Cardiovascular events and intensity of treatment in polycythemia vera

Associations between per- and polyfluoroalkyl chemicals and abdominal aortic calcification in middle-aged and older adults

INTRODUCTION

Per- and polyfluoroalkyl substances (PFAS) have infiltrated countless everyday products, raising concerns about potential effects on human health, specifically on the cardiovascular system and the development of abdominal aortic calcification (AAC). However, our understanding of this relationship is still limited.

OBJECTIVES

This study aims to investigate the effects of PFAS on AAC using machine learning algorithms.

METHODS

Leveraging the power of machine learning technique, extreme gradient boosting (XGBoost), we assessed the relationship between PFAS exposure and AAC risk. We focused on three PFAS compounds, perfluorodecanoic acid (PFDeA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) through multiple logistic regression, restricted cubic spline (RCS), and quantile g-computation (QGC) models. To get more insight into the underlying mechanisms, mediation analyses are used to investigate the potential mediating role of fatty acids and blood cell fractions in AAC.

RESULTS

Our findings indicate that elevated serum levels of PFHxS and PFDeA are associated with the increased risk of AAC. The QGC analyses underscore the overall positive association between the PFAS mixture and AAC risk, with PFHxS carrying the greatest weight, followed by PFDeA. The RCS analyses reveal a dose-dependent increase between serum PFHxS concentration and AAC risk in an inverted V-shape way. Moreover, age and PFHxS exposure are identified as the primary factors contributing to abdominal aortic calcification risk in SHapley Additive exPlanation (SHAP) summary plot combined with XGBoost technique. Although PFAS significantly change the profile of fatty acids, we do not find any mediating roles of them in AAC. Despite strong associations between PFAS exposure and hematological indicators, our analysis does not find evidence that these indicators mediate the development of AAC.

CONCLUSIONS

In summary, our study highlights the detrimental impact of PFAS on abdominal aortic health and emphasizes the need for further research to understand the underlying mechanisms involved.

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

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

Cancer-associated thrombosis in hematologic malignancies

Patients with hematologic malignancies are often complicated not only by severe bleeding due to thrombocytopenia and disseminated intravascular coagulation but also by thromboembolic events, just like in patients with solid cancers, and these events can negatively impact patient outcomes. Nevertheless, the prevention and treatment of cancer-associated thrombosis (CAT) in hematologic malignancies has not been adequately investigated due to the limited size, heterogeneity, and unique pathophysiology of the patient population. This article summarizes the current understanding, risk factors, prediction models, and optimal prevention and treatment strategies of CAT in hematologic malignancies on a disease-by-disease basis, including acute leukemia, lymphoma, myeloma, and myeloproliferative neoplasms. Specific considerations of novel molecular targeted therapeutics introduced in recent years, such as immunomodulatory drugs and tyrosine kinase inhibitors, are also discussed based on the latest clinical trials.

Investigation on the relationship between hemoglobin concentration and stroke risk: a bidirectional Mendelian randomization study

Background

The relationship between hemoglobin concentration and stroke has garnered significant interest in the research community. However, findings from published observational epidemiological studies on this relationship have been inconclusive. By using publicly available genome-wide association study (GWAS) aggregated statistics, a two-sample Mendelian randomization analysis is conducted to explore the causal relationship between hemoglobin concentration and stroke.

Methods

Summary statistics data from UK Biobank for hemoglobin concentration and from the FinnGen R9 and MEGASTROKE consortium for stroke are used. A series of quality control steps are taken to select eligible instrumental SNPs closely related to exposure. In order to make the conclusion more robust and reliable, several robust analysis methods are employed including inverse variance weighted, weighted median, MR-Egger regression, which are based on different assumptions of two-sample MR Analysis. Meanwhile, sensitivity analyses such as pleiotropy test and MR-Egg regression, are performed to mitigate horizontal pleiotropy and heterogeneity.

Results

The two-sample Mendelian randomized study indicates a negative association between hemoglobin concentration and stroke, suggesting that hemoglobin concentration acts as a protective factor against stroke. From the FinnGen database, there is a negative association between hemoglobin concentration and stroke, with an odds ratio (OR) of 0.82 and a 95% confidence interval (CI) of 0.73-0.92, p = 0.0006. Similarly, the MEGASTROKE database findings reinforce this observation. The negative association between hemoglobin concentration and stroke (OR: 0.91, 95%CI: 0.83-1.00, p = 0.040), ischemic stroke (OR: 0.87, 95%CI: 0.79-0.96, p = 0.004), and cardiogenic stroke (OR: 0.82, 95% CI: 0.69-0.99, p = 0.039) further suggests that higher hemoglobin levels might confer a protective effect against these conditions.

Conclusion

Hemoglobin concentration serves as a protective factor against stroke, and managing abnormal hemoglobin levels can effectively reduce the incidence of stroke.

Association between elevated white blood cell counts and thrombotic events in polycythemia vera: analysis from REVEAL

ABSTRACT

Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by clonal proliferation of hematopoietic progenitor cells and is associated with an increased risk of thrombotic events (TEs). Established risk factors for TEs in patients with PV include advanced age, TE history, and elevated hematocrit. Although an association of TE with elevated white blood cell (WBC) counts has been suggested by retrospective studies, this relationship needs further validation. The prospective observational study of patients with polycythemia vera in US clinical practices (REVEAL) study collected prospective clinical data from 2510 patients with PV with a median follow-up of 44.7 months (range, 2-59 months) from enrollment. Using time-dependent covariate Cox proportional hazards models, blood counts were individually modeled with sex, age, disease duration, TE history at enrollment (baseline covariates), and treatment (time-dependent covariate). Analysis of 2271 participants identified 142 TEs in 106 patients. Significant associations with initial TE occurrence during the study period were observed for hematocrit level >45% (hazard ratio [HR], 1.84; 95% confidence interval [95% CI], 1.234-2.749; P = .0028) and WBCs >11 × 109/L (HR, 2.35; 95% CI, 1.598-3.465; P < .0001). Elevated WBC count was significantly associated with initial TE occurrence in both low-risk and high-risk PV. When hematocrit was controlled at ≤45%, WBC count >12 × 109/L was significantly associated with TE occurrence (HR, 1.95; 95% CI, 1.066-3.554; P = .0300). The results support incorporation of WBC count into PV risk stratification and studies of treatment strategies, and indicate the importance of controlling both hematocrit and WBC count in disease management. This trial was registered at www.clinicaltrials.gov as #NCT02252159.

Erythrocytosis and CKD

Erythrocytosis or polycythemia is defined as an increase in red blood cell concentration above the age- and sex-specific normal levels. Unlike anemia that is very common in chronic kidney disease (CKD) patients, erythrocytosis is less frequent but requires specific understanding by healthcare professionals in order to provide the best care. Erythrocytosis, especially when undiagnosed and untreated, can lead to serious thrombotic events and higher mortality. Classical causes of erythrocytosis associated with CKD include cystic kidney diseases, kidney or other erythropoietin-secreting neoplasms, high-altitude renal syndrome, overdosage of erythropoietin-stimulating agents, androgen therapy, heavy smoking, chronic lung disease, obstructive sleep apnea, IgA nephropathy, post-kidney transplant erythrocytosis, renal artery stenosis and congenital etiologies. After ruling out the common acquired causes of erythrocytosis, and/or in the presence of suggestive parameters, primary erythrocytosis or polycythemia vera (PV) should be considered and patients screened for JAK2V617F somatic mutation. The newest entity inducing erythrocytosis is linked to the use of sodium-glucose cotransporter-2 (SGLT2) inhibitors that hypothetically activate hypoxia-inducible factor 2-alpha (HIF-2α), and in some cases unmask PV. This review focusses on the pathogenesis, renal manifestations and management of PV, the pathophysiology of erythrocytosis induced by SGLT2 inhibitors and the relevance of timely JAK2 mutation screening in these patients.

