Conventional Cytogenetic Analysis and Array CGH + SNP Identify Essential Thrombocythemia and Prefibrotic Primary Myelofibrosis Patients Who Are at Risk for Disease Progression

The Philadelphia chromosome-negative myeloproliferative neoplasms (Ph-MPNs) are a heterogeneous group of clonal hematopoietic malignancies that include polycythemia vera (PV), essential thrombocythemia (ET), and the prefibrotic form of primary myelofibrosis (prePMF). In this study, we retrospectively reviewed the karyotypes from conventional cytogenetics (CC) and array Comparative Genomic Hybridization + Single Nucleotide Polymorphism (aCGH + SNP) in patients with ET or prePMF to determine whether the combined analysis of both methodologies can identify patients who may be at a higher risk of disease progression. We performed a comprehensive genomic review on 169 patients with a clinical diagnosis of ET (154 patients) or prePMF (15 patients). Genomic alterations detected by CC or array-CGH + SNP were detected in 36% of patients. In patients who progressed, 68% had an abnormal genomic finding by either technology. There was a shorter progression-free survival (PFS) among patients who were cytogenetically abnormal or who were cytogenetically normal but had an abnormal aCGH + SNP result. Leveraging the ability to detect submicroscopic copy number alterations and regions of copy neutral-loss of heterozygosity, we identified a higher number of patients harboring genomic abnormalities than previously reported. These results underscore the importance of genomic analysis in prognostication and provide valuable information for clinical management and treatment decisions.

Successful management of VTE with essential thrombocythemia and cavernous transformation of the portal vein in early pregnancy: a case report

Due to the thrombohemorrhagic potential of essential thrombocythemia, pregnancy complicated by essential thrombocythemia should be recognized as a risk factor for obstetric complications. Here, we report the case of a patient with essential thrombocythemia with two significantly different pregnancy outcomes. Her first pregnancy (at 30 years of age) ended with an uneventful term delivery. However, the patient progressed to cavernous transformation of the portal vein in the period between her two pregnancies and subsequently experienced deep venous thrombosis during the first trimester of her second pregnancy (at 36 years of age). The patient's platelet count during pregnancy was within the normal range, so she ignored previous instances of essential thrombocytosis (at 26 years of age). The patient's main symptom was unrelieved pain in her leg. After that, she was successfully treated with anticoagulant throughout her entire pregnancy, resulting in a term vaginal delivery. This case highlights the importance of assessing pregnant patients with essential thrombocythemia according to their risk stratification. Specifically, risk assessments for potential pregnancy complications should take into account advanced maternal age and a previous history of thrombosis. Patients with essential thrombocythemia should be encouraged to participate in preconception counseling for risk assessment and to initiate prophylactic anticoagulation as soon as possible.

Essential thrombocythemia: 2024 update on diagnosis, risk stratification, and management

OVERVIEW

Essential thrombocythemia is a Janus kinase 2 (JAK2) mutation-prevalent myeloproliferative neoplasm characterized by clonal thrombocytosis; clinical course is often indolent but might be interrupted by thrombotic or hemorrhagic complications, microcirculatory symptoms (e.g., headaches, lightheadedness, and acral paresthesias), and, less frequently, by disease transformation into myelofibrosis (MF) or acute myeloid leukemia.

DIAGNOSIS

In addition to thrombocytosis (platelets ≥450 × 109 /L), formal diagnosis requires the exclusion of other myeloid neoplasms, including prefibrotic MF, polycythemia vera, chronic myeloid leukemia, and myelodysplastic syndromes with ring sideroblasts and thrombocytosis. Bone marrow morphology typically shows increased number of mature-appearing megakaryocytes distributed in loose clusters.

GENETICS

Approximately 80% of patients express myeloproliferative neoplasm driver mutations (JAK2, CALR, MPL), in a mutually exclusive manner; in addition, about 50% harbor other mutations, the most frequent being TET2 (9%-11%), ASXL1 (7%-20%), DNMT3A (7%), and SF3B1 (5%). Abnormal karyotype is seen in <10% of patients and includes +9/20q-/13q-.

SURVIVAL AND PROGNOSIS

Life expectancy is less than that of the control population. Median survival is approximately 18 years but exceeds >35 years in younger patients. The triple A survival risk model, based on Age, Absolute neutrophil count, and Absolute lymphocyte count, effectively delineates high-, intermediate-1-, intermediate-2-, and low-risk disease with corresponding median survivals of 8, 14, 21, and 47 years.

RISK FACTORS FOR THROMBOSIS

Four risk categories are considered: very low (age ≤60 years, no thrombosis history, JAK2 wild-type), low (same as very low but JAK2 mutation present), intermediate (same as low but age >60 years), and high (thrombosis history or age >60 years with JAK2 mutation).

MUTATIONS AND PROGNOSIS

MPL and CALR-1 mutations have been associated with increased risk of MF transformation; spliceosome with inferior overall and MF-free survival; TP53 with leukemic transformation, and JAK2V617F with thrombosis. Leukemic transformation rate at 10 years is <1% but might be higher in JAK2-mutated patients with extreme thrombocytosis and those with abnormal karyotype.

TREATMENT

The main goal of therapy is to prevent thrombosis. In this regard, once-daily low-dose aspirin is advised for all patients and twice daily for low-risk disease. Cytoreductive therapy is advised for high-risk and optional for intermediate-risk disease. First-line cytoreductive drugs of choice are hydroxyurea and pegylated interferon-α and second-line busulfan.

