Clinical course of essential thrombocythemia in 147 cases

Thrombotic Prediction Model Based on Epigenetic Regulator Mutations in Essential Thrombocythemia Patients Using Survival Analysis in Recurrent Events

INTRODUCTION

Essential thrombocythemia (ET) involves the proliferation of megakaryocytes and platelets and is associated with an increased risk of thrombosis. We aimed to evaluate thrombotic risks in patients with epigenetic regulator mutations and generate a model to predict thrombosis in ET.

MATERIALS AND METHODS

This cohort study enrolled patients aged > 15 years diagnosed with ET at the Songklanakarind Hospital between January 2002 and December 2019. Twenty-five targeted gene mutations, including somatic driver mutations (JAK2, CALR, MPL), epigenetic regulator mutations (TET2, DNMT3A, IDH1, IDH2, TET2, ASXL1, EZH2, SF3B1, SRSF2) and other genes relevant to myeloid neoplasms, were identified using next-generation sequencing. Thrombotic events were confirmed based on clinical condition and imaging findings, and thrombotic risks were analyzed using five survival models with the recurrent event method.

RESULTS

Ninety-six patients were enrolled with a median follow-up of 6.91 years. Of these, 15 patients experienced 17 arterial thrombotic events in total. Patients with JAK2 mutation and IDH1 mutation had the highest frequency of thrombotic events with somatic driver mutations (17.3%) and epigenetic regulator mutations (100%). The 10-year thrombosis-free survival rate was 81.3% (95% confidence interval: 72.0-91.8%). IDH1 mutation was a significant factor for thrombotic risk in the multivariate analysis for all models. The Prentice, William, and Peterson (PWP) gap-time model was the most appropriate prediction model.

CONCLUSIONS

The PWP gap-time model was a good predictive model for thrombotic risk in patients with ET. IDH1 mutation was significant risk factors for thrombosis; however, further studies with a larger sample size should confirm this and provide more insight.

The effect of thrombocytapheresis on hemogram and biochemistry parameters in patients with essential thrombocytemia

BACKGROUND

Essential thrombocythemia is one of the chronic myeloproliferative neoplasms characterized by clonal proliferation of myeloid cells with variable morphological maturation and hematopoietic activity.It is characterized by excessive clonal platelet production with a tendency to thrombosis and bleeding. Thrombocytapheresıs is the removal of platelets by apheresis techniques. Thrombocytapheresıs is generally recommended in patients with essential thrombocythemia with acute, severe thrombotic or hemorrhagic events.

METHODS

The study included 39 patients who were diagnosed with essential thrombocythemia, started cytoreductive and aspirin therapy, and underwent thrombocytapheresıs due to the development of acute severe thrombotic or hemorrhagic events, diagnosed in the adult hematology clinic of İnönü University Turgut Ozal Medical Center. Hemogram and biochemistry values of the patients were scanned retrospectively.

RESULTS

After thrombocytapheresıs, a statistically significant difference was found between the first and last measurements of hemoglobin, mean platelet volume, White blood cell, neutrophil, platelet, platelet distribution width, creatine, lactate dehydrogenase, fibronogen and calcium levels of the patients.

CONCLUSION

The use of thrombocytapheresıs in patients with essential thrombocytosis causes a rapid decrease in platelet values as well as an effect on hemogram and biochemistry parameters. Other hemogram and biochemistry parameters such as platelet value should be monitored in patients.

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.

Allelic burden of Janus kinase 2 in a 6-month course of therapy for myeloproliferative neoplasms

BACKGROUND

Janus kinase 2 (JAK2) V617F gene mutation is an important marker for the diagnosis of Philadelphia negative Myeloproliferative neoplasms (MPN) which is subdivided into Polycythemia Vera (PV), Primary Myelofibrosis (PMF), and Essential Thrombocythemia (ET). The aim here is to investigate the JAK2 allele burden of the patients diagnosed with the subgroups of MPN and to demonstrate the alterations of hematological parameters and spleen size between diagnosis and 6 months of treatment.

METHODS

A total of 107 patients with the diagnosis of MPN and negative Philadelphia chromosome, 51 males and 56 females with a mean age of 59,74 ± 16,41 years, were included in the study. Diagnosis of MPN was based on the World Health Organization (WHO) criteria. Subgroups of MPN distributed as 49,5% ET, 46,7% PV, and 3,8% PMF. Findings such as the age of the patients, JAK-2 allele burden, and laboratory findings of splenomegaly were examined at the time of diagnosis, 3rd month, and 6th month. JAK2 allele burden and spleen size were re-evaluated in 6th month.

RESULTS

Our study confirmed the findings of high Hb, HCT, and RBC but low platelet values in PV patients with high JAK2 allele burden with respect to other groups, a positive correlation between JAK2 allele burden and LDH.

CONCLUSIONS

A novel finding of our study is, that there is not any reducing effect of the phlebotomy on JAK2 allele burden in PV patients whether they receive phlebotomy or not. Evaluation of the spleen size alteration during 6 months within the subgroups demonstrated a decrease in PV and ET groups whereas no statistically significant difference was found in the PMF group.

