placed on hydroxyurea. During the one-year postoperative period, repeated examinations showed a slight increase in PLTs, but the patient no longer had chest tightness, chest pain or bleeding or developed new thromboembolisms.

CONCLUSION

Routine physical examinations and screenings are conducive to the early detection of ET, and the risk for thrombosis should be assessed. Then, active antiplatelet therapy and myelosuppression therapy should be used for high-risk ET patients.

Hematocrit Self-Testing in Patients with Polycythemia Vera and Other Hematological Conditions: Assessing the Accuracy of the StatStrip Xpress® 2 LAC/Hb/Hct Device and User Opinion about the Device in Real-World Clinical Practice

Maintaining hematocrit (Hct) levels below 45% can reduce morbidity and mortality in patients with polycythemia vera (PV). A device that patients can use to self-monitor Hct levels could enable timely interventions if Hct levels increase above 45%, and could improve quality of life (QoL). This study evaluated the accuracy of the StatStrip Xpress® 2 LAC/Hb/Hct meter (Hb/Hct meter) when used by healthcare professionals (HCPs) or patients in clinical practice. Blood samples from 68 visits for 60 patients with PV or other hematological conditions were collected and analyzed by HCPs using a laboratory hematological analyzer, and by patients (self-test) and HCPs (professional test) using the Hb/Hct meter at two Swiss centers. Accuracy was assessed as the mean difference in readings between two users/methods (mdiff, 90% confidence interval; Spearman correlation [r]). The Hct values were similar between the professional test and analyzer (n = 66 comparisons, mdiff = 0.1% [−0.5 to 0.8]; r = 0.95, p < 0.001), the self-test and professional test (n = 62 comparisons, mdiff = −0.2% [−1.1 to 0.7]; r = 0.93, p < 0.001), and the self-test and analyzer (n = 63 comparisons, mdiff = 0.0% [−0.8 to 0.7]; r = 0.94, p < 0.001). The hemoglobin values across users/methods were also similar. Reporting their opinion on the Hb/Hct meter at visit 1, 100% of the patients found it easy to use, and 97% were willing to use it at home. Of the patients with PV, approximately 71% and 56%, respectively, stated that they would feel safer using a self-testing device, and that it would improve their QoL. These findings demonstrate the potential of the Hb/Hct meter for HCP and patient use in real-world settings.

Janus Kinase-2 V617F Mutation and Antiphospholipid Syndrome in Cerebral Sinus Venous Thrombosis: Natural History and Retrospective Bicenter Analysis

Background

Cerebral sinus venous thrombosis (CSVT) is a rare neurovascular entity, usually associated with acquired or genetic hypercoagulable states. In up to 30% of the cases it remains idiopathic. Bone marrow proliferation disorders that are associated with Janus Kinase 2 V617F mutation (JAK-2) are known causes of the systemic and cerebral thrombosis—at times despite normal blood counts—for which hematologic treatment exists. However, JAK-2 prevalence in the CSVT cases is not clear.

Methods

In this retrospective analysis, data of 236 patients with CSVT admitted to two tertiary centers between 2010 and 2020 were analyzed, with emphasis on laboratory and imaging data and clinical and interventional outcomes.

Results

A total of 236 patients were included in the analysis. The patients' median age was 42 years and the average age was 44 years (±19 years), with 59% female patients. JAK-2 positivity rate was 18% (among 77 patients tested for the mutation). Patients with normal blood counts on presentation comprised 36% of the JAK-2 positive cases. Other hypercoagulability states were also investigated, with the antiphospholipid syndrome (APLA) showing the highest prevalence (11%) followed by other etiologies including oral contraceptive use, Factor V Leiden, prothrombin mutation, and malignancy. Selected JAK-2, APLA, and prothrombin mutation cases showed a more severe clinical course.

Conclusion

JAK-2 mutation is underdiagnosed and its screening may be warranted in the cases of idiopathic CSVT, even despite normal blood counts, to allow disease-modifying treatment and blood cell count monitoring. JAK-2, APLA, and prothrombin mutation may be associated with a more complicated clinical course.

Management of Myeloproliferative Neoplasms (MPNs)

PURPOSE

To provide up to date guidance, practice recommendations and highlight barriers to medication adherence in the long-term management of chronic myeloproliferative neoplasms (MPNs).

AIM

Current drug therapy for MPN is not curative and has not been shown to prolong survival. The main indication for treatment is the prevention of thrombosis and medication adherence remains a challenge in this group of patients. Identifying potentially modifiable barriers to medication adherence including primary nonadherence and non-persistent adherence enables timely interventions to be put in place and improve overall medication adherence.