ADDITIONAL CONTENT

The current review includes specific treatment strategies in the context of extreme thrombocytosis, pregnancy, splanchnic vein thrombosis, perioperative care, and post-essential thrombocythemia MF, as well as new investigational drugs.

Genomic classification and outcomes of young patients with polycythemia vera and essential thrombocythemia according to the presence of splanchnic vein thrombosis and its chronology

To elucidate the role of splanchnic vein thrombosis (SVT) and genomic characteristics in prognosis and survival, we compared patients with polycythemia vera (PV) or essential thrombocythemia (ET) presenting SVT at diagnosis (n = 69, median age 43 years) or during follow-up (n = 21, median age 46 years) to a sex- and age-matched control group of PV/ET without SVT (n = 165, median age 48 years). The majority of patients presenting with SVT at diagnosis were classified as myeloproliferative neoplasm with heterozygous JAK2 mutation (87% of cases vs. 69% in PV/ET control group, p < 0.05), characterized by low JAK2 allele burden and no high-risk mutations. Despite this lower molecular complexity, patients presenting with SVT showed a higher risk of death (HR 3.0, 95% CI 1.5-6.0, p = 0.003) and lower event-free survival (HR 3.0, 95% CI 1.9-4.8, p < 0.001) than age- and sex-matched PV/ET controls. In patients presenting with SVT, molecular high-risk was associated with increased risk of venous re-thrombosis (HR 5.8, 95% CI 1.4-24.0, p = 0.01). Patients developing SVT during follow-up were more frequently allocated in molecular high-risk than those with SVT at diagnosis (52% versus 13%, p < 0.05). In the whole cohort of patients, molecular classification identified PV/ET patients at higher risk of disease progression whereas DNMT3A/TET2/ASXL1 mutations were associated with higher risk of arterial thrombosis. In conclusion, clinical and molecular characteristics are different in PV/ET patients with SVT, depending on whether it occurs at diagnosis or at follow-up. Molecular characterization by NGS is useful for assessing the risk of thrombosis and disease progression in young patients with PV/ET.

Detecting Multiple Driver Mutations in a Patient with Essential Thrombocythemia

BACKGROUND Three driver mutations have been identified in patients with essential thrombocythemia - JAK2 V617F, CALR, and MPL. Out of these, JAK2 V617F is mostly common. These mutations are thought to be mutually exclusive; therefore, the initial workup may not include the identification of all mutations separately. CASE REPORT We present a case of a 55-year-old woman who was referred to the hematology clinic for an elevated platelet count noted when she was hospitalized for a renal stone. The patient was asymptomatic. A workup was initiated for essential thrombocythemia, and she was tested for JAK2 V617F mutation using an allele-specific polymerase chain reaction (AS-PCR) test in peripheral blood, which came back positive. The variant allele frequency was 2%. She underwent a bone marrow biopsy, and next-generation sequencing (NGS) showed a CALR mutation. A 52 bp deletion-type mutation was detected in the CALR gene on exon 9, with a variant allele frequency of 7%. The NGS did not detect JAK2 mutation due to its low sensitivity. She was started on aspirin alone as she was less than 60 years old and had no history of thrombotic events. The patient has been following up with the hematology clinic for the last 2 years and has not had any thrombotic events. CONCLUSIONS We propose that in patients with a low JAK2 V617 allele variant, testing for other driver mutations should be performed. In our patient, JAK2 mutation could be clonal hematopoiesis of indeterminate potential; therefore, the dominant mutation (CALR) would determine the disease phenotype.

Bilateral Adrenal Infarction That Developed in Latent Essential Thrombocythemia

Bilateral adrenal infarction is an extremely rare disease, and it has been reported that some coagulation abnormalities, including essential thrombocythemia (ET), exist in the background. We herein report a 76-year-old patient in whom the platelet count had been in the normal range at the onset of adrenal infarction but subsequently increased to 102×104/μL at 7 months later, leading to the diagnosis of JAK2V617F-positive ET. As the presence of the JAK2V617F mutation increases the risk of thrombosis, Janus kinase 2 (JAK2) genetic testing should be considered in some cases of nonspecific unknown thrombosis, even if there are no obvious hematological findings, such as clonal hematopoiesis of indeterminate potential (CHIP).

Correlation between IPSET-t risk at diagnosis and subsequent hemorrhage in patients with essential thrombocythemia; a single institution experience

Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by an increased risk of thrombotic and hemorrhagic events, that represent the leading causes of mortality and morbidity. Currently, while thrombotic risk is assessed through the IPSET-t and r-IPSET scores, there is no specific prognostic tool used to predict hemorrhagic risk in ET. The aim of the study was to define incidence and risk factors connected to hemorrhagic events by retrospectively analyzing 308 ET patients diagnosed between 1996 and 2022 at the Division of Hematology of Udine and treated according to the current international guidelines. According to molecular status, 193 patients (62.7%) were JAK2 mutated, 66 (21.4%) had a CALR mutation, 14 (4.5%) had a MPL mutation, 21 patients (6.8%) were "triple negative," and 14 patients (4.5%) were not evaluable. According to IPSET-t score, 49.7% patients were at high, 24.3% at intermediate, and 26.0% at low-risk, respectively. Twelve (3.9%) patients experienced bleeding at ET diagnosis, while 24 (7.8%) had at least one hemorrhagic event during follow-up at a median time of 103 months (range: 1-309). Forty hemorrhagic events were totally recorded and defined as minor in 22 cases, moderate in 11 cases, and severe in 7 cases. Cumulative incidence (CI) of hemorrhage at 10 and 20 years was 6.0% and 12.0%, respectively. A statistically significant correlation between hemorrhagic risk and IPSET-t score emerged: 10 years hemorrhage CI was 3.2% for low-risk, 2.9% for intermediate-risk, and 9.8% for high-risk patients, respectively (p=0.002). We found no correlation between hemorrhagic risk and gender or mutational status. Results of our study highlight the validity of IPSET-t score in predicting individual hemorrhagic risk among ET patients, suggesting a possible role of IPSET-t scoring system as a global evaluator for vascular events in ET patients.