Effective Management of Polycythemia Vera With Ropeginterferon Alfa-2b Treatment

Background

Polycythemia vera (PV) is a myeloproliferative neoplasm. Ropeginterferon alfa-2b is a new-generation polyethylene glycol-conjugated proline-interferon. It is approved for the treatment of PV at a starting dose of 100 µg (50 µg for patients receiving hydroxyurea (HU)) and dose titrations up to 500 µg by 50 µg increments. The study was aimed at assessing its efficacy and safety at a higher starting dose and simpler intra-patient dose escalation.

Methods

Forty-nine patients with PV having HU intolerance from major hospitals in China were treated biweekly with an initial dose of 250 µg, followed by 350 µg and 500 µg thereafter if tolerated. Complete hematological response (CHR) was assessed every 12 weeks based on the European LeukemiaNet criteria. The primary endpoint was the CHR rate at week 24. The secondary endpoints included CHR rates at weeks 12, 36 and 52, changes of JAK2V617F allelic burden, time to first CHR, and safety assessments.

Results

The CHR rates were 61.2%, 69.4% and 71.4% at weeks 24, 36, and 52, respectively. Mean allele burden of the driver mutation JAK2V617F declined from 58.5% at baseline to 30.1% at 52 weeks. Both CHR and JAK2V617F allele burden reduction showed consistent increases over the 52 weeks of the treatment. Twenty-nine patients (63.0%) achieved partial molecular response (PMR) and two achieved complete molecular response (CMR). The time to CHR was rapid and median time was 5.6 months according to central lab results. The CHRs were durable and median CHR duration time was not reached at week 52. Mean spleen index reduced from 55.6 cm2 at baseline to 50.2 cm2 at week 52. Adverse events (AEs) were mostly mild or moderate. Most common AEs were reversible alanine aminotransferase and aspartate aminotransferase increases, which were not associated with significant elevations in bilirubin levels or jaundice. There were no grade 4 or 5 AEs. Grade 3 AEs were reversible and manageable. Only one AE led to discontinuation. No incidence of thromboembolic events was observed.

Conclusion

The 250-350-500 µg dosing regimen was well tolerated and effectively induced CHR and MR and managed spleen size increase. Our findings demonstrate that ropeginterferon alfa-2b at this dosing regimen can provide an effective management of PV and support using this dosing regimen as a treatment option.

Analysis of real-world data demonstrating the efficacy of current management of polycythaemia vera in attaining and maintaining therapeutic haematocrit

BACKGROUND

Polycythaemia vera (PV) is a Philadelphia-negative myeloproliferative neoplasm, typically driven by acquired JAK2 mutation and characterised by elevated red cell mass and increased risk of thrombotic events. Patients are managed with phlebotomy to maintain haematocrit (Hct) < 0.45, and patients stratified as 'high risk' for thrombosis are additionally treated with cytoreductive agents to attain this target.

STUDY

This analysis of newly diagnosed JAK2 mutant PV patients (n = 50) over 2 years aimed to determine how effectively patients attained and maintained target Hct according to recommended practice.

CONCLUSIONS

We found that patients spent the majority of time in target Hct range. Findings are supportive of current management guidelines.

Exposure-efficacy and exposure-safety analyses of ropeginterferon alfa-2b treatment in patients with polycythaemia vera

AIMS

To investigate the exposure-response (E-R) relationship, including exposure-efficacy and exposure-safety, of ropeginterferon alfa-2b treatment in patients with polycythaemia vera (PV).

METHODS

Based on the results of the phase II trial A20-202 regarding ropeginterferon alfa-2b in patients with PV, E-R analyses were performed to evaluate the efficacy and safety of the given dosing regimen. The E-R analyses were based on logistic and linear regression and the relationship between exposure to ropeginterferon alfa-2b and key efficacy and safety variables. The key efficacy variables included complete haematologic response (CHR) and reduction of the driver mutation JAK2V617F. The safety variable was treatment-related adverse events (TRAEs).

RESULTS

A clear relationship between the exposure to ropeginterferon alfa-2b and CHR was observed, with an increase in drug exposure resulting in an increased probability of achieving CHR. Similar CHR probabilities were observed in the third and fourth quantiles of the average concentration at Week 24. The results from the exposure-JAK2V617F model indicated that the JAK2V617F allele burden decreased with increasing exposure to ropeginterferon alfa-2b and baseline body surface area. Exposure-safety analysis revealed a risk of AEs associated with transaminase abnormalities, which were not associated with clinical significance.

CONCLUSIONS

Our analyses have shown that patients with PV treated with ropeginterferon alfa-2b had an increased probability of achieving CHR and a molecular response with acceptable safety risks at the 250-350-500 μg titration dosing regimen. This study has provided the relevant data for the application of a biologics licence of ropeginterferon alfa-2b for PV treatment in China.

Chorea and polycythaemia vera

We report two patients with chorea associated with polycythaemia vera, in whom the haematocrit and haemoglobin were within the reference range. Polycythaemia vera is potentially easily treatable and so is important to consider in people developing late-onset chorea.

Significant thrombus in saccular aneurysm in a patient with polycythemia: a case report

BACKGROUND

Morphologically, the risk of aortic aneurysm rupture is mainly evaluated based on its type (e.g., fusiform or saccular) and diameter. Based on the finite element analysis, peak wall stress has been identified as a more sensitive and specific predictor of rupture in recent years. Moreover, in finite analysis, the neck of aneurysm is the highest peak wall stress and is associated with the rupture point.

CASE PRESENTATION

A saccular aortic aneurysm (84 mm) was incidentally detected during preoperative examination for chronic empyema in a 74-year-old male patient with a history of polycythemia. Aortic arch graft replacement using an open stent was performed.

CONCLUSIONS

Morphologically, this case was associated with a very high risk of rupture; nevertheless, it did not rupture. In this case, a mural thrombus (likely formed due to polycythemia) covered the neck of aneurysm that is experiencing the highest peak wall stress and is associated with the rupture point. The mural thrombus decreased peak wall stress and could reduce the risk of rupture even for huge saccular aneurysms. Furthermore, the mural thrombus was fully occupied in aneurysms, such as during coil embolization. Thus, polycythemia could decrease the risk of rupture of huge saccular aneurysms.

