The underappreciated risk of thrombosis and bleeding in patients with myelofibrosis: a review

A randomized, double-blind, placebo-controlled phase 3 study to assess efficacy and safety of ropeginterferon alfa-2b in patients with early/lower-risk primary myelofibrosis

Primary myelofibrosis (PMF) is the most aggressive of the myeloproliferative neoplasms and patients require greater attention and likely require earlier therapeutic intervention. Currently approved treatment options are limited in their selective suppression of clonal proliferation resulting from driver- and coexisting gene mutations. Janus kinase inhibitors are approved for symptomatic patients with higher-risk PMF. Additionally, most ongoing clinical studies focus on patients with higher-risk disease and/or high rates of transfusion dependency. Optimal treatment of early/lower-risk PMF remains to be identified and needs randomized clinical trial evaluations. Pegylated interferon alfa is recommended for symptomatic lower-risk PMF patients based on phase 2 non-randomized studies and expert opinion. Ropeginterferon alfa-2b (ropeg) is a new-generation pegylated interferon-based therapy with favorable pharmacokinetics and safety profiles, requiring less frequent injections than prior formulations. This randomized, double-blind, placebo-controlled phase 3 trial will assess its efficacy and safety in patients with "early/lower-risk PMF", defined as pre-fibrotic PMF or PMF at low or intermediate-1 risk according to Dynamic International Prognostic Scoring System-plus. Co-primary endpoints include clinically relevant complete hematologic response and symptom endpoint. Secondary endpoints include progression- or event-free survival, molecular response in driver or relevant coexisting gene mutations, bone marrow response, and safety. Disease progression and events are defined based on the International Working Group criteria and well-published reports. 150 eligible patients will be randomized in a 2:1 ratio to receive either ropeg or placebo. Blinded sample size re-estimation is designed. Ropeg will be administered subcutaneously with a tolerable, higher starting-dose regimen. The study will provide important data for the treatment of early/lower-risk PMF for which an anti-clonal, disease-modifying agent is highly needed.

Anticoagulation for splanchnic vein thrombosis in myeloproliferative neoplasms: a systematic review and meta-analysis

BACKGROUND

Optimal anticoagulation management in patients with myeloproliferative neoplasms (MPN) experiencing splanchnic vein thrombosis (SpVT) requires balancing risks of bleeding and recurrent thrombosis.

OBJECTIVES

We conducted a systematic review and meta-analysis to assess the incidence of bleeding and thrombosis recurrence in patients with MPN-SpVT.

METHODS

We included retrospective or prospective studies in English with ≥10 adult patients with MPN-SpVT. Outcomes included recurrent venous thrombosis (SpVT and non-SpVT), arterial thrombosis, and major bleeding. Pooled rates per 100 patient years with 95% CIs were calculated by DerSimonian-Laird method using random-effects model.

RESULTS

Out of 4624 studies screened, 9 studies with a total of 443 patients were included in the meta-analysis with median follow-up of 3.5 years. In the 364 patients with MPN-SpVT treated with anticoagulation, pooled event rate for major bleeding was 2.8 (95% CI, 1.5-5.1; I2 = 95%), for recurrent venous thrombosis was 1.4 (95% CI, 0.8-2.2; I2 = 72%), and for arterial thrombosis was 1.4 (95% CI, 0.6-3.3; I2 = 92%) per 100 patient years. Among 79 patients (n = 4 studies) who did not receive anticoagulation, pooled event rate for major bleeding was 3.2 (95% CI, 0.7-12.7; I2 = 97%), for recurrent venous thrombosis 3.5 (95% CI, 1.8-6.4; I2 = 88%), and for arterial thrombosis rate 1.6 (95% CI, 0.4-6.6; I2 = 95%) per 100 patient years.

CONCLUSION

Patients with MPN-SpVT treated with anticoagulation have significant risks for both major bleeding and thrombosis recurrence. Further studies are necessary to determine the optimal anticoagulation approach in patients with MPN-SpVT.

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

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

No impact of steatotic liver disease on clinical outcomes in patients with essential thrombocythemia and polycythemia vera: A pilot study

The presence of steatotic liver disease (SLD) is associated with an increased cardiovascular risk in the general population. Chronic myeloproliferative neoplasms (MPNs), essential thrombocythemia (ET) and polycythemia vera (PV), are characterized by clonal myeloproliferation, chronic inflammatory state, and increased cardiovascular morbidity and mortality. The aim of this single-center study was to analyze clinical associations and the potential prognostic impact of SLD in ET and PV patients. We retrospectively included 108 patients (64 ET and 44 PV); median age was 70.5 years (range 21-92), 68 (63 %) were females, and the median follow-up time was 69 months. Baseline SLD presence was defined ultrasonographically and was detected in 25 (23.1 %) patients. There were no associations of SLD with any of the clinical and laboratory patient characterictics. Also, baseline ultrasonographic presence of SLD did not have an impact on future thrombotic, bleeding and disease transformation risk, nor patient survival. None of the patients experienced signs of liver failure during the follow-up. In conclusion, the presence of SLD in ET and PV patients does not seem to have major clinical implications. Therefore, patients may be advised about the generally harmless nature of SLD when occurring in the MPN context.

