The effect of arterial hypertension on thrombosis in low-risk polycythemia vera

DNMT3A/TET2/ASXL1 Mutations are an Age-independent Thrombotic Risk Factor in Polycythemia Vera Patients: An Observational Study

BACKGROUND

 Polycythemia vera (PV) patients are classified as high or low thrombotic risk based on age and prior history of thrombosis. Despite adherence to treatment recommendations, vascular events remain frequent, leading us to question whether thrombotic risk stratification could be improved. We previously reported an association between thrombotic events and mutations in DTA genes (DNMT3A, TET2, and ASXL1). The objective of this study was to confirm this observation in a larger series of PV patients.

METHODS

 PV patients with a minimum follow-up of 3 years were recruited from 8 European centers. Medical history was searched for thrombotic event recorded at any time and next-generation sequencing carried out with a myeloid panel. Multivariable logistic regression evaluated the impact of variables on thrombotic risk. Kaplan-Meier thrombosis-free survival curves were compared by the log rank test. Associations in the total cohort were confirmed in a case-control study to exclude selection bias.

RESULTS

 Of the 136 patients recruited, 74 (56.1%) had a thrombotic event, with an incidence density of 2.83/100 person-years. In multivariable analysis, DTA mutation was a risk factor for thrombotic event, being predictive for shorter thrombosis-free survival in the whole cohort (p = 0.007), as well as in low-risk patients (p = 0.039) and older patients (p = 0.009), but not for patients with a prediagnostic event. A gender- and age-matched case-control study confirmed the increased risk of thrombotic event for PV patients with a DTA mutation.

CONCLUSION

 Our results support the use of molecular testing at diagnosis to help predict which PV patients are at higher risk of developing thrombosis.

Diagnosis and Management of Cardiovascular Risk in Patients with Polycythemia Vera

Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by aberrant myeloid lineage hematopoiesis with excessive red blood cell and pro-inflammatory cytokine production. Patients with PV present with a range of thrombotic and hemorrhagic symptoms that affect quality of life and reduce overall survival expectancy. Thrombotic events, transformation into acute myeloid leukemia, and myelofibrosis are largely responsible for the observed mortality. Treatment of PV is thus primarily focused on symptom control and survival extension through the prevention of thrombosis and leukemic transformation. Patients with PV frequently experience thrombotic events and have elevated cardiovascular risk, including hypertension, dyslipidemias, obesity, and smoking, all of which negatively affect survival. To reduce the risk of thrombotic complications, PV therapy should aim to normalize hemoglobin, hematocrit, and leukocytosis and, in addition, identify and modify cardiovascular risk factors. Herein, we review what is currently known about the associated cardiovascular risk and propose strategies for diagnosing and managing patients with PV.

Renin-angiotensin inhibitors reduce thrombotic complications in Essential Thrombocythemia and Polycythemia Vera patients with arterial hypertension

Essential Thrombocythemia (ET) and Polycythemia Vera (PV) are chronic myeloproliferative neoplasms (MPNs) characterized by thrombotic and hemorrhagic complications, leading to a high risk of disability and mortality. Although arterial hypertension was found to be the most significant modifiable cardiovascular (CV) risk factor in the general population, little is known about its role in MPNs as well as a possible role of renin-angiotensin system inhibitors (RASi) in comparison with other anti-hypertensive treatments. We investigated a large cohort of 404 MPN adult patients, 133 diagnosed with PV and 271 with ET. Over half of the patients (53.7%) reported hypertension at MPN diagnosis. The 15-year cumulative incidence of thrombotic-adverse events (TAEs) was significantly higher in patients with hypertension (66.8 ± 10.3% vs 38.5 ± 8.4%; HR = 1.83; 95%CI 1.08-3.1). Multivariate analysis showed that PV diagnosis and hypertension were independently associated with a higher risk of developing TAEs (HR = 3.5; 95%CI 1.928-6.451, p < 0.001 and HR = 1.8; 95%CI 0.983-3.550, p = 0.05, respectively). In multivariate analysis, the diagnosis of PV confirmed a significant predictive role in developing TAEs (HR = 4.4; 95%CI 1.92-10.09, p < 0.01), also considering only MPN patients with hypertension. In addition, we found that the use of RASi showed a protective effect from TAEs both in the whole cohort of MPN with hypertension (HR = 0.46; 95%CI 0.21-0.98, p = 0.04) and in the subgroup of thrombotic high-risk score patients (HR = 0.49; 95%CI 0.24-1.01, p = 0.04). In particular, patients with ET and a high risk of thrombosis seem to benefit most from RASi treatment (HR = 0.27; 95%CI 0.07-1.01, p = 0.03). Hypertension in MPN patients represents a significant risk factor for TAEs and should be adequately treated.

Polycythemia vera: 2024 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Polycythemia vera (PV) is a JAK2-mutated myeloproliferative neoplasm characterized by clonal erythrocytosis; other features include leukocytosis, thrombocytosis, splenomegaly, pruritus, constitutional symptoms, microcirculatory disturbances, and increased risk of thrombosis and progression into myelofibrosis (post-PV MF) or acute myeloid leukemia (AML).

DIAGNOSIS

A working diagnosis is considered in the presence of a JAK2 mutation associated with hemoglobin/hematocrit levels of >16.5 g/dL/49% in men or 16 g/dL/48% in women; morphologic confirmation by bone marrow examination is advised but not mandated.