Portal Vein Thrombosis: State-of-the-Art Review

Background: Portal vein thrombosis (PVT) is a rare disease with an estimated incidence of 2 to 4 cases per 100,000 inhabitants. The most common predisposing conditions for PVT are chronic liver diseases (cirrhosis), primary or secondary hepatobiliary malignancy, major infectious or inflammatory abdominal disease, or myeloproliferative disorders. Methods: PVT can be classified on the basis of the anatomical site, the degree of venous occlusion, and the timing and type of presentation. The main differential diagnosis of PVT, both acute and chronic, is malignant portal vein invasion, most frequently by hepatocarcinoma, or constriction (typically by pancreatic cancer or cholangiocarcinoma). Results: The management of PVT is based on anticoagulation and the treatment of predisposing conditions. The aim of anticoagulation in acute thrombosis is to prevent the extension of the clot and enable the recanalization of the vein to avoid the development of complications, such as intestinal infarction and portal hypertension. Conclusions: The treatment with anticoagulant therapy favors the reduction of portal hypertension, and this allows for a decrease in the risk of bleeding, especially in patients with esophageal varices. The anticoagulant treatment is generally recommended for at least three to six months. Prosecution of anticoagulation is advised until recanalization or lifelong if the patient has an underlying permanent pro-coagulant condition that cannot be corrected or if there is thrombosis extending to the mesenteric veins.

Idiopathic erythrocytosis: A diagnostic and management challenge with emerging areas for exploration

Despite published algorithms for approaching the work-up of erythrocytosis, a significant proportion of patients are left with uncertainty as to its aetiology and prognosis. The term 'idiopathic erythrocytosis' (IE) is applied when known primary and secondary aetiologies have been ruled out. However, the assignment of secondary aetiologies is not always straightforward or evidence based, which can lead to misdiagnosis and heterogeneity in cohort studies. Furthermore, new studies have identified germline or somatic mutations that may affect prognosis. Epidemiological and cohort data are inconsistent as to whether IE increases the risk for complications such as arterial and venous thromboembolism, clonal transformation or comorbid conditions. Randomized trials assessing the role of phlebotomy for long-term management of IE have not been performed, so treatment remains a vexing problem for clinicians. Standardization of terminology and testing strategies, including comprehensive genetic screening in clinical research, are key to refining our understanding of IE.

SOHO State of the Art Update and Next Questions: Novel Therapies for Polycythemia Vera

In the recent years, landmark advancements in the treatment of polycythemia vera (PV) have been achieved. We witnessed the regulatory approval of ropeginterferon and the advanced clinical development of other novel agents that may affect the underlying pathophysiological mechanisms of the disease. Agents with the potential of disease modification may soon overtake preceding treatment options that were based on the patient's age and history of thrombosis. Recent studies using ropeginterferon in low-risk PV patients earlier in the disease course challenge the current treatment paradigm and shift the focus on modifying the course of the disease. Hepcidin mimetics offer an excellent alternative to phlebotomy, providing better quality of life, and may lead to improved outcomes in PV by tight hematocrit control. Novel agents, such as histone deacetylase inhibitors, hold promise to complement the therapeutic landscape of PV and might be particularly promising in rationale combinations. Ruxolitinib is well established as an approved second-line treatment for PV. In the frontline setting, the precise role of ruxolitinib, which also represents an appealing agent in combination regimens, will be determined in ongoing research studies. Longer follow-up is necessary to assess whether novel agents/regimens elicit fewer thromboembolic/ hemorrhagic events and halt disease progression to myelofibrosis and acute myeloid leukemia. We aspire that disease-modifying approaches in PV are on the horizon, and that we will be empowered to ultimately change the natural course of the disease and profoundly impact the lives of PV patients in the near future.

Ruxolitinib in patients with polycythemia vera resistant and/or intolerant to hydroxyurea: European observational study

BACKGROUND

Hydroxyurea (HU) is a commonly used first-line treatment in patients with polycythemia vera (PV). However, approximately 15%-24% of PV patients report intolerance and resistance to HU.

METHODS

This phase IV, European, real-world, observational study assessed the efficacy and safety of ruxolitinib in PV patients who were resistant and/or intolerant to HU, with a 24-month follow-up. The primary objective was to describe the profile and disease burden of PV patients.

RESULTS

In the 350 enrolled patients, 70% were >60 years old. Most patients (59.4%) had received ≥1 phlebotomy in the 12 months prior to the first dose of ruxolitinib. Overall, 68.2% of patients achieved hematocrit control with 92.3% patients having hematocrit <45% and 35.4% achieved hematologic remission at month 24. 85.1% of patients had no phlebotomies during the study. Treatment-related adverse events were reported in 54.3% of patients and the most common event was anemia (22.6%). Of the 10 reported deaths, two were suspected to be study drug-related.

CONCLUSION

This study demonstrates that ruxolitinib treatment in PV maintains durable hematocrit control with a decrease in the number of phlebotomies in the majority of patients and was generally well tolerated.

Rusfertide, a Hepcidin Mimetic, for Control of Erythrocytosis in Polycythemia Vera

BACKGROUND

Polycythemia vera is a chronic myeloproliferative neoplasm characterized by erythrocytosis. Rusfertide, an injectable peptide mimetic of the master iron regulatory hormone hepcidin, restricts the availability of iron for erythropoiesis. The safety and efficacy of rusfertide in patients with phlebotomy-dependent polycythemia vera are unknown.

METHODS

In part 1 of the international, phase 2 REVIVE trial, we enrolled patients in a 28-week dose-finding assessment of rusfertide. Part 2 was a double-blind, randomized withdrawal period in which we assigned patients, in a 1:1 ratio, to receive rusfertide or placebo for 12 weeks. The primary efficacy end point was a response, defined by hematocrit control, absence of phlebotomy, and completion of the trial regimen during part 2. Patient-reported outcomes were assessed by means of the modified Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) patient diary (scores range from 0 to 10, with higher scores indicating greater severity of symptoms).

RESULTS

Seventy patients were enrolled in part 1 of the trial, and 59 were assigned to receive rusfertide (30 patients) or placebo (29 patients) in part 2. The estimated mean (±SD) number of phlebotomies per year was 8.7±2.9 during the 28 weeks before the first dose of rusfertide and 0.6±1.0 during part 1 (estimated difference, 8.1 phlebotomies per year). The mean maximum hematocrit was 44.5±2.2% during part 1 as compared with 50.0±5.8% during the 28 weeks before the first dose of rusfertide. During part 2, a response was observed in 60% of the patients who received rusfertide as compared with 17% of those who received placebo (P = 0.002). Between baseline and the end of part 1, rusfertide treatment was associated with a decrease in individual symptom scores on the MPN-SAF in patients with moderate or severe symptoms at baseline. During parts 1 and 2, grade 3 adverse events occurred in 13% of the patients, and none of the patients had a grade 4 or 5 event. Injection-site reactions of grade 1 or 2 in severity were common.

CONCLUSIONS

In patients with polycythemia vera, rusfertide treatment was associated with a mean hematocrit of less than 45% during the 28-week dose-finding period, and the percentage of patients with a response during the 12-week randomized withdrawal period was greater with rusfertide than with placebo. (Funded by Protagonist Therapeutics; REVIVE ClinicalTrials.gov number, NCT04057040.).

Ischemic stroke as an initial performance of polycythemia vera in young adults: A case report and literature review

INTRODUCTION

As the second leading cause of death and disability worldwide, stroke is mainly caused by atherosclerosis and cardiac embolism, particularly in older individuals. Nevertheless, in young and otherwise healthy individuals, the causes of stroke can be more diverse and may include conditions such as patent foramen ovale, vasculitis, coagulopathies, genetic factors, or other undetermined causes. Although these other causes of stroke account for a relatively small proportion compared to ischemic stroke, they are becoming increasingly common in clinical practice and deserve attention. Here, we present a rare female patient with polycythemia vera (PV) who was admitted to the hospital as a stroke patient without any previous medical history.