One thousand patients with essential thrombocythemia: the Mayo Clinic experience

We describe 1000 patients with essential thrombocythemia seen at the Mayo Clinic between 1967 and 2023: median age 58 years (18-90), females 63%, JAK2/CALR/MPL-mutated 62%/27%/3%, triple-negative (TN) 8%, extreme thrombocytosis (ExT; platelets ≥1000 × 109/L) 26%, leukocytosis (leukocyte count >11 × 109/L) 20%, and abnormal karyotype 6%. JAK2-mutated patients were older (median 71 years), and CALR mutated (52 years), and TN (50 years) younger (p < 0.01). Female gender clustered with TN (73%) and JAK2 (69%) vs. CALR/MPL (49%/47%) mutations (p < 0.01). ExT clustered with CALR (type-2 more than type-1) and TN and leukocytosis with JAK2 mutation (p < 0.01). In multivariable analysis, risk factors for overall survival were older age (p < 0.01), male gender (HR 1.8), absolute neutrophil count (ANC) ≥ 8 × 109/L (HR 1.6), absolute lymphocyte count (ALC) < 1.7 × 109/L (HR 1.5), hypertension (HR 1.7), and arterial thrombosis history (HR 1.7); for leukemia-free survival, ExT (HR 2.3) and abnormal karyotype (HR 3.1); for myelofibrosis-free survival, ANC ≥ 8 × 109/L (HR 2.3) and MPL mutation (HR 3.9); for arterial thrombosis-free survival, age ≥60 years (HR 1.9), male gender (HR 1.6), arterial thrombosis history (HR 1.7), hypertension (HR 1.7), and JAK2 mutation (HR 1.8); for venous thrombosis-free survival, male gender (HR 1.8) and venous thrombosis history (HR 3.0). Associations between ExT and leukemic transformation and between ANC and fibrotic progression were limited to JAK2-mutated cases. Aspirin therapy appeared to mitigate both arterial (HR 0.4) and venous (HR 0.4) thrombosis risk. HR-based risk models delineated patients with median survivals ranging from 10 years to not reached and 20-year leukemia/myelofibrosis incidences from 3%/21% to 12.8%/49%. The current study provides both novel and confirmatory observations of essential thrombocythemia.

Real-world clinical characteristics of post-essential thrombocythemia and post-polycythemia vera myelofibrosis

There are few prospective studies on patients with post-essential thrombocythemia myelofibrosis (PET-MF) and post-polycythemia vera myelofibrosis (PPV-MF). Therefore, we conducted a nationwide longitudinal prospective survey to clarify the clinical characteristics of these diseases. A total of 197 PET-MF and 117 PPV-MF patients diagnosed between 2012 and 2021 were analyzed. The median age at diagnosis was 70.0 years for both diseases. The time from diagnosis of ET or PV to that of MF was 9.6 and 10.4 years, respectively, with no significant difference. Patients with PPV-MF had higher hemoglobin levels and white blood cell counts than those with PET-MF, whereas those with PET-MF had higher platelet counts than those with PPV-MF. Although splenomegaly was more frequent in patients with PPV-MF at diagnosis, there was no difference in the frequency of constitutional symptoms. Ruxolitinib was the most common treatment administered to 74.6% and 83.8% of patients with PET-MF and PPV-MF, respectively. Patients with PET-MF and PPV-MF had similar prognoses, with 3-year overall survival (OS) of 0.742 in PET-MF and 0.768 in PPV-MF patients. In both diseases, leukemic transformation was the leading cause of death, followed by infection. The 3-year OS for patients with PET/PPV-MF and primary MF diagnosed during the same period was 0.754 and 0.626, respectively, with no significant difference. This survey provides real-world clinical features and prognostic data on secondary myelofibrosis in the ruxolitinib era.

A case in which baricitinib was effective for both rheumatoid arthritis and essential thrombocythemia

We experienced a case of rheumatoid arthritis and JAK2V617F mutation-positive essential thrombocythemia treated with baricitinib. The patient was a 72-year-old male. He was diagnosed with rheumatoid arthritis at a local clinic in April 2018. Methotrexate (MTX) was started and the dose was increased to 16 mg/week. In October of the same year, anaemia was observed and MTX was reduced, but anaemia progressed. Blood tests showed pancytopenia, and he was referred to Rheumatology on suspicion of drug-induced pancytopenia. Pancytopenia improved with discontinuation of MTX and administration of folic acid. His platelet count was markedly increased to 1,400,000/μl at one point, decreased to 400,000/μl, and then gradually increased to 700,000-1,000,000/μl. Despite taking an antiplatelet drug, he developed cerebral infarction in June 2019. The JAK2V617F mutation was noted, and he was diagnosed with essential thrombocythemia. Hydroxycarbamide was started, but the effect was insufficient. Baricitinib, a JAK1/2 inhibitor indicated for rheumatoid arthritis, was started in August with the expectation that it would also be effective for essential thrombocythemia. The platelet count decreased to ∼400,000-600,000 cells/μl, and a decrease in the C-reactive protein level and the improvement of arthritis were noted. We report this case because it is considered to be a valuable case, suggesting that baricitinib may be effective for essential thrombocythemia.