Structural and Dynamic Differences between Calreticulin Mutants Associated with Essential Thrombocythemia

Essential thrombocythemia (ET) is a blood cancer. ET is characterized by an overproduction of platelets that can lead to thrombosis formation. Platelet overproduction occurs in megakaryocytes through a signaling pathway that could involve JAK2, MPL, or CALR proteins. CALR mutations are associated with 25–30% of ET patients; CALR variants must be dimerized to induce ET. We classified these variants into five classes named A to E; classes A and B are the most frequent classes in patients with ET. The dynamic properties of these five classes using structural models of CALR’s C-domain were analyzed using molecular dynamics simulations. Classes A, B, and C are associated with frameshifts in the C-domain. Their dimers can be stable only if a disulfide bond is formed; otherwise, the two monomers repulse each other. Classes D and E cannot be stable as dimers due to the absence of disulfide bonds. Class E and wild-type CALR have similar dynamic properties. These results suggest that the disulfide bond newly formed in classes A, B, and C may be essential for the pathogenicity of these variants. They also underline that class E cannot be directly related to ET but corresponds to human polymorphisms.

Risk of thrombosis in essential thrombocythemia according to three prediction models: an external validation study

BACKGROUND

Thrombosis is a major complication of essential thrombocythemia (ET). There are three well-known prediction models for thrombotic risk in ET patients. However, only few external validation studies for the performance of these models in Asian populations have been conducted. Thus, we aimed to evaluate the performance of these models for predicting the risk of thrombosis in Thai patients with ET.

METHODS

We retrospectively evaluated the clinical characteristics and thrombotic risk of 149 Thai ET patients in a university hospital in Southern Thailand between 2002 and 2019. Thrombotic risk variables were evaluated using Cox proportional hazard regression. The Brier score, calibration plot, and Harrel concordance index (C-index) were used to evaluate the performance of the three models.

RESULTS

With a median follow-up of 5.2 years, there were a total of 28 thrombotic events in 26 patients. Age > 60 years was a significant prognostic factor for thrombosis in the multivariate Cox regression analysis. The Brier scores were 0.251, 0.273, and 0.276 in the conventional, IPSET-thrombosis, and revised IPSET-thrombosis models, respectively. The conventional model had optimal calibration and good discrimination (C-index, 0.67; 95%CI:0.55-0.79). The IPSET thrombosis (C-index 0.33; 95%CI:0.20-0.49) and revised IPSET thrombosis (C-index 0.31; 95%CI:0.18-0.44) models showed poor discrimination.

CONCLUSION

The conventional model, which is based on age and history of thrombosis, is the best model to predict thrombotic risk in Thai ET patients. Further studies with a larger number of patients with thrombotic events are needed to validate the IPSET-thrombosis and revised IPSET-thrombosis models.

Clinical characteristics and management of headache in patients with myeloproliferative neoplasms

Background

Headache is frequently reported as a neurological manifestation of myeloproliferative neoplasms (MPNs), including polycythemia vera and essential thrombocythaemia. This study sought to clarify the clinical characteristics and response to treatment of headaches in patients with MPNs.

Methods

We prospectively studied 137 patients with MPNs. The following information was gathered to assess the features of headache at baseline and at follow-up (>6 months): (1) average duration of headache attacks, (2) number of headache days per month, (3) numerical rating scale (NRS), (4) Headache Impact Test-6 (HIT-6), and (5) Migraine Disability Assessment (MIDAS). We compared those parameters for headaches between the baseline and follow-up interviews according to the management.

Results

Thirty-seven (27.0%) patients had headache. The prevalence of headaches gradually decreased with increasing age (Age ≤ 49 years: 61.0%, 50-59 years: 38.5%, 60-69 years: 17.2%, 70-79 years: 5.1%, and ≥80 years: 0.0%, P < 0.001). Multiple logistic regression analysis showed that younger age, but not platelet counts or the JAK2 V617F mutation, was independently associated with headaches (Odds Ratios 2.004, 95% confidence intervals 1.293-3.108, P = 0.002). Scintillating scotomas were present in 22 (59.5%) of 37 patients with headaches, while four patients developed sudden headaches that lasted for only 0-10 min. Follow-up interviews were available for 31 (83.8%) of 37 patients with headaches. Twenty-one (67.7%) patients were treated with low-dose aspirin (100 mg once daily) [low-dose aspirin alone: n = 9; combined cytoreductive therapy: n = 12] for headache management. All parameters for headache [average duration of headache attacks, number of headache days per month, NRS score, HIT-6 score, and MIDAS score (all P < 0.001)] were significantly improved at follow-up in patients taking low-dose aspirin. However, there were no significant differences in these parameters of headaches in patients who did not receive low-dose aspirin.

Conclusion

Headaches is common in patients with MPNs, particularly in younger patients. MPN-related headaches may be managed by using low-dose aspirin and controlling MPNs.

Essential Thrombocytosis in Patients <40 Years Old With Acute Coronary Syndromes: A Not So Uncommon Underlying Diagnosis Often Overlooked

BACKGROUND

In patients under <40 years, traditional cardiovascular (CV)-risk factors are a less likely cause of acute coronary syndromes (ACS) compared to older counterparts.

AIMS

To estimate the prevalence of essential thrombocytosis (ET), a hematological disorder and less-prevalent risk factor, in young patients presenting with ACS.

METHODS

We constructed a retrospective database of all patients <40 years (n=271) that had consecutively undergone coronary angiography (CAG) after their first ACS within our hospital within the last ten years (2010-2020) and had known thrombocyte counts (n=241). Patients with thrombocytes >450x10*9/L were screened for this hematological disorder.

