Prevalence of polycythemia vera and essential thrombocythemia

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.

Brain perfusion changes in beta-thalassemia

BACKGROUND

Brain injury in hereditary hemoglobinopathies is commonly attributed to anemia-related relative hypoperfusion in terms of impaired oxygen blood supply. Supratentorial and infratentorial vascular watershed regions seem to be especially vulnerable, but data are very scarce.

AIMS

We investigated a large beta-thalassemia sample with arterial spin labeling in order to characterize regional perfusion changes and their correlation with phenotype and anemia severity.

METHODS

We performed a multicenter single-scanner cross-sectional 3T-MRI study analyzing non-invasively the brain perfusion in 54 transfusion-dependent thalassemia (TDT), 23 non-transfusion-dependent thalassemia (NTDT) patients and 56 Healthy Controls (HC). Age, hemoglobin levels, and cognitive functioning were recorded.

RESULTS

Both TDT and NTDT patients showed globally increased brain perfusion values compared to healthy controls, while no difference was found between patient subgroups. Using age and sex as covariates and scaling the perfusion maps for the global cerebral blood flow, beta-thalassemia patients showed relative hyperperfusion in supratentorial/infratentorial watershed regions. Perfusion changes correlated with hemoglobin levels (p = 0.013) and were not observed in the less severely anemic patients (hemoglobin level > 9.5 g/dL). In the hyperperfused regions, white matter density was significantly decreased (p = 0.0003) in both patient subgroups vs. HC. In NTDT, white matter density changes correlated inversely with full-scale Intelligence Quotient (p = 0.007) while in TDT no correlation was found.

CONCLUSION

Relative hyperperfusion of watershed territories represents a hemodynamic hallmark of beta-thalassemia anemia challenging previous hypotheses of brain injury in hereditary anemias. A careful management of anemia severity might be crucial for preventing structural white matter changes and subsequent long-term cognitive impairment.

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.

General anesthesia with nerve blocks for a patient with femoral fracture and essential thrombocythemia: a case report

Essential thrombocythemia (ET) is a type of myeloproliferative neoplasm characterized by an abnormal increase in platelets. We report a female patient with a severe femoral fracture and ET who underwent the femoral intramedullary fracture fixation procedure. Her past medical history included hypertension and ET. On the second day of hospitalization, her platelet count was 922 × 109/L. In our case, general anesthesia combined with a femoral nerve block and a lateral femoral cutaneous nerve block were used when the platelet count was within normal range. After surgery, the platelet count increased to 979 × 109/L despite using anticoagulant drugs and hydroxyurea. The postoperative recovery went well after the follow-up of this patient. In this case report, we provide our experience of anesthesia management and review the progress of relevant literature to provide some reference.

Toe Gangrene as the First Presenting Symptom of Essential Thrombocythemia: A Case Report

Essential thrombocythemia is a myeloproliferative neoplasm. Thrombosis and bleeding complications are common with myeloproliferative neoplasms, particularly essential thrombocythemia and polycythemia vera. Here, we report the case of a 52-year-old female who presented initially with painful toe swelling and discoloration. Initial imaging showed a small abscess. An incision and drainage, and debridement of toe dry gangrene were performed twice in two months with no improvement in her complaint and worsening discoloration, ending in a toe amputation. Two years later, the patient was referred to a hematology clinic for a high platelet count. On review of her medical records, the patient had the same numbers during the initial presentation. The patient's condition was diagnosed retrogradely by a hematologist as essential thrombocythemia. This case sheds light on myeloproliferative neoplasm as a differential diagnosis in patients with atypical thrombosis. Thinking in such a way could have diagnosed our patient two years earlier.

Real-world patient characteristics and treatment patterns of polycythemia vera in Taiwan between 2016 and 2017: a nationwide cross-sectional study

Background

Polycythemia vera (PV) patients often experience constitutional symptoms and are at risk of thromboembolism as well as disease progression to myelofibrosis or acute myeloid leukemia. Not only is PV often overlooked but treatment options are also limited, however.

Objectives

To explore the patient characteristics and treatment pattern of PV patients in Taiwan, and compare with other countries reported in the literature.

Design

This is a nationwide cross-sectional study.

Methods

The National Health Insurance Research Database in Taiwan, which covers 99% of the population, was utilized. Patients were identified during the cross-sectional period between 2016 and 2017, and their retrospective data were retrieved from 2001 to 2017.

Results

A total of 2647 PV patients were identified between 1 January 2016 and 31 December 2017. This study described the demographic information of these patients, including number of patients by risk stratification and by sex, age at diagnosis, age at cross-sectional period, rate of bone marrow aspiration/biopsy at diagnosis, comorbidities, number of postdiagnosis thrombosis, number of disease progression, and death. The mortality rate of PV patients (4.1%) over 60 of age was higher than the general population of the same age group (2.8%). This study also compared the different treatment patterns between sexes and risk groups. Hydroxyurea was deferred to an older age, but conversely was prescribed at higher dose to younger patients. Alarmingly, a high proportion of patients did not receive phlebotomy or hydroxyurea for at least 2 years. Furthermore, discrepancies in prevalence, age at diagnosis, sex ratio, incidence of thrombosis and mortality were also found when compared with data reported in other countries.

Conclusion

The clinical landscape of PV in Taiwan between 2016 and 2017 was examined. Distinctive patterns of phlebotomy and hydroxyurea were identified. Overall, these findings highlight the importance of understanding the patient characteristics and treatment patterns of PV in different regions to better inform clinical practice and improve patient outcomes.

Polycythemia with elevated erythropoietin production in a patient with a urinary stone and unilateral hydronephrosis: a case report

BACKGROUND

Absolute polycythemia can be primary or secondary. Erythropoietin-producing diseases (for example, hypoxia) are the major cause of secondary polycythemia. There are reports of polycythemia secondary to hydronephrosis. However, to our knowledge, there is no report on polycythemia secondary to hydronephrosis due to a urinary stone. Herein, we present a case of polycythemia with an elevated erythropoietin level in a patient with a urinary stone and unilateral hydronephrosis.

CASE PRESENTATION

A 57-year-old Japanese man presented with polycythemia and an elevated erythropoietin level. Erythropoietin accumulation was not due to erythropoietin secretion by a tumor as no obvious lesions were detected on contrast-enhanced computed tomography. Abdominal ultrasonography revealed a stone in the left urinary tract and renal hydronephrosis, and 2 weeks later, the patient underwent transurethral ureterolithotripsy without complications. Blood tests 2 weeks after transurethral ureterolithotripsy showed that the erythropoietin level had declined. Hemoglobin concentration decreased from 20.8 mg/dL before and immediately after transurethral ureterolithotripsy to 15.8 mg/dL 3 months after transurethral ureterolithotripsy. This case was diagnosed as erythropoietin elevation due to unilateral hydronephrosis with a urinary stone, resulting in polycythemia.

CONCLUSIONS

Hydronephrosis is a common disease but is not often associated with polycythemia. Further studies are required to elucidate the mechanism and implications of elevated erythropoietin production in hydronephrosis.

Polycythemia Rubra Vera and Sporadic Bilateral Renal Angiomyolipomas: A Case Report

Polycythemia rubra vera (PRV) is a clonal myeloproliferative neoplasm characterized by autonomous production of erythrocytes, neutrophils, and platelets. Angiomyolipomas (AMLs) are benign renal perivascular epithelioid cell neoplasms of which approximately 80% are sporadic. Here, we report synchronous diagnoses of PRV and asymptomatic sporadic bilateral renal AMLs in a 71-year-old woman. We describe her treatment with phlebotomy and hydroxyurea for PRV and surveillance for renal AMLs. We compare the features and treatment of the present case with those of two previously reported women who also had PRV and sporadic renal AMLs. Finally, we discuss the management and acquired genetic basis of both neoplasms.