Aberrant Platelet Aggregation as Initial Presentation of Essential Thrombocythemia: Failure of Entero-Coated Aspirin to Reduce Platelet Hyperactivation

Essential thrombocythemia (ET) is a myeloproliferative neoplasm variant characterized by excessive production of platelets. Since the most common cause of mortality and morbidity in ET patients is thrombosis, the excessive production of platelets may cause thrombotic events. However, little is known about the function of platelets in ET. We report a female patient who presented as asymptomatic, without a remarkable medical history, and ET was diagnosed after an incidental finding of moderate thrombocytosis. Notably, together with thrombocytosis, an abnormal platelet phenotype was found for the presence of a massive, rapid and spontaneous formation of aggregates and platelet hypersensitivity to subthreshold concentrations of aggregating agonists. Bone marrow histopathological examination and genetic analysis with the JAK2 (V617F) gene mutation findings confirmed the initial suspicion of ET. Although the ET patient was placed on aspirin, the persistence of the platelet hyperactivation and hyperaggregability prompted a switch in antiplatelet medication from entero-coated (EC) to plain aspirin. As result, platelet hypersensitivity to agonists and spontaneous aggregation were no longer found. Collectively, our study demonstrates that platelet function analysis could be a reliable predictor of ET and that plain aspirin should be preferred over EC aspirin to attenuate platelet hyperreactivity.

Cytoreduction for ET and PV: who, what, when, and how?

Thrombotic complications are the primary contributor to morbidity and mortality in essential thrombocythemia (ET) and polycythemia vera (PV). Cytoreductive therapy is the main tool for primary or tertiary thrombosis prevention in these diseases. In general, high-thrombotic-risk patients and those with symptoms that may be ameliorated from cytoreductive therapy are candidates for this treatment, although the decision is highly individualized. Approved options for cytoreduction in ET and PV include hydroxyurea, long-acting interferons, anagrelide in ET, and ruxolitinib in PV. Selecting the ideal agent requires careful consideration of the toxicity profiles and individual treatment goals. In this review the existing literature on cytoreductive decisions in ET and PV is summarized, with an emphasis on risk-stratification, highlighting the need for personalized care in order to maximize the benefit of these therapies while minimizing toxicities.

[Expression level of Wilms' tumor 1 gene and its correlation with clinical features in patients with myeloproliferative neoplasms]

Objective: To investigate the expression level of WT1 gene in patients with classical Philadelphia chromosome (Ph)-negative myeloproliferative neoplasms (MPN) and its correlation with clinical features. Methods: A retrospective study included 252 patients with newly diagnosed MPN in Zhongnan Hospital of Wuhan University from January 2015 to March 2023, including 128 males and 124 females, aged［M（Q1，Q3）］62 (53, 69) years. The WT1-positive group (n=93) and the WT1-negative group (n=159) were split based on the level of WT1 gene expression, and the variations in clinical indicators between the two groups were compared. Its levels of expression in each subtype and its relationships to thrombotic events and clinically significant variables were analyzed. As of March 31, 2023, the follow-up period [M (Q1, Q3)] was 12.0(6.5,21.0)months. The risk factors of thrombosis in MPN patients were analyzed by using the logistic regression analysis. Results: The WT1 gene expression level in the overall bone marrow samples of 252 patients with newly diagnosed MPN was 0.30% (0.10%, 1.10%). The expression level in primary myelofibrosis (PMF) patients was 1.45% (0.41%, 3.24%), which was higher than 0.15% (0.02%, 0.32%), 0.37% (0.16%, 1.09%) in essential thrombocythemia (ET) and polycythemia vera (PV) patients (both P<0.05). Positive correlations were found between WT1 gene expression levels and JAK2V617F gene mutation load, RDW, MPV (r=0.478, 0.346, 0.236, all P<0.01). While negative correlations between WT1 gene expression levels and PLT, LYM, PTTA, LDH were found (r=-0.339, -0.170, -0.206, -0.388, all P<0.01). Patients in the WT1-positive group exhibited a higher percentage of somatic symptoms, splenomegaly, positive JAK2V617F gene mutation, and higher levels of RDW, LDH, NEUT, and MPV compared to the WT1-negative group. In contrast, the proportion of triple-negative (negative for all three hot mutations of JAK2V617F, CALR and MPL) was lower, and the levels of PLT, LYM and PTTA were lower (all P<0.05). The thrombotic event rates of WT1-positive group and WT1-negative group were 32.3% (30/93) and 32.1% (51/159), respectively, and the difference was not statistically significant (P=0.883). Logistic regression analysis showed that male (OR=2.41,95%CI:1.02-5.71,P=0.046) and positive JAK2V617F gene mutation (OR=3.96,95%CI:1.50-10.42,P=0.005) were risk factors for thrombotic events in ET patients. Conclusions: WT1 gene expression is elevated in PMF patients and correlated with indicators of disease progression and transformation in MPN patients. It can be utilized as an auxiliary diagnostic indicator for classical MPN staging but is not correlated with the incidence of thrombotic events. Male and positive JAK2V617F gene mutation are risk factors for thrombotic events in ET patients.