PATIENT CONCERNS

A 40-year-old young woman felt sudden dizziness and slow response. After 4 days of being admitted, she developed blurry vision on the right.

DIAGNOSES

Cranial magnetic resonance imaging revealed aberrant signals in the left temporal and parietal lobe, as well as multiple small focal signal abnormalities were observed in the left frontal lobe. Magnetic resonance angiography revealed partial stenosis of the left internal carotid artery. The patient's blood routine examination revealed a significant elevation in complete blood counts, particularly the increase in red blood cells, as well as prolonged clotting time. An abdominal ultrasound and abdomen computed tomography showed splenomegaly. The outcome of the genetic testing was positive for the Janus kinase JAK2 exon V617F mutation (JAK2/V617F). The patient was diagnosed with PV-related stroke.

INTERVENTIONS

The patient was treated with phlebotomy, cytoreductive therapy, and low-dose aspirin antiplatelet therapy and was regularly followed up in hematology and neurology clinics after discharge.

OUTCOMES

The patient's red blood cell, leukocyte, and thrombocyte counts had fully normalized, with her hemoglobin level measuring at 146 g/L and hematocrit value at 43%. Furthermore, there had been a significant improvement in neurological symptoms.

LESSONS

PV, a rare hematological disorder, can present with ischemic stroke as the initial performance, and the diagnosis mainly relies on routine blood tests, bone marrow biopsies, and genetic test. Therefore, clinicians should pay attention to PV, a low-prevalence disease, when encountering stroke in youth.

Functional hemostatic hydrogels: design based on procoagulant principles

Uncontrolled hemorrhage results in various complications and is currently the leading cause of death in the general population. Traditional hemostatic methods have drawbacks that may lead to ineffective hemostasis and even the risk of secondary injury. Therefore, there is an urgent need for more effective hemostatic techniques. Polymeric hemostatic materials, particularly hydrogels, are ideal due to their biocompatibility, flexibility, absorption, and versatility. Functional hemostatic hydrogels can enhance hemostasis by creating physical circumstances conducive to hemostasis or by directly interfering with the physiological processes of hemostasis. The procoagulant principles include increasing the concentration of localized hemostatic substances or establishing a physical barrier at the physical level and intervention in blood cells or the coagulation cascade at the physiological level. Moreover, synergistic hemostasis can combine these functions. However, some hydrogels are ineffective in promoting hemostasis or have a limited application scope. These defects have impeded the advancement of hemostatic hydrogels. To provide inspiration and resources for new designs, this review provides an overview of the procoagulant principles of hemostatic hydrogels. We also discuss the challenges in developing effective hemostatic hydrogels and provide viewpoints.

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

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

Exploring the Molecular Aspects of Myeloproliferative Neoplasms Associated with Unusual Site Vein Thrombosis: Review of the Literature and Latest Insights

Myeloproliferative neoplasms (MPNs) are the leading causes of unusual site thrombosis, affecting nearly 40% of individuals with conditions like Budd-Chiari syndrome or portal vein thrombosis. Diagnosing MPNs in these cases is challenging because common indicators, such as spleen enlargement and elevated blood cell counts, can be obscured by portal hypertension or bleeding issues. Recent advancements in diagnostic tools have enhanced the accuracy of MPN diagnosis and classification. While bone marrow biopsies remain significant diagnostic criteria, molecular markers now play a pivotal role in both diagnosis and prognosis assessment. Hence, it is essential to initiate the diagnostic process for splanchnic vein thrombosis with a JAK2 V617F mutation screening, but a comprehensive approach is necessary. A multidisciplinary strategy is vital to accurately determine the specific subtype of MPNs, recommend additional tests, and propose the most effective treatment plan. Establishing specialized care pathways for patients with splanchnic vein thrombosis and underlying MPNs is crucial to tailor management approaches that reduce the risk of hematological outcomes and hepatic complications.

Red Blood Cell Contribution to Thrombosis in Polycythemia Vera and Essential Thrombocythemia

Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms (MPN) characterized by clonal erythrocytosis and thrombocytosis, respectively. The main goal of therapy in PV and ET is to prevent thrombohemorrhagic complications. Despite a debated notion that red blood cells (RBCs) play a passive and minor role in thrombosis, there has been increasing evidence over the past decades that RBCs may play a biological and clinical role in PV and ET pathophysiology. This review summarizes the main mechanisms that suggest the involvement of PV and ET RBCs in thrombosis, including quantitative and qualitative RBC abnormalities reported in these pathologies. Among these abnormalities, we discuss increased RBC counts and hematocrit, that modulate blood rheology by increasing viscosity, as well as qualitative changes, such as deformability, aggregation, expression of adhesion proteins and phosphatidylserine and release of extracellular microvesicles. While the direct relationship between a high red cell count and thrombosis is well-known, the intrinsic defects of RBCs from PV and ET patients are new contributors that need to be investigated in depth in order to elucidate their role and pave the way for new therapeutical strategies.

Differences in Clinical Outcomes Between Hydroxyurea-Resistant and -Intolerant Polycythemia Vera Patients

BACKGROUND

Previous studies have suggested that patients with polycythemia vera (PV) who exhibit hydroxyurea-resistance (HU-R) and -intolerance (HU-I) may have distinct characteristics and clinical outcomes. However, to date, no studies have reported a comparison between these two groups or assessed prognostic factors in these patients.

METHODS

The objective of this study was to evaluate clinical outcomes and identify prognostic factors among PV patients with HU-R or HU-I. We conducted a review of PV patients who received frontline treatment with HU from nine centers and identified 90 patients with HU-R or HU-I.

RESULTS

The cumulative incidence of thrombosis after 7 years of HU-R/I was 21.4%, and the incidence of disease progression was 22.5%. Comparing the HU-R and HU-I groups, the HU-R group had a significantly higher rate of disease progression (36.7% vs. 0.56%, P = 0.009), while there was no significant difference in thrombosis incidence (19.0% vs. 22.9%, P = 0.463). Multivariate analysis revealed that HU-R was an independent prognostic factor for progression-free survival (hazard ratio, 6.27, 95% confidence interval, 1.83-21.47, P = 0.003). Additionally, higher lactate dehydrogenase levels, multiple cardiovascular risk factors, and prior thrombosis were identified as unfavorable predictors of overall survival.

CONCLUSION

These findings suggest that patients with HU-R face a higher risk of hematological transformation, but have a comparable risk of thrombosis to patients with HU intolerance. These distinctions should guide decisions on second-line treatment options and clinical trials involving these patients.

A safety evaluation of ruxolitinib for the treatment of polycythemia vera

INTRODUCTION

Polycythemia Vera (PV) is a chronic myeloproliferative neoplasm hallmarked by deregulated proliferation of hematopoietic stem cells leading to prevalent expansion of red cell mass, increased rate of vascular events, splenomegaly, disease-associated symptoms, and risk of evolution to secondary myelofibrosis and blast phase. PV is pathogenetically associated with autonomously persistent activation of JAK2, which causes overproduction of blood cells and an inflammatory condition responsible for the clinical manifestations of the disease. Extensively supported by preclinical studies, targeting JAK2-dependent signaling represents a rational therapeutic approach to PV, finally leading to the approval of ruxolitinib, a JAK1/2 inhibitor.