Hydralazine Associated With Reduced Therapeutic Phlebotomy Frequency in a Nationwide Cohort Study: Real-World Effectiveness for Drug Repurposing

Background: Therapeutic phlebotomy, known as scheduled bloodletting, has been the main method for managing erythrocytosis symptoms and thrombocytosis-associated complications in various blood disorders. One of the major indications for phlebotomy is polycythemia vera (PV). The main goal of current treatment strategies for patients who require phlebotomy is to prevent thrombohemorrhagic complications rather than to prolong survival or lessen the risk of myelofibrotic or leukemic progression. Additional cytoreductive therapy is recommended for high-risk PV, for which the common first-line drug is hydroxyurea. However, recent evidence suggests that phlebotomy may not reduce the risk of thrombosis in patients with PV. Further evidence suggests that patients with PV treated with hydroxyurea who require three or more phlebotomy procedures per year have a higher risk of thrombotic complications.

Methods: We hypothesized that a drug-repurposing strategy of utilizing antineoplastic drugs for patients who require phlebotomy would result in greater benefits than would phlebotomy. The antihypertensive hydralazine and the anticonvulsant valproate, which have both been reported to have antineoplastic activity that mimics cytoreductive agents, were selected as candidates for the drug-repositioning strategy in a retrospective cohort study. We measured the hazard ratios (HR) and the frequencies of phlebotomy in patients with prescriptions for hydralazine or valproate or the two drugs in combination by using data from Taiwan’s National Health Insurance Research Database from 2000 to 2015 (n = 1,936,512).

Results: The HRs of undergoing phlebotomy in groups with hydralazine, valproate, and combination hydralazine–valproate prescriptions were reduced to 0.729 (p = 0.047), 0.887 (p = 0.196), and 0.621 (p = 0.022), respectively. The frequency of undergoing phlebotomy decreased from 2.27 to 1.99, 2.01, and 1.86 per person-year (p = 0.015), respectively. However, no significant differences were observed for the hydralazine group or the hydralazine–valproate combination group.

Conclusion: Whether a repurposed drug can serve as a cytoreductive agent for patients who require phlebotomy depends on its risk–benefit balance. We suggest that hydralazine, instead of the hydralazine–valproate combination, is a reasonable alternative for patients who require regular phlebotomy.

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

Introduction

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

Methods

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

Results

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

Conclusion

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

Polycythaemia Vera and Coronary Artery Bypass Graft Surgery: A Systematic Review of the Literature

OBJECTIVES

Polycythaemia vera (PV) is a condition that may potentially put patients undergoing cardiac surgery at an increased risk of bleeding and thrombosis; however, there is currently a paucity of literature regarding the management of these patients. We aim to examine the literature in this systematic review to indicate the interventions that may be considered to minimise complications.

METHODS

We conducted a literature search using keywords and MeSH terms to identify articles discussing PV and cardiac surgery. The studies were identified and qualitatively analysed using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) protocol.

RESULTS

In total, 10 case reports representing 11 patients were identified for this systematic review and were included in qualitative analysis. 63.6% of patients had preoperative intermittent phlebotomy, and the majority of patients received postoperative therapy that involved one antiplatelet and one anticoagulant. Generous perioperative fluid management, phlebotomy, preservation of core body temperature, early extubation, monitoring of myocardial ischaemia, infarction and vascular events, intense chest physiotherapy and patient mobilisation are important to consider to reduce the risk of complications arising from surgery.

CONCLUSION

These considerations should be systematically discussed in a multidisciplinary team, where the acute surgical need can be balanced appropriately against the risk of haemorrhage and thrombosis.

Secondary polycythemia in chronic obstructive pulmonary disease: prevalence and risk factors

BACKGROUND

Secondary polycythemia is associated with cigarette smoking and chronic obstructive pulmonary disease (COPD). However, the prevalence of polycythemia in COPD and the contributing risk factors for polycythemia in COPD have not been extensively studied.

METHODS

We analyzed the presence of secondary polycythemia in current and former smokers with moderate to very severe COPD at the five-year follow-up visit in the observational COPDGene study. We used logistic regression to evaluate the association of polycythemia with age, sex, race, altitude, current smoking status, spirometry, diffusing capacity for carbon monoxide (DLCO), quantitative chest CT measurements (including emphysema, airway wall thickness, and pulmonary artery to aorta diameter ratio), resting hypoxemia, exercise-induced hypoxemia, and long-term oxygen therapy.

RESULTS

In a total of 1928 COPDGene participants with moderate to very severe COPD, secondary polycythemia was found in 97 (9.2%) male and 31 (3.5%) female participants. In a multivariable logistic model, severe resting hypoxemia (OR 3.50, 95% CI 1.41-8.66), impaired DLCO (OR 1.28 for each 10-percent decrease in DLCO % predicted, CI 1.09-1.49), male sex (OR 3.60, CI 2.20-5.90), non-Hispanic white race (OR 3.33, CI 1.71-6.50), current smoking (OR 2.55, CI 1.49-4.38), and enrollment in the Denver clinical center (OR 4.42, CI 2.38-8.21) were associated with higher risk for polycythemia. In addition, continuous (OR 0.13, CI 0.05-0.35) and nocturnal (OR 0.46, CI 0.21-0.97) supplemental oxygen were associated with lower risk for polycythemia. Results were similar after excluding participants with anemia and participants enrolled at the Denver clinical center.

CONCLUSIONS

In a large cohort of individuals with moderate to very severe COPD, male sex, current smoking, enrollment at the Denver clinical center, impaired DLCO, and severe hypoxemia were associated with increased risk for secondary polycythemia. Continuous or nocturnal supplemental oxygen use were associated with decreased risk for polycythemia.

Recent Advances in the Use of Molecular Analyses to Inform the Diagnosis and Prognosis of Patients with Polycythaemia Vera

Genetic studies in the past decade have improved our understanding of the molecular basis of the BCR-ABL1-negative myeloproliferative neoplasm (MPN) polycythaemia vera (PV). Such breakthroughs include the discovery of the JAK2V617F driver mutation in approximately 95% of patients with PV, as well as some very rare cases of familial hereditary MPN caused by inherited germline mutations. Patients with PV often progress to fibrosis or acute myeloid leukaemia, both associated with very poor clinical outcome. Moreover, thrombosis and major bleeding are the principal causes of morbidity and mortality. As a result of increasingly available and economical next-generation sequencing technologies, mutational studies have revealed the prognostic relevance of a few somatic mutations in terms of thrombotic risk and risk of transformation, helping to improve the risk stratification of patients with PV. Finally, knowledge of the molecular basis of PV has helped identify targets for directed therapy. The constitutive activation of the tyrosine kinase JAK2 is targeted by ruxolitinib, a JAK1/JAK2 tyrosine kinase inhibitor for PV patients who are resistant or intolerant to cytoreductive treatment with hydroxyurea. Other molecular mechanisms have also been revealed, and numerous agents are in various stages of development. Here, we will provide an update of the recent published literature on how molecular testing can improve the diagnosis and prognosis of patients with PV and present recent advances that may have prognostic value in the near future.