Real-World Electronic Medical Records Data Identify Risk Factors for Myelofibrosis and Can Be Used to Validate Established Prognostic Scores

Myelofibrosis (MF) is a myeloproliferative neoplasia arising de novo as primary myelofibrosis (PMF) or secondary to polycythemia vera or essential thrombocythemia. Patients experience a high symptom burden and a marked reduction in life expectancy. Despite progress in molecular understanding and treatment, the clinical and prognostic heterogeneity of MF complicates treatment decisions. The International Prognostic Scoring System (IPSS) integrates clinical factors for risk stratification in MF. This study leverages the TriNetX database with more than 64,000 MF patients to assess the impact of accessible parameters on survival and complicating events, including AML transformation, cachexia, increased systemic inflammation, thrombosis and hemorrhage. Age over 65 years correlated with increased risks of death, AML transformation, thrombosis and hemorrhage. Anemia (Hb < 10 g/dL), leukocytosis (>25 × 103/µL) and thrombocytopenia (<150 × 103/µL) reduced survival and increased risks across all assessed events. Monocytosis is associated with decreased survival, whereas eosinophilia and basophilia were linked to improved survival. Further, as proof of concept for the applicability of TriNetX for clinical scores, we devised a simplified IPSS, and confirmed its value in predicting outcomes. This comprehensive study underscores the importance of age, anemia, leukocytosis and thrombocytopenia in predicting disease trajectory and contributes to refining prognostic models, addressing the challenges posed by the disease's heterogeneity.

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.

In-Hospital and readmission outcomes of patients with myeloproliferative neoplasms and atrial fibrillation: insights from the National Readmissions Database

INTRODUCTION

Patients with myeloproliferative neoplasms (MPNs) and atrial fibrillation (AF) are at increased risk of thrombosis and bleeding. However, the risk of thrombosis and bleeding in patients with AF and MPN compared with the general population with AF is unclear. Additionally, traditional risk scores (CHA2DS2-VASC and HAS-BLED) for risk/benefit estimation of thromboprophylaxis in AF do not account for MPN status. Therefore, we aimed to investigate bleeding and thrombosis risk in patients with MPN hospitalized for AF.

METHODS

We utilized the National Readmission Database (NRD) to identify patients with AF with and without MPN. Primary bleeding and thrombosis outcomes were in-hospital or 30-day readmission for bleeding or thrombosis, respectively. We propensity score (PS) matched patients with and without MPN. Risk of primary outcomes in MPN was assessed in PS matched cohort using logistic regression. Receiver operating characteristic (ROC) curve used to evaluate predictive ability of CHA2DS2-VASC and HAS-BLED of primary thrombosis and bleeding outcomes, respectively.

RESULTS

24,185 patients without MPN were matched with 1,617 patients with MPN and variables were balanced between groups. Patients with MPN were at increased risk of meeting the thrombosis (OR 1.98, 95% CI 1.23-3.21) but not bleeding (OR 0.87, 95% CI 0.63-1.19) primary outcomes. In MPN, CHA2DS2-VASC predicted thrombosis (C-statistic 0.66, 95% CI 0.54-0.78) but HAS-BLED was a poor predictor of bleeding (C-statistic 0.55, 95% CI 0.46-0.64).

CONCLUSION

In patients with AF, MPN was associated with increased risk of bleeding and thrombosis. HAS-BLED scores did not accurately predict bleeding in MPN. Further investigation is needed to refine risk scores in MPN.

The spectrum of glomerular and vascular kidney pathology associated with myeloproliferative neoplasms

A high prevalence of chronic kidney disease (CKD) occurs in patients with myeloproliferative neoplasms (MPN). However, MPN-related glomerulopathy (MPN-RG) may not account for the entirety of CKD risk in this population. The systemic vasculopathy encountered in these patients raises the hypothesis that vascular nephrosclerosis may be a common pattern of injury in patients with MPN and with CKD. In an exhaustive, retrospective, multicenter study of MPN kidney biopsies in four different pathology departments, we now describe glomerular and vascular lesions and establish clinicopathologic correlations. Our study encompassed 47 patients with MPN who underwent a kidney biopsy that included 16 patients with chronic myeloid leukemia (CML) and 31 patients with non-CML MPN. Fourteen cases met a proposed definition of MPN-RG based on mesangial sclerosis and hypercellularity, as well as glomerular thrombotic microangiopathy. MPN-RG was significantly associated with both myelofibrosis and poorer kidney survival. Thirty-three patients had moderate-to-severe arteriosclerosis while 39 patients had moderate-to-severe arteriolar hyalinosis. Multivariable models that included 188 adult native kidney biopsies as controls revealed an association between MPN and chronic kidney vascular damage, which was independent of established risk factors such as age, diabetes mellitus and hypertension. Therefore, MPN-RG is associated with myelofibrosis and has a poor kidney prognosis. Thus, our findings suggest that the kidney vasculature is a target during MPN-associated vasculopathy and establish a new link between MPN and CKD. Hence, these results may raise new hypotheses regarding the pathophysiology of vascular nephrosclerosis in the general population.