RESULTS

In our database, we identified 15 subjects with thrombocytosis. One was previously known as ET. Of the remaining 14 patients, five were considered reactive/secondary thrombocytosis, and four were lost to follow-up, four were eventually diagnosed with ET, one remains uncertain. The diagnosis was newly established before the initiation of this study in two patients (average delay: six years). Two patients were identified as a result of this study.  Conclusion: With a prevalence of at least 2.1%, ET appears not uncommon in patients <40 years with ACS. Moreover, screening patients with ACS and elevated thrombocytes yielded a novel diagnosis of ET in 27% of patients. The diagnosis was initially missed in all cases. Since the timing of revascularization should be adjusted to thrombocyte count/initiation of ET therapy to prevent thrombotic complications, cardiologists should know, recognize and screen for this pathology in ACS-patients, notably in those with absent traditional CV-risk factors: an 'ACS-protocol' aimed at less-prevalent risk factors could support this.

A multicenter, open-label study for efficacy and safety evaluation of anagrelide in patients with treatment-naïve, high-risk essential thrombocythemia as a primary treatment

As the discussion of first-line anagrelide treatment is ongoing, we aimed to prospectively examine the efficacy and safety of anagrelide in cytoreduction therapy-naïve high risk essential thrombocythemia (ET) patients in Korea. Seventy patients from 12 centers were treated with anagrelide monotherapy for up to 8 weeks, followed up until 24 months. At week 8, 50.0% of the patients were able to achieve platelet < 600 x 109/L, and by 12 months, 55/70 (78.6%) patients stayed on anagrelide, and 40.0% patients showed platelet normalization. 14 patients required additional hydroxyurea (HU) for cytoreduction. The median daily dose of needed HU was 500mg (range 250mg - 1500mg). The efficacy was independent of the somatic mutation status. There were 4 thromboembolic events and 7 bleeding events during the follow-up period. The most common adverse events associated with anagrelide use were headache, followed by palpitation/chest discomfort, edema and generalized weakness/fatigue. 7 patients wished to discontinue anagrelide treatment due to adverse events (3 due to headache; 2 due to edema; 1 due to palpitation and 1 due to skin eruption). All in all, first-line anagrelide treatment showed a favorable response with tolerable safety profiles regardless of somatic mutation status.

Pro106Leu MPL mutation is associated with thrombocytosis and a low risk of thrombosis, splenomegaly and marrow fibrosis

The P106L mutation in the human myeloproliferative leukemia virus oncogene (MPL) was shown to be associated with hereditary thrombocythemia in Arabs. The clinical and bone marrow (BM) features of P106L mutation are unknown. Genetic databases at two tertiary hospitals in Saudi Arabia were searched to identify patients with the MPL P106L mutation. Clinical data were collected retrospectively and the BM aspirates and biopsies were independently reviewed by two hematopathologists. In total, 115 patients were included. Median age was 33 years of which 31 patients were pediatric and 65 were female. The mutation was homozygous in 87 patients. Thrombocytosis was documented in 107 patients, with a median platelet count of 667 × 10⁹/L. The homozygous genotype was associated with a higher platelet count. Thirty-three patients had an evaluable BM and clustering of megakaryocytes was observed in 30/33 patients. At the time of last follow-up, 114 patients were alive. The median follow-up was 7.8 years from the time of thrombocytosis. No patients developed disease progression to myelofibrosis. The P106L mutation was associated with marked thrombocytosis at a younger age and with a low risk of thrombosis, splenomegaly, and marrow fibrosis. The BM demonstrated normal or hypocellular marrow with megakaryocyte clusters.

Insights into the Potential Mechanisms of JAK2V617F Somatic Mutation Contributing Distinct Phenotypes in Myeloproliferative Neoplasms

Myeloproliferative neoplasms (MPN) are a group of blood cancers in which the bone marrow (BM) produces an overabundance of erythrocyte, white blood cells, or platelets. Philadelphia chromosome-negative MPN has three subtypes, including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The over proliferation of blood cells is often associated with somatic mutations, such as JAK2, CALR, and MPL. JAK2V617F is present in 95% of PV and 50–60% of ET and PMF. Based on current molecular dynamics simulations of full JAK2 and the crystal structure of individual domains, it suggests that JAK2 maintains basal activity through self-inhibition, whereas other domains and linkers directly/indirectly enhance this self-inhibited state. Nevertheless, the JAK2V617F mutation is not the only determinant of MPN phenotype, as many normal individuals carry the JAK2V617F mutation without a disease phenotype. Here we review the major MPN phenotypes, JAK-STAT pathways, and mechanisms of development based on structural biology, while also describing the impact of other contributing factors such as gene mutation allele burden, JAK-STAT-related signaling pathways, epigenetic modifications, immune responses, and lifestyle on different MPN phenotypes. The cross-linking of these elements constitutes a complex network of interactions and generates differences in individual and cellular contexts that determine the phenotypic development of MPN.

Is It Possible to Predict Clonal Thrombocytosis in Triple-Negative Patients with Isolated Thrombocytosis Based Only on Clinical or Blood Findings?

JAK2, MPL, and CALR mutations define clonal thrombocytosis in about 90% of patients with sustained isolated thrombocytosis. In the remainder of patients (triple-negative patients) diagnosing clonal thrombocytosis is especially difficult due to the different underlying conditions and possible inconclusive bone marrow biopsy results. The ability to predict patients with sustained isolated thrombocytosis with a potential clonal origin has a prognostic value and warrants further examination. The aim of our study was to define a non-invasive clinical or blood parameter that could help predict clonal thrombocytosis in triple-negative patients. We studied 237 JAK2 V617-negative patients who were diagnosed with isolated thrombocytosis and referred to the haematology service. Sixteen routine clinical and blood parameters were included in the logistic regression model which was used to predict the type of thrombocytosis (reactive/clonal). Platelet count and lactate dehydrogenase (LDH) were the only statistically significant predictors of clonal thrombocytosis. The platelet count threshold for the most accurate prediction of clonal or reactive thrombocytosis was 449 × 10⁹/L. Other tested clinical and blood parameters were not statistically significant predictors of clonal thrombocytosis. The level of LDH was significantly higher in CALR-positive patients compared to CALR-negative patients. We did not identify any new clinical or blood parameters that could distinguish clonal from reactive thrombocytosis. When diagnosing clonal thrombocytosis triple-negative patients are most likely to be misdiagnosed. Treatment in patients with suspected triple negative clonal thrombocytosis should not be delayed if cardiovascular risk factors or pregnancy coexist, even in the absence of firm diagnostic criteria. In those cases the approach “better treat more than less” should be followed.