Pharmacokinetics and Pharmacodynamics of Ropeginterferon Alfa-2b in Healthy Japanese and Caucasian Subjects After Single Subcutaneous Administration

BACKGROUND AND OBJECTIVES

Ropeginterferon alfa-2b is a novel monopegylated recombinant interferon alfa-2b for the treatment of patients with polycythemia vera. The objectives of this study were to evaluate the pharmacokinetics, pharmacodynamics, safety, and tolerability of ropeginterferon alfa-2b in healthy Japanese subjects compared with Caucasian subjects.

METHODS

In this multicenter, parallel-group phase I study, a cohort consisting of six Japanese and six Caucasian subjects was designated to receive a single subcutaneous dose of ropeginterferon alfa-2b (100, 200, 300, and 450 µg). Pharmacokinetic and pharmacodynamic parameters, and immunogenicity were evaluated. Safety was assessed throughout the study.

RESULTS

Cohort 4 (450-µg dose) was not initiated because the primary objective of this study was achieved based on the three completed cohorts. A total of 36 enrolled subjects (18 Japanese and 18 Caucasian) in three cohorts were included in the safety, pharmacokinetic, and pharmacodynamic analysis sets. Ropeginterferon alfa-2b exposure in terms of the area under the serum concentration-time curve (AUC) from time zero extrapolated to infinity and the AUC from time zero to the time of the last quantifiable concentration was approximately 1.7-fold and two-fold higher in Japanese subjects than in Caucasian subjects, respectively. Across the same dose range, the maximum serum concentration was approximately 1.25-fold higher in Japanese subjects than in Caucasian subjects. The time to reach the median maximum serum concentration was similar between ethnicities (approximately 96-111 h). The terminal half-life was 48-57 h in Japanese subjects and 31-75 h in Caucasian subjects. The slope of the relationship between dose and drug exposure was greater than 1 in both ethnicities. The dose-dependent induction of beta-2 microglobulin and neopterin expression was observed in both ethnicities, and the two groups showed similar pharmacodynamic parameters. At the end of the study, 22.2% of Japanese subjects and 11.1% of Caucasian subjects developed anti-ropeginterferon alfa-2b-binding antibodies. The neutralizing capacity of these antibodies was not tested. Ropeginterferon alfa-2b up to 300 µg was safe and well tolerated, with no unexpected safety findings based on previous experiences with ropeginterferon alfa-2b and other forms of interferon.

CONCLUSIONS

Ropeginterferon alfa-2b exposure was higher in Japanese subjects than in Caucasian subjects. The increase in ropeginterferon alfa-2b exposure was greater than the dose proportion in the dose range of 100-300 µg. Ropeginterferon alfa-2b was safe and well tolerated.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT03546465, registered on 6 June, 2018.

Epidemiology of the Philadelphia Chromosome-Negative Classical Myeloproliferative Neoplasms

Polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) comprise the BCR-ABL-negative classical myeloproliferative neoplasms (MPNs). These clonal myeloid diseases are principally driven by well-described molecular events; however, factors leading to their acquisition are not well understood. Beyond increasing age, male sex, and race/ethnicity differences, few consistent risk factors for the MPNs are known. PV and ET have an incidence of 0.5 to 4.0 and 1.1 to 2.0 cases per 100,000 person-years, respectively, and predict similar survival. PMF, which has an incidence of about 0.3 to 2.0 cases per 100,000 person-years, is associated with the shortest survival of the MPNs.

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

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

Oral Lichen Planus and Polycythemia: Possible Association

Oral lichen planus is a chronic inflammatory disease of established immune-mediated pathogenesis that affects the oral mucosa. Polycythemia is a nonaggressive myeloproliferative disorder, characterized by an increase in red blood cell mass, often with uncontrolled production of granulocytes and platelets. Their association was rarely mentioned in the scientific literature. The aim of this paper was to report their occurrence in a 52-year-old male patient. Although a casual connection cannot be excluded, both diseases share many similarities in the immune dysfunctions involved in their pathogenesis and their clinical features. Such a hypothesis remains to be demonstrated by further studies. The presence of oral lesions should alert the clinicians in the process of identifying and early diagnosing these diseases. Thus, complications can be prevented and treatment can be started at an early stage, avoiding further damage.

Does Polycythemia Vera Increase Risk of Postoperative Complications Following Primary Total Joint Arthroplasty? A Retrospective Matched Control Cohort Study of 6932 Polycythemia Vera Patients

BACKGROUND

There is sparsity of data on outcomes following joint arthroplasty among polycythemia vera (PV) patients. The aim of this study is to evaluate postoperative outcomes following primary total knee (TKA) and hip (THA) arthroplasty among PV patients.

METHODS

A retrospective Medicare database review identified 6932 PV patients who underwent a primary total joint arthroplasty (4643 TKAs and 2289 THAs) from 2006 to 2013. A comparison of hospital length of stay, mortality, and the diagnosis of surgical site infections (SSIs), stroke, myocardial infarction, acute pulmonary embolism (PE), deep vein thrombosis (DVT), and other postoperative complications was made between PV patients undergoing TKA and THA and their respective matched control groups.

RESULTS

PV was significantly associated with increased rates of acute PE (2.3% vs 1.6%; odds ratio [OR] 1.44, 95% confidence interval [CI] 1.17-1.75), DVT (4.2% vs 3.6%; OR 1.40, 95% CI 1.20-1.61, P < .001), postoperative hematoma (0.6% vs 0.4%; OR 1.57, 95% CI 1.03-2.28), and SSI (4.5% vs 3.6%; OR 1.25, 95% CI 1.08-1.44, P = .002) following TKA. Among PV patients who underwent a primary THA, PV was significantly associated with increased rate of acute PE (1.9% vs 1.4%; OR 1.40, 95% CI 1.01-1.88, P = .035), DVT (3.5% vs 2.6%; OR 1.32, 95% CI 1.04-1.66, P = .035), postoperative hematoma (1.1% vs 0.6%; OR 1.86, 95% CI 1.22-2.80), and 1-year mortality (2.2% vs 1.6%; OR 1.43, 95% CI 1.06-1.89, P = .016).

CONCLUSION

PV was significantly associated with increased risk for DVT, PE, postoperative hematoma, SSI (TKA only), and 1-year mortality (THA only) following primary total joint arthroplasty.

Epidemiology of the classical myeloproliferative neoplasms: The four corners of an expansive and complex map

The classical myeloproliferative neoplasms (MPNs), specifically chronic myeloid leukemia (CML), polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF), represent clonal myeloid disorders whose pathogenesis is driven by well-defined molecular abnormalities. In this comprehensive review, we summarize the epidemiological literature and present our own analysis of the most recent the Surveillance, Epidemiology, and End Results (SEER) program data through 2016. Older age and male gender are known risk factors for MPNs, but the potential etiological role of other variables is less established. The incidences of CML, PV, and ET are relatively similar at 1.0-2.0 per 100,000 person-years in the United States, while PMF is rarer with an incidence of 0.3 per 100,000 person-years. The availability of tyrosine kinase inhibitor therapy has dramatically improved CML patient outcomes and yield a life expectancy similar to the general population. Patients with PV or ET have better survival than PMF patients.

Beyond Hemoglobin: When and How to Work Up Possible Polycythemia Vera

BACKGROUND

World Health Organization (WHO) 2017 diagnostic criteria for hemoglobin levels in polycythemia vera (PV) were lowered from 185 g/L to 165 g/L for men and from 165 g/L to 160 g/L for women, but these cutoffs were not designed for screening.