Increased bleeding and thrombosis in myeloproliferative neoplasms mediated through altered expression of inherited platelet disorder genes

An altered thrombo-hemorrhagic profile has long been observed in patients with myeloproliferative neoplasms (MPNs). We hypothesized that this observed clinical phenotype may result from altered expression of genes known to harbor genetic variants in bleeding, thrombotic, or platelet disorders. Here, we identify 32 genes from a clinically validated gene panel that were also significantly differentially expressed in platelets from MPN patients as opposed to healthy donors. This work begins to unravel previously unclear mechanisms underlying an important clinical reality in MPNs. Knowledge of altered platelet gene expression in MPN thrombosis/bleeding diathesis opens opportunities to advance clinical care by: (1) enabling risk stratification, in particular, for patients undergoing invasive procedures, and (2) facilitating tailoring of treatment strategies for those at highest risk, for example, in the form of antifibrinolytics, desmopressin or platelet transfusions (not current routine practice). Marker genes identified in this work may also enable prioritization of candidates in future MPN mechanistic as well as outcome studies.

Predictors of increased risk of adverse cardiovascular outcomes among patients with myeloproliferative neoplasms and atrial fibrillation

BACKGROUND

Patients with myeloproliferative neoplasms (MPNs), essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF), have increased risk of cardiovascular (CV) disease. Atrial fibrillation (AF) is associated with adverse CV outcomes including arterial thrombosis, heart failure (HF), and CV death and coexists with MPN. Traditional risk scores (CHA2DS2-VASC and HAS-BLED) for estimating risks/benefits of anticoagulation to prevent thrombotic events in AF do not include MPN status. Therefore, we aimed to investigate CV outcomes in patients with MPN and AF and evaluate the predictive ability of traditional risk scores.

METHODS

We conducted a single-center, retrospective cohort study of patients with MPN and AF. Primary outcome was composite of CV death and arterial thromboembolism; secondary outcomes were bleeding requiring emergency department visit or hospitalization, hospitalization for HF, and all-cause death. Multivariable competing-risk and Cox proportional hazards regression models were used to estimate risk of outcomes. Receiver operating characteristic (ROC) curve used to evaluate predictive ability of CHA2DS2-VASC and HAS-BLED of composite outcome and bleeding, respectively.

RESULTS

A total 142 patients was included (62 ET, 54 PV, 26 MF). Composite outcome, bleeding, HF hospitalization and all-cause death occurred in 39 %, 30 %, 34 %, and 48 %, of patients respectively. After multivariable modeling, MF was associated with increased risk of composite outcome (SHR 2.70, 95 % CI 1.38-5.27) and all-cause mortality (HR 9.77, 95 % CI 4.88-19.54) but not bleeding (SHR 1.19, 95 % CI 0.51-2.80) or HF admissions (SHR 0.57, 95 % CI 0.19-1.72). CHA2DS2-VASC and HAS-BLED were poor predictors of composite outcome (C-statistic 0.52, 95 % CI 0.43-0.62) and bleeding (C-statistic 0.49, 95 % CI 0.40-0.58), respectively.

CONCLUSION

In patients with MPN and AF, MF is associated with increased risk of CV death and arterial thrombosis and traditional risk scores do not accurately predict outcomes in this patient population. Further investigation is needed to refine risk scores in this patient population.

Leukocytosis and MPNs: Where do we stand?

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

An alternative dosing strategy for ropeginterferon alfa-2b may help improve outcomes in myeloproliferative neoplasms: An overview of previous and ongoing studies with perspectives on the future

Ropeginterferon alfa-2b is a novel, long-acting mono-pegylated proline-IFN-alpha-2b approved for treatment of polycythemia vera in adults, regardless of thrombotic risk level or treatment history. Clinical trial data indicate the dose and titration of ropeginterferon alfa-2b is safe and effective. However, additional studies may provide rationale for an amended, higher initial dosage and rapid titration. This article is an overview of current and upcoming studies of ropeginterferon alfa-2b in myeloproliferative neoplasms that support the exploration of an amended dosing scheme in order to optimize patient tolerability and efficacy outcomes.

Exploration and identification of anoikis-related genes in polycythemia vera

Background: Polycythemia Vera (PV) is a type of typical Myeloproliferative Neoplasms (MPNs) characterized with excessive erythropoiesis and thrombosis. Anoikis is a special programmed cell death mode induced by the adhesion disorder between cells and extracellular matrix (ECM) or adjacent cells facilitating cancer metastasis. However, few studies have focused on the role of anoikis in PV, especially on the development of PV. Methods: The microarray and RNA-seq results were screened from the Gene Expression Omnibus (GEO) database and the anoikis-related genes (ARGs) were downloaded from Genecards. The functional enrichment analysis of intersecting differentially expressed genes (DEGs) and protein-protein interaction (PPI) network analysis were performed to discover hub genes. The hub genes expression was tested in the training (GSE136335) and validation cohort (GSE145802), and RT-qPCR was performed to verify the gene expression in PV mice. Results: In the training GSE136335, a total of 1,195 DEGs was obtained from Myeloproliferative Neoplasm (MPN) patients compared with controls, among which 58 were anoikis-related DEGs. The significant enrichment of the apoptosis and cell adhesion pathways (i.e., cadherin binding) were shown in functional enrichment analysis. The PPI network was conducted to identify top five hub genes (CASP3, CYCS, HIF1A, IL1B, MCL1). The expression of CASP3 and IL1B were significantly upregulated both in validation cohort and PV mice and downregulated after treatment, suggesting that CASP3 and IL1B could be important indicators for disease surveillance. Conclusion: Our research revealed a relationship between anoikis and PV for the first time by combined analysis of gene level, protein interaction and functional enrichment, allowing novel insights into mechanisms of PV. Moreover, CASP3 and IL1B may become promising indicators of PV development and treatment.