CYTOGENETICS

Abnormal karyotype is seen in 15%-20% of patients with the most frequent sole abnormalities being +9 (5%), loss of chromosome Y (4%), +8 (3%), and 20q- (3%).

MUTATIONS

Over 50% of patients harbor DNA sequence variants/mutations other than JAK2, with the most frequent being TET2 (18%) and ASXL1 (15%). Prognostically adverse mutations include SRSF2, IDH2, RUNX1, and U2AF1, with a combined incidence of 5%-10%.

SURVIVAL AND PROGNOSIS

Median survival is ⁓15 years but exceeds 35 years for patients aged ≤40 years. Risk factors for survival include older age, leukocytosis, abnormal karyotype, and the presence of adverse mutations. Twenty-year risk for thrombosis, post-PV MF, or AML are ⁓26%, 16% and 4%, respectively.

RISK FACTORS FOR THROMBOSIS

Two risk categories are considered: high (age >60 years or thrombosis history) and low (absence of both risk factors). Additional predictors for arterial thrombosis include cardiovascular risk factors and for venous thrombosis higher absolute neutrophil count and JAK2V617F allele burden.

TREATMENT

Current goal of therapy is to prevent thrombosis. Periodic phlebotomy, with a hematocrit target of <45%, combined with once- or twice-daily aspirin (81 mg) therapy, absent contraindications, is the backbone of treatment in all patients, regardless of risk category. Cytoreductive therapy is reserved for high-risk disease with first-line drugs of choice being hydroxyurea and pegylated interferon-α and second-line busulfan and ruxolitinib. In addition, systemic anticoagulation is advised in patients with venous thrombosis history.

ADDITIONAL TREATMENT CONSIDERATIONS

At the present time, we do not consider a drug-induced reduction in JAK2V617F allele burden, which is often incomplete and seen not only with peg-IFN but also with ruxolitinib and busulfan, as an indicator of disease-modifying activity, unless accompanied by cytogenetic and independently-verified morphologic remission. Accordingly, we do not use the specific parameter to influence treatment choices. The current review also includes specific treatment strategies in the context of pregnancy, splanchnic vein thrombosis, pruritus, perioperative care, and post-PV MF.

Polycythemia vera disease profile in an African population-experience from a tertiary facility in Ghana

Objectives

The study describes the clinical and laboratory profile of the patients with polycythemia vera at Komfo Anokye Teaching Hospital in Kumasi, Ghana.

Methods and design

This was a retrospective hospital-based cohort study conducted from September 2020 to August 2022. Hematology clinic entry book was used to identify the patient's unique hospital code. Using these unique codes, retrospective data were collected using an Excel spreadsheet from the Hospital Lightwave health information management system (LHIMS) database.

Results

A total of 20 participants were recruited over the period of 2 years. The overall mean age was 51.53 ± 16.39 years. The hematological profile of the male participants revealed a mean hemoglobin of 18.25 ± 1.373 g/dl, mean hematocrit of 52 ± 3.47%, and a mean platelet of 345.5 ± 180.82. Comparatively, the mean hemoglobin, hematocrit, and platelet for the female participants were higher with figures of 19.26 ± 1.43 g/dl, 53 ± 3.61%, and 816 ± 935.32, respectively. Headache, tiredness, numbness, splenomegaly, and abnormal labs were the most common reasons why participants sought medical attention. Majority (60%) of the study participants had Janus Kinase 2 mutation. New-onset hypertension was identified in 45% of the study participants during follow-up. Thromboembolism was seen in 10% of the study population.

Conclusion

Polycythemia vera is an uncommon disease in Ghana mostly found in older males above 50 years. It is important to recognize it early to initiate therapy aimed at preventing common complications such as hypertension and thromboembolism. Polycythemia vera should be considered a differential diagnosis for patients with secondary hypertension.

Identifying Patients with Polycythemia Vera at Risk of Thrombosis after Hydroxyurea Initiation: The Polycythemia Vera-Advanced Integrated Models (PV-AIM) Project

Patients with polycythemia vera (PV) are at significant risk of thromboembolic events (TE). The PV-AIM study used the Optum® de-identified Electronic Health Record dataset and machine learning to identify markers of TE in a real-world population. Data for 82,960 patients with PV were extracted: 3852 patients were treated with hydroxyurea (HU) only, while 130 patients were treated with HU and then changed to ruxolitinib (HU-ruxolitinib). For HU-alone patients, the annualized incidence rates (IR; per 100 patients) decreased from 8.7 (before HU) to 5.6 (during HU) but increased markedly to 10.5 (continuing HU). Whereas for HU-ruxolitinib patients, the IR decreased from 10.8 (before HU) to 8.4 (during HU) and was maintained at 8.3 (after switching to ruxolitinib). To better understand markers associated with TE risk, we built a machine-learning model for HU-alone patients and validated it using an independent dataset. The model identified lymphocyte percentage (LYP), neutrophil percentage (NEP), and red cell distribution width (RDW) as key markers of TE risk, and optimal thresholds for these markers were established, from which a decision tree was derived. Using these widely used laboratory markers, the decision tree could be used to identify patients at high risk for TE, facilitate treatment decisions, and optimize patient management.