AREAS COVERED (LITERATURE RESEARCH)

We analyzed reports of phase 2 and phase 3 trials with ruxolitinib in PV and relevant literature dealing with efficacy and safety aspects, including most recent real-world reports.

EXPERT OPINION

Ruxolitinib is the only JAK2 inhibitor approved for the treatment of PV with well-known efficacy for splenomegaly, symptoms, and potentially reduction of vascular events. The treatment regimen is notably manageable and safe, with the most prevalent side effects primarily encompassing myelosuppression, hyperlipidemia, non-melanoma skin cancer and infections, mainly reactivation of Herpes Zoster. These effects necessitate ongoing surveillance and proactive preventive measures.

The molecular landscape of myeloproliferative neoplasms associated with splanchnic vein thrombosis: Current perspective

BCR::ABL1-negative myeloproliferative neoplasms (MPNs) are classically represented by polycythemia vera, essential thrombocythemia, and primary myelofibrosis. BCR::ABL1-negative MPNs are significantly associated with morbidity and mortality related to an increased risk of thrombo-hemorrhagic events. They show a consistent association with splanchnic vein thrombosis (SVT), either represented by the portal, mesenteric or splenic vein thrombosis, or Budd-Chiari Syndrome. SVT is also a frequent presenting manifestation of MPN. MPNs associated with SVT show a predilection for younger women, high association with JAK2V617F mutation, low JAK2V617F variant allele frequency (generally <10 %), and low rates of CALR, MPL, or JAK2 exon 12 mutations. Next-Generation Sequencing techniques have contributed to deepening our knowledge of the molecular landscape of such cases, with potential diagnostic and prognostic implications. In this narrative review, we analyze the current perspective on the molecular background of MPN associated with SVT, pointing as well future directions in this field.

A comparison between erythrocytapheresis and venesection for the treatment of JAK2-mutated polycythaemia

BACKGROUND

JAK2-mutated polycythaemia vera (PV) is associated with reduced survival because of thrombotic events and haematological disease transformation. Therapeutic venesection has traditionally been used to lower haematocrit, but the technique of erythrocytapheresis has emerged over the last decade.

AIM

To compare erythrocytapheresis with venesection as treatment for PV by assessing medical efficacy and financial viability.

METHODS

One hundred sixteen patients with PV who received red cell depletion therapy at Barwon Health between 2014 and 2021 were identified. The haematocrit drop after each session, interval between treatment times and number of sessions required to achieve a haematocrit <0.45 were compared with an independent t test. Thrombosis rates were compared with Pearson's chi-squared test. Cost-funding analysis was done by assessing the Weighted Inlier Equivalent Separation and National Weighted Activity Unit funding models.

RESULTS

Patients treated with erythrocytapheresis achieved a greater haematocrit drop each treatment session (0.075 vs 0.03, P < 0.01), required fewer sessions to achieve a haematocrit <0.45 (1 vs 4, P < 0.01) and experienced fewer thrombotic complications (8.7% vs 32.1%, P = 0.02) than those treated with venesection. Cost-funding analysis demonstrated that erythrocytapheresis was more financially viable with a surplus of AU$297 per session compared to a deficit of AU$176 with venesection. Even if funding for venesection is increased, the cost of erythrocytapheresis may be mitigated by a lower number of procedures required per year (3.8 vs 5.3, P < 0.01).

CONCLUSIONS

Erythrocytapheresis is more efficacious than venesection for the treatment of PV and is accompanied by rapid reductions in haematocrit and reduced thrombotic complications.

Polycythemia Vera: Barriers to and Strategies for Optimal Management

Polycythemia vera (PV) is a subtype of myeloproliferative neoplasms characterized by impaired quality of life and severe complications. Despite the increasingly in-depth knowledge of this condition, it necessitates a multifaceted management approach to mitigate symptoms and prevent thrombotic and hemorrhagic events, ensuring prolonged survival. The therapeutic landscape has been revolutionized in recent years, where venesection and hydroxycarbamide associated with antiplatelet therapy have a central role and are now accompanied by other drugs, such as interferon and Janus kinase inhibitors. Ongoing research and advancements in targeted therapies hold promise for further enhancing the therapeutic choice for PV management.

Management of classical Philadelphia chromosome-negative myeloproliferative neoplasms in Asia: consensus of the Asian Myeloid Working Group

Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized clinically by the proliferation of one or more hematopoietic lineage(s). The classical Philadelphia-chromosome (Ph)-negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The Asian Myeloid Working Group (AMWG) comprises representatives from fifteen Asian centers experienced in the management of MPN. This consensus from the AMWG aims to review the current evidence in the risk stratification and treatment of Ph-negative MPN, to identify management gaps for future improvement, and to offer pragmatic approaches for treatment commensurate with different levels of resources, drug availabilities and reimbursement policies in its constituent regions. The management of MPN should be patient-specific and based on accurate diagnostic and prognostic tools. In patients with PV, ET and early/prefibrotic PMF, symptoms and risk stratification will guide the need for early cytoreduction. In younger patients requiring cytoreduction and in those experiencing resistance or intolerance to hydroxyurea, recombinant interferon-α preparations (pegylated interferon-α 2A or ropeginterferon-α 2b) should be considered. In myelofibrosis, continuous risk assessment and symptom burden assessment are essential in guiding treatment selection. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) in MF should always be based on accurate risk stratification for disease-risk and post-HSCT outcome. Management of classical Ph-negative MPN entails accurate diagnosis, cytogenetic and molecular evaluation, risk stratification, and treatment strategies that are outcome-oriented (curative, disease modification, improvement of quality-of-life).

Moving toward disease modification in polycythemia vera

Polycythemia vera (PV) belongs to the BCR-ABL1-negative myeloproliferative neoplasms and is characterized by activating mutations in JAK2 and clinically presents with erythrocytosis, variable degrees of systemic and vasomotor symptoms, and an increased risk of both thromboembolic events and progression to myelofibrosis and acute myeloid leukemia (AML). Treatment selection is based on a patient's age and a history of thrombosis in patients with low-risk PV treated with therapeutic phlebotomy and aspirin alone, whereas cytoreductive therapy with either hydroxyurea or interferon alfa (IFN-α) is added for high-risk disease. However, other disease features such as significant disease-related symptoms and splenomegaly, concurrent thrombocytosis and leukocytosis, or intolerance of phlebotomy can constitute an indication for cytoreductive therapy in patients with otherwise low-risk disease. Additionally, recent studies demonstrating the safety and efficacy (ie, reduction in phlebotomy requirements and molecular responses) of ropegylated IFN-α2b support its use for patients with low-risk PV. Additionally, emerging data suggest that early treatment is associated with higher rates of molecular responses, which might eventually enable time-limited therapy. Nonetheless, longer follow-up is needed to assess whether molecular responses associate with clinically meaningful outcome measures such as thrombosis and progression to myelofibrosis or AML. In this article, we provide an overview of the current and evolving treatment landscape of PV and outline our vision for a patient-centered, phlebotomy-free, treatment approach using time-limited, disease-modifying treatment modalities early in the disease course, which could ultimately affect the natural history of the disease.

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.

Current therapies for classic myeloproliferative neoplasms: A focus on pathophysiology and supportive care

PURPOSE

This article concisely evaluates current therapies that have received regulatory approval for the treatment of classic myeloproliferative neoplasms (MPNs). Pertinent pathophysiology and supportive care are discussed. Emerging therapies are also briefly described.