Platelets and osteoblasts: secretome connections

Megakaryocyte hyperplasia associated with myeloproliferative neoplasms commonly leads to abnormal bone tissue deposition in the bone marrow, known as osteosclerosis. In this study, we aimed to synthesize the known proteomics literature describing factors released by megakaryocytes and platelets and to examine if any of the secreted factors have a known ability to stimulate the bone-forming cells, osteoblasts. Using a systematic search of Medline, we identified 77 articles reporting on factors secreted by platelets and megakaryocytes. After a full-text screening and analysis of the studies, we selected seven papers that reported proteomics data for factors secreted by platelets from healthy individuals. From 60 proteins reported in at least two studies, we focused on 23 that contained a putative signal peptide, which we searched for a potential osteoblast-stimulatory function. From nine proteins with a positive effect on osteoblast formation and function, two extracellular matrix (ECM) proteins, secreted protein acidic and rich in cysteine (SPARC) and tissue inhibitor of metalloproteinase-1 (TIMP1), and three cellular proteins with known extracellular function, the 70-kDa heat shock protein (HSP70), thymosin-β4 (TB4), and super dismutase (SOD), were identified as hypothetical candidate molecules to be examined as potential mediators in mouse models of osteomyelofibrosis. Thus, careful analysis of prior literature can be beneficial in assisting the planning of future experimental studies.

Thrombosis in Myeloproliferative Neoplasms: A Single Center Experience of Using Whole Blood Platelet Aggregation Studies for Risk Assessment and Thromboprophylaxis

Thromboembolic complications are the most common causes of morbidity and mortality in patients with Philadelphia chromosome-negative myeloproliferative neoplasms (MPN); and prevention of these complications remains a significant clinical challenge. Effective thromboprophylaxis in MPN patients generally requires use of anti-platelet therapy, commonly aspirin; however, there are no standardized or universally accepted guidelines regarding the dose of aspirin. This study evaluates the usefulness of whole blood platelet aggregation (WBPA) studies to identify patients at risk for thrombosis and to achieve safe and effective long term thromboprophylaxis. One hundred and thirty-two consecutive patients were enrolled into this study. WBPA studies were performed at diagnosis in 125 patients to identify those with platelet hyperactivity (deemed to be at risk for thrombosis) and repeated 4 weeks after commencement of anti-platelet therapy to ascertain the efficacy. In patients with incomplete drug effect, treatment was revised and the study repeated until optimum effect was achieved. Results of the WBPA studies and anti-platelet therapy requirements were correlated with the underlying driver mutations and various international prognostic score of thrombosis for essential thrombocythemia (IPSET- Thrombosis) sub-groups. WBPA studies showed varying degrees of platelet hyper-activity in 115 patients. Based on these results, the patients were commenced on anti-platelet therapy comprising aspirin (dose ranging from 100mg twice or thrice weekly to 400mg daily) and clopidogrel (75mg daily) alone or in combination with aspirin or odorless garlic. None of the patients developed thrombosis during the follow up period ranging from 1-23 years (median 8yrs), while on the prescribed, individualized anti-platelet therapy. No significant differences were noted in terms of aspirin dose requirements between the JAK-2 positive and CALR or MPL positive patients, and, among the four IPSET-Thrombosis sub-groups. Patients with normal (9) or hypo (1) – activity were not given any anti-platelet therapy at diagnosis.

Thrombotic and Hemorrhagic Issues Associated with Myeloproliferative Neoplasms

Thrombotic and hemorrhagic complications are related to a significant rate of morbidity and mortality in patients with myeloproliferative neoplasms (MPNs), they are therefore called “thrombohemorrhagic” syndromes. Several clinical factors, such as age and presence of cardiovascular comorbidities are responsible for thrombotic complications. High blood counts, platelet alterations, presence of JAK2 mutation and possibly of other CHIP mutations such as TET2, DNMT3A, and ASXL1, procoagulant microparticles, NETs formation, endothelial activation and neo-angiogenesis are some of the parameters accounting for hypercoagulability in patients with myeloproliferative neoplasms. Bleeding complications emerge as a result of platelet exhaustion. They can be also linked to a functional deficiency of von Willebrand factor, when platelet counts rise above 1000G/L. The mainstay of management consists on preventing hemostatic complications, by antiplatelet and/or anticoagulant treatment and myelosuppressive agents in high-risk patients.Circumstances related to a high thrombohemorrhagic risk, such as pregnancy and the perioperative period, prompt for specific management with regards to anticoagulation and myelosuppression treatment type. In order to apply a patient-specific treatment strategy, there is a need for a risk score assessment tool encompassing clinical parameters and hemostasis biomarkers.