METHODS

A systematic review of peer-reviewed literature and expert opinions was performed using electronic databases (PubMed, EMBASE, MEDLINE, and Web of Science) that were searched for articles reporting MPN and medication adherence. Discussions A case vignette is discussed throughout the article and expert opinion with international peer reviewed guidelines that are authored to support clinical decision making at the point of care were utilised. The evidence base was combined with more practical/clinical (data based) insight from real world clinical practice. Adoption of a broad range of digital health care activities and services in the health care system (telehealth applications) by the advanced practice providers (Non-Medical Prescribers-NMPs) in MPN clinics included medication prescribing and management, oral drug compliance and adherence evaluations, interventions, chronic care management, counselling and patient education on treatments.

CONCLUSION

Current drug therapy for MPN is neither curative nor has it been shown to prolong survival, and medication adherence remains a challenge in this group of patients. The longevity of the patients' disease course may contribute to the high risk of non-adherence in this patient cohort. Poor adherence to long-term therapies severely compromises the effectiveness of treatment. Adherence interventions should be tailored to the needs of the patient in order to achieve maximum impact. Interventions aimed at improving adherence provide the best experience and outcome for the patient and their families and can have a profound impact on the quality of life and mitigation of disease consequences.

Comparison of Clinical and Hematological Parameters of Janus Kinase 2, Calreticulin or Myeloproliferative Leukemia Virus Oncogene Mutant Essential Thrombocythemia and Triple-Negative Essential Thrombocythemia

Introduction

Essential thrombocythemia (ET) is one of the chronic myeloproliferative neoplasms. While Janus kinase 2 (JAK2) V617F mutation is defined in more than half of the patients with ET, calreticulin (CALR) or myeloproliferative leukemia virus oncogene (MPL) mutations are encountered more rarely. The discovery of the JAK2 V617F mutation in 2005, followed by the recognition of MPL and CALR mutations, brought up the idea of subdividing ET according to the mutation status. Our aim in this study is to investigate whether genetic mutations detected in patients diagnosed with ET cause a different clinical phenotype compared to triple-negative ET.

Methods

This retrospective study was conducted by evaluating the patients who were followed up with the diagnosis of ET in the hematology clinic of two tertiary centers in Turkey between 2009 and 2021. Patients with negative JAK2, CALR, and MPL mutations and meeting the diagnostic criteria for ET were defined as triple-negative ET. The patients were divided into two groups as triple-negative ET and mutation-positive ET according to the presence of a mutation. It was investigated whether there was a difference between these two groups in terms of demographic, laboratory, and clinical characteristics.

Results

A total of 109 patients were included in the study. The mean age of these patients was 54 (18-91) years and 85 (78%) patients were females. A total of 48 patients (44.0%) had JAK2 mutation, six (5.5%) had CALR mutation, and one (0.9%) had MPL mutation. It was observed that there was a significant difference between the two groups in terms of gender, mean age, and hemoglobin value. While 87% of patients with triple-negative ET were females, this rate was 69% in patients with mutation-positive ET (p = 0.036). The mean age was 41.8 years in triple-negative ET and 67.1 years in patients with mutation-positive ET (p = 0.0001). While the mean hemoglobin value was 12.9 g/dl in patients with triple-negative ET, it was 14.4 g/dl in patients with mutation-positive ET (p = 0.0001).

Conclusion

It has been observed that ET with JAK2, CALR, or MPL mutations may have different phenotypic features compared to triple-negative ET, resulting in a clinical condition consisting of older patients with a higher erythrocyte count.

JAK2 allele burden is correlated with a risk of venous but not arterial thrombosis

BACKGROUND

Thrombosis is the main complication in myeloproliferative neoplasms (MPN). A JAK2V617F mutation has been shown to be a risk factor for thrombosis. The implication of other risk factors alongside a mutation allele burden needs to be clarified (Trifa et al., 2018; Borowczyk et al., 2015).

OBJECTIVE

Our aim was to investigate the role of the JAK2 mutation allele burden in the risk of cardiovascular events (CVE) and/or venous thrombosis (VTE) in a cohort of patients with confirmed MPN, as well as in patients without confirmed MPN.

METHODS

We restrospectively included all consecutive patients who were positive for JAK2V617F seen by our unit between December 2008 and September 2016. Inclusion criteria were a positive test for the JAK2V617F mutation, with at least 1% allele burden, with or without confirmed MPN.