Postoperative bleeding in essential thrombocytosis patients with colorectal cancer: Case report and literature review

Introduction and importance

Essential thrombocythemia (ET) is a myeloproliferative disorder characterized by increased platelet count and a high risk of bleeding or thrombotic events due to platelet dysfunction. Patients with ET are treated according to their risk of complications with cytoreductive or anti-aggregant treatment. Neither guidelines for oncologic patients nor perioperative management of patients with ET have been determined.

Case presentation

A 41-year-old female patient with ET who had alternating constipation and diarrhea was referred after a screening colonoscopy diagnosing a locally advanced rectosigmoid junction colon adenocarcinoma with liver metastases. Systemic preoperative chemotherapy was indicated. The patient underwent laparoscopic low anterior resection plus volume-preserving right lobectomy of the liver. Postoperative bleeding of the internal iliac artery (IIA) associated with hematoma at the lower pelvic cavity was diagnosed and treated by interventional radiology; the patient was discharged without other complications 16 days after surgery.

Clinical discussion

ET has been related to the development of hematologic complications or second non-hematologic malignancies. A systematic review was conducted to seek guidance for the management of such patients in the perioperative period. Special perioperative care must be taken, and complications management should avoid further hemorrhages or cloth formation.

Conclusion

Under oncologic and hematological guidance, minimally invasive surgery and non-invasive management of complications are advised in the lack of published perioperative management guidelines of ET patients with colorectal cancer.

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Essential thrombocythemia (ET) is a rare clonal myeloproliferative disorder.

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ET can manifest as hemorrhage, thrombosis, and functional microvascular symptoms.

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Cytoreductive treatment and anti-aggregants are indicated in ET with a high risk of complications.

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Colorectal cancer, with its surgical and oncologic treatment, may increase the risk of adverse vascular events.

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Perioperative management of patients with ET has not been determined.

Ischemic Stroke in a Young Man: Unraveling the Domain of Myeloproliferative Disorders

Ischemic stroke is a rare phenomenon in young adults. A complete workup for hypercoagulable and myeloproliferative disorders is a cornerstone of evaluation. Essential thrombocytosis is a chronic myeloproliferative disorder that primarily involves platelets. It may remain undiagnosed in patients and subsequently present in the form of ischemic stroke. The management of this disorder is complex and often involves cytoreduction therapies. The initiation of these drugs in such patients may lead to unnecessary adverse effects and complications. This case report is an attempt to highlight an underappreciated cause of stroke when assessing young individuals.

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

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

Hemodynamic Instability in Emergency Department: Giant Rectus Sheath Hematoma and Point-of-Care Ultrasonography

Iatrogenic rectus sheath hematoma (RSH) developed after paracentesis is a rare but life-threatening complication. Mortality rates of patients may increase due to delays in treatment and comorbid conditions. In this article, we present the case of a patient who was unstable in the emergency department and was diagnosed with RSH using point-of-care ultrasonography (POCUS). The importance of POCUS has increased as hematoma manifestations of patients with severe ascites tend to be obscured. POCUS has varied uses in the emergency department, and in this article we emphasize the use of POCUS in a life-threatening case of RSH.

CALR-ETdb, the database of calreticulin variants diversity in essential thrombocythemia

Essential thrombocythemia (ET) is a blood cancer defined by a strong increase of platelet numbers. A quarter of patients suffering from ET show mutations in the last exon of calreticulin (CALR) gene. Two variants named type 1 and type 2 represent 85% of these patients. However, a large number of other variants have been determined. In this study, we have compiled variants taken from COSMIC database and literature leading to 155 different variants. This large number of variants allowed redefining 5 new classes extending the classification of type 1-like and type 2-like to a finer description. These analyses showed that last class, named E, corresponding to more than 10% of CALR variants seemed not attached to ET. Structural properties analyzed showed that CALR variants associated to ET have common features. All the compiled and refined information had been included into a freely dedicated database CALR-ETdb (https://www.dsimb.inserm.fr/CALR-ET).

The 2020 revision of the guidelines for the management of myeloproliferative neoplasms

In 2016, the World Health Organization revised the diagnostic criteria for myeloproliferative neoplasms (MPNs) based on the discovery of disease-driving genetic aberrations and extensive analysis of the clinical characteristics of patients with MPNs. Recent studies have suggested that additional somatic mutations have a clinical impact on the prognosis of patients harboring these genetic abnormalities. Treatment strategies have also advanced with the introduction of JAK inhibitors, one of which has been approved for the treatment of patients with myelofibrosis and those with hydroxyurea-resistant or intolerant polycythemia vera. Recently developed drugs aim to elicit hematologic responses, as well as symptomatic and molecular responses, and the response criteria were refined accordingly. Based on these changes, we have revised the guidelines and present the diagnosis, treatment, and risk stratification of MPNs encountered in Korea.