Risk assessment and prognostic analysis of patients with splenic infarction in emergency department: a multicenter retrospective study

Splenic infarction is a thromboembolic disease that is frequently missed in acute settings. Previous reviews were rarely presented from a clinical perspective. We aimed to evaluate the clinical characteristics, risk factors with diagnostic value, and prognostic factors using large cohort data and a matched case–control study method. A retrospective medical record review of six hospitals in Taiwan from January 1, 2005, to August 31, 2020, was conducted. All patients who underwent contrast CT with confirmed the diagnosis of splenic infarction were included. Their characteristics were presented and compared to a matched control group with similar presenting characteristics. Prognostic factors were also analyzed. A total of 130 cases were included, two-thirds of whom presented with abdominal pain. Atrial fibrillation was the most common associated predisposing condition, followed by hematologic disease. A higher proportion of tachycardia, positive qSOFA score, history of hypertension or atrial fibrillation, leukocytosis, and thrombocytopenia were found in splenic infarction patients compared to their counterparts. An underlying etiology of infective endocarditis was associated with a higher proportion of ICU admission. Splenic infarction patients often presented with left upper abdominal pain and tachycardia. A history of hypertension, atrial fibrillation, a laboratory result of leukocytosis or thrombocytopenia may provide a clue for clinicians to include splenic infarction in the differential list. Among the patients diagnosed with splenic infarction, those with an underlying etiology of infectious endocarditis may be prone to deterioration or ICU admission.

Repeated haploidentical allogeneic hematopoietic stem cell transplantation with TCR αβ/CD19 depletion in patient with primary myelofibrosis. Case report

Indications of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with primary myelofibrosis are intermediate-2 and high-risk group of DIPSS (Dynamic International Prognostic Scoring System), beginning of the disease in childhood. The other adverse factors affect engraftment and survival after allo-HSCT, example partialy matched donor. But the result of allo-HSCT from matched related donors and result of allo-HSCT from haploidentical donors are comparable. The method for haploidentical hematopoietic stem cell transplantation is T-cell-depletion. This is clinical case of T-cell-depleted haploidentical hematopoietic stem cell transplantation in patient with primary myelofibrosis, the diagnosis was established in childhood.

Thrombosis in patients with myeloproliferative neoplasms. Case report

Thrombotic complications are the most significant factors determining the prognosis in myeloproliferative neoplasms. Markers for assessing the risk of thrombosis are the number of leukocytes, platelets, hemoglobin level, hematocrit, age, molecular status, history of thrombosis, obesity, arterial hypertension, hyperlipidemia, hereditary or acquired thrombophilia. The pathogenesis of thrombosis in patients with myeloproliferative neoplasms is complex and multifactorial. In most cases, the etiological factor remains unknown. Currently, antiplatelet and anticoagulant therapy is carried out on an individual basis. The algorithm for primary and secondary (after thrombosis) prevention requires development and testing. We present a clinical case of repeated arterial and venous thrombotic complications in a patient with primary myelofibrosis.

The pathobiology of thrombosis, microvascular disease, and hemorrhage in the myeloproliferative neoplasms

Thrombotic, vascular, and bleeding complications are the most common causes of morbidity and mortality in the Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs). In these disorders, circulating red cells, leukocytes, and platelets, as well as some vascular endothelial cells, each have abnormalities that are cell-intrinsic to the MPN driver mutations they harbor (eg, JAK2 V617F). When these cells are activated in the MPNs, their interactions with each other create a highly proadhesive and prothrombotic milieu in the circulation that predisposes patients with MPN to venous, arterial, and microvascular thrombosis and occlusive disease. Bleeding problems in the MPNs are caused by the MPN blood cell-initiated development of acquired von Willebrand disease. The inflammatory state created by MPN stem cells in their microenvironment extends systemically to amplify the clinical thrombotic tendency and, at the same time, preferentially promote further MPN stem cell clonal expansion, thereby generating a vicious cycle that favors a prothrombotic state in these diseases.

The Contemporary Approach to CALR-Positive Myeloproliferative Neoplasms

CALR mutations are a revolutionary discovery and represent an important hallmark of myeloproliferative neoplasms (MPN), especially essential thrombocythemia and primary myelofibrosis. To date, several CALR mutations were identified, with only frameshift mutations linked to the diseased phenotype. It is of diagnostic and prognostic importance to properly define the type of CALR mutation and subclassify it according to its structural similarities to the classical mutations, a 52-bp deletion (type 1 mutation) and a 5-bp insertion (type 2 mutation), using a statistical approximation algorithm (AGADIR). Today, the knowledge on the pathogenesis of CALR-positive MPN is expanding and several cellular mechanisms have been recognized that finally cause a clonal hematopoietic expansion. In this review, we discuss the current basis of the cellular effects of CALR mutants and the understanding of its implementation in the current diagnostic laboratorial and medical practice. Different methods of CALR detection are explained and a diagnostic algorithm is shown that aids in the approach to CALR-positive MPN. Finally, contemporary methods joining artificial intelligence in accordance with molecular-genetic biomarkers in the approach to MPN are presented.

Analysis of Common Driver Mutations in Philadelphia-Negative Myeloproliferative Neoplasms

BACKGROUND

Philadelphia-negative myeloproliferative neoplasms (MPNs) are a group of hematopoietic stem cell disorders that include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). This study examines the driver mutations among patients with MPNs in Kuwait.

PATIENTS AND METHODS

This study was a retrospective review of 942 MPN cases with a driver mutation from July 2007 to June 2019 to examine their demographic, clinical, and laboratory attributes.