RESULTS

We included 239 patients of median age 71 years [60-81], followed-up for a median of 82.8 months [41.08-146.88]. For JAK2V617F positive patients having an allele burden superior to 50% the cumulative incidence of VTE was significantly higher than for those with an allele burden inferior to 50% (HR 3.11 95% CI [1.10-8.76] p = 0.031). The cumulative incidence of VTE was also higher in patients with obesity (HR 4.58 95% CI [1.33-15.8] p = 0.016). There was no significant association between a JAK2V617F allele burden and arterial thrombosis (manifesting as CVE). Previous VTE was also associated with a higher cumulative incidence of recurrence during follow-up HR 3.22 95% CI [1.17-8.81] p = 0.0231.

CONCLUSION

We show that a JAK2V617F allele burden is associated with risk of VTE but not with CVE.

Management Issues and Controversies in Low-Risk Patients with Essential Thrombocythemia and Polycythemia Vera

PURPOSE OF REVIEW

Essential thrombocythemia (ET) and polycythemia vera (PV) are the most common myeloproliferative neoplasms (MPNs). Treatment of ET and PV is based on the risk for subsequent thrombosis. High-risk patients, defined as older than 60, JAK2 V617F-positive patients, or patients with a history of prior thrombosis, merit cytoreduction to control blood counts, whereas a watchful waiting paradigm is utilized in low-risk patients. However, low-risk patients have a host of other specific management issues that arise during their disease course. This review will discuss the most common management issues specific to the care of low-risk patients, including anti-platelet therapy dosing, pregnancy, and indications for early cytoreduction.

RECENT FINDINGS

Although low-dose aspirin is well established in PV, its indications and dosing regimens are less clear in ET. Recent evidence has supported twice daily low-dose aspirin in ET and observation alone in very low-risk ET patients. Pregnancy is not contraindicated in MPNs, and we recommend aspirin throughout pregnancy with consideration for prophylactic postpartum anticoagulation. High phlebotomy needs, symptom burden, and extreme thrombocytosis are common reasons for initiation of cytoreduction in low-risk patients, although we typically do not start cytoreduction for an isolated high platelet count alone. Recent data has also demonstrated a potential disease-modifying effect of interferons in MPNs, with some experts now advocating the early use of interferon in low-risk patients, although more mature data is needed before practice guidelines change. We evaluate the literature to inform clinical decision-making regarding these controversies, including most recent data that has challenged the "watchful waiting" paradigm. Our discussion provides guidance on common clinical scenarios seen in low-risk ET and PV patients, who face a myriad of complex management decisions in their care.

NK Cells in Myeloproliferative Neoplasms (MPN)

Simple Summary

NK cells are important innate immune effectors that contribute substantially to tumor control, however the role of NK cells in haematological cancers is not as well understood. The aim of this review is to highlight the importance of the role of NK cells in the management of Ph+ Myeloproliferative Neoplasms, and emphasize the need and possible benefits of a more in-depth investigation into their role in classical MPNs and show potential strategies to harness the anti-tumoral capacities of NK cells.

Abstract

Myeloproliferative neoplasms (MPNs) comprise a heterogenous group of hematologic neoplasms which are divided into Philadelphia positive (Ph+), and Philadelphia negative (Ph−) or classical MPNs. A variety of immunological factors including inflammatory, as well as immunomodulatory processes, closely interact with the disease phenotypes in MPNs. NK cells are important innate immune effectors and substantially contribute to tumor control. Changes to the absolute and proportionate numbers of NK cell, as well as phenotypical and functional alterations are seen in MPNs. In addition to the disease itself, a variety of therapeutic options in MPNs may modify NK cell characteristics. Reports of suppressive effects of MPN treatment strategies on NK cell activity have led to intensive investigations into the respective compounds, to elucidate the possible negative effects of MPN therapy on control of the leukemic clones. We hereby review the available literature on NK cells in Ph+ and Ph− MPNs and summarize today’s knowledge on disease-related alterations in this cell compartment with particular focus on known therapy-associated changes. Furthermore, we critically evaluate conflicting data with possible implications for future projects. We also aim to highlight the relevance of full NK cell functionality for disease control in MPNs and the importance of considering specific changes related to therapy in order to avoid suppressive effects on immune surveillance.