SUMMARY

MPNs are a heterogeneous group of diseases characterized by acquired abnormalities of hematopoietic stem cells (HSCs), resulting in the generation of transformed myeloid progenitor cells that overproduce mature and immature cells within the myeloid lineage. Mutations in JAK2 and other driver oncogenes are central to the genetic variability of these diseases. Cytoreductive therapies such as hydroxyurea, anagrelide, interferon, and therapeutic phlebotomy aim to lower the risk of thrombotic events without exposing patients to an increased risk of leukemic transformation. However, no comparisons can be made between these therapies, as reduction of thrombotic risk has not been used as an endpoint. On the other hand, Janus kinase (JAK) inhibitors such as ruxolitinib, fedratinib, pacritinib, and momelotinib (an investigational agent at the time of writing) directly target the constitutively activated JAK-signal transducer and activator of transcription (JAK-STAT) pathway of HSCs in the bone marrow. Mutations of genes in the JAK-STAT signaling pathway provide a unifying understanding of MPNs, spur therapeutic innovations, and represent opportunities for pharmacists to optimize mitigation strategies for both disease-related and treatment-related adverse effects.

CONCLUSION

Treatment options for MPNs span a wide range of disease mechanisms. The growth of targeted therapies holds promise for expanding the treatment arsenal for these rare, yet complex diseases and creates opportunities to optimize supportive care for affected patients.

Philadelphia chromosome-negative myeloproliferative chronic neoplasms: is clonal hematopoiesis the main determinant of autoimmune and cardio-vascular manifestations?

In this article, we reviewed the possible mechanisms linking the clonal hematopoiesis of indeterminate potential (CHIP) to chronic myeloproliferative neoplasms (MPNs), autoimmune diseases (ADs), and cardiovascular diseases (CADs). CHIP is characterized by the presence of clonal mutations with an allelic frequency >2% in the peripheral blood without dysplasia, overt hematological neoplasms, or abnormalities in blood cell count. The prevalence may reach 20% of elderly healthy individuals and is considered a risk factor for myelodysplastic neoplasms and acute leukemia. In MPNs, CHIP is often associated with mutations such as JAK2V617F or DNMT3A, TET2, or ASXL1, which exhibit a 12.1- and 1.7-2-fold increase in CADs. Specifically, JAK2-mutated cells produce excessive cytokines and reactive oxygen species, leading to proinflammatory modifications in the bone marrow microenvironment. Consequently, the likelihood of experiencing thrombosis is influenced by the variant allele frequency (VAF) of the JAK2V617F mutation, which also appears to be correlated with anti-endothelial cell antibodies that sustain thrombosis. However, DNMT3A mutations induce pro-inflammatory T-cell polarization and activate the inflammasome complex, while TET2 downregulation leads to endothelial cell autophagy and inflammatory factor upregulation. As a result, in patients with TET2 and DNMT3A-related CHIP, the inflammasome hyperactivation represents a potential cause of CADs. CHIP also occurs in patients with large and small vessel vasculitis, while ADs are more frequently associated with MPNs. In these diseases, monocytes and neutrophils play a key role in the formation of neutrophil extracellular trap (NET) as well as anti-endothelial cell antibodies, resulting in a final procoagulant effect. ADs, such as systemic lupus erythematosus, psoriasis, and arthritis, are also characterized by an overexpression of the Rho-associated coiled-coil containing protein kinase 2 (ROCK2), a serine/threonine kinase that can hyperactivate the JAK-STAT pathway. Interestingly, hyperactivation of ROCK2 has also been observed in myeloid malignancies, where it promotes the growth and survival of leukemic cells. In summary, the presence of CHIP, with or without neoplasia, can be associated with autoimmune manifestations and thrombosis. In the presence of these manifestations, it is necessary to consider a "disease-modifying therapy" that may either reduce the clonal burden or inhibit the clonally activated JAK pathway.

Survey on the usage of therapeutic erythrocytapheresis in transfusion services in Italy for the treatment of polycythemia vera, secondary erythrocytosis and hemochromatosis

INTRODUCTION

Erythrocytapheresis, an apheresis treatment which selectively removes red blood cells, is an alternative to therapeutic phlebotomy, over which it has several advantages. Actually there is a high degree of variability in the use of this treatment. This prompted SIdEM (Italian Society of Hemapheresis and Cell Manipulation) to conduct a survey on the use of erythrocytapheresis in the Italian Transfusion Services. The purpose is to monitor this activity in the treatment of Polycythemia Vera (pv), secondary erythrocytosis and hemochromatosis.

MATERIALS AND METHODS

A data collection file was sent to the SIdEM regional delegates who, in turn, involved the Transfusion Centers in the areas they cover. The data collected were processed on a Microsoft Excel spreadsheet.

RESULTS

75 centers from 14 Italian regions responded to the Survey: 36 centers (48 %) use erythrocytapheresis (35 centers perform therapeutic apheresis and 1 center only donor apheresis), 39 centers (52 %) do not (15 centers perform therapeutic apheresis, 18 centers only donor apheresis and 6 centers do not perform either therapeutic apheresis or donor apheresis). Although most centers have a substantially uniform attitude concerning the indications for which erythrocytapheresis is used, the survey shows that there are still differences more evident in the treatment of secondary erythrocytosis than in the treatment of pv or hemochromatosis.

CONCLUSIONS

This survey has been useful to document the current Italian reality and to raise awareness about the need for improvement in optimizing and standardizing the use of a therapy with a great potential to exploit properly.

Real-World Clinical Characterisation of Polycythaemia Vera Patients from a Prospective Registry in Portugal: Is Resistance to Hydroxyurea a Reality?

Patients with polycythaemia vera (PV) are at increased risk of thrombosis and haemorrhages. Although hydroxyurea (HU) has been the frontline therapy for patients at high risk of vascular complications, about 25% of patients develop resistance/intolerance to this therapy. The aim of this non-interventional, multicentre cohort study was to understand the clinical characteristics and HU treatment response of Portuguese PV patients. HU resistance/intolerance was defined according to adjusted European LeukemiaNet (ELN) criteria. In total, 134 PV patients with a mean (SD) disease duration of 4.8 (5.0) years were included and followed up for 2 years. At baseline, most patients were ≥60 years old (83.2%), at high risk for thrombotic events (87.2%), and receiving HU therapy (79.1%). A total of 10 thrombotic events and 8 haemorrhagic events were reported, resulting in a 5-year probability of thrombo-haemorrhagic events of 17.2%. Haematocrit (p = 0.007), haemoglobin (p = 0.012) and MPN10 symptom score (12.0 (11.6) vs. 10.3 (9.1); p = 0.041) decreased significantly at the 24-month visit compared to baseline. Overall, 75.9% of patients met at least one of the adjusted ELN criteria for HU resistance, and 14.4% of patients remained on HU throughout the study. The results from this real-world study may help identify the subset of patients at higher risk for disease sequelae who may benefit from earlier second-line treatment.

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.