Primary Arterial Hypertension and Drug-Induced Hypertension in Philadelphia-Negative Classical Myeloproliferative Neoplasms: A Systematic Review

The impact of primary arterial hypertension (HTN) in myeloproliferative neoplasms (MPNs) remains unclear, with scant literature available, mostly focusing on cardiovascular risk factors as a singular entity or on organ-specific HTN. Furthermore, available studies reporting findings on drug-induced HTN in MPNs report varying and contradictory findings. In consideration of the above, this study set out to systematically review the available literature and shed light on the occurrence of HTN in MPNs, its association with thrombosis, as well as the drugs used in MPN management that could increase blood pressure. The literature search yielded 598 potentially relevant records of which 315 remained after the duplicates (n = 283) were removed. After we screened the titles and the abstracts of these publications, we removed irrelevant papers (n = 228) and evaluated the full texts of 87 papers. Furthermore, 13 records did not meet the inclusion criteria and were excluded from the systematic review. Finally, a total of 74 manuscripts were entered into the qualitative synthesis and included in the present systematic review. Our systematic review highlights that HTN is the most common comorbidity encountered in MPNs, with an impact on both the occurrence of thrombosis and survival. Moreover, drug-induced HTN remains a challenge in the management of MPNs. Further research should investigate the characteristics of patients with MPNs and HTN, as well as clarify the contribution of HTN to the development of thrombotic complications, survival and management in MPNs. In addition, the relationship between clonal hematopoiesis of indeterminate potential, HTN, cardiovascular disease and MPNs requires examination in upcoming assessments.

Clinical characteristics of Japanese patients with polycythemia vera: results of the JSH-MPN-R18 study

The presence of a JAK2 V617F or JAK2 exon 12 mutation is one of the three major criteria listed for the diagnosis of polycythemia vera (PV) in the 2017 World Health Organization Classification. However, a nationwide study has not yet been conducted in Japan since the discovery of JAK2 mutations. Therefore, the Japanese Society of Hematology (JSH) retrospectively analyzed the clinical characteristics of 596 Japanese patients with PV diagnosed between April 2005 and March 2018. Among the 473 patients with complete data on JAK2 mutations available, 446 (94.3%) and 10 (2.1%) were positive for the JAK2 V617F and JAK2 exon 12 mutations, respectively. During a median follow-up of 46 months (range: 0-179 months), 47 (7.9%) deaths occurred. The major causes of death were secondary malignancies (23.4%), acute leukemia (12.8%), non-leukemic progressive disease (10.6%) and thrombotic (6.4%) and hemorrhagic complications (6.4%). Thrombotic and hemorrhagic events occurred during the clinical course in 4.0% (n = 24) and 3.5% (n = 21) of patients, respectively. These results show that the international PV prognostic score (age, venous thrombosis and leukocytosis) is applicable to Japanese patients with PV.

Treatment and Clinical Endpoints in Polycythemia Vera: Seeking the Best Obtainable Version of the Truth

Polycythemia vera (PV) is a Philadelphia chromosome-negative myeloproliferative neoplasm driven by the JAK2 V617F (or rarely exon 12) mutation. Its natural history can extend over a few decades, and therefore treatment planning is predicated on continual re-assessment of traditional risk features (age, prior thrombosis) to evaluate the need for cytoreduction besides foundational therapy with low-dose aspirin and stringent phlebotomy. Shorter- and longer-term patient goals should be considered in light of several variables such as co-morbid conditions (especially cardiovascular risk factors), disease symptoms, and the risk-benefit profile of available drugs. While hydroxyurea has been the pro forma choice of cytoreduction for many practitioners over the last half-century, the more recent regulatory approvals of ruxolitinib and ropeginterferon-alfa-2b, based on phase 3 randomized trials, highlight an expanding portfolio of active drugs. Obtaining high-level evidence for short-term clinical trial endpoints such as hematocrit control, symptom burden/quality of life, splenomegaly, and JAK2 V617F allele burden lies within the timeline of most studies. However, in many cases, it may not be possible to adequately power trials to capture significant differences in the typically low event rates of thrombosis, as well as longer-horizon endpoints such as evolution to myelofibrosis and acute myeloid leukemia, and survival. This Perspective highlights the challenges of addressing these data gaps and outstanding questions in the emerging treatment landscape of PV.

Polycythemia vera: historical oversights, diagnostic details, and therapeutic views

Polycythemia vera (PV) is a relatively indolent myeloid neoplasm with median survival that exceeds 35 years in young patients, but its natural history might be interrupted by thrombotic, fibrotic, or leukemic events, with respective 20-year rates of 26%, 16%, and 4%. Current treatment strategies in PV have not been shown to prolong survival or lessen the risk of leukemic or fibrotic progression and instead are directed at preventing thrombotic complications. In the latter regard, two risk categories are considered: high (age >60 years or thrombosis history) and low (absence of both risk factors). All patients require phlebotomy to keep hematocrit below 45% and once-daily low-dose aspirin, in the absence of contraindications. Cytoreductive therapy is recommended for high-risk or symptomatic low-risk disease; our first-line drug of choice in this regard is hydroxyurea but we consider pegylated interferon as an alternative in certain situations, including in young women of reproductive age, in patients manifesting intolerance or resistance to hydroxyurea therapy, and in situations where treatment is indicated for curbing phlebotomy requirement rather than preventing thrombosis. Additional treatment options include busulfan and ruxolitinib; the former is preferred in older patients and the latter in the presence of symptoms reminiscent of post-PV myelofibrosis or protracted pruritus. Our drug choices reflect our appreciation for long-term track record of safety, evidence for reduction of thrombosis risk, and broader suppression of myeloproliferation. Controlled studies are needed to clarify the added value of twice- vs once-daily aspirin dosing and direct oral anticoagulants. In this invited review, we discuss our current approach to diagnosis, prognostication, and treatment of PV in general, as well as during specific situations, including pregnancy and splanchnic vein thrombosis.