Comparison of the effects between MPL and JAK2V617F on thrombosis and peripheral blood cell counts in patients with essential thrombocythemia: a meta-analysis

To assess the effects between MPL and JAK2V617F on the thrombosis risk and peripheral blood cell counts in patients with essential thrombocythemia (ET), we identified eligible studies from PubMed, Embase, and the Cochrane Library. Seven studies were ultimately included in this meta-analysis. All studies reported the peripheral blood cell counts of ET patients, and three of them reported the eligible thrombotic events. In comparing the effect of MPL versus JAK2V617F on thrombosis, 1257 ET patients (73 MPL + and 1184 JAK2V617F +) were included. MPL-positive (MPL +) ET patients had a higher risk of thrombosis than JAK2V617F-positive (JAK2V617F +) ET patients [RR = 1.80 (1.08-3.01), P = 0.025]. And 3453 ET patients (138 MPL + and 3315 JAK2V617F +) were included in the comparison of peripheral blood cell counts. Platelet counts of MPL + ET patients were higher than that of JAK2V617F + ET patients [WMD = 81.18 (31.77-130.60), P = 0.001]. MPL + ET patients had lower hemoglobin [WMD =  - 11.66 (- 14.32 to - 9.00), P = 0.000] and white blood cell counts [WMD =  - 1.01 (- 1.47 to - 0.56), P = 0.000] than JAK2V617F + ET patients. These findings indicate that the MPL mutation is a high-risk factor for thrombosis in ET patients, and it may be rational to include MPL mutation in the revised IPSET as a criterion for thrombosis prediction scores. And given the differences in peripheral blood, it is necessary to further study whether MPL + ET patients differ from JAK2V617F + ET patients in bleeding and survival.

Calreticulin mutations in myeloproliferative neoplasms

Calreticulin (CALR) is a chaperone present in the endoplasmic reticulum, which is involved in the quality control of N-glycosylated proteins and storage of calcium ions. In 2013, the C-terminal mutation in CALR was identified in half of the patients with essential thrombocythemia and primary myelofibrosis who did not have a JAK2 or MPL mutation. The results of 8 years of intensive research are changing the clinical practice associated with treating myeloproliferative neoplasms (MPNs). The presence or absence of CALR mutations and their mutation types already provide important information for diagnosis and treatment decision making. In addition, the interaction with the thrombopoietin receptor MPL, which is the main mechanism of transformation by CALR mutation, and the expression of the mutant protein on the cell surface have a great potential as targets for molecular-targeted drugs and immunotherapy. This chapter presents recent findings on the clinical significance of the CALR mutation and the molecular basis by which this mutation drives MPNs.

Essential Thrombocythemia Due to Janus Kinase 2 Mutation Unmasked After Splenectomy

Reactive thrombocytosis after splenectomy is common and often self-limiting. However, thrombocytosis can be multifactorial, especially extreme thrombocytosis (platelet count > 100 x 10⁴/cubic mm). It can lead to thrombotic or hemorrhagic complications. Hence, in patients with rising platelet count after splenectomy, detailed evaluation may be required to rule out other causes of thrombocytosis, such as infection, iron deficiency, and myeloproliferative disorders. Timely treatment of patients with thrombocytosis can prevent the development of life-threatening complications. The index case highlights the importance of regular follow-up of the patients after splenectomy to detect thrombocytosis and suspect other causes if the spleen was diseased or the platelet count fails to resolve spontaneously.

Successful thrombolysis in essential thrombocythemia-related acute ischaemic stroke

Essential thrombocythemia (ET)-related acute ischaemic stroke (AIS) may account for approximately 0.25%-0.5% of all ischaemic strokes. If left undiagnosed and untreated, patients with ET carry an increased risk of recurrent thrombosis involving major organs including the brain. We report an interesting case of a 67-year-old man, who was successfully thrombolysed for AIS resulting from ET. He presented with sudden onset of left-sided hemiparesis with a left-ventricular clot. His subsequent investigations including positive JAK2 V617F mutation confirmed the diagnosis of ET. He made a significant recovery with thrombolysis, anticoagulation, antiplatelet and hydroxyurea. A fear of post-thrombolytic haemorrhagic complications appears the major reason for the lack of reports of thrombolysis in ET-related AIS. Although the diagnosis of ET was confirmed on subsequent investigations, successful thrombolysis in our case provides preliminary evidence that ET-related AIS cases can undergo successful thrombolysis using tenecteplase. To date, ours is only the second case of ET-related AIS being thrombolysed.