CIN or not: An approach to the evaluation and management of chronic idiopathic neutrophilia

Neutrophilia refers to an increase in the number of circulating neutrophils in the peripheral blood. Some common etiologies include infection, inflammatory conditions, myeloproliferative disorders, malignancies, endocrinopathies, drugs, and anemia. Rare disorders such as leukocyte adhesion deficiency can also cause neutrophilia. In many cases, there is an elevation of neutrophil count that persists for months or even years with no clear underlying cause in an otherwise asymptomatic patient. This is referred to as chronic idiopathic neutrophilia (CIN). Despite being a condition encountered by many physicians, there is a paucity of literature addressing CIN. Certain conditions such as stress, exercise, smoking, obesity, and obstructive sleep apnea have been associated with CIN and may provide explanations for neutrophilia previously thought to be idiopathic. Herein, we present a review of the literature on CIN and propose a systematic approach to this commonly encountered clinical condition.

Ocular Manifestations in Patients with Philadelphia-Negative Myeloproliferative Neoplasms

The major complications of Philadelphia-negative (Ph-Negative) myeloproliferative neoplasms (MPNs) are thrombosis, haemorrhage and leukemic transformation. As systemic and haematological diseases, MPNs have the potential to affect many tissues and organs. Some complications lead to the diagnosis of MPNs, but other signs and symptoms are often misdiagnosed or neglected as a sign of MPN disease. Therefore, we reviewed the current literature to investigate and delineate the clinical manifestations seen in the eyes of Ph-negative MPN patients. We found that ocular manifestations are common among patients with MPNs. The most frequently described manifestations are due to the consequences of haematological abnormalities causing microvascular disturbances and hyperviscosity. More serious and vision-threatening complications as thrombotic events in the eyes have been repeatedly reported as well. These ocular symptoms may precede more serious extraocular complications. Accordingly, combined ophthalmological and haematological management have the potential to discover these diseases earlier and prevent morbidity and mortality in these patients. Furthermore, routine ophthalmological screening of all newly diagnosed MPN patients may be a preventive approach for early diagnosis and timely treatment of the ocular manifestations.

Thiol-disulphide Homeostasis in Essential Thrombocythemia Patients

Background

This study aimed to show the status of thioldisulphide homeostasis in essential thrombocytosis patients, which is known to play a role in platelet function.

Methods

The study included 27 ET patients and a control group of 36 healthy subjects. Serum total (-SH + -S-S-) and native (-SH) thiol levels were measured in all subjects using an automatic method.

Results

Age and gender distribution were similar in both groups. Compared with the control group, in the ET group, there were increased native thiol and total thiol levels (p = 0.001, p = 0.046). There was no correlation between thiol, total thiol and disulphide ratios with Jak2 mutation, hemorrhage and thrombosis. A positive correlation was determined between thrombosis and thiol disulphide homeostasis (p = 0.058). The study results showed that thiol-disulphide homeostasis shifted to the proliferative side in ET, in which ineffective erythropoiesis was predominant. It is also known that platelets are more active in ET cases and thiol disulphide balance is important in platelet function.

Conclusions

This result suggests that thrombotic complications may be reduced if the formation is achieved of mechanisms (oxidation mechanisms) that will trigger the increase of disulphide groups. However, more extensive research is needed on this subject.

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.

Developments in diagnosis and treatment of essential thrombocythemia

INTRODUCTION

Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm characterized by thrombocytosis, increased risk of thrombotic/hemorrhagic events and clonal evolution into blast phase or myelofibrosis. Areas covered: The authors will discuss biology, diagnosis, prognosis, therapy, and outcome of ET. An accurate molecular-morphologic assessment is necessary in order to properly establish diagnosis and prognosis of ET. Stratification for thrombosis prediction is essential, and IPSET-t model is widely applied. The current treatment strategy is directed to lower the rate of vascular events using cytoreduction in patients at high risk. Prophylactic low dose aspirin indication is more uncertain. To date, therapies for patients who are resistant or intolerant to first-line treatments are scarce. Overall, life expectancy indicates an indolent disease, but IPSET model helps in predicting survival at the time of diagnosis. Expert opinion: Challenging for the future will be to share criteria for ET diagnosis with the community. New insights into the molecular pathogenesis of the disease will improve the prediction of clonal evolution and outcome, and lead to the use of disease-modifying treatments.

Assessment of Endothelial Dysfunction With Flow-Mediated Dilatation in Myeloproliferative Disorders

BACKGROUND

Thrombosis is the most important cardiovascular complication of classical myeloproliferative disorders (MPDs). Endothelial dysfunction (ED) is known to play a major role in the mechanism of thrombophilia in MPDs.

METHODS

Endothelial dysfunction and its associations with other parameters were investigated. A total of 18 patients with polycythemia vera (PV), 24 with essential thrombocytosis (ET), 7 with primary myelofibrosis (PMF), and 30 healthy patients as a control group were included in the study. To assess the ED, flow-mediated dilatation (FMD) measurements were used.

RESULTS

The FMD (%) result showing ED was determined as 9.9 (0.0-21.6) in the patients with PV, 7.3 (0.0-30.5) in patients with ET, 7.5 (0.0-18.0) in patients with PMF, and 13.9 (6.2-26.7) in the control group. The FMD (%) was markedly impaired in all patients with MPD compared to the control patients (7.8 [0.0-30.5] vs 13.9 [6.15-26.8], P = .02). According to the disease subtypes, FMD (%) was significantly lower in the ET group than in the control group ( P = .01).

CONCLUSION

Endothelial function was assessed in patients with MPD having FMD and was determined to demonstrate ED. Lower FMD was associated with older age, leukocytosis, thrombocytosis, and thrombosis history.