Arterial Thrombosis in Cancer Patients: An Update

Cancer is associated with an increased incidence of both venous thromboembolism (VTE) and arterial thrombosis (cardiovascular events and ischemic stroke). Cancer-associated arterial thrombotic events are less well studied than VTE, but increasingly recognized, particularly in specific malignancies and in association with specific anticancer therapies. The pathogenesis of arterial thrombotic events in cancer is complex and involves generation of tumor-associated procoagulant factors and a variety of alterations in platelet function as well as in the coagulation and fibrinolytic systems, and endothelial injury and dysfunction, that combine to produce hypercoagulability. The multifactorial interaction between this prothrombotic state, the individual cardiovascular risk, advanced age and presence of comorbidities, and the specific neoplasm characteristics and therapy, may induce the vascular events. Recent studies based on population databases and prospective or retrospective analyses with prolonged follow-up highlight that cancer patients experience an increased (approximately 1.5-2-fold) risk of both cerebrovascular and cardiovascular events compared with noncancer individuals, which peaks in the time period of the diagnosis of cancer but may persist for years. Beyond the type of cancer, the risk reflects the tumor burden, being higher in advanced stages and metastatic cancers. The occurrence of arterial thromboembolic events is also associated with increased overall mortality. We here present an update of the pathophysiology, risk factors, clinical evidence, and treatment considerations on cancer-associated arterial thrombosis, in the light of the need for specific multidisciplinary prevention and surveillance strategies in this setting, in the frame of cardio-oncology approaches.

Polycythemia vera as a rare cause of hypertension in a young man

Polycythemia vera (PV) is an orphan haematological disease and one of the most common myeloproliferative diseases, with the incidence rate of about 0.4-2.8 cases per 100 000 population per year. In patients, proliferation of all three haematopoietic lineages is observed, typically with the development of erythrocytosis. As a rule, PV occurs in patients aged 60-70 years, slightly more often in men. The main clinical signs of PV are weakness, significant burning sensation in fingers and palms due to the increased blood viscosity and microcirculation disorders, discomfort in the left hypochondrium due to splenomegaly at the background of extramedullary haematopoietic sites development, as well as gross vascular complications (thrombosis) of various localisation. Our clinical case represents a rare cardiac manifestation of the PV in a young man.

Polycythemia Vera (PV): Update on Emerging Treatment Options

Polycythemia Vera (PV) is a chronic myeloproliferative neoplasm characterized by exuberant red cell production leading to a broad range of symptoms that compromise quality of life and productivity of patients. PV reduces survival expectation, primarily due to thrombotic events, transformation to blast phase and post-PV myelofibrosis or to development of second cancers, which are associates with poor prognosis. Current therapeutic first line recommendations based on risk adapted classification divided patients into two groups, according to age (< or >60 years) and presence of prior thrombotic events. Low-risk patients (age <60 years and no prior history of thrombosis) should be treated with aspirin (81-100 mg/d) and phlebotomy, to maintain hematocrit <45%. High-risk patients (age >60 years and/or prior history of thrombosis), in addition to aspirin and phlebotomies, should receive cytoreductive therapy in order to reduce thrombotic risk. Nowadays hydroxyurea still remains the cytoreductive agent of first choice, reserving Interferon to young patients or childbearing women. During the last years, ruxolitinib emerged as a new treatment in PV patients, as second line therapy: it appeared especially effective in patients with severe pruritus, symptomatic splenomegaly, or post-PV myelofibrosis symptoms. Currently, in PV treatment, several molecules have been tested or are under investigation. At present, the drug that has shown the most encouraging results is givinostat.

Impact of comorbidities and body mass index on the outcome of polycythemia vera patients