RESULTS

The annual incidence of MPNs is 1.6 per 100,000 persons, and ET is the most common subtype. The median age of our cohort was 55 years, and the patients were predominantly male. We found that the most frequent gene mutation of MPNs in our cohort was the JAK2V617F mutation, which was present in 90% of cases, followed by the CALR exon 9, MPLW515L/K, and JAK2 exon 12 mutations. In our cohort, thrombotic events were observed in 18.7% of cases.

CONCLUSION

Although Philadelphia-negative MPNs are rare hematologic malignancies, thrombosis is a relatively common initial presentation. The JAK2V617F mutation was the driver mutation in the majority of patients with MPN.

Thrombocytopenia: Perioperative Considerations for Patients Undergoing Cardiac Surgery

The etiologies of thrombocytopenia in patients presenting for cardiac surgery are extensive, but clinically relevant conditions generally can be categorized by those related to decreased platelet production or increased platelet destruction. Many causes require mere acknowledgment and availability of allogeneic platelet transfusion; others have unique considerations for which providers should be familiar. The purpose of this review is to provide an overview of the common causes of thrombocytopenia, summarize the literature, and discuss perioperative considerations for patients undergoing cardiac surgery.

Immune Complex Associated Glomerulonephritis in a Patient with Prefibrotic Primary Myelofibrosis: A Case Report

A case of prefibrotic myelofibrosis with immune complex-mediated glomerulonephritis is presented. A 45-year-old female, with history of right subclavian and axillary vein thrombosis, presented with abdominal distension, facial puffiness, and pedal edema. Evaluation revealed deranged renal functions with nephrotic range proteinuria and acute kidney injury. JAK2 mutation evaluated in view of portal vein thrombosis and splenomegaly was positive. Renal biopsy revealed mesangial proliferative glomerulonephritis with full house immune complex deposition on direct immunofluorescence (DIF). The patient had no signs or symptoms of systemic lupus erythematosus and serological markers for autoimmune or collagen vascular disease were negative. Renal involvement in myeloproliferative neoplasms (MPNs) is uncommon and histological patterns of DIF negative mesangial proliferative glomerulonephritis, focal segmental glomerulosclerosis, and immunoglobulin A nephropathy have been reported.

Higher serum uric acid is associated with higher risks of thrombosis and death in patients with primary myelofibrosis

BACKGROUND

Serum uric acid (SUA) can promote inflammation and is associated with increased cardiovascular morbidity. Primary (PMF) and secondary myelofibrosis (SMF) are myeloproliferative neoplasms characterized by high cellular turnover and substantial risk of thrombosis and death.

METHODS

We have retrospectively investigated SUA in 173 patients with myelofibrosis (125 PMF; 48 SMF) and 30 controls.

RESULTS

The PMF patients had significantly higher SUA in comparison to SMF and controls. In both PMF and SMF higher SUA was significantly associated with arterial hypertension and decreased renal function. Among PMF patients, higher SUA was significantly associated with older age, larger spleen, higher white blood cell counts, higher lactate dehydrogenase, lower immunoglobulin G levels, allopurinol use and non-smoking. Among SMF patients, higher SUA was associated with male sex (P < 0.05 for all analyses). In PMF higher SUA was univariately associated with inferior survival (> 427 μmol/L hazard ratio (HR) = 2.22; P = 0.006) and shorter time to thrombosis (> 444 μmol/L HR = 5.05; P = 0.006), which could be shown separately for arterial (> 380 μmol/L; HR = 4.9; P = 0.013) and venous thromboses (> 530 μmol/L; HR = 17.9; P < 0.001). In multivariate analyses, SUA remained significantly associated with inferior survival independent of the Dynamic International Prognostic Staging System and with shorter time to thrombosis independent of age in PMF patients; however, the prognostic significance of SUA was diminished after including serum creatinine in the models. SUA was not prognostic in SMF patients.

CONCLUSION

The PMF patients present with higher SUA levels, which are associated with features of more advanced disease and higher risks of arterial and venous thrombosis and death.

Thrombocytosis and Thrombosis: Is There Really a Correlation?

PURPOSE OF REVIEW

Thrombocytosis is common to all myeloproliferative neoplasms (MPN), including essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis. Despite the traditionally held belief amongst many clinicians that thrombocytosis correlates with thrombosis risk, there is little evidence in the literature to support that claim. Herein we critically analyze the literature to better understand the relationship between thrombocytosis and risk of thrombosis in MPN.

RECENT FINDINGS

Both retrospective and prospective studies argue against associations between thrombocytosis and risk of thrombosis in patients with ET and PV. Rather, most studies suggest that the presence of extreme thrombocytosis is instead associated with an increased risk of hemorrhagic events, a paradoxical phenomenon with important clinical implications. Thrombosis risk has a multifactorial set of etiologies in MPNs. While qualitative abnormalities of the platelets may contribute, associations between platelet quantity and thrombosis risk are weak in MPN patients.