OBJECTIVES

The primary aim of this study was to assess the value of laboratory and clinical parameters in deciding whether to further pursue a diagnosis of PV. A secondary aim was to explore the diagnostic utility of bone marrow morphology.

METHODS

We evaluated clinical and laboratory parameters that may be useful when considering further diagnostic work-up, emphasizing PV vs. secondary erythrocytosis (SE). We classified 200 patients with JAK2 V617F testing using WHO criteria.

RESULTS

Patients with myeloproliferative neoplasms (MPN) were rarely under age 40 and uncommonly obese (BMI ≥ 30 kg/m²). Current smoking history favored SE, and these patients rarely had a platelet count ≥ 450 × 10³/uL. Laboratory parameters suggesting greater PV likelihood were: RBC > 6.8 × 10⁶ for men or > 5.9 × 10⁶ for women; low erythropoietin; and low MCV or low ferritin. Bone marrow morphology (available in 111 cases) was generally more cellular in PV vs. SE and assessed disease progression.

CONCLUSIONS

Readily accessible clinical and laboratory data can assist in considering a PV workup, and a possible diagnostic algorithm is presented. These preliminary findings warrant larger studies to develop a more formal PV-risk scoring system with optimal cutoffs and weighting.

Prevalence Estimate of Blood Doping in Elite Track and Field Athletes During Two Major International Events

In elite sport, the Athlete Biological Passport (ABP) was invented to tackle cheaters by monitoring closely changes in biological parameters, flagging atypical variations. The hematological module of the ABP was indeed adopted in 2011 by World Athletics (WA). This study estimates the prevalence of blood doping based on hematological parameters in a large cohort of track and field athletes measured at two international major events (2011 and 2013 WA World Championships) with a hypothesized decrease in prevalence due to the ABP introduction. A total of 3683 blood samples were collected and analyzed from all participating athletes originating from 209 countries. The estimate of doping prevalence was obtained by using a Bayesian network with seven variables, as well as "blood doping" as a variable mimicking doping with low-doses of recombinant human erythropoietin (rhEPO), to generate reference cumulative distribution functions (CDFs) for the Abnormal Blood Profile Score (ABPS) from the ABP. Our results from robust hematological parameters indicate an estimation of an overall blood doping prevalence of 18% in 2011 and 15% in 2013 (non-significant difference) in average in endurance athletes [95% Confidence Interval (CI) 14-22 and 12-19% for 2011 and 2013, respectively]. A higher prevalence was observed in female athletes (22%, CI 16-28%) than in male athletes (15%, CI 9-20%) in 2011. In conclusion, this study presents the first comparison of blood doping prevalence in elite athletes based on biological measurements from major international events that may help scientists and experts to use the ABP in a more efficient and deterrent way.

Outcomes Following Posterior Lumbar Fusion in Patients with Polycythemia Vera

BACKGROUND

Polycythemia vera (PV) is a chronic myeloproliferative neoplasm that is associated with increased risk for venous and arterial thromboembolism. The aim of this study was to evaluate outcomes following elective posterior lumbar fusion (PLF) and/or posterior interbody fusion (PLIF) among patients with PV.

METHODS

Using PearlDiver retrospective national database, Medicare patients <85 years old who underwent elective primary PLF (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 81.07) and/or PLIF (ICD-9-CM code 81.08) for degenerative lumbar spine pathologies during 2006-2013 were identified. Patients included in the PLF and/or PLIF cohort were separated into patients with a prior diagnosis of PV (ICD-9-CM code 238.4) and a control cohort of patients without PV. Comparisons of postoperative outcomes were made between the PV patient group and matched control group. Significance was set at 0.05.

RESULTS

Selected study participants included 1491 patients with PV and 29,056 patients in the matched control group. Patients with PV had a significantly increased rate of 90-day acute pulmonary embolism (1.9% vs. 1.2%, odds ratio [OR] 1.65, 95% confidence interval [CI] 1.10-2.38, P = 0.010), 90-day lower extremity deep vein thrombosis (3.4% vs. 1.9%, OR 1.81, 95% CI 1.33-2.40, P < 0.001), and 1-year diagnosis of surgical site infection (5.4% vs. 4.2%, OR 1.30, 95% CI 1.02-1.63, P = 0.027) compared with patients without PV. Nonetheless, PV was not associated with other major medical complications, including stroke, myocardial infarction, and mortality, following PLF and/or PLIF.

CONCLUSIONS

Patients with PV undergoing elective PLF and/or PLIF have a significantly increased risk for pulmonary embolism, lower extremity deep vein thrombosis, and surgical site infection.

Identification of significant geographic clustering of polycythemia vera cases in Montreal, Canada

BACKGROUND

Polycythemia vera (PV) is a chronic myeloproliferative neoplasm associated at times with debilitating symptoms and a significant mortality rate. Understanding the demographics, epidemiology, and geography of this disease may provide further insight into important risk factors associated with its development. The objective of this study was to analyze patient demographics, incidence, and mortality rates, as well as the geographic distribution of PV patients in Canada between 1992 and 2010.

METHODS

This study was achieved by analyzing the Canadian Cancer Registry, Le Registre Québécois du Cancer, and the Canadian Vital Statistics patient databases.

RESULTS

A total of 4645 patients were diagnosed with PV between 1992 and 2010. While the annual incidence rate of this cancer fluctuated in Canada, mortality rate analysis indicated a decreasing trend. Geographically, PV incidence rates were notably elevated in the province of Quebec compared with the Canadian average. Further analysis of high-incidence forward sortation areas indicated a striking clustering of cases in the H4W region encompassing the Côte-Saint-Luc borough of Montreal, with an incidence of 102.97 (95% confidence interval, 75.11-137.79) cases per million per year, which is >13 times the national average.

CONCLUSION

The residential area of Côte-Saint-Luc is an important PV cluster in Canada, with high concentration of retirement homes and geriatric hospices. Also, Jewish residents comprise >60% of the population in this neighborhood. These findings suggest that an older age and, potentially, an inherent genetic predisposition may be implicated in the pathogenesis of this malignancy. This study provides a comprehensive overview of PV burden/geographic distribution of cases in Canada.

Emerging drugs for essential thrombocythemia

Introduction: Despite our recent progress in the understanding of essential thrombocythemia (ET) pathogenesis, the therapeutic management of this disease has remained largely unchanged in the past decades. Treatment has mostly focused on decreasing the risk of complications, especially prevention of thrombotic or hemorrhagic events. Areas covered: Over recent years, the treatment options of ET have been expanding with some novel agents on the horizon. The classes of agents described in this review include targeted and immunomodulatory agents, such as JAK1/2 inhibitors, interferon-α, histone deacetylase inhibitors, telomerase inhibitors and human double minute 2 inhibitors. These compounds entered various stages of development, albeit the only portion of them is currently actively undergoing evaluation in clinical trials. In this review, we look at the current therapies and discuss novel agents available in the management of ET. Expert opinion: The drug development in ET possesses several challenges stemming from its relatively benign and prolonged disease course. Therapy focused on reducing the risk of thrombotic and hemorrhagic complications and symptom management needs to be chosen wisely as a vast majority of these patients have a near-normal life expectancy. To date, no therapy has shown effective and definitive alteration of the disease behavior. Although novel agents are in development and hopefully some of them will extend treatment armamentarium of ET, their exact role remains to be determined.