In 816 patients with 2016 World Health Organization-defined polycythemia vera (PV) enrolled in a multicenter retrospective study, we investigated the predictive value of Charlson comorbidity index (CCI) and body mass index (BMI) on thrombosis, progression to post-PV myelofibrosis (PPV-MF) and survival. Patients were subgrouped according to CCI = 0 (58.1%, no comorbidities) or CCI ≥ 1 (41.9%) and according to normal/underweight (BMI < 25, 54.5%) or overweight/obesity (BMI ≥ 25, 45.5%) at PV diagnosis. BMI was available for 529 patients. Patients with CCI ≥ 1 were older and more frequently presented cardiovascular risk factors compared to patients with CCI = 0 (p < 0.001), while overweight/obese patients were more frequently males (p < 0.001). Cumulative incidence of thromboses with death as competing risk was 13.3% at 10 years. Multivariable analysis with death as competing risk showed that previous thromboses (subdistribution hazard ratio [SHR]: 2.1, p = 0.01) and hypertension (SHR: 1.77, p = 0.04) were significantly associated with a higher thrombotic risk, while BMI ≥ 25 lost statistical significance (SHR: 1.69, p = 0.05) and CCI ≥ 1 was excluded after evaluation of goodness of fit. After a median follow-up of 6.1 years, progression to PPV-MF occurred in 44 patients, and 75 patients died. BMI ≥ 25 was associated with a lower probability of progression to PPV-MF (SHR: 0.38, CI95%: 0.15-0.94, p = 0.04) and better survival (hazard ratio [HR]: 0.42, CI95%: 0.18-0.97, p = 0.04). CCI ≥ 1 did not affect progression to PPV-MF (p = 0.44) or survival (p = 0.71).  The evaluation of CCI and BMI may improve the prognostic definition of PV. In patients with hypertension an accurate evaluation of thrombotic risk is warranted.

MPN: The Molecular Drivers of Disease Initiation, Progression and Transformation and their Effect on Treatment

Myeloproliferative neoplasms (MPNs) constitute a group of disorders identified by an overproduction of cells derived from myeloid lineage. The majority of MPNs have an identifiable driver mutation responsible for cytokine-independent proliferative signalling. The acquisition of coexisting mutations in chromatin modifiers, spliceosome complex components, DNA methylation modifiers, tumour suppressors and transcriptional regulators have been identified as major pathways for disease progression and leukemic transformation. They also confer different sensitivities to therapeutic options. This review will explore the molecular basis of MPN pathogenesis and specifically examine the impact of coexisting mutations on disease biology and therapeutic options.

New Perspectives on Polycythemia Vera: From Diagnosis to Therapy

Polycythemia vera (PV) is mainly characterized by elevated blood cell counts, thrombotic as well as hemorrhagic predisposition, a variety of symptoms, and cumulative risks of fibrotic progression and/or leukemic evolution over time. Major changes to its diagnostic criteria were made in the 2016 revision of the World Health Organization (WHO) classification, with both hemoglobin and hematocrit diagnostic thresholds lowered to 16.5 g/dL and 49% for men, and 16 g/dL and 48% for women, respectively. The main reason leading to these changes was represented by the recognition of a new entity, namely the so-called “masked PV”, as individuals suffering from this condition have a worse outcome, possibly owing to missed or delayed diagnoses and lower intensity of treatment. Thrombotic risk stratification is of crucial importance to evaluate patients’ prognosis at diagnosis. Currently, patients are stratified into a low-risk group, in the case of younger age (<60 years) and no previous thromboses, and a high-risk group, in the case of patients older than 60 years and/or with a previous thrombotic complication. Furthermore, even though they have not yet been formally included in a scoring system, generic cardiovascular risk factors, particularly hypertension, smoking, and leukocytosis, contribute to the thrombotic overall risk. In the absence of agents proven to modify its natural history and prevent progression, PV management has primarily been focused on minimizing the thrombotic risk, representing the main cause of morbidity and mortality. When cytoreduction is necessary, conventional therapies include hydroxyurea as a first-line treatment and ruxolitinib and interferon in resistant/intolerant cases. Each therapy, however, is burdened by specific drawbacks, underlying the need for improved strategies. Currently, the therapeutic landscape for PV is still expanding, and includes several molecules that are under investigation, like long-acting pegylated interferon alpha-2b, histone deacetylase inhibitors, and murine double minute 2 (MDM2) inhibitors.

Leukocytosis and thrombosis in essential thrombocythemia and polycythemia vera: a systematic review and meta-analysis

In the last years, a growing amount of evidence has been produced regarding the role of leukocytosis as a risk factor for thrombosis in patients with myeloproliferative neoplasms, predominantly in polycythemia vera (PV) and essential thrombocythemia (ET). Results from epidemiologic studies on this issue, however, are inconclusive. We conducted a systematic review and meta-analysis of articles published in the last 12 years addressing the issue, according to a predefined protocol. Forty-one articles analyzing >30 000 patients met our inclusion criteria and were deemed of acceptable methodologic quality. In addition to data on thrombosis, data were collected on bleeding, hematologic evolution, secondary cancer, and death. The relative risk (RR) of thrombosis in the presence of leukocytosis was 1.59 (95% CI, 1.40-1.80), mainly accounted for by ET (RR, 1.65; 95% CI, 1.43-1.91) and arterial thrombosis (RR, 1.45; 95% CI, 1.13-1.86) subgroups; the effect was not significant in venous thrombosis alone. Sensitivity analyses considering recurrent events as well as white blood cell estimates adjusted or unadjusted for confounding factors confirmed the primary results. In addition, the pooled RR of studies that tested white blood cell counts in time-dependent models suggested a causative effect of leukocytes in the mechanism that triggers thrombosis. The effect of leukocytosis on bleeding (RR, 1.87; 95% CI, 1.26-2.77) and death (RR, 1.89; 95% CI, 1.59-2.23) was confirmed, whereas conclusions on hematologic evolutions and solid tumors were uncertain. To confirm the accuracy of these results, an investigation on individual patient data in a large collective archive of homogeneous patients is warranted.