Antithrombotic Management in Ischemic Stroke with Essential Thrombocythemia: Current Evidence and Dilemmas

Thrombotic diseases like ischemic stroke are common complications of essential thrombocythemia (ET) due to abnormal megakaryopoiesis and platelet dysfunction. Ischemic stroke in ET can occur as a result of both cerebral arterial and venous thrombosis. Management of ET is aimed at preventing vascular complications including thrombosis. Acute management of ischemic stroke in ET is the same as that in the general population without myeloproliferative disorders. However, an ET patient with ischemic stroke is at high risk for rethrombosis and is therefore additionally managed with cytoreductive therapy and antithrombotic agents. Given abnormal platelet production in ET, there is suboptimal suppression of platelets with the standard recommended dose of aspirin for cardiovascular (CV) prevention. Hence, for optimal CV protection in ET, low-dose aspirin is recommended twice daily in an arterial thrombotic disease like atherothrombotic ischemic stroke in presence of the following risk factors: age >60 years, Janus kinase2 V617F gene mutation, and presence of CV risk factors. In the presence of the same risk factors, concurrent antiplatelet and anticoagulant therapy is suggested for venous thrombosis. However, increased risk of bleeding with dual antithrombotic agents poses a significant challenge in their use in cerebral venous thromboembolism or atrial fibrillation in presence of the above-mentioned risk factors. We discuss these dilemmas regarding antithrombotic management in ischemic stroke in ET in this case-based review of literature in the light of current evidence.

Disease and Clinical Characteristics of Patients With a Clinical Diagnosis of Essential Thrombocythemia Enrolled in the MOST Study

Few data exist regarding the disease and clinical characteristics of patients with essential thrombocythemia (ET) in the United States. The ongoing, multicenter, noninterventional, prospective, Myelofibrosis and Essential Thrombocythemia Observational STudy (MOST) was designed to collect data pertaining to the demographics, clinical management, and patient-reported outcomes in patients with myelofibrosis or ET in the United States (NCT02953704). This analysis examines the clinical characteristics of patients with clinical diagnoses of high-risk or low-risk ET receiving ET-directed therapy at enrollment. At data cutoff (June 17, 2019), 1207 of 1234 enrolled patients were eligible for this analysis (median age, 70 years; 65% female; 88% white); 917 patients (76%) had mutation testing results available. The median time from ET diagnosis to study enrollment was 4.2 years. The majority of patients (87%) had high-risk ET. Of 333 patients with a history of thrombotic events, 247 had at least 1 event classified as arterial and/or venous. Platelet count was above normal range in 54% of patients. Hypertension (56%) was the most common comorbidity. At enrollment, the majority of patients (low-risk ET, 94%; high-risk ET, 79%) were receiving ET-directed monotherapy. Additional prospective analyses from MOST will help to identify areas of unmet need.

Cerebrovascular manifestations in hematological diseases: an update

Patients with hematological diseases often experience cerebrovascular complications including ischemic stroke, intracerebral and subarachnoid hemorrhage, microbleeds, posterior reversible encephalopathy syndrome, and dural sinus and cerebral vein thrombosis (CVT). In this update, we will review recent advances in the management of cerebrovascular diseases in the context of myeloproliferative neoplasms, leukemias, lymphomas, multiple myeloma, POEMS, paroxysmal nocturnal hemoglobinuria (PNH), thrombotic thrombocytopenic purpura (TTP), and sickle-cell disease. In acute ischemic stroke associated with hematological diseases, thrombectomy can in general be applied if there is a large vessel occlusion. Intravenous thrombolysis can be used in myeloproliferative neoplasms and sickle-cell anemia, but in other diseases, a case-by-case evaluation of the bleeding risks is mandatory. Patients with sickle-cell disease and acute stroke need very often to be transfused. In PNH, acute ischemic stroke patients must be anticoagulated. Most patients with CVT can be treated with low-molecular weight heparin (LMWH) acutely, even those with leukemias. Prevention of recurrence of cerebral thrombotic events depends on the control of the underlying disease, combined in some conditions with antithrombotic drugs. The recent introduction of specific monoclonal antibodies in the treatment of PHN and TTP has dramatically reduced the risk of arterial and venous thrombosis.

Prevention of recurrent thromboembolism in myeloproliferative neoplasms: review of literature and focus on direct oral anticoagulants

Myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (MF) are stem cell clonal neoplasms characterized by expansion of late myeloid cells. Thrombosis risk is elevated in MPNs and contributes significantly to morbidity and mortality. Current consensus guidelines make no specific recommendations regarding anticoagulant choice for the treatment of venous thromboembolism (VTE) in MPNs, with most evidence supporting the use of vitamin K antagonists (VKAs) for secondary prophylaxis. However, direct oral anticoagulants (DOACs) are now increasingly being used, although with limited data on safety and efficacy in MPNs specifically. The widespread adoption of DOACs is based on new, high-quality evidence demonstrating safety and efficacy of DOAC treatment for cancer-associated VTE. However, these studies include few if any MPN patients, and MPNs have disease-specific considerations that may elevate thrombosis and bleeding risk. The purpose of this review is to discuss evidence behind current treatment recommendations for thrombosis in MPNs, with special attention to the use of DOACs.