Identification of myeloproliferative neoplasm drug agents via predictive simulation modeling: assessing responsiveness with micro-environment derived cytokines

Previous studies have shown that the bone marrow micro-environment supports the myeloproliferative neoplasms (MPN) phenotype including via the production of cytokines that can induce resistance to frontline MPN therapies. However, the mechanisms by which this occurs are poorly understood. Moreover, the ability to rapidly identify drug agents that can act as adjuvants to existing MPN frontline therapies is virtually non-existent. Here, using a novel predictive simulation approach, we sought to determine the effect of various drug agents on MPN cell lines, both with and without the micro-environment derived inflammatory cytokines. We first created individual simulation models for two representative MPN cell lines; HEL and SET-2, based on their genomic mutation and copy number variation (CNV) data. Running computational simulations on these virtual cell line models, we identified a synergistic effect of two drug agents on cell proliferation and viability; namely, the Jak2 kinase inhibitor, G6, and the Bcl-2 inhibitor, ABT737. IL-6 did not show any impact on the cells due to the predicted lack of IL-6 signaling within these cells. Interestingly, TNFα increased the sensitivity of the single drug agents and their use in combination while IFNγ decreased the sensitivity. In summary, this study predictively identified two drug agents that reduce MPN cell viability via independent mechanisms that was prospectively validated. Moreover, their efficacy is either potentiated or inhibited, by some of the micro-environment derived cytokines. Lastly, this study has validated the use of this simulation based technology to prospectively determine such responses.

Polycythemia causing posterior segment vascular occlusions

A 44-year-old male patient presented with features suggestive of transient central retinal artery occlusion (CRAO) followed by permanent CRAO and lateral posterior ciliary artery occlusion. He had diagnostic features of polycythemia vera (PV). When presented for the first time, the patient had features of ocular ischemia such as ocular pain, conjunctival congestion, and retinal opacification but with normal arm-to-retina time and normal arteriovenous transit time. During the second presentation, he had ocular pain, congested conjunctiva, retinal opacification, cherry red spot with box-carrying of retinal vessels, and choroidal infarct (Amalric's sign). He had lost light perception in that eye. Patients with polycythemia are prone to multifocal vascular occlusions and this can be the presenting feature in PV. A timely diagnosis and prompt management can prevent these repeated thromboembolic occlusive episodes.

Comprehensive Gene expression meta-analysis and integrated bioinformatic approaches reveal shared signatures between thrombosis and myeloproliferative disorders

Thrombosis is a leading cause of morbidity and mortality in patients with myeloproliferative disorders (MPDs), particularly polycythemia vera (PV) and essential thrombocythemia (ET). Despite the attempts to establish a link between them, the shared biological mechanisms are yet to be characterized. An integrated gene expression meta-analysis of five independent publicly available microarray data of the three diseases was conducted to identify shared gene expression signatures and overlapping biological processes. Using INMEX bioinformatic tool, based on combined Effect Size (ES) approaches, we identified a total of 1,157 differentially expressed genes (DEGs) (697 overexpressed and 460 underexpressed genes) shared between the three diseases. EnrichR tool’s rich library was used for comprehensive functional enrichment and pathway analysis which revealed “mRNA Splicing” and “SUMO E3 ligases SUMOylate target proteins” among the most enriched terms. Network based meta-analysis identified MYC and FN1 to be the most highly ranked hub genes. Our results reveal that the alterations in biomarkers of the coagulation cascade like F2R, PROS1, SELPLG and ITGB2 were common between the three diseases. Interestingly, the study has generated a novel database of candidate genetic markers, pathways and transcription factors shared between thrombosis and MPDs, which might aid in the development of prognostic therapeutic biomarkers.

Risk of second primary malignancies in a population-based study of adult patients with essential thrombocythemia

AIM: To determine the risk of second primary malignancy (SPM) and survival of patients with essential thrombocythemia (ET).

METHODS: We identified all patients with ET diagnosed during 2001 to 2011 from the Surveillance, Epidemiology and End Results (SEER) 18 database. Actuarial and relative survival methods were used to calculate the survival statistics. We utilized the SEER 13 database to calculate SPM. We used multiple primary standardized incidence ratio (SIR) session of the SEER*Stat software (version 8.1.5) to calculate SIR and excess risk of SPM for ET patients.

RESULTS: Age standardized five-year cause-specific survival was greater for patients < 50 years vs those ≥ 50 years (99.4% vs 93.5%, P < 0.01). Five-year cause-specific survival was lower for men vs women (70.2% vs 79.7%). A total of 201 patients (2.46%) developed SPM at a median age of 75 years. SPMs occurred at an observed/expected (O/E) ratio of 1.26 (95%CI: 1.09-1.45, P = 0.002) with an absolute excess risk (AER) of 37.44 per 10000 population. A significantly higher risk was noted for leukemia (O/E 3.78; 95%CI: 2.20-6.05, P < 0.001; AER 11.28/10000).

CONCLUSION: ET patients have an excellent cause-specific five-year survival but are at an increased risk of SPM, particularly leukemia, which may contribute to excess deaths.

Janus kinase (JAK) inhibitors in the treatment of inflammatory and neoplastic diseases

The Janus kinase (JAK) family of non-receptor protein-tyrosine kinases consists of JAK1, JAK2, JAK3, and TYK2 (tyrosine kinase-2). Each of these proteins contains a JAK homology pseudokinase (JH2) domain that regulates the adjacent protein kinase domain (JH1). JAK1/2 and TYK2 are ubiquitously expressed whereas JAK3 is found predominantly in hematopoietic cells. The Janus kinase family is regulated by numerous cytokines including interleukins, interferons, and hormones such as erythropoietin, thrombopoietin, and growth hormone. Ligand binding to cytokine and hormone receptors leads to the activation of associated Janus kinases, which then mediate the phosphorylation of the receptors. The SH2 domain of STATs (signal transducers and activators of transcription) binds to the receptor phosphotyrosines thereby promoting STAT phosphorylation by the Janus kinases and consequent activation. STAT dimers are translocated to the nucleus where they participate in the regulation of the expression of thousands of proteins. JAK-STAT dysregulation results in autoimmune disorders such as rheumatoid arthritis, ulcerative colitis, and Crohn disease. JAK-STAT dysregulation also plays a role in the pathogenesis of myelofibrosis, polycythemia vera, and other myeloproliferative illnesses. An activating JAK2 V617F mutation occurs in 95% of people with polycythemia vera and in a lower percentage of people with other neoplasms. JAK1/3 signaling participates in the pathogenesis of inflammatory afflictions while JAK1/2 signaling participates in the development of several malignancies including leukemias and lymphomas as well as myeloproliferative neoplasms. Tofacitinib is a pan-JAK inhibitor that is approved by the FDA for the treatment of rheumatoid arthritis and ruxolitinib is a JAK1/2 inhibitor that is approved for the treatment of polycythemia vera and myelofibrosis.

Myeloid malignancies in the real-world: Occurrence, progression and survival in the UK's population-based Haematological Malignancy Research Network 2004-15

BACKGROUND

Population-based information on cancer incidence, prevalence and outcome are required to inform clinical practice and research; but contemporary data are lacking for many myeloid malignancy subtypes.

METHODS

Set within a socio-demographically representative UK population of ∼4 million, myeloid malignancy data (N=5231 diagnoses) are from an established patient cohort. Information on incidence, survival (relative & overall), transformation/progression, and prevalence is presented for >20 subtypes.