Duration of neonatal oxygen supplementation, erythropoiesis and blood pressure in young adults born preterm

BACKGROUND

Although erythropoiesis is impaired and anaemia frequent in neonates born preterm, haematopoiesis in adults born preterm has not been previously studied.

OBJECTIVE

We, thus, aimed to evaluate haemoglobin and erythropoietin levels in young adults born preterm, to identify neonatal events associated with erythropoiesis in adulthood and to examine the relationships of haemoglobin levels with respiratory function and blood pressure.

METHODS

We assessed a cohort of 101 young adults (ages 18-29) born preterm (≤29 weeks of gestation), in comparison to 105 full-term controls. We measured haemoglobin, erythropoietin levels and blood pressure. We also assessed respiratory function using spirometry.

RESULTS

Compared with controls, tobacco use and sex-adjusted haemoglobin levels were 5.3 (95% CI 2.9 to 7.7) g/L higher in preterm-born individuals, but erythropoietin levels were similar. Duration of oxygen supplementation in the neonatal period was independently associated with higher haemoglobin levels in the preterm group. In young adults born preterm with bronchopulmonary dysplasia, airflow limitation was associated with higher haemoglobin levels. Both systolic (SBP) and diastolic (DBP) blood pressure were increased in individuals born preterm (p=0.042 and p=0.0008, respectively). Higher haemoglobin levels were associated with higher SBP and DBP, independently of term or preterm status. Mediation analysis suggests that haemoglobin increase contributes to 37% and 32% of the effect of preterm birth on SBP and DBP, respectively.

CONCLUSIONS

Haemoglobin levels are higher in young adults born preterm, while erythropoietin levels are similar, especially in case of bronchopulmonary dysplasia and airflow limitation, and haemoglobin increase is associated with elevated blood pressure in this population.

From Budd-Chiari syndrome to acquired von Willebrand syndrome: thrombosis and bleeding complications in the myeloproliferative neoplasms

Thrombotic and hemorrhagic complications are prevalent in patients with essential thrombocythemia, polycythemia vera, and myelofibrosis. Given the impact on morbidity and mortality, reducing the risk of thrombosis and/or hemorrhage is a major therapeutic goal. Historically, patients have been risk stratified on the basis of traditional factors, such as advanced age and thrombosis history. However, multiple factors contribute to the thrombotic tendency, including gender, mutational profile, inflammatory stress, and abnormal cell adhesion. Management includes cardiovascular risk reduction and use of antiplatelet therapy, depending on myeloproliferative neoplasm subtype and mutational status. Anticoagulation is a mainstay of therapy for those with venous thrombosis, but practice patterns remain heterogeneous. Cytoreduction is indicated for higher-risk patients, but efficacy may depend on the involved vascular bed. Management of special situations, such as unusual site thrombosis, bleeding, the perioperative period, and pregnancy, are especially challenging. In this article, risk factors and treatment strategies for myeloproliferative neoplasm thrombosis and bleeding, including special situations, are reviewed. Insights gained from recent studies may lead to the development of a more precise risk classification and tailored therapy.

Diurnal rhythm of blood pressure in patients with polycythemia vera

AIMS

Polycythemia vera increases the risk of hypertension, but there is limited information about the effect on daily blood pressure fluctuations. This study aimed to demonstrate how diurnal blood pressure rhythm is affected in polycythemia vera patients.

METHODS

Fifty (50) patients (33 men; mean age 48 ± 15 years) with a diagnosis of polycythemia vera and 51 age and sex-matched healthy subjects for the control group were prospectively evaluated. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were evaluated by ambulatory blood pressure monitoring (ABPM) as average 24-hour, daytime and nighttime measures.

RESULTS

Average 24-hour SBP and DBP, daytime SBP and DBP were similar in both groups. However, nighttime SBP and DBP were significantly higher in the polycythemia vera group compared with the control group (125.3 ± 17.2 and 73.7 ± 12.2 vs. 118.9 ± 12.2 and 69.5 ± 8.5; P = 0.034 and P = 0.044). Both nocturnal SBP fall and nocturnal DBP fall were blunted in the polycythemia vera group compared with the control group (-6.9 ± 8.9 and -11.3 ± 12.2 vs. -11.6 ± 7.7 and -16.3 ± 12.0, respectively). Both hemoglobin and hematocrit levels were positively correlated with nocturnal SBP fall (r = 0.306, P = 0.002 and r = 0.355, P < 0.001; respectively) in all patients.

CONCLUSION

We found that the polycythemia vera group had significantly decreased nocturnal dipping compared with healthy controls. The SBP fall was also positively correlated with hemoglobin and hematocrit levels.

From Budd-Chiari syndrome to acquired von Willebrand syndrome: thrombosis and bleeding complications in the myeloproliferative neoplasms

Thrombotic and hemorrhagic complications are prevalent in patients with essential thrombocythemia, polycythemia vera, and myelofibrosis. Given the impact on morbidity and mortality, reducing the risk of thrombosis and/or hemorrhage is a major therapeutic goal. Historically, patients have been risk stratified on the basis of traditional factors, such as advanced age and thrombosis history. However, multiple factors contribute to the thrombotic tendency, including gender, mutational profile, inflammatory stress, and abnormal cell adhesion. Management includes cardiovascular risk reduction and use of antiplatelet therapy, depending on myeloproliferative neoplasm subtype and mutational status. Anticoagulation is a mainstay of therapy for those with venous thrombosis, but practice patterns remain heterogeneous. Cytoreduction is indicated for higher-risk patients, but efficacy may depend on the involved vascular bed. Management of special situations, such as unusual site thrombosis, bleeding, the perioperative period, and pregnancy, are especially challenging. In this article, risk factors and treatment strategies for myeloproliferative neoplasm thrombosis and bleeding, including special situations, are reviewed. Insights gained from recent studies may lead to the development of a more precise risk classification and tailored therapy.