Renovascular hypertension associated with JAK2 V617F positive myeloproliferative neoplasms treated with angioplasty: 2 cases and literature review

Myeloproliferative neoplasms (MPNs) with Janus kinase 2 (JAK2) mutation are associated with a high risk for occlusive vascular diseases. We report 2 cases of renovascular hypertension associated with JAK2 V617F mutation-positive MPNs and provide a literature review. In Case 1, a 63-year-old woman had resistant hypertension, massive proteinuria, and erythrocytosis. Evaluations revealed right renal artery stenosis causing renovascular hypertension and polycythemia vera with JAK2 V617F mutation. Renin-angiotensin system inhibitors and subsequent angioplasty controlled the blood pressure and the proteinuria resolved. In Case 2, a 74-year-old woman had resistant hypertension and thrombocytosis. Evaluations confirmed left renal artery stenosis and essential thrombocythemia with JAK2 V617F. Angioplasty cured the hypertension. A literature review of 18 cases revealed the following as the most common characteristics of MPN-associated renovascular hypertension: manifests primarily in women; is associated with untreated polycythemia vera and essential thrombocythemia, concomitant leukocytosis, and JAK2 mutation positivity; and is responsive to angioplasty. This report demonstrates that JAK2 mutation-positive MPNs are a less common but important underlying cause of adult renovascular hypertension.

Abdominal surgery in patients with essential thrombocythemia: A case report and systematic review of literature

INTRODUCTION

Essential thrombocythemia/thrombocytosis (ET) is characterized by increased bleeding and thrombosis risk during the perioperative period. We report the case of a woman with ET and sigmoid colon cancer, in whom the postoperative course was complicated by anastomotic bleeding. A systematic review was conducted to seek guidance for the management of such patient in the perioperative period.

METHODS

A systematic literature review was conducted using EMBASE, Medline, and PubMed databases to detect relevant English language articles. Published studies with full-text articles were included. Two authors independently searched and extracted the data. Any differences were resolved by consensus. Studies on abdominal surgery were manually retrieved.

RESULTS

Four case reports (including our case report) that described abdominal surgery in patients with ET were included. All patients were females, with a mean age of 47 years. Laparoscopic surgery was performed in 2 patients, and open surgery was performed in the other 2 patients. Two patients had postoperative bleeding that occurred on the first postoperative day. There was one case of pseudohyperkalemia after surgery and one case of Budd-Chiari syndrome caused by hepatic vein thrombosis. No guidelines for patients with ET undergoing abdominal surgery were found.

CONCLUSION

In conclusion, there are currently no definitive guidelines for the perioperative management of patients with ET. Furthermore, there are few reports of ET in patients with malignancy undergoing surgery. Further studies in this unique group of patients are required.

Role of treatment on the development of secondary malignancies in patients with essential thrombocythemia

Aim of this study is to explore the role of different treatments on the development of secondary malignancies (SMs) in a large cohort of essential thrombocythemia (ET) patients. We report the experience of a regional cooperative group in a real‐life cohort of 1026 patients with ET. We divided our population into five different groups: group 0, no treatment; group 1, hydroxyurea (HU); group 2, alkylating agents (ALK); group 3, ALK + HU sequentially or in combination; and group 4, anagrelide (ANA) and/or α‐interferon (IFN) only. Patients from groups 1, 2, and 3 could also have been treated either with ANA and/or IFN in their medical history, considering these drugs not to have an additional cytotoxic potential. In all, 63 of the 1026 patients (6%) developed 64 SM during the follow‐up, after a median time of 50 months (range: 2–158) from diagnosis. In univariate analysis, a statistically significant difference was found only for gender (P = 0.035) and age (P = 0.0001). In multivariate analysis, a statistically significant difference was maintained for both gender and age (gender HR1.7 [CI 95% 1.037–2.818] P = 0.035; age HR 4.190 [CI 95% 2.308–7.607] P = 0.0001). The impact of different treatments on SMs development was not statistically significant. In our series of 1026 ET patients, diagnosed and followed during a 30‐year period, the different therapies administered, comprising HU and ALK, do not appear to have impacted on the development of SM. A similar rate of SMs was observed also in untreated patients. The only two variables which showed a statistical significance were male gender and age >60 years.

The role of thrombocytapheresis in the contemporary management of hyperthrombocytosis in myeloproliferative neoplasms: A case-based review

Extreme thrombocytosis induces an acquired thrombotic-hemorrhagic diathesis, and left uncontrolled is a harbinger of potentially fatal vascular complications. Currently, cytoreduction with medical therapy remains the mainstay of hyperthrombocytosis management. However, it offers a less-than-ideal option in situations where a rapid reduction in platelets is urgently needed, as in the presence of vital end-organ ischemia or to ameliorate of life-threatening hemorrhage. The role of thrombocytapheresis, or plateletpheresis, in hyperthrombocytosis has become increasingly obsolete given the proactive titration of cytoreductive therapies and early identification and correction of reversible causes of reactive thrombocytosis. Despite its narrowed indications, plateletpheresis continues to offer a valuable temporizing measure in platelet count reduction before cytoreductive agents exert their maximal effect. In this context, it is important for the treating physician to be aware of the symptoms and risks associated with hyperthrombocytosis to inform best clinical practices. In this review, we discuss the role of plateletpheresis in the modern-day management of hyperthrombocytosis in patients with myeloproliferative neoplasms through a case based review of the literature. It becomes apparent throughout the discussion that the decision to perform plateletpheresis should be individualized based upon the clinical scenario, degree of thrombocytosis, available infrastructure and every patient's risk profile.