Normal and dysregulated crosstalk between iron metabolism and erythropoiesis

Erythroblasts possess unique characteristics as they undergo differentiation from hematopoietic stem cells. During terminal erythropoiesis, these cells incorporate large amounts of iron in order to generate hemoglobin and ultimately undergo enucleation to become mature red blood cells, ultimately delivering oxygen in the circulation. Thus, erythropoiesis is a finely tuned, multifaceted process requiring numerous properly timed physiological events to maintain efficient production of 2 million red blood cells per second in steady state. Iron is required for normal functioning in all human cells, the erythropoietic compartment consuming the majority in light of the high iron requirements for hemoglobin synthesis. Recent evidence regarding the crosstalk between erythropoiesis and iron metabolism sheds light on the regulation of iron availability by erythroblasts and the consequences of insufficient as well as excess iron on erythroid lineage proliferation and differentiation. In addition, significant progress has been made in our understanding of dysregulated iron metabolism in various congenital and acquired malignant and non-malignant diseases. Finally, we report several actual as well as theoretical opportunities for translating the recently acquired robust mechanistic understanding of iron metabolism regulation to improve management of patients with disordered erythropoiesis, such as anemia of chronic inflammation, β-thalassemia, polycythemia vera, and myelodysplastic syndromes.

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.

Thromboelastography and Traditional Coagulation Testing in Non-ICU-Admitted Patients with Acute Kidney Injury: An Observational Cohort Study

INTRODUCTION

This study aimed to elucidate the coagulation disorders in non-ICU patients with acute kidney injury (AKI) and their contribution to clotting-related outcomes of intermittent kidney replacement therapy (KRT).

METHODS

We included non-ICU-admitted patients with AKI requiring intermittent KRT, clinically having a risk of bleeding and against systemic anticoagulant use during KRT between April and December 2018. The premature termination of treatment due to circuit clotting was considered a poor outcome. We analyzed the characteristics of thromboelastography (TEG)-derived and traditional coagulation parameters and explored the potential-affecting factors.

RESULTS

In total, 64 patients were enrolled. Hypocoagulability was detected in 4.7%-15.6% of patients by a combination of the traditional parameters, i.e., prothrombin time (PT)/international normalized ratio, activated partial PT, and fibrinogen. No patient had hypocoagulability observed on TEG-derived reaction time; only 2.1%, 3.1%, and 10.9% of patients had hypocoagulability on TEG-derived kinetic time (K-time), α-angle, and maximum amplitude (MA), respectively, which were also platelet-related coagulation parameters, despite 37.5% of the cohort having thrombocytopenia. In contrast, hypercoagulability was more prevalent, involving 12.5%, 43.8%, 21.9%, and 48.4% of patients on TEG K-time, α-angle, MA, and coagulation index (CI), respectively, although thrombocytosis was only in 1.5% of the cohort. Patients with thrombocytopenia showed lower fibrinogen level (2.6 vs. 4.0 g/L, p = 0.00), α-angle (63.5° vs. 73.3°, p = 0.00), MA (53.5 vs. 66.1 mm, p = 0.00), and CI (1.8 vs. 3.6, p = 0.00) but higher thrombin time (17.8 vs. 16.2 s, p = 0.00) and K-time (2.0 vs. 1.2 min, p = 0.00) than those with a platelet count over 100 × 109/L. 41 patients were treated with heparin-free protocol, and 23 were treated with regional citrate anticoagulation (RCA). The premature termination rate was 41.5% on heparin-free patients, while 8.7% of patients underwent an RCA protocol (p = 0.006). Heparin-free protocol was the strongest adverse factor to poor outcomes. A heparin-free subgroup analysis found that the circuit clotting risk was increased by 61.7% with a 10 × 109/L elevation in platelet count (odds ratio [OR] = 1.617, p = 0.049) and decreased by 67.5% following a second increase of PT (OR = 0.325, p = 0.041). No significant correlation was found between TEG parameters and premature circuit clotting.

CONCLUSIONS

Most non-ICU-admitted patients with AKI had normal-to-enhanced hemostasis and activated platelet function based on TEG results, as well as a high rate of premature circuit clotting when receiving heparin-free protocol despite thrombocytopenia. Further studies are needed to better determine the use of TEG in respect to management of anticoagulation and bleeding complications in AKI patients with KRT.

Higher estimated plasma volume status is associated with increased thrombotic risk and impaired survival in patients with primary myelofibrosis

Introduction

Blood plasma represents a large reservoir of cytokines and other mediators of inflammation. Higher estimated plasma volume status (ePVS) has been shown to correlate with increased thrombotic risk in polycythemia vera patients, but its clinical and prognostic associations in patients with myelofibrosis are unknown which we aim to evaluate in this study.

Materials and methods

We retrospectively analysed a multicentric cohort of 238 patients with primary (PMF) and secondary myelofibrosis (SMF). Estimated plasma volume status was calculated using the Strauss-derived Duarte formula. Overall survival (OS) and time to thrombosis (TTT) considering both arterial and venous thromboses were primary endpoints of interest.

Results

Median ePVS was 5.8 dL/g and it did not significantly differ between PMF and SMF patients. Patients with more advanced disease features, more pronounced inflammation and higher comorbidity burden had higher ePVS. Higher ePVS (> 5.6 dL/g) was associated with shorter OS in PMF (unadjusted hazard ratio, HR = 2.8, 95% confidence interval, CI (1.79-4.41), P < 0.001) and SMF (unadjusted HR = 2.55, 95% CI (1.1-5.71), P =0.025) and with shorter TTT in PMF (> 7 dL/g, unadjusted HR = 4.1, 95% CI (1.44-11.59), P = 0.009) patients. Associations with OS diminished in multivariate analyses after adjustments for the dynamic-international-prognostic-scoring-system (DIPSS) and myelofibrosis-secondary-to-PV-and ET-prognostic-model (MYSEC-PM), respectively. Association with TTT remained significant independently of JAK2 mutation, white blood cell count and chronic kidney disease.

Conclusions

Myelofibrosis patients with more advanced disease features and more pronounced inflammation have higher ePVS, indicative of expanded plasma volume. Higher ePVS is associated with impaired survival in PMF and SMF and higher thrombotic risk in PMF patients.

Ropeginterferon versus Standard Therapy for Low-Risk Patients with Polycythemia Vera

Ropeginterferon for Patients with Polycythemia VeraPatients with low-risk polycythemia vera were randomly assigned to receive ropeginterferon alfa-2b and phlebotomy or phlebotomy alone. The trial met its end point of maintenance of a hematocrit target (≤45%) without thrombotic events, progression of leukocytosis, thrombocytosis, and worsening of splenomegaly in the ropeginterferon alfa-2b group.

JAK2 unmutated erythrocytosis: 2023 Update on diagnosis and management

DISEASE OVERVIEW

JAK2 unmutated or non-polycythemia vera (PV) erythrocytosis encompasses a heterogenous spectrum of hereditary and acquired entities.