Thromboembolic events in polycythemia vera

Thromboembolic events and cardiovascular disease are the most prevalent complications in patients with polycythemia vera (PV) compared with other myeloproliferative disorders and are the major cause of morbidity and mortality in this population. Moreover, a vascular complication such as arterial or venous thrombosis often leads to the diagnosis of PV. The highest rates of thrombosis typically occur shortly before or at diagnosis and decrease over time, probably due to the effects of treatment. Important risk factors include age (≥ 60 years old) and a history of thrombosis; elevated hematocrit and leukocytosis are also associated with an increased risk of thrombosis. The goal of therapy is to reduce the risk of thrombosis by controlling hematocrit to < 45%, a target associated with reduced rates of cardiovascular death and major thrombosis. Low-risk patients (< 60 years old with no history of thrombosis) are managed with phlebotomy and low-dose aspirin, whereas high-risk patients (≥ 60 years old and/or with a history of thrombosis) should be treated with cytoreductive agents. Interferon and ruxolitinib are considered second-line therapies for patients who are intolerant of or have an inadequate response to hydroxyurea, which is typically used as first-line therapy. In this review, we discuss factors associated with thrombosis and recent data on current treatments, including anticoagulation, highlighting the need for more controlled studies to determine the most effective cytoreductive therapies for reducing the risk of thrombosis in patients with PV.

Hematological Malignancies and Arterial Thromboembolism

Established guidelines exist for prevention and treatment of venous thromboembolism in hematological malignancies, but none for arterial thromboembolism. However, arterial and venous thromboembolism share the same provoking features—including altered procoagulant factors and defective fibrinolytic system. The morbidity for arterial thromboembolism is increasing in hematological malignancies, with the advent of immunomodulatory and targeted therapy. However, survival rate for hematological malignancy is improving. Consequently, as patients with hematological malignancies live longer, comorbidities including diabetes, hypertension and dyslipidemia, may accentuate arterial thrombosis. Thus far, the scientific literature on prophylaxis and treatment for arterial thromboembolism in hematological malignancies is limited. This review highlights the pathogenesis, incidence and clinical features of arterial thromboembolism in hematological malignancies.

Thrombosis in the Philadelphia Chromosome-Negative Myeloproliferative Neoplasms

The myeloproliferative neoplasms (MPNs) are clonal stem cell-derived diseases. This chapter focuses on the subcategory of Philadelphia (Ph) chromosome-negative classical MPNs, polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF). These MPNs are associated with both microvascular and macrovascular thrombosis, which may occur in the venous and arterial circulation. Erythrocytosis, leukocytosis, and increased JAK2V617F allele burden are known to be risk factors. In this chapter, we review the thrombotic and hemostatic manifestations of the Philadelphia (Ph) chromosome-negative classical MPNs, including the clinical manifestations, the pathophysiology, as well as management.

Chronic myeloproliferative neoplasms in the elderly

This review focuses on the management of elderly patients with chronic myeloid leukemia and chronic myeloproliferative neoplasms, including polycythemia vera, essential thrombocythemia and primary myelofibrosis. Median age in these neoplasms is within the 6th decades of age. All new therapies can be done at any age without absolute contraindication. However, the selection of the precise therapy for the single patient is mandatory. For these reasons, an accurate definition of diagnosis and prognostication is necessary. Precision in disease definition and prognostication is definitively helpful for personalizing therapeutic approach.

Recommendations for the diagnosis and treatment of patients with polycythaemia vera

OBJECTIVES

To present the Central European Myeloproliferative Neoplasm Organisation (CEMPO) treatment recommendations for polycythaemia vera (PV).

METHODS

During meetings held from 2015 through 2017, CEMPO discussed PV and its treatment and recent data.

RESULTS

PV is associated with increased risks of thrombosis/thrombo-haemorrhagic complications, fibrotic progression and leukaemic transformation. Presence of Janus kinase (JAK)-2 gene mutations is a diagnostic marker and standard diagnostic criterion. World Health Organization 2016 diagnostic criteria for PV, focusing on haemoglobin levels and bone marrow morphology, are mandatory. PV therapy aims at managing long-term risks of vascular complications and progression towards transformation to acute myeloid leukaemia and myelodysplastic syndrome. Risk stratification for thrombotic complications guides therapeutic decisions. Low-risk patients are treated first line with low-dose aspirin and phlebotomy. Cytoreduction is considered for low-risk (phlebotomy intolerance, severe/progressive symptoms, cardiovascular risk factors) and high-risk patients. Hydroxyurea is suspected of leukaemogenic potential. IFN-α has demonstrated efficacy in many clinical trials; its pegylated form is best tolerated, enabling less frequent administration than standard interferon. Ropeginterferon alfa-2b has been shown to be more efficacious than hydroxyurea. JAK1/JAK2 inhibitor ruxolitinib is approved for hydroxyurea resistant/intolerant patients.