A Case of Critical Essential Thrombocythemia Complicated by Severe Lower-Extremity Arterial Disease

Patient: Male, 66-year-old

Final Diagnosis: Essential thrombocythemia with CML • peripheral artery disease

Symptoms: Fever • infection • necrosis • pain

Medication: —

Clinical Procedure: —

Specialty: Cardiology • Dermatology • Diagnostics, Laboratory • Hematology

Platelet count evaluation compared with the immunoplatelet reference method and performance evaluation of the hematology analyzer Celltac G

INTRODUCTION

The hematology analyzer, Celltac G (Nihon Kohden), designed to improve platelet count (Plt) accuracy, is equipped with new sheath flow control technology. Clinical evaluation of the Celltac G was assessed by comparability with XN-9000 (Sysmex Corporation) and CELL-DYN Sapphire (Abbott Diagnostics). The accuracy of all three analyzers, which use different measuring principles, was compared with the immunoplatelet reference method (FCM-Ref).

METHODS

Repeatability and within-laboratory imprecision were assessed using 10 clinical fresh whole blood samples and three control materials with differing levels. Carryover was evaluated using 6 clinical fresh whole blood samples. For method comparison between the three analyzers, 388 samples were used. Plt accuracy among the three analyzers was evaluated using 54 blood samples, including 42 samples with a platelet count less than 50x10⁹ /L. The International Council for Standardization in Haematology method for Plt was used as the FCM-Ref.

RESULTS

The Celltac G showed sufficient performance with regard to imprecision, carryover, and comparability. The Analytical Measurement Interval (AMI) and linearity for all parameters of Plt were validated within 4.6 to 809.1 (×10⁹ /L). All hematology analyzers showed some disagreement in Plt when compared with the immunoplatelet reference method.

CONCLUSION

The Celltac G hematology analyzer is suitable for clinical use. Platelet count evaluation of the three analyzers suggests the need to determine a reportable measurement interval (RMI) in the clinical laboratory for adequate reporting of a Plt from multiple different values.

Aspirin in the Prevention of Cardiovascular Disease and Cancer

More than a century after its synthesis, daily aspirin, given at a low dose, is a milestone treatment for the secondary prevention of cardiovascular disease (CVD). Its role in primary prevention of CVD is still debated. Older randomized controlled trials showed that aspirin reduced the low incidence of myocardial infarction but correspondingly increased the low incidence of serious gastrointestinal bleeds without altering mortality. More recent trials see the benefit attenuated, perhaps obscured by other cardioprotective practices, while the bleeding risk remains, especially in older patients. Indirect evidence, both preclinical and clinical, suggests that aspirin may protect against sporadic colorectal cancer and perhaps other cancers. However, further studies are still necessary to warrant the consumption of aspirin for primary prevention of CVD and cancer by apparently healthy individuals.

The Essential Thrombocythemia in 2020: What We Know and Where We Still Have to Dig Deep

The Essential Thrombocythemia is a Chronic Philadelphia-negative Myeloproliferative Neoplasm characterized by a survival curve that is only slightly worse than that of age- and sex-adjusted healthy population. The criteria for diagnosis were reviewed in 2016 by WHO. The incidence varies from 0.2 to 2.5:100 000 people per year, with a prevalence of 38 to 57 cases per 100 000 people. The main characteristics of ET are the marked thrombocytosis and the high frequency of thrombosis. The spectrum of symptoms is quite wide, but fatigue results to be the most frequent. Thrombosis is frequently observed, often occurring before or at the time of diagnosis. The classification of thrombotic risk has undergone several revisions. Recently, the revised-IPSET-t has distinguished 4 risk classes, from very low risk to high risk. Driver mutations seem to influence thrombotic risk and prognosis, while the role of sub-driver mutations still remains uncertain. Antiplatelet therapy is recommended in all patients aged ⩾ 60 years and in those with a positive history of thrombosis or with cardiovascular risk factors, while cytoreductive therapy with hydroxyurea or interferon is reserved for high-risk patients.