DIAGNOSIS

Foremost in the evaluation of erythrocytosis is the exclusion of PV through JAK2 (inclusive of exons 12-15) mutation screening. Initial assessment should also include gathering of previous records on hematocrit (Hct) and hemoglobin (Hgb) levels, in order to streamline the diagnostic process by first distinguishing longstanding from acquired erythrocytosis; subsequent subcategorization is facilitated by serum erythropoietin (Epo) measurement, germline mutation screening, and review of historical data, including comorbid conditions and medication list. Hereditary erythrocytosis constitutes the main culprit in the context of longstanding erythrocytosis, especially when associated with a positive family history. In this regard, a subnormal serum Epo level suggests EPO receptor mutation. Otherwise, considerations include those associated with decreased (high oxygen affinity Hgb variants, 2,3-bisphosphoglycerate deficiency, PIEZO1 mutations, methemoglobinemia) or normal oxygen tension at 50% Hgb saturation (P50). The latter include germline oxygen sensing pathway (HIF2A-PHD2-VHL) and other rare mutations. Acquired erythrocytosis commonly results from central (e.g., cardiopulmonary disease, high-altitude habitat) or peripheral (e.g., renal artery stenosis) hypoxia. Other noteworthy conditions associated with acquired erythrocytosis include Epo-producing tumors (e.g., renal cell carcinoma, cerebral hemangioblastoma) and drugs (e.g., testosterone, erythropoiesis stimulating agents, sodium-glucose cotransporter-2 inhibitors). Idiopathic erythrocytosis is an ill-defined terminology that presumes the existence of an increased Hgb/Hct level without an identifiable etiology. Such classification often lacks accounting for normal outliers and is marred by truncated diagnostic evaluation.

MANAGEMENT

Current consensus treatment guidelines are not supported by hard evidence and their value is further undermined by limited phenotypic characterization and unfounded concerns for thrombosis. We are of the opinion that cytoreductive therapy and indiscriminate use of phlebotomy should be avoided in the treatment of non-clonal erythrocytosis. However, it is reasonable to consider therapeutic phlebotomy if one were to demonstrate value in symptom control, with frequency determined by symptoms rather than Hct level. In addition, cardiovascular risk optimization and low dose aspirin is often advised.

FUTURE DIRECTIONS

Advances in molecular hematology might result in better characterization of "idiopathic erythrocytosis" and expansion of the repertoire for germline mutations in hereditary erythrocytosis. Prospective controlled studies are needed to clarify potential pathology from JAK2 unmutated erythrocytosis, as well as to document the therapeutic value of phlebotomy.

A phase II trial to assess the efficacy and safety of ropeginterferon α-2b in Chinese patients with polycythemia vera

Ropeginterferon α-2b is a mono-PEGylated proline-interferon for the treatment of polycythemia vera (PV). This drug is used biweekly with a starting dose of 100 μg (50 μg if patients receiving hydroxyurea) and 50 μg increments up to a maximum dose of 500 μg. Increasing evidence indicates that patients can tolerate higher starting doses of ropeginterferon α-2b. This phase II trial utilizes 250 μg as the starting dose, 350 μg at week 2 and 500 μg at week 4 as the target dose. Doses can be adjusted according to tolerability. This study assesses the safety, efficacy and molecular response of ropeginterferon α-2b in Chinese patients with PV utilizing the 250-350-500 μg dosing schema. This study will be used to support the application of a biologics license for PV treatment in China.

Pathological and genomic features of myeloproliferative neoplasms associated with splanchnic vein thrombosis in a single-center cohort

Here, we reviewed clinical-morphological data and investigated mutational profiles by NGS in a single-center series of 58 consecutive MPN-SVT patients admitted to our hospital between January 1979 and November 2021. We identified 15.5% of PV, 13.8% of ET, 34.5% of PMF, 8.6% of SMF and 27.6% of MPN-U. Most cases (84.5%) carried JAK2V617F mutation, while seven patients were characterized by other molecular markers, namely MPL in four and CALR mutations in three cases. NGS was performed in 54 (93.1%) cases: the most frequent additional mutations were found in TET2 (27.8%) and DNMT3A (16.7%) genes, whereas 25 (46.3%) patients had no additional mutation. Cases with JAK2V617F homozygosity had a higher median number of additional mutations than those with low allele burden. More importantly, all cases of leukemic evolution were characterized by a higher median number of co-mutations, and a co-mutational pattern of high-risk lesions, such as truncating mutations of ASXL1, bi-allelic TP53 loss, and CSMD1 mutations. Nevertheless, no difference was found between cases with and without additional somatic mutations regarding fibrotic progression, SVT recurrence, other thrombo-hemorrhagic complications, or death. After a median follow-up of 7.1 years, ten deaths were recorded; fibrotic progression/leukemic evolution was ascertained in one (1.7%) and six (10.3%) patients, respectively, while 22 (37.9%) patients suffered from recurrent thrombosis. In conclusion, our data underline the importance of using NGS analysis in the management of MPN-related SVT as it can support the MPN diagnosis, particularly in "triple-negative" cases, and provide additional information with potential consequences on prognosis and therapeutic strategies.

JAK2 V617F allele burden in polycythemia vera: burden of proof

Polycythemia vera (PV) is a hematopoietic stem cell neoplasm defined by activating somatic mutations in the JAK2 gene and characterized clinically by overproduction of red blood cells, platelets, and neutrophils; a significant burden of disease-specific symptoms; high rates of vascular events; and evolution to a myelofibrosis phase or acute leukemia. The JAK2V617F variant allele frequency (VAF) is a key determinant of outcomes in PV, including thrombosis and myelofibrotic progression. Here, we critically review the dynamic role of JAK2V617F mutation burden in the pathogenesis and natural history of PV, the suitability of JAK2V617F VAF as a diagnostic and prognostic biomarker, and the utility of JAK2V617F VAF reduction in PV treatment.

TMPRSS6 as a Therapeutic Target for Disorders of Erythropoiesis and Iron Homeostasis

TMPRSS6 is a serine protease highly expressed in the liver. Its role in iron regulation was first reported in 2008 when mutations in TMPRSS6 were shown to be the cause of iron-refractory iron deficiency anemia (IRIDA) in humans and in mouse models. TMPRSS6 functions as a negative regulator of the expression of the systemic iron-regulatory hormone hepcidin. Over the last decade and a half, growing understanding of TMPRSS6 biology and mechanism of action has enabled development of new therapeutic approaches for patients with diseases of erythropoiesis and iron homeostasis.ClinicalTrials.gov identifier NCT03165864.

Evaluating ropeginterferon alfa-2b for the treatment of adults with polycythemia vera

INTRODUCTION

Interferons (IFNs) have been used for decades to treat polycythemia vera (PV). Single-arm clinical trials assessing IFN in PV patients demonstrated high hematological and molecular response rates, indicating potential disease-modifying activity of IFN. However, discontinuation rates of IFNs have been rather high due to frequent treatment-related side-effects.

AREAS COVERED

Ropeginterferon alfa-2b (ROPEG) is a monopegylated IFN consisting of a single isoform, which differentiates it from previous IFNs with respect to tolerability and dosing frequency. ROPEG has improved pharmacokinetic and pharmacodynamic properties, which allow extended dosing every 2 weeks and monthly administration during maintenance phase. This review covers ROPEG's pharmacokinetic and pharmacodynamic properties, presents results of randomized clinical trials (RCT) that evaluated ROPEG in the treatment of PV patients, and discusses contemporary findings regarding the potential disease-modifying activity of ROPEG.

EXPERT OPINION

RCT have demonstrated high rates of hematological and molecular responses in PV patients treated with ROPEG, irrespective of thrombotic risk. Drug discontinuation rates were generally low. However, even though RCT captured the most important surrogate endpoints of thrombotic risk and disease progression in PV, they were not statistically powered to fully determine whether therapeutic intervention with ROPEG indeed has a direct positive effect on these important clinical outcomes.