RESULTS

The median diagnostic age was 72.4years (InterQuartile Range 61.6-80.2), but there was considerable subtype heterogeneity, particularly among the acute myeloid leukaemias (AML) where medians ranged from 20.3 (IQR 13.9-43.8) for AML 11q23 through to 73.7 (IQR 57.3-79.1) for AML with no recurrent genetic changes. Five-year Relative Survival (RS) estimates varied hugely; from <5% for aggressive entities like therapy-related AML (2.6%, 95% Confidence Interval 0.4-9.0) to >85% for indolent/treatable conditions like chronic myeloid leukaemia (89.8%, 95% CI 84.0-93.6). With a couple of notable exceptions, males experienced higher rates and worse survival than females: the age-standardized incidence rates of several conditions was 2-4 higher in males than females, and the 5-year RS for all subtypes combined was 48.8% (95% CI 46.5-51.2) and 60.4% (95% CI 57.7-62.9) for males and females respectively. During follow-up (potential minimum 2 years and maximum 11years) myelodysplastic syndrome (MDS) progression to AML ranged from 25% for refractory anaemia with excess blasts through to 5% for refractory anaemia with ring sideroblasts: the median interval between MDS and AML diagnosis was 9.0 months (IQR 4.8-17.4months).

CONCLUSIONS

The marked incidence and outcome variations seen by subtype, sex and age, confirm the requirement for "real-world" longitudinal data to inform aetiological hypotheses, healthcare planning, and future monitoring of therapeutic change. Several challenges for routine cancer registration were identified, including the need to link more effectively to diagnostic and clinical data sources, and to review policies on the recording of progressions and transformations.

Clinico-Epidemiological Profile of Patients with Polycythaemia Rubra Vera - a Five Year Experience from a Tertiary Care Center

BACKGROUND

Polycythaemia rubra vera (PV) is a Philadelphia chromosome negative myeloproliferative neoplasm characterized by increased red cell production, independent of the mechanisms that regulate normal erythropoiesis. The aim of this study was to analyze the clinico-epidemiological profile of Pakistani patients with PV.

MATERIALS AND METHODS

In this retrospective cross sectional study, 26 patients with PV were enrolled from January 2010 to December 2014. They were diagnosed based on WHO criteria.

RESULTS

The mean age was 53.4±9.31 years (range 36-72) and the male to female ratio was 2:1. Overall 30.7% of patients were asymptomatic. In symptomatic patients, major complaints were headache (30.8%), abdominal discomfort (23.1%), blurred vision (15.3%), pruritus (11.5%) and vascular incidents (11.5%). Physical examination revealed plethoric face and splenomegaly as predominant findings, detected in 34.6% and 30.7%, respectively, with the mean splenic span of 15.9±2.04cm. The mean hemoglobin was 18.1±1.9 g/dl with the mean hematocrit of 55.6±8.3%. The mean total leukocyte count was 12.8±7.1x109/l and the platelet count 511±341.9x109/l. Mean erythrocyte sedimentation rate was 3.5±1.22mm/hr. Serum lactate dehydrogenase, serum creatinine and uric acid were 552.7±309.2, 0.8±0.17 and 6.60±1.89 respectively.

CONCLUSIONS

PV in Pakistani patients, unlike in the West, is seen in a moderately young population. The disease is frequently seen in male gender and primarily patients present with symptoms related to hyperviscosity.

Somatic JAK-2 V617F Mutational Analysis in Polycythemia Rubra Vera: a Tertiary Care Center Experience

BACKGROUND

Polycythemia rubra vera (PV), being a primary polycythemia, is caused by neoplastic proliferation of erythroid, megakaryocytic and granulocytic lineages which result in panmyelosis. PV patients have a somatic acquired mutation in the Janus kinase (JAK2) pathway, rendering cell proliferation independent of the normal regulatory mechanisms that regulate erythropoiesis. The rational of this study was to determine the prevalence of the JAK-2 V617F mutation in Pakistani patients with PV.

MATERIALS AND METHODS

In this cross sectional study, 26 patients with PV were enrolled from January 2010 to December 2014. Patients were diagnosed based on WHO criteria for PV. All were screened for G-T point mutation (V617F) in the JAK2 gene on chromosome 9 by an allele specific PCR.

RESULTS

The mean age was 53.4±9.31 years (range 36-72) and the male to female ratio was 2:1. The frequency of JAK2 V617F positivity in our PV patients was found to be 92.3%. Overall 30.7% of patients were asymptomatic and remaining 69.3% presented with symptomatic disease. The mean hemoglobin was 18.1±1.9g/dl with the mean hematocrit of 55.6±8.3%. The mean total leukocyte count was 12.8±7.1x109/l and the platelet count was 511±341.9x109/l. A positive correlation of JAK2 V617F mutation was established with high TLC count (P=0.01). No correlation of JAK2 V617F could be established with age or gender (P>0.05).

CONCLUSIONS

The JAK2 V617F mutation frequency in our PV patients was similar to those reported internationally. Screening for the mutation in all suspected PV cases could be beneficial in differentiating patients with reactive and clonal erythrocytosis.

Clinico-Hematological Profile and Risk Stratification in Patients with Essential Thrombocythemia: Experience from Pakistan

BACKGROUND

Essential thrombocythemia (ET) is a Philadelphia chromosome-negative myeloproliferative neoplasm characterized by sustained thrombocytosis and megakaryocytic hyperplasia. It is an uncommon hematological malignancy which primarily affects elderly individuals. The rational of this study was to determine its clinico-hematological profile along with risk stratification in Pakistan patients.

MATERIALS AND METHODS

In this retrospective cross sectional study, 21 patients with ET were enrolled from January 2011 to December 2014. Data was analyzed with SPSS version 21.

RESULTS

The mean age was 56.7 ± 19.0 years (range 18-87) and the male to female ratio was 1:1.1. Of the total, 62% of patients were above 50 years of age. Overall 61.9% were diagnosed incidentally and were asymptomatic. In symptomatic patients, major complaints were weakness (19%); erythromelalgia (14.2%), transit ischemic attack (9.5%) and gastrointestinal bleed (4.7%). The mean hemoglobin count was 11.7 ± 2.4 g/dl with a total leukocyte count of 13.3 ± 8.1 x 10(9)/l and platelets count of 1188.8 ± 522.2 x 10(9)/l. Serum lactate dehydrogenase, serum creatinine and uric acid were 454.3 ± 127.8, 1.2 ± 0.5 and 7.4 ± 3.4 respectively. According to risk stratification, 57.1% were in high risk; 23.8% in intermediate risk while 19.1% in low risk group.

CONCLUSIONS

ET in our patients in Pakistan, unlike in the West, is seen in a relatively young population. Primarily patients were asymptomatic and risk stratification revealed predominance of high risk disease in our setting.

Hormonal and Reproductive Factors and Risk of Myeloproliferative Neoplasms in Postmenopausal Women

BACKGROUND

Hormonal and reproductive history has been associated with risk of some hematologic malignancies, but their role in myeloproliferative neoplasms (MPN) is largely unknown.

METHODS

Using a population-based cohort study, we evaluated the association of these factors with risk of MPN overall, and for essential thrombocythemia (ET) and polycythemia vera (PV) specifically. Incident MPN cases from 1993 to 2004 were identified via linkage to Medicare. RR and 95% confidence intervals (CI) were estimated utilizing Cox proportional hazard regression.