Rapid Cytoreduction by Plateletapheresis in the Treatment of Thrombocythemia

The objective of this chapter is to provide a systematic overview of current knowledge regarding therapeutic apheresis—primarily therapeutic plateletapheresis (TP)—and to summarize evidence-based practical approaches related to cytapheresis treatment of “hyperthrombocytosis” or “extreme thrombocytosis” (ETC). Our results of platelet (Plt) quantitative/qualitative analyses and evaluation of efficacy of apheresis systems/devices—on the basis of Plt removal and in vivo Plt depletion—will be presented. Our preclinical researches confirmed that in Plt concentrates, the initial ratio of discoid shapes was 70%, spherical 20%, and less valuable (dendritic/balloonized) shapes 10%—with morphological score of platelets (MSP = 300–400). After storage, the ratio of discoid and spherical shapes was decreased, while the less valuable ones progressively increased (MSP = 200). Electron microscopy has shown discoid shapes with typical ultrastructural properties. Spherical shapes with reduced electron density and peripheral location of granules/organelles were detected. Also, dendritic shapes with cytoskeletal “rearrangement,” membrane system integrity damages, and pseudopodia formations were documented. Our clinical study demonstrated that TP was useful in ETC treatment and should help prevention of “thrombo-hemorrhagic” events—until chemotherapy, antiplatelet drugs, and other medication take effect. During TP treatment, Plt count and morphology/ultrastructure were examined. Plt functions by multiplate analyzer were evaluated. We concluded that intensive TP was an effective, safe, and rapid cytoreductive treatment for ET.

Occurrence of immune thrombocytopenic purpura in a patient with essential thrombocythemia: How the immune system can overcome a neoplastic clone

Our case highlights the possible coexistence of essential thrombocythemia (ET) and idiopathic thrombocytopenic purpura (ITP), two pathological entities with opposite clinical and laboratory manifestations. It also underlines how an autoimmune attack has been temporarily able to overcome a neoplastic clone.

Novel and combination therapies for polycythemia vera and essential thrombocythemia: the dawn of a new era

INTRODUCTION

Essential thrombocythemia (ET) and polycythemia vera (PV) belong to the BCR-ABL1-negative myeloproliferative neoplasms and are characterized by the clonal proliferation of hematopoietic stem and progenitor cells. The contribution of aberrant immune regulation within the bone marrow microenvironment to ET and PV pathogenesis as well as the underlying molecular landscape is becoming increasingly understood.

AREAS COVERED

Authors searched PubMed and conference abstracts in August 2020 for preclinical and clinical studies to provide an overview of the immune pathobiology in ET and PV and the rationale for several novel agents. A discussion of recent clinical trials on interferon and ruxolitinib in ET and PV patients is provided followed by an outline of the future challenges in the field particularly for novel therapeutics and an increasingly individualized, molecularly driven approach to treatment selection. Several novel agents are currently being actively evaluated and are reviewed herein as well.

EXPERT OPINION

While hydroxyurea remains the first-line treatment for cytoreduction in most high-risk ET and PV patients, the disease-modifying potential of IFN is promising and could make it a preferred option for selected patients. Advances in molecular testing will enable a more individualized approach to prognostication and treatment selection.

Patients with Essential Thrombocythemia may be Poor Responders to Enteric-Coated Aspirin, but not to Plain Aspirin

Essential thrombocythemia (ET) patients are treated with aspirin (acetylsalicylic acid [ASA]) to prevent thrombosis. Previous studies showed that serum thromboxane (Tx) B₂ was high 24 hours after enteric-coated (EC)-ASA in ET patients, due to increased number of noninhibited reticulated platelets (RPs), consequent to high platelet turnover, and that ASA should be given twice a day to ET patients. We studied ET patients (n = 17) and healthy subjects (n = 10) on 100 mg EC-ASA once daily; experiments were repeated after 14-day treatment with 100 mg plain-ASA once daily. Serum TxB₂, plasma ASA, and salicylic acid (SA) were measured before the morning dose and up to 8 hours thereafter. Blood activity of ASA-deacethylating esterases, in vitro inhibition of collagen-induced TxB₂ production by ASA (10-1,000 µM), and number of RP were measured. TxB₂ inhibition by ASA in vitro and esterases activities were normal in all subjects. EC-ASA elicited highly variable responses; 6 ET patients were poor responders, as their serum TxB₂ was high after EC-ASA; their plasma levels of ASA and SA were low/undetectable. In contrast to EC-ASA, plain ASA decreased serum TxB₂ and increased plasma ASA and SA in all subjects. Serum TxB₂ was high in ET patients at 24 hours and significantly correlated with RP count (but not RP percentage) and platelet count. Plain ASA should be used in ET patients to inhibit platelets efficiently. The identification of ET patients who might benefit from twice a day ASA could simply be based on their platelet count: since their platelet turnover is not increased, ET patients with normalized platelet count should not need twice a day ASA treatment.