Significant heterogeneity in management of calreticulin-mutated essential thrombocythemia and its progression to myelofibrosis: results of a national survey

Despite the recent publication of calreticulin (CALR)-mutated essential thrombocythemia (ET) management guidelines by the European Leukemia Net (ELN), there remains a paucity of data regarding the optimal way to manage this condition. To determine practice around Australia, we constructed a survey asking investigation and treatment questions in a hypothetical case of a young woman with CALR-mutated ET and subsequent progression to myelofibrosis. 51 of 88 hematologists replied. The responses demonstrated significant heterogeneity in specific issues such as the use of aspirin, when to initiate cytoreduction, the preferred type of cytoreduction, and platelet targets. These observations support the ELN acknowledgment that a strong evidence base for many management recommendations is lacking in this disease, and that substantial further research is needed.

Is very high platelet count always associated with essential thrombocythemia? An unusual presentation in a child

Myeloproliferative neoplasms are rare in childhood. They are categorized as Philadelphia chromosome-positive and Philadelphia chromosome-negative. Chronic myeloid leukemia (CML) is the most common myeloproliferative disease in which the Philadelphia chromosome is detected as a result of BCR-ABL rearrangements. In others, the most common genetic abnormality is JAK2V617F mutation. The coexistence of these 2 abnormalities in CML is unexpected, and rare cases have recently been reported in adults. We present a child who had a very high platelet count in which we found this coexistence. The clinical presentation, laboratory findings, management, and prognosis of this coexistence is challenging in such a rare condition.

Asymptomatic Essential Thrombocytosis Presenting with Extrahepatic Portal Vein Thrombosis: A Case Report

BACKGROUND Essential thrombocytosis (ET) is a myeloproliferative neoplasm variant that leads to excessive platelet production in the bone marrow. Janus kinase 2 (JAK2) mutation is observed in 60% of ET cases. The risk of thrombosis increases with the presence of this mutation. ET can cause systemic thrombosis, including extra-portal vein thrombosis (EHPVT). In patients with ET-induced EHPVT, varied symptoms generally occur. However, our case was asymptomatic. This condition is relatively rare. CASE REPORT A 49-year-old woman presented to our hospital for a detailed clinical examination 1 month after a health examination, and blood tests revealed microcytic anemia and thrombocytosis. The patient had no current concerns and had no relevant medical or alcohol consumption history. Esophagogastroduodenoscopy demonstrated esophageal varices, with portal hypertension suspected as the underlying cause. Contrast-enhanced computed tomography scans revealed a thrombus in the portal vein, but liver cirrhosis and a tumor were ruled out. JAK2 mutation was positive, which led to myeloproliferative neoplasms being considered as the differential diagnosis. Bone marrow biopsy demonstrated many mature megakaryocytes with large and irregular nuclei and platelet aggregation in the field of view, leading to the diagnosis of ET. CONCLUSIONS This case study describes a patient with EHPVT caused by JAK2-positive ET. This case report emphasizes that physicians should consider myeloproliferative neoplasms as part of their differential diagnosis when presented with EHPVT.

BCR::ABL1 negative myeloproliferative neoplasms: A review focused on essential thrombocythemia and polycythemia vera

The classical myeloproliferative neoplasms are divided into chronic myeloid leukemia, and the Philadelphia negative polycythemia vera, essential thrombocythemia and primary myelofibrosis. These are heterogenous diseases, originating from the clonal proliferation of myeloid stem cells, resulting in increased mature cell numbers in one or more myeloid lineages. The most commonly seen mutations in the Philadelphia negative myeloproliferative neoplasms include those in Janus kinase, myeloproliferative leukemia protein and the calreticulin genes. Philadelphia negative myeloproliferative neoplasms occur infrequently, with a combined annual incidence of 2.58 per 100,000. There are many overlapping symptoms of Philadelphia negative MPNs, such as fatigue, night sweats, hepatosplenomegaly and circulatory symptoms due to increased cell numbers. Total Symptom Score of the MPN Symptom Assessment Form is used to assess symptom burden on patients. The most worrisome complications are thrombo-hemorrhagic events, and risk stratification is especially important as treatment of disease is based on their category. Phlebotomy and aspirin are the mainstay of treatment in low-risk polycythemia vera and essential thrombocythemia patients, whereas high-risk disease calls for additional cytoreduction, usually with hydroxyurea.

Clinical Phenotype and Outcomes of Pulmonary Hypertension Associated with Myeloproliferative Neoplasms: A Population-based Study

Rationale: Precapillary pulmonary hypertension (PH) is a rare and largely unrecognized complication of myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (MF). Objectives: To describe characteristics and outcomes of MPN-associated PH. Methods: We report clinical, functional, and hemodynamic characteristics, classification, and outcomes of patients with PV, ET, or primary MF in the French PH registry. Measurements and Main Results: Ninety patients with MPN (42 PV, 35 ET, 13 primary MF) presented with precapillary PH with severe hemodynamic impairment, with a median mean pulmonary arterial pressure and pulmonary vascular resistance of 42 mm Hg and 6.7 Wood units, respectively, and impaired clinical conditions, with 71% in New York Heart Association functional classes III/IV and having a median 6-minute-walk distance of 310 m. Half of the patients were diagnosed with chronic thromboembolic PH (CTEPH); the other half were considered to have group 5 PH. MF was preferentially associated with group 5 PH, whereas PV and ET were generally related to CTEPH. Proximal lesions were diagnosed in half of the patients with CTEPH. Thromboendarterectomy was performed in 18 selected patients with high risk of complications (5 early deaths). Overall survival at 1, 3, and 5 years was 67%, 50%, and 34% in group 5 PH and 81%, 66%, and 42% in CTEPH, respectively. Conclusions: PH is a life-threatening condition potentially occurring in MPN. There are multiple mechanisms, with equal diagnoses of CTEPH and group 5 PH. Physicians should be aware that PH strongly affects the burden of patients with MPN, especially in group 5 PH, with unknown pathophysiological mechanisms.