RESULTS

After >250,000 person-years of follow-up, 257 cases of MPN were identified (172 ET, 64 PV). Ever use of hormone therapy (HT) was associated with an increased risk of ET (RR = 1.63; 95% CI, 1.19-2.23) but a decreased risk of PV (RR = 0.58; 95% CI, 0.34-0.98). There were no statistically significant associations of oral contraceptives or reproductive factors with MPN risk overall, or by MPN subtype. Bilateral oophorectomy was associated with increased risk of ET (RR = 1.58; 95% CI, 1.11-2.25) and decreased risk of PV (RR = 0.32; 95% CI, 0.12-0.88). There was no association of ovulatory years with ET risk; however, there was increased risk of PV (RR = 1.68 for >36.8 compared with ≤27.6 years; P trend = 0.045). Adjustment for potential confounding factors did not alter these associations.

CONCLUSIONS

HT use and bilateral oophorectomy had opposite associations for ET and PV. Except for ovulatory years and PV risk, reproductive history did not appear to play a role in the etiology of MPN.

IMPACT

This study suggests different mechanistic impacts of estrogen, and perhaps distinct etiologies, for the two major MPN subtypes.

Leukemic transformation in essential thrombocythemia

Essential thrombocythemia patients develop acute myeloid leukemia (AML) at a rate of 1-4% during a median follow-up of 7-10 years. The risk increases with advanced age, anemia, platelet count ≥ 1000 × 10(9)/l, the presence of ≥ 2 somatic mutations and after the first decade of diagnosis. The use of alkylating agents and (32)radiophosphorus, particularly in higher doses, but not hydroxyurea and anagrelide, increases the risk. AML in essential thrombocythemia patients is frequently associated with unfavorable cytogenetics and poor prognosis. In young and fit patients, AML-type induction chemotherapy followed by allogeneic stem cell transplantation may offer the best chance of long-term disease control. In select elderly patients with poor performance status, hypomethylating agent such as azacytidine may prolong survival.

[The impact of autophagy on proliferation of HEL cells and hematopoietic cells of polycythemia vera patients with JAK2 V617F mutation]

目的

通过检测JAK2 V617F阳性HEL细胞及真性红细胞增多症（PV）患者造血细胞自噬水平，探索自噬调控对HEL细胞及PV患者造血细胞增殖的影响。

方法

应用流式细胞术、吖啶橙染色法、Western blot法检测JAK2 V617F阳性HEL细胞和12例PV患者造血细胞中LC3-Ⅱ蛋白的表达水平；通过雷帕霉素和3-甲基腺嘌呤（3-MA）分别诱导和抑制HEL细胞及3例PV患者骨髓细胞自噬水平，应用上述方法检测细胞中LC3-Ⅱ蛋白表达水平的改变，并采用CellTiter-Glo^®发光法检测细胞增殖活力。

结果

HEL细胞内LC3-Ⅱ蛋白的平均荧光强度（159 389±29 001）及自噬体水平明显高于JAK2 V617F阴性K562细胞（96 047±24 134）（P=0.044），PV患者外周血中髓系细胞内LC3-Ⅱ蛋白平均荧光强度（92 842±4 250）明显高于健康志愿者（86 633±2 504）（P=0.001）；自噬诱导剂雷帕霉素作用于HEL细胞和PV患者骨髓细胞12、24、48 h后，各时间点细胞增殖活力与常规培养组相比明显增强，48 h时HEL细胞和PV患者骨髓细胞增殖活力分别为101 413±3 720和18 744±1 015；自噬抑制剂3-MA作用于HEL细胞和PV患者骨髓细胞12、24、48 h后，各时间点细胞增殖活力与常规培养组相比明显减弱，48 h时HEL细胞和PV患者骨髓细胞增殖活力分别为5 732±166和5 371±56。

结论

JAK2 V617F阳性HEL细胞和PV患者造血细胞存在较高的基础自噬水平，上调自噬活性可促进其增殖；下调自噬活性对其增殖有明显抑制作用。

Genetic variation at MECOM, TERT, JAK2 and HBS1L-MYB predisposes to myeloproliferative neoplasms

Clonal proliferation in myeloproliferative neoplasms (MPN) is driven by somatic mutations in JAK2, CALR or MPL, but the contribution of inherited factors is poorly characterized. Using a three-stage genome-wide association study of 3,437 MPN cases and 10,083 controls, we identify two SNPs with genome-wide significance in JAK2(V617F)-negative MPN: rs12339666 (JAK2; meta-analysis P=1.27 × 10(-10)) and rs2201862 (MECOM; meta-analysis P=1.96 × 10(-9)). Two additional SNPs, rs2736100 (TERT) and rs9376092 (HBS1L/MYB), achieve genome-wide significance when including JAK2(V617F)-positive cases. rs9376092 has a stronger effect in JAK2(V617F)-negative cases with CALR and/or MPL mutations (Breslow-Day P=4.5 × 10(-7)), whereas in JAK2(V617F)-positive cases rs9376092 associates with essential thrombocythemia (ET) rather than polycythemia vera (allelic χ(2) P=7.3 × 10(-7)). Reduced MYB expression, previously linked to development of an ET-like disease in model systems, associates with rs9376092 in normal myeloid cells. These findings demonstrate that multiple germline variants predispose to MPN and link constitutional differences in MYB expression to disease phenotype.

How common are myeloproliferative neoplasms? A systematic review and meta-analysis

Myeloproliferative neoplasms (MPNs) are a heterogeneous group of diseases including polycythemia vera (PV), essential thrombocythemia (ET), and primary(idiopathic) myelofibrosis (PMF). In this systematic review, we provide a comprehensive report on the incidence and prevalence of MPNs across the globe. Electronic databases (PubMed, EMBASE, MEDLINE, and Web of Science) were searched from their inception to August 2012 for articles reporting MPN incidence or prevalence rates. A random effects meta-analysis was undertaken to produce combined incidence rates for PV, ET, and PMF. Both heterogeneity and small study bias were assessed. Thirty-four studies were included. Reported annual incidence rates ranged from 0.01 to 2.61, 0.21 to 2.27, and 0.22 to 0.99 per 100,000 for PV, ET, and PMF, respectively. The combined annual incidence rates for PV, ET, and PMF were 0.84, 1.03, and 0.47 per 100,000. There was high heterogeneity across disease entities (I(2) 97.1-99.8%) and evidence of publication bias for ET and PMF (Egger test, P = 50.007 and P ≤ 0.001, respectively).The pooled incidence reflects the rarity of MPNs. The calculated pooled incidence rates do not reflect MPN incidence across the globe due to the high unexplained heterogeneity. Improved, widespread registration of MPNs would provide better information for global comparison of the incidence and prevalence of MPNs.

Application of the optimized CO-rebreathing method for determination of hemoglobin mass in patients with polycythemia vera

Determination of red cell volume (RCV) might contribute to establishing the diagnosis of polycythemia vera (PV). A novel simplified method to detect RCV through CO rebreathing is nowadays applied in healthy young individuals but was not tested in a clinical or PV setting. The aim of the present study is to evaluate whether this spirometric approach is applicable in older subjects and contributes to PV diagnosis in a proof-of-concept approach. At first, RCV was determined by the optimized CO-rebreathing method in healthy subjects >50 years of age (n = 81, age 66 ± 9 years). Failure rate and age distribution of subjects who failed with CO rebreathing were analyzed. Then, RCV was measured in male PV patients (n = 7) and compared to healthy male controls (n = 35). RCV values in relation to several anthropometric references (body weight, body surface area (BSA), lean body mass (LBM)) were calculated to determine the sensitivity and specificity of established RCV thresholds when using optimized CO rebreathing. In healthy subjects, test failure rate was 9.9 %, but failure was not associated with age. Sensitivity and specificity (sens/spec) to detect PV was 100 %/83 % using the criteria of the PV study group. Using criteria based on BSA, sens/spec was 14 %/100 %. An arbitrary threshold of 50 ml/kg LBM yielded sens/spec of 100 %/97 %. In conclusion, this proof-of-concept indicates that optimized CO rebreathing is applicable in older subjects and allows determining RCV for the diagnosis of PV. Normalized values for RCV measures obtained from CO rebreathing are needed to grant sufficient sensitivity and/or specificity.