Reduced renal function strongly affects survival and thrombosis in patients with myelofibrosis

We retrospectively investigated a cohort of 176 myelofibrosis patients (128 primary-PMF; 48 secondary-SMF) from five hematology centers. The presence of chronic kidney disease (CKD) was determined in addition to other clinical characteristics. CKD was present in 26.1% of MF patients and was significantly associated with older age (P < 0.001), higher WBC (P = 0.015), and its subsets (neutrophil, monocyte, and basophil counts), higher platelets (P = 0.001), lower albumin (P = 0.018), higher serum uric acid (P = 0.001), higher LDH (P = 0.022), and the presence of CV risk factors (P = 0.011). There was no significant association with driver mutations, degree of bone marrow fibrosis, PMF/SMF, or DIPSS risk categories (P > 0.05 for all analyses). The presence of CKD was significantly associated with shorter time to arterial (HR = 3.49; P = 0.041) and venous thrombosis (HR = 7.08; P = 0.030) as well as with shorter overall survival (HR 2.08; P = 0.009). In multivariate analyses, CKD (HR = 1.8; P = 0.014) was associated with shorter survival independently of the DIPSS (HR = 2.7; P < 0.001); its effect being more pronounced in lower (HR = 3.56; P = 0.036) than higher DIPSS categories (HR = 2.07; P = 0.023). MF patients with CKD should be candidates for active management aimed at the improvement of renal function. Prospective studies defining the optimal therapeutic approach are highly needed.

Association between myelofibrosis and thromboembolism: A population-based retrospective cohort study

BACKGROUND

The risk of thromboembolism in myelofibrosis remains incompletely understood.

OBJECTIVES

To examine the association between myelofibrosis and each of venous and arterial thromboembolism.

METHODS

A cohort of 1 469 790 adults without a diagnosis of myelofibrosis was identified on 1 January 2007, from the electronic medical records of the largest health-care provider in Israel. Participants were followed until 31 December 2016 for the occurrence of myelofibrosis. Four randomly selected controls (without myelofibrosis) were matched to each case of myelofibrosis on age, sex, religious identification, and index date. The two groups were followed from the index date until 31 December 2017 for the occurrence of venous and arterial thromboembolism.

RESULTS

The study included 642 patients with myelofibrosis and 2568 matched controls. Myelofibrosis was independently associated with increased risk of venous thromboembolism but not with arterial thromboembolism. The propensity score adjusted hazard ratios (HRs) were 6.88 (95% confidence interval [CI], 2.02-23.45) for venous thromboembolism, and 0.94 (0.49-1.77) for arterial thromboembolism. Atypical sites of venous thromboembolism occurred almost exclusively in patients with myelofibrosis (four events of Budd Chiari versus none, and two mesenteric vein thrombosis events versus one) and were more likely to occur around the time of myelofibrosis diagnosis. No significant association was found between JAK2 inhibitor treatment (ruxolitinib) and the risk of venous HR 0.97 (0.30-3.12) or arterial thromboembolism 1.68 (0.78-3.62).

CONCLUSIONS

Myelofibrosis is associated with increased risk of venous thromboembolism but not of arterial thromboembolism. Atypical sites of venous thromboembolism are more frequent in myelofibrosis and are more likely to occur shortly after diagnosis.

CALR mutations in a cohort of JAK2 V617F negative patients with suspected myeloproliferative neoplasms

Suspicion of myeloproliferative neoplasms (MPNs) and especially essential thrombocythemia (ET) in primary care is often based solely on blood counts, with patients referred to a haematologist without a thorough evaluation. We retrospectively assessed the role of calreticulin gene (CALR) mutations in the diagnosis of MPN in this population. We studied CALR mutations in 524 JAK2 V617F-negative patients with suspected MPN. Uncommon CALR mutations were confirmed by Sanger sequencing and searched for in the COSMIC or HGMD database. Mutations were defined as frameshift or non-frameshift mutations. CALR mutations were detected in 23 patients (23/524 = 4.4%). Four mutations detected in our study were newly identified mutations. Non-frameshift mutations were detected in two patients. Most patients (380/524 = 72.5%) were diagnosed with secondary conditions leading to blood count abnormalities such as iron deficiency, inflammatory and infectious diseases, malignancy and hyposplenism. Nine patients (9/23 = 39%) were retrospectively diagnosed with ET based on CALR mutation confirmation. Two patients with non-frameshift CALR mutations were diagnosed with reactive thrombocytosis and MPN unclassifiable, respectively. Our study showed that CALR mutations are important, non-invasive diagnostic indicators of ET and can aid in its diagnosis. Moreover, the type of CALR mutation must be accurately defined, as non-frameshift mutations may not be associated with ET. Finally, CALR mutation detection should be reserved for patients with high suspicion of clonal haematological disease.

Severe acquired platelet dysfunction because of primary myelofibrosis with full functional and morphological recovery after allogeneic hematopoietic cell transplantation

: Primary myelofibrosis (PMF) is a clonal hematopoietic stem cell disorder characterized by fibrosis of the marrow cavity, marked megakaryocyte atypia and progressive cytopenias. Although thrombosis predominates, bleeding is the primary manifestation in up to 20% of patients and may be life-threatening. In this report, we document restoration of megakaryocyte and platelet structure and function in PMF after allogeneic hematopoietic cell transplantation (HCT). A 59-year-old man presented with recurrent episodes of postoperative bleeding preceding a diagnosis of primary myelofibrosis (PMF). Platelet aggregation and secretion studies showed abnormal responses to all agonists tested (epinephrine, ADP, arachidonic acid, U46619, collagen, ristocetin) despite the presence of thrombocytosis. After an allogeneic HCT, platelet morphology and function studies were all normal. The pathophysiology of platelet dysfunction in myeloid neoplasia is not well understood but, as highlighted in our report, restoration of platelet function by HCT supports a clonal process involving an early hematopoietic progenitor cell.