Clinical Impact of JAK2V617F Allele Burden in Philadelphia-Negative Myeloproliferative Neoplasms

Objective

The impact of JAK2V617F allele burden on clinical course in Philadelphia-negative (Ph-negative) myeloproliferative neoplasms (MPNs) is not clear. We analyzed the clinical impact of JAK2V617F allele burden in a relatively large series of patients with Ph-negative MPNs and long-term follow-up.

Materials and Methods

A total of 228 patients with Ph-negative MPNs, including 118 with essential thrombocythemia (ET), 84 with primary myelofibrosis (PMF), and 26 with polycythemia vera (PV), were analyzed. The JAK2 MutaScreen assay was used to quantify JAK2V617F allele burden in genomic DNA.

Results

In PV cases, high JAK2V617F allele burden was associated with a trend towards inferior overall survival. In ET, high JAK2V617F allele burden was associated with lower hemoglobin and hematocrit levels, higher lactate dehydrogenase (LDH) levels, larger spleen size, and increased bleeding and mortality rates. In PMF, high JAK2V617F allele burden was associated with higher leukocyte counts and larger spleen size. In the entire cohort, high allele burden was associated with higher leukocyte and lower platelet counts, higher LDH levels, larger spleen size, higher percentage of bleeding events, higher death rate, and inferior overall survival.

Conclusion

Our results suggest that high JAK2V617F allele burdens are associated with more severe disease in PV and ET. In PMF, high JAK2V617F allele burdens were associated with more pronounced myeloproliferative phenotypes. In Ph-negative MPNs, high allele burdens were associated with more aggressive phenotypes. Our data with a long follow-up period support the possibility of JAK2V617F allele burden being used as a marker for predicting clinical phenotype in cases of Ph-negative MPNs.

Characterization of myeloproliferative neoplasms in the paediatric and young adult population

The aim of this study was to compare the genomic features and clinical outcomes between paediatric and young adult patients (PAYA, <40 years) and older adults (OA, ≥40 years) with myeloproliferative neoplasms (MPN) to gain insight into pathogenesis, disease prognosis and management. Of 630 MPN patients, 171 (27%) were PAYA with an average age at diagnosis of 31 years. Females were more prevalent in PAYA than OA (71% vs 58%; p = 0.002), and PAYA more frequently presented with essential thrombocytosis (ET) at diagnosis (67% vs 39%; p < 0.001). The presence of a JAK2 somatic mutation was higher in OA (80.4% vs 64.3%; p < 0.001), while a CALR mutation or lack of any traditional driver mutation was more common in PAYA (20.5% vs 10.5%; p = 0.001, 8.8% vs 3.7%; p = 0.01 respectively). Venous thrombosis was more common in PAYA compared to OA (19.8% vs 10.7%; p = 0.002). PAYA had a higher prevalence of familial MPN and familial cancer predisposition, and two PAYA patients harboured pathogenic germline JAK2 lesions. PAYA demonstrated longer survival from diagnosis than OA (median not reached vs 13 years), while disease transformation was less frequent (19.3% vs 37.9%).

Continuous Indexing of Fibrosis (CIF): improving the assessment and classification of MPN patients

The grading of fibrosis in myeloproliferative neoplasms (MPN) is an important component of disease classification, prognostication and monitoring. However, current fibrosis grading systems are only semi-quantitative and fail to fully capture sample heterogeneity. To improve the quantitation of reticulin fibrosis, we developed a machine learning approach using bone marrow trephine (BMT) samples (n = 107) from patients diagnosed with MPN or a reactive marrow. The resulting Continuous Indexing of Fibrosis (CIF) enhances the detection and monitoring of fibrosis within BMTs, and aids MPN subtyping. When combined with megakaryocyte feature analysis, CIF discriminates between the frequently challenging differential diagnosis of essential thrombocythemia (ET) and pre-fibrotic myelofibrosis with high predictive accuracy [area under the curve = 0.94]. CIF also shows promise in the identification of MPN patients at risk of disease progression; analysis of samples from 35 patients diagnosed with ET and enrolled in the Primary Thrombocythemia-1 trial identified features predictive of post-ET myelofibrosis (area under the curve = 0.77). In addition to these clinical applications, automated analysis of fibrosis has clear potential to further refine disease classification boundaries and inform future studies of the micro-environmental factors driving disease initiation and progression in MPN and other stem cell disorders.

Essential Thrombocythemia and Post-Essential Thrombocythemia Myelofibrosis: Updates on Diagnosis, Clinical Aspects, and Management

Although several decades have passed since the description of myeloproliferative neoplasms (MPN), many aspects of their pathophysiology have not been elucidated. In this review, we discuss the mutational landscape of patients with essential thrombocythemia (ET), prognostic scores and salient pathology, and clinical points. We discuss also the diagnostic challenges of differentiating ET from prefibrotic MF. We then focus on post-essential thrombocythemia myelofibrosis (post-ET MF), a rare subset of MPN that is usually studied in conjunction with post-polycythemia vera MF. The transition of ET to post-ET MF is not well studied on a molecular level, and we present available data. Patients with secondary MF could benefit from allogenic hematopoietic stem cell transplantation, and we present available data focusing on post-ET MF.