Management of extreme thrombocytosis in myeloproliferative neoplasms: an international physician survey

Extreme thrombocytosis (ExT) has been associated with an increased bleeding risk in myeloproliferative neoplasm (MPN) patients and is included in the high risk category in treatment guidelines. Treatment of patients with ExT has not been studied in prospective trials. To study physicians' approaches to ExT, we distributed a web based questionnaire with clinical case scenarios to 202 members of MPN working groups. Cases included low thrombotic risk essential thrombocythemia (ET) with either JAK2V617F or CALR mutation, polycythemia vera with ExT either with or without leukocytosis, an ET patient needing urgent orthopedic surgery, and a poorly controlled ET patient with acute cerebral venous sinus thrombosis. Responses were received from 90 physicians (45 %) and were variable in most case scenarios. Country of practice had the most significant influence on physician response. The USA and Israel physicians responded similarly in most cases and differently to the Europe physicians. Treatment of asymptomatic JAK2V617F positive ET and target platelet count on cytoreduction were significantly influenced by physician years of experience. Responses were not influenced by the volume of MPN practice or by whether MPN was considered a major interest by the physician. Our results show a lack of consensus on how to manage MPN patients with ExT. Randomized controlled trials properly designed to address these questions are needed.

Associations between gender, disease features and symptom burden in patients with myeloproliferative neoplasms: an analysis by the MPN QOL International Working Group

The myeloproliferative neoplasms, including polycythemia vera, essential thrombocythemia and myelofibrosis, are distinguished by their debilitating symptom profiles, life-threatening complications and profound impact on quality of life. The role gender plays in the symptomatology of myeloproliferative neoplasms remains under-investigated. In this study we evaluated how gender relates to patients' characteristics, disease complications and overall symptom expression. A total of 2,006 patients (polycythemia vera=711, essential thrombocythemia=830, myelofibrosis=460, unknown=5) were prospectively evaluated, with patients completing the Myeloproliferative Neoplasm-Symptom Assessment Form and Brief Fatigue Inventory Patient Reported Outcome tools. Information on the individual patients' characteristics, disease complications and laboratory data was collected. Consistent with known literature, most female patients were more likely to have essential thrombocythemia (48.6% versus 33.0%; P<0.001) and most male patients were more likely to have polycythemia vera (41.8% versus 30.3%; P<0.001). The rate of thrombocytopenia was higher among males than females (13.9% versus 8.2%; P<0.001) and males also had greater red-blood cell transfusion requirements (7.3% versus 4.9%; P=0.02) with shorter mean disease duration (6.4 versus 7.2 years, P=0.03). Despite there being no statistical differences in risk scores, receipt of most therapies or prior complications (hemorrhage, thrombosis), females had more severe and more frequent symptoms for most individual symptoms, along with overall total symptom score (22.8 versus 20.3; P<0.001). Females had particularly high scores for abdominal-related symptoms (abdominal pain/discomfort) and microvascular symptoms (headache, fatigue, insomnia, concentration difficulties, dizziness; all P<0.01). Despite complaining of more severe symptom burden, females had similar quality of life scores to those of males. The results of this study suggest that gender contributes to the heterogeneity of myeloproliferative neoplasms by influencing phenotypic profiles and symptom expression.

The Plasma Levels of Prostanoids and Plasminogen Activator Inhibitor-1 in Primary and Secondary Thrombocytosis

An elevated platelet count is a common finding in both hospitalized and ambulatory patients. Thrombosis and bleeding complications are more frequently observed in patients with clonal thrombocytosis than secondary thrombocytosis. The aim of this study was to investigate the behaviors of plasminogen activator inhibitor type 1 (PAI-1), the inhibitor of fibrinolysis; and thromboxane A2 and 6-keto-PGF1 α, the products of endoperoxides, in 16 patients affected with clonal thrombocytemia as compared with 16 patients with reactive thrombocytosis and 15 normal controls. In the clonal thrombocytemia group, plasma levels of PAI-1 antigen and activity were significantly higher than both reactive thrombocytosis and control group. Plasma levels of 6-keto-PGF1α were significantly higher in the clonal thrombocytemia group than the other two groups and also higher in the reactive thrombocytosis group than the control group, which was also significant. This study confirms that arachidonate metabolism is frequently deranged in patients with thrombocytosis and hypofibrinolysis due to increased PAI-1 plasma levels as shown in the clonal thrombocytosis group. This may explain the thrombotic tendency in myeloproliferative disorders.

γ-Glutamyl Transferase Is an Independent Biomarker of Splanchnic Thrombosis in Patients With Myeloproliferative Neoplasm

Myeloproliferative neoplasms (MPNs) are associated with an increased risk of thrombotic events and constitute the major risk factor of splanchnic venous thrombosis (SVT) in Western countries. Although timely anticoagulation resolves SVT, unrecognized SVT frequently leads to portal hypertension and, potentially, variceal bleeding, which may render anticoagulation difficult. Thus, early identification of SVT development is clinically relevant in MPN patients.In this retrospective analysis, we included 126 patients with MPN and/or SVT referred to our hospital between 2009 and 2014. A total of 86 patients diagnosed with MPN formed the first cohort (PV n = 18, ET n = 16, and MF n = 40), whereas 40 patients who had SVT without adjunct MPN formed a control cohort. Median follow-up period was 960 days. Clinical and laboratory data were collected and analyzed for the identification of potential biomarkers applying descriptive statistics, nonparametric testing, Kaplan-Meier, and logistic regression analysis. The relevance of the identified biomarkers was evaluated in an independent 2nd cohort of 181 patients from the MPN registry of the Study Alliance of Leukemia (SAL-MPN).Thirty-three MPN patients (38%) in the 1st cohort had SVT. Elevated levels of aspartate aminotransferase, alanine aminotransferase, serum bilirubin, or γ-GT were significantly correlated to the presence of SVT. In multivariate testing, CRP and aspartate aminotransferase were predictors for survival and γ-GT remained the only significant variable associated with SVT in MPN patients (P < 0.05). These findings were confirmed in the 2nd cohort comprising 42% of patients with MPN suffering from SVT.Elevated γ-GT levels indicate SVT in MPN patients, whereas CRP levels are independent predictors of patient survival.