Emerging Factors Implicated in Fibrotic Organ-Associated Thrombosis: The Case of Two Organs

Thrombosis is at the heart of cardiovascular complications observed in specific diseases. A heightened thrombosis risk above that in general population in diseases such as myelofibrosis and chronic kidney disease implicates disease-specific mediators of thrombosis. This relative lack of information regarding the mechanisms of thrombosis in specific organ pathologies hitherto has remained limited. Evolving literature implicates some soluble factors in the blood of patients with discrete disorders, inflicting fundamental changes in the components of thrombosis. In this era of precision medicine, integrating these disease-specific factors in a comprehensive thrombotic risk assessment of patients is imperative in guiding therapeutic decisions. A complex network of mechanisms regulates each organ pathology and resultant thrombotic phenotypes. This review surveys different effectors of thrombogenicity associated with two pathologically fibrotic organs used as model systems, the bone marrow and kidney, as well as focuses attention to a common inducer of fibrosis and thrombosis, lysyl oxidase.

A systematic review and meta-analysis of the prevalence of thrombosis and bleeding at diagnosis of Philadelphia-negative myeloproliferative neoplasms

BACKGROUND

Philadelphia (Ph) chromosome-negative myeloproliferative neoplasms (MPNs) are a heterogeneous group of hematopoietic stem cell clonal diseases. Most patients with MPN are asymptomatic at diagnosis although some of them suffer from constitutional symptoms. Thrombosis and bleeding can also be one of the initial manifestations although the reported prevalence varied considerably across the studies. This systematic review and meta-analysis was conducted with the aims to better understand the prevalence and characteristics of thrombosis and bleeding among patients with newly-diagnosed MPN.

METHODS

Using a search strategy that included the terms for myeloproliferative neoplasms, thrombosis, and bleeding, two investigators independently searched for published articles indexed in the MEDLINE and EMBASE databases from inception to August 2018. The pooled prevalence was calculated using the DerSimonian-Laird random-effects model with a double arcsine transformation.

RESULTS

A total of 29 cohort studies (8 prospective and 21 retrospective) with 13,436 patients with MPN were included into this meta-analysis. At diagnosis, the pooled prevalence of overall thrombosis among patients with MPN was 20.0% (95% CI, 16.6-23.8%; I2 96%), with the pooled prevalence of arterial thrombosis of 16.2% (95% CI, 13.0-20.0%; I2 95%) and the pooled prevalence of venous thrombosis of 6.2% (95% CI, 4.9-7.8%; I2 89%). Common thrombotic events included cerebrovascular disease/transient ischemic attack, coronary heart disease, and deep venous thrombosis. The pooled prevalence of hemorrhagic complications among patients who were newly diagnosed with MPN patients was 6.2% (95% CI, 5.0-7.8%; I2 85%). Common sites of bleeding included gastrointestinal, mucosal, and cutaneous bleeding.

CONCLUSIONS

Thrombosis and bleeding are common initial manifestations of MPN. Investigations for MPN should be considered for patients who present with unexplained thrombosis or abnormal bleeding.

Prefibrotic myelofibrosis: treatment algorithm 2018

Prefibrotic myelofibrosis (pre-PMF) is a distinct entity among chronic myeloproliferative neoplasm diagnosed according to the revised 2016 WHO classification. The clinical picture is heterogeneous, ranging from isolated thrombocytosis, mimicking essential thrombocythemia (ET), to symptoms of high-risk PMF. Retrospective studies showed that survival of patients with pre-PMF is worse than that of ET and better than overt PMF. Whilst a specific prognostic score is lacking, the International Prognostic Scoring System is able to predict survival in pre-PMF patients, yet failing to separate intermediate-1 and -2 groups, and can be used in clinical practice. Each patient should be evaluated for, and interventions adapted to, both life-expectancy and the risk of bleeding and thrombosis. In low-risk patients with expected long survival, observation only is recommended; in cumulated intermediate-1 and -2 risk cases, whose median survival is projected at more than 10 years, treatment is based on symptoms; in high risk cases, with median survival lower than 5 years, intensive management is required. A pragmatic approach to address the risk of bleeding and thrombosis includes: no treatment or low-dose aspirin in asymptomatic patients; aspirin or oral anticoagulation if previous arterial or venous thrombosis, and hydroxyurea as first-line cytoreduction in case of thrombocytosis or leukocytosis.

Pacritinib and its use in the treatment of patients with myelofibrosis who have thrombocytopenia

The treatment landscape for myelofibrosis (MF) has reached the molecular era by targeting different pathways that are implied in this myeloproliferative neoplasm. A few years ago, the first-in-class JAK1/JAK2 inhibitor ruxolitinib, demonstrated reductions in both constitutional symptoms and splenomegaly, leading to the US FDA approval. The development or worsening of cytopenias in patients receiving ruxolitinib uncovered an unmet need that has been addressed by alternative approaches. Pacritinib, a dual JAK2 and FLT3 inhibitor which also inhibits IRAK1, has demonstrated the ability to favorably impact MF-associated splenomegaly and symptom burden, while having limited myelosuppression with manageable gastrointestinal toxicity. Herein, we provide an overview of pacritinib, from early preclinical studies to the latest and ongoing PAC203 trial, as an emerging therapy for MF.