HRAS mutation positive multiple myeloma in the type 2 CALR mutation positive essential thrombocythemia: A case report

Out of BCR-ABL negative myeloproliferative neoplasm (MPNPh- ) patients, 3%-14% display a concomitant monoclonal gammopathy of unknown significance (MGUS). In most cases, the diagnosis of plasma cell dyscrasia is either synchronous with that of MPNPh- or occurs later on. We present a 50-year-old patient with type 2 CALR Lys385Asnfs*47 mutation positive essential thrombocythemia (ET) who developed symptomatic multiple myeloma (MM) 13 years after the diagnosis of ET during PEG-INF2α treatment. The NGS study performed at the time of the MM diagnosis revealed the HRAS Val14Gly/c.41T〉G mutation and the wild type CALR, JAK2 and MPL gene sequence. In the presented case, the complete molecular remission of ET was achieved after 16 months of PEG-INF2α treatment. The origin of MM cells in MPNPh- patients remains unknown. Published data suggests that type 2 CALRins5 up-regulate the ATF6 chaperone targets in hematopoietic cells and activate the inositol-requiring enzyme 1α-X-box-binding protein 1 pathway of the unfolded protein response (UPR) system to drive malignancy. It cannot be excluded that endoplasmic reticulum stress induced by the increased ATF6 resulted in an abnormal redox homeostasis and proteostasis, which are factors linked to MM. The presented case history and the proposed mechanism of mutant CALR interaction with UPR and/or ATF6 should initiate the discussion about the possible impact of the mutant CALR protein on the function and genomic stability of different types of myeloid cells, including progenitor cells.

Development of rapidly fatal TAFRO syndrome-like features in a patient with essential thrombocythemia

TAFRO syndrome is a rare systemic inflammatory disease characterized by thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly. We encountered a case of calreticulin mutation-positive essential thrombocythemia (ET) with TAFRO syndrome-like features, followed by a rapid fatal course. The patient had been on anagrelide therapy for approximately three years for management of ET; however, she suddenly stopped going for follow-up and discontinued the medicine for a year. She presented with fever and hypotension, suggestive of septic shock, and was transferred to our hospital. The platelet count at the time of admission to another hospital was 50 × 10⁴ / μL; however, it decreased to 25 × 10⁴ / μL upon transfer to our hospital and further decreased to 5 × 10⁴ / μL on the day of her death. In addition, the patient showed remarkable systemic edema and progression of organomegaly. Her condition suddenly worsened and led to her death on the 7th day of hospitalization. Postmortem, serum and pleural effusion interleukin (IL)-6 and vascular endothelial growth factor (VEGF) levels were significantly increased. Consequently, a diagnosis of TAFRO syndrome, since she met the diagnostic criteria for clinical findings and had high cytokine concentrations. Dysregulation of cytokine networks has also been reported in ET. Therefore, concurrent ET and TAFRO syndrome may have further triggered cytokine storms and contributed to the aggravation of the disease on development of TAFRO syndrome. To the best of our knowledge, this is the first report of complications seen in a patient with TAFRO syndrome due to ET.

Splenic Infarction in Patients with Philadelphia-negative Myeloproliferative Neoplasms

Objective We retrospectively analyzed the prevalence and clinical features of splenic infarctions in patients with Philadelphia chromosome-negative myeloproliferative neoplasms (Ph^- MPNs). Patients Patients diagnosed with essential thrombocythemia (ET), polycythemia vera (PV), prefibrotic/early primary myelofibrosis (pre-PMF), or PMF from January 1996 to October 2020 in Chungnam National University Hospital, Daejeon, Korea, were reviewed. Results A total of 347 patients (143 ET, 129 PV, 44 pre-PMF, and 31 PMF patients; 201 men and 146 women) with a median age of 64 (range 15-91) years old were followed up for a median of 4.7 (range 0.1-26.5) years. Fifteen (4.3%) patients exhibited splenic infarctions at the diagnosis. These were most common in PMF patients (12.9%), followed by pre-PMF (9.1%) and PV (5.4%) patients. Multifocal infarcts (60.0%) were most common, followed by solitary (33.3%) and extensive infarcts (6.7%). The cumulative incidence of thrombosis in patients with splenic infarctions tended to be higher than in those lacking infarctions (10-year incidence 46.7% vs. 21.0% in PV; p=0.215; 33.3% vs. 17.9% in pre-PMF; p=0.473) patients, but statistical significance was lacking. Palpable splenomegaly (hazard ratio 14.89; 95% confidence interval 4.00-55.35; p<0.001) was the only independent risk factor for splenic infarction. During follow-up, 5 (1.4%) patients developed splenic infarctions. Conservative treatment adequately controlled the symptoms; no serious complications were noted in any patient. Conclusion Splenic infarctions occurred most frequently in patients with PMF; it was rare in patients with ET. The clinical courses were generally mild.

Neutrophil-lymphocyte ratio and carotid plaque burden in patients with essential thrombocythemia and polycythemia vera

BACKGROUND AND AIMS

Chronic inflammation plays a critical role in the pathogenesis of myeloproliferative neoplasm (MPN), and inflammatory conditions are closely related to the development and exacerbation of atherosclerosis. This study aimed to compare carotid plaque burden and neutrophil-lymphocyte ratio (NLR) in the essential thrombocythemia (ET)/polycythemia vera (PV) and control groups.

METHODS AND RESULTS

We retrospectively assessed carotid plaque burden and NLR in patients with ET/PV between January 2010 and September 2021 and propensity-score matched these patients to control subjects from the general population. All patients underwent carotid imaging using carotid ultrasonography for atherosclerosis screening. After 3:1 propensity-score matching, 140 patients in the control group were matched to 51 patients in ET/PV group. The mean NLR was significantly higher in the MPN group than in the control group (4.77 ± 3.96 vs. 1.93 ± 1.03, p < 0.001). The carotid plaque score was also higher in MPN group than in the control group (2.37 ± 1.47 vs. 1.94 ± 1.17, p = 0.038).