CONCLUSIONS

Greater understanding of PV is serving as a platform for new therapy development and treatment response predictors.

Risk Factors for and Management of MPN-Associated Bleeding and Thrombosis

PURPOSE OF THE REVIEW

The Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) are characterized by both thrombotic and bleeding complications. The purpose of this review is to describe the risk factors associated with bleeding and thrombosis in MPN, as well as to review prevention strategies and management of these complications.

RECENT FINDINGS

Well-described risk factors for thrombotic complications include older age and history of prior thrombosis, along with traditional cardiovascular and venous thromboembolic risk factors. More recently, JAK2 V617F mutation has been found to carry an increased risk of thrombotic complications, whereas CALR has a lower risk than JAK2 mutation. Factors associated with an increased risk of bleeding in MPN include a prior history of bleeding, acquired von Willebrand syndrome, and primary myelofibrosis. Recent findings suggest that thrombocytosis carries a higher risk of bleeding than thrombosis in MPN, and aspirin may exacerbate this risk of bleeding, particularly in CALR-mutated ET. Much of the management of MPN focuses on predicting risk of bleeding and thrombosis and initiating prophylaxis to prevent complications in those at high risk of thrombosis. Emerging evidence suggests that sub-populations may have bleeding risk that outweighs thrombotic risk, particularly in setting of antiplatelet therapy. Future work is needed to better characterize this balance. At present, a thorough assessment of the risks of bleeding and thrombosis should be undertaken for each patient, and herein, we review risk factors for and management of these complications.

Polycythemia vera treatment algorithm 2018

Recently reported mature survival data have confirmed the favorable prognosis in polycythemia vera (PV), with an estimated median survival of 24 years, in patients younger than age 60 years old. Currently available drugs for PV have not been shown to prolong survival or alter the natural history of the disease and are instead indicated primarily for prevention of thrombosis. Unfortunately, study endpoints that are being utilized in currently ongoing clinical trials in PV do not necessarily target clinically or biologically relevant outcomes, such as thrombosis, survival, or morphologic remission, and are instead focused on components of disease palliation. Even more discouraging has been the lack of critical appraisal from "opinion leaders", on the added value of newly approved drugs. Keeping these issues in mind, at present, we continue to advocate conservative management in low-risk PV (phlebotomy combined with once- or twice-daily aspirin therapy) and include cytoreductive therapy in "high-risk" patients; in the latter regard, our first, second, and third line drugs of choice are hydroxyurea, pegylated interferon-α and busulfan, respectively. In addition, it is reasonable to consider JAK2 inhibitor therapy, in the presence of protracted pruritus or markedly enlarged splenomegaly shown to be refractory to the aforementioned drugs.

What are the current treatment approaches for patients with polycythemia vera and essential thrombocythemia?

Polycythemia vera (PV) and essential thrombocythemia (ET) are chronic myeloproliferative neoplasms that are characterized by thrombohemorrhagic complications, symptom burden, and impaired survival mainly due to thrombosis, progression to myelofibrosis, and transformation to acute leukemia. In this manuscript, we will review the most recent changes in diagnostic criteria, the improvements in risk stratification, and the "state of the art" in the daily management of these disorders. The role of conventional therapies and novel agents, interferon α and the JAK2 inhibitor ruxolitinib, is critically discussed based on the results of a few basic randomized clinical studies. Several unmet needs remain, above all, the lack of a curative approach that might overcome the still burdensome morbidity and mortality of these hematologic neoplasms, as well as the toxicities associated with therapeutic agents.

A reappraisal of the benefit-risk profile of hydroxyurea in polycythemia vera: A propensity-matched study

The use of hydroxyurea (HU) as first line therapy in polycythemia vera (PV) has been criticized because no solid demonstration that this drug prevents thrombosis or prolongs survival has been so far produced. Here we present the outcomes of a large cohort of patients with PV included in the European Collaborative Low-dose Aspirin (ECLAP) study. We selected 1,042 patients who, during the follow-up, had received only phlebotomy (PHL) or HU to maintain the hematocrit level < 45%. To assure comparability, we conducted a propensity score matching analysis. The two groups (PHL n = 342 and HU n = 681) were well balanced for the parameters included in the propensity score (overall balance: χ²  = 2.44, P = 0.964). Over a comparable period of follow-up (PHL = 29.9 vs. HU = 34.7 months), we documented an advantage of HU over PHL consistently significant with respect to the incidence of fatal/non-fatal cardiovascular (CV) events (5.8 vs. 3.0 per 100 person-years in PHL vs. HU group, P = 0.002) and myelofibrosis transformation that was only experienced by patients of PHL group. Evolution to acute leukemia was registered in three patients (two in PHL and one in HU group). The excess of mortality and total CV events in the PHL patients was restricted to the high-risk group, and, compared with HU cases, was significant higher in the PHL patients who failed to reach the hematocrit target < 0.45% (P = 0.000). In conclusion, this analysis provides reliable and qualified estimates of the therapeutic profile of HU and PHL treatments for future experimental studies and for the management of PV in clinical practice.