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.

Risk and Cause of Death in Patients Diagnosed With Myeloproliferative Neoplasms in Sweden Between 1973 and 2005: A Population-Based Study

PURPOSE

Myeloproliferative neoplasms (MPNs) are associated with a shortened life expectancy. We assessed causes of death in patients with MPN and matched controls using both relative risks and absolute probabilities in the presence of competing risks.

PATIENTS AND METHODS

From Swedish registries, we identified 9,285 patients with MPN and 35,769 matched controls. A flexible parametric model was used to estimate cause-specific hazard ratios (HRs) of death and cumulative incidence functions, each with 95% CIs.

RESULTS

In patients with MPN, the HRs of death from hematologic malignancies and infections were 92.8 (95% CI, 70.0 to 123.1) and 2.7 (95% CI, 2.4 to 3.1), respectively. In patients age 70 to 79 years at diagnosis (the largest patient group), the HRs of death from cardiovascular and cerebrovascular disease were 1.5 (95% CI, 1.4 to 1.7) and 1.5 (95% CI, 1.3 to 1.8), respectively; all were statistically significantly elevated compared with those of controls. In the same age group, no difference was observed in the 10-year probability of death resulting from cardiovascular disease in patients with MPN versus controls (16.8% v 15.2%) or cerebrovascular disease (5.6% v 5.2%). In patients age 50 to 59 years at diagnosis, the 10-year probability of death resulting from cardiovascular and cerebrovascular disease was elevated, 4.2% versus 2.1% and 1.9% versus 0.4%, respectively. Survival in patients with MPN increased over time, mainly because of decreased probabilities of dying as a result of hematologic malignancies, infections, and, in young patients, cardiovascular disease.

CONCLUSION

Patients with MPN had an overall higher mortality rate than that of matched controls, primarily because of hematologic malignancy, infections, and vascular events in younger patients. Evidently, there is still a need for effective disease-modifying agents to improve patient outcomes.

[Essential thrombocythemia: baseline characteristics and risk factors for survival and thrombosis in a series of 214 patients]

BACKGROUND AND OBJECTIVE

Two prognostic models to predict overall survival and thrombosis-free survival have been proposed: International Prognostic Score for Essential Thrombocythemia (IPSET) and IPSET-Thrombosis, respectively, based on age, leukocytes count, history of previous thrombosis, the presence of cardiovascular risk factors and the JAK2 mutational status. The aim of the present study was to assess the clinical and biological characteristics at diagnosis and during evolution in essential thrombocythemia (ET) patients as well as the factors associated with survival and thrombosis and the usefulness of these new prognostic models.

PATIENTS AND METHODS

We have evaluated the clinical data and the mutation status of JAK2, MPL and calreticulin of 214 ET patients diagnosed in a single center between 1985 and 2012, classified according to classical risk stratification, IPSET and IPSET-Thrombosis.

RESULTS

With a median follow-up of 6.9 years, overall survival was not associated with any variable by multivariate analysis. Thrombotic history and leukocytes>10×10(9)/l were associated with thrombosis-free survival (TFS). In our series, IPSET prognostic systems of survival and thrombosis did not provide more clinically relevant information regarding the classic risk of thrombosis stratification.

CONCLUSION

Thrombotic history and leukocytosis>10×10(9)/l were significantly associated with lower TFS, while the prognostic IPSET-Thrombosis system did not provide more information than classical thrombotic risk assessment.

Target hematologic values in the management of essential thrombocythemia and polycythemia vera

Treatment of essential thrombocythemia (ET) and polycythemia vera (PV) is aimed at preventing vascular complications, which are the main cause of morbidity and mortality in these diseases. Over the years, clinical trials have demonstrated that the incidence of thrombosis and bleeding can be reduced by controlling the blood cell counts, but the target hematological levels have varied across the studies. In this article, we review the evidence supporting the use of predefined target hematologic values for the management of ET and PV in routine clinical practice. At present, the recommended target hematocrit in PV is below 45%, regardless of the patients' risk profile. Concerning platelet counts, no direct correlation has been demonstrated with thrombotic risk in either ET or PV. Thus, although cytoreductive treatment reduces the rate of vascular complications in high-risk patients, no particular threshold of the platelet counts has been shown to be more protective against thrombosis. Extreme thrombocytosis is a risk factor for bleeding, particularly when aspirin or anagrelide are given. Leukocytosis at baseline or during follow-up appears to be a risk factor for thrombosis, mostly in high-risk patients. However, the clinical benefit of strictly controlling this parameter is not yet established. Finally, standardized definitions of response to cytoreductive treatment in ET and PV have recently been published. Nevertheless, they have been produced to compare the efficacy of new therapies in clinical trials, whereas its relevance in clinical practice has been questioned in retrospective studies showing that such response definitions do not correlate with the patients' clinical outcome.