Combination treatment for myeloproliferative neoplasms using JAK and pan-class I PI3K inhibitors

Current JAK2 inhibitors used for myeloproliferative neoplasms (MPN) treatment are not specific enough to selectively suppress aberrant JAK2 signalling and preserve physiological JAK2 signalling. We tested whether combining a JAK2 inhibitor with a series of serine threonine kinase inhibitors, targeting nine signalling pathways and already used in clinical trials, synergized in inhibiting growth of haematopoietic cells expressing mutant and wild-type forms of JAK2 (V617F) or thrombopoietin receptor (W515L). Out of 15 kinase inhibitors, the ZSTK474 phosphatydylinositol-3′-kinase (PI3K) inhibitor molecule showed strong synergic inhibition by Chou and Talalay analysis with JAK2 and JAK2/JAK1 inhibitors. Other pan-class I, but not gamma or delta specific PI3K inhibitors, also synergized with JAK2 inhibitors. Synergy was not observed in Bcr-Abl transformed cells. The best JAK2/JAK1 and PI3K inhibitor combination pair (ruxolitinib and GDC0941) reduces spleen weight in nude mice inoculated with Ba/F3 cells expressing TpoR and JAK2 V617F. It also exerted strong inhibitory effects on erythropoietin-independent erythroid colonies from MPN patients and JAK2 V617F knock-in mice, where at certain doses, a preferential inhibition of JAK2 V617F mutated progenitors was detected. Our data support the use of a combination of JAK2 and pan-class I PI3K inhibitors in the treatment of MPNs.

Anthropometric, medical history and lifestyle risk factors for myeloproliferative neoplasms in the Iowa Women's Health Study cohort

Classical myeloproliferative neoplasms (MPNs) are composed of essential thrombocythemia (ET), polycythemia vera (PV) and myelofibrosis (MF), the etiology of which is largely unknown. We investigated the role of anthropometric, medical and lifestyle factors with risk of MPN in a prospective cohort of 27,370 women aged 55-69 years at enrollment. After >250,000 person-years of follow-up, 257 cases of MPN were identified (172 ET, 64 PV, 21 MF). Risk factor profiles were mostly unique for the two most common types, ET and PV. ET was associated with energy balance factors including body mass index (RR = 1.52 for >29.3 vs. <23.4 kg/m(2) ; p-trend = 0.042), physical activity (RR = 0.66 for high vs. low; p-trend = 0.04) and adult onset diabetes (RR = 1.82; p = 0.009), while PV was not. PV was associated with current smoking (RR = 2.83; p-trend = 0.016), while ET was not. Regular use of aspirin was associated with lower risk of ET (RR = 0.68; p = 0.017). These results broadly held in multivariate models. Our results suggest distinct etiologies for these MPN subtypes and raise mechanistic hypotheses related to obesity-related inflammatory pathways for ET and smoking-related carcinogenic pathways for PV. Regular aspirin use may lower risk for ET.

Essential thrombocythaemia: a single institution experience of 16 years

This presentation is a clinical narrative and long term follow up (6-16 years) of 21 prospectively studied patients with essential thrombocythaemia (ET) in Kuwait. The median age (55.9 years) is younger than reported by others. Two patients were below the age of 40 years with one of them presenting as post-polycytheamia ET at 16 years of age. Twelve patients (57.1 %) remained asymptomatic throughout the period of follow up. Four patients complained of erythromelalgia, three (19 %) suffered from thrombotic episodes and only one (4.3 %) had excessive bleeding. Four patients presented with splenomegaly. Intensity of thrombocytosis or duration of very high platelet count had no relationship with these complications. Two patients transformed to post-ET myelofibrosis and one patient developed chronic myeloid leukaemia (CML). None transitioned to acute leukaemia. All patients are still alive after follow up for 6-16 years. Janus kinase 2 mutation was positive in eight (38 %) patients. It had no bearing on transition of our ET patients to post-ET myelofibrosis or CML. Platelet aggregation tests were performed in 14 patients. Six (42.9 %) showed defective response to ADP. Only one of these patients suffered from bleeding. All patients were given aspirin (81 mg/day). Cyto-reductive therapy with hydroxyurea was taken by six (42.9 %) subjects. Two patients who were treated with anagrelide and one with alpha-interferon did not continue treatment for long.

Efficacy and safety of cytoreductive therapies in patients with essential thrombocythaemia aged >80 years: an interim analysis of the EXELS study

Background

The median age of patients diagnosed with essential thrombocythaemia (ET) is 65–70 years but the management of very elderly patients (aged >80 years) with ET has not been well characterized.

Objective

This study aimed to document the treatment patterns of very elderly patients with ET in a multinational, real-world setting.

Study Design

EXELS (Evaluation of Xagrid Efficacy and Long-term Safety) is a phase IV observational study, designed to monitor the efficacy and safety of cytoreductive therapies in clinical practice. In total, 3,598 high-risk patients with ET were recruited from May 2005 to April 2009, in 13 European countries. Data were collected at registration and every 6 months thereafter for 5 years. This analysis was performed on a data-cut taken approximately 2 years after the last patient was registered.

Patients

In total, 395 patients aged >80 years at registration into EXELS were included in the analysis; of these, 42.2 % had experienced a previous thrombohaemorrhagic event.

Results

At registration, the most frequently prescribed cytoreductive therapy for patients aged >80 years was hydroxycarbamide (HC), which accounted for 82.8 % of patients whereas anagrelide use was less frequent (8.6 %). Very elderly patients were more likely to be switched from anagrelide than from HC (47.1 vs. 17.4 %; 95 % confidence interval for difference in proportion 12.4–46.9; Chi-squared test p < 0.001). Median platelet count during treatment was ~430 × 10⁹/L. In patients aged >80 years, the main reason for switch was intolerance/side effects (34.1 %); 0/16 patients reported treatment with anagrelide was non-efficacious compared with 8/57 (14 %) patients receiving HC, and 7/16 (43.8 %) anagrelide patients switched because of intolerance versus 18/57 (31.6 %) patients receiving HC. At least one predefined clinical event (PDE) was experienced by 27.3 % of patients aged >80 years. The most common PDEs reported in the very elderly age group were death (non-PDE related; 11.1 %), other cardiovascular symptoms (5.8 %), haematological transformation (3.8 %), congestive heart failure (3.3 %), myocardial infarction and angina (2.8 %), and thromboembolic events (6.3 %).

Conclusion

Well-tolerated and effective cytoreductive therapy has been achieved in patients aged >80 years by following individual treatment modalities that appear in agreement with the recent European LeukemiaNet (ELN) guidelines.

Clinical Trial Registration

Registered as ClinicalTrials.gov identifier NCT00567502; Protocol No: SPD422-401.