Clinical features of children with polycythemia vera, essential thrombocythemia, and primary myelofibrosis in Japan: A retrospective nationwide survey

Background

Philadelphia-negative (Ph-negative) myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are exceptionally rare during childhood. Thus, clinical features of pediatric Ph-negative MPNs remain largely unknown. This study was therefore performed to address this.

Methods

We performed a retrospective study to collect clinical information of children diagnosed with Ph-negative MPNs from 2000 to 2016 using questionnaires in qualified institutions in Japan. The results obtained from the questionnaire survey were then combined with those from the national registry data.

Results

Among 50 children identified, five had PV, 44 had ET, and one had PMF. Median age at diagnosis was 14.0, 9.0, and 0 years, respectively. Male to female ratio was 4:1, 21:23, and 1:0, respectively. Detection rates of the JAK2 V617F variant were 0/5 in PV and 9/39 in ET. Frequencies of complications, such as thrombosis and subsequent leukemia, were lower than complication frequencies in adults. We identified two children who developed subsequent leukemia, which has not been reported previously, and one of them died.

Conclusion

This is the first nationally representative survey of pediatric Ph-negative MPNs. Given its rarity, an international collaboration with comprehensive genetic analyses might be needed to fully elucidate the clinical and genetic features.

Clonal hematopoietic mutations linked to platelet traits and the risk of thrombosis or bleeding

Platelets are key elements in thrombosis, particularly in atherosclerosis-associated arterial thrombosis (atherothrombosis), and hemostasis. Megakaryocytes in the bone marrow, differentiated from hematopoietic stem cells are generally considered as a uniform source of platelets. However, recent insights into the causes of malignancies, including essential thrombocytosis, indicate that not only inherited but also somatic mutations in hematopoietic cells are linked to quantitative or qualitative platelet abnormalities. In particular cases, these form the basis of thrombo-hemorrhagic complications regularly observed in patient groups. This has led to the concept of clonal hematopoiesis of indeterminate potential (CHIP), defined as somatic mutations caused by clonal expansion of mutant hematopoietic cells without evident disease. This concept also provides clues regarding the importance of platelet function in relation to cardiovascular disease. In this summative review, we present an overview of genes associated with clonal hematopoiesis and altered platelet production and/or functionality, like mutations in JAK2 We consider how reported CHIP genes can influence the risk of cardiovascular disease, by exploring the consequences for platelet function related to (athero)thrombosis, or the risk of bleeding. More insight into the functional consequences of the CHIP mutations may favor personalized risk assessment, not only with regard to malignancies but also in relation to thrombotic vascular disease.

Anagrelide in Essential Thrombocythemia (ET): Results from 150 patients over 25 years by the "Ph1-negative Myeloproliferative Neoplasms Latium Group"

BACKGROUND AND AIMS

Anagrelide is a drug effective in reducing platelet counts in essential thrombocythemia (ET) and Ph1-negative myeloproliferative neoplasms. The aim of this study was to evaluate the real-life use of anagrelide in patients with ET followed over 25 years at the Haematological Institutes belonging to "Ph1-negative Myeloproliferative Neoplasms Latium Group."

PATIENTS AND METHODS

Eligibility criteria were diagnosis of ET and treatment with anagrelide. Data were collected through an ad hoc case report form.

RESULTS

One hundred and fifty patients received anagrelide for a median time of 7.4 years (0.1-23.2). Anagrelide was administered as first-line therapy in 34.7% of patients, as second-line in 52% and as third-line in 13.3%: 85.4% responded to therapy. Sixty-eight/136 evaluable patients reported side effects: palpitations, peripheral vasodilation, anaemia, diarrhoea and gastric distress. Fourteen thrombotic (arterial 10, venous 4) and 51 bleeding events (minor 48, major 3) occurred. Sixteen/150 (10.6%) patients developed secondary myelofibrosis and 3/150 (2%) an acute myeloid leukaemia.

CONCLUSIONS

In our experience, anagrelide is an effective drug in reducing platelet levels in a high percentage of patients with ET. It is especially addressed to younger people. A careful assessment of the thrombotic risk and monitoring of cardiac function, at diagnosis and during follow-up, is mandatory.