CONCLUSION

Patients with PV/ET show a higher NLR and carotid plaque burden than the normal population. This reflected that PV/ET was a highly inflammatory and atherosclerotic condition expressing potentially increased cardiovascular risk.

Increased cleavage of von Willebrand factor by ADAMTS13 may contribute strongly to acquired von Willebrand syndrome development in patients with essential thrombocythemia

BACKGROUND

Patients with essential thrombocythemia (ET) often experience bleeding associated with acquired von Willebrand syndrome (AVWS) when the platelet count is markedly increased.

OBJECTIVE

We investigated whether von Willebrand factor (VWF) degradation is enhanced in patients with ET.

METHODS

Seventy patients with ET underwent VWF multimer (VWFM) analysis and measurement of VWF-related parameters. We calculated the VWFM index, defined as the ratio of intensities of a patient's molecular weight-categorized VWFMs, and those of a healthy subject's, using densitometric analysis. VWF degradation product (DP) was measured via ELISA using a monoclonal antibody that specifically recognizes Y1605 at the C-terminal boundary, which is exposed following ADAMTS13-mediated cleavage of the Y1605-M1606 bond of the VWF A2 domain.

RESULTS

Patients with higher platelet counts had a significantly reduced high molecular weight (HMW)-VWFM index and an increased VWF-DP:VWF antigen (Ag) ratio compared to those with lower platelet counts. On multivariate analysis, the VWF-DP/VWF:Ag ratio was an independent predictor of the HMW-VWFM index. Patients who underwent cytoreductive therapy had a significantly higher HMW-VWFM index and lower VWF-DP/VWF:Ag ratio than those who did not. Among individual patients, there was also a significant increase in the HMW-VWFM index and a decrease in the VWF-DP/VWF:Ag ratio after cytoreductive therapy compared to pre-therapy values.

CONCLUSION

In patients with ET, an increased platelet count is associated with enhanced cleavage of VWF at the Y1605-M1606 bond, primarily by ADAMTS13, leading to AVWS. Cytoreductive therapy reduces the platelet count, prevents excessive VWF cleavage, and improves VWFM distributions.

[Search for mutations in patients with Philadelphia negative myeloproliferative neoplasms in a public hospital in Chile]

BACKGROUND

Philadelphia negative myeloproliferative neoplasms (Ph-MPN) are clonal disorders whose pathogenesis has been elucidated in recent years, creating diagnostic and prognostic algorithms.

AIM

To study JAK2, CALR y MPL gene mutations in patients with Ph-MPN.

MATERIALS AND METHODS

Descriptive cross-sectional observational study of patients with MPN (2015-2019), reviewing clinical, demographic and laboratory data. JAK2, CALR and MPL gene mutations were analyzed by RT-PCR.

RESULTS

We studied 72 patients. Fifty percent had essential thrombocythemia (ET), 26.4% had polycythemia vera (PV) and 23.6% had primary myelofibrosis (PM). Bone marrow biopsy was available in 76.5%. At diagnosis, the mean age was 65.5 years and 61% were symptomatic. A thrombotic event was the most frequent problem in 20% and 25% had splenomegaly. There were statistically significant differences in hematological parameters between the different MPNs. JAK2 V617F mutation was detected in 61.1%. Only 19 JAK2 V617F negative patients were available for CALR and MPL mutation studies, identifying 10 triple negative cases. Kaplan Meier curves showed a median survival of 88 months, being similar in the three MPNs. Causes of death in 20 patients were thrombotic complications in 30%, disease progression in 25%, infection in 20%, other neoplasms in 15% and other causes in 10%.

CONCLUSIONS

The presentation and frequency of JAK2 V617F, CALR and MPL mutations in our cohort was similar to those reported in other studies for ET and PM. JAK2 V617F mutation was lower for PV. No significant differences between the three MPNs were observed for overall survival. We could not assess the prognostic value of the mutations.

Challenges of diagnosing and managing pre-fibrotic myelofibrosis: A case-based and practical approach

Pre-Fibrotic Myelofibrosis is a frequently under-recognised entity that has distinct features separate to those of both Essential Thrombocythaemia and overt Primary Myelofibrosis. Misdiagnosis is relatively common due to subtle differences in bone marrow trephine morphology and multidisciplinary approaches are required. The clinical phenotype and disease course is heterogeneous and hence management approaches tend to vary widely. Although patients may initially be asymptomatic, disease-related complications can include troublesome symptom burdens, increased incidence of both arterial and venous thromboses, haemorrhage, anaemia and an inherent risk of disease evolution to either overt myelofibrosis or blastic phase disease. Specific prognostic tools with high discriminatory power are lacking. Within this review we use case-based approaches to review the current literature, highlight challenges in both diagnostics and disease management and suggest contemporary approaches to improve patient outcomes.

Essential Thrombocythemia among Patients with Myeloproliferative Neoplasms in Haematology Unit of a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction: Essential thrombocythemia, a myeloproliferative condition with an increased number of circulating platelets, is a rare hematological malignancy. The aim of the study is to find out the prevalence of essential thrombocythemia among patients with myeloproliferative neoplasms presenting in haematology unit of a tertiary care centre. Methods: This was a descriptive cross-sectional study at a tertiary care centre from September, 2020 to September, 2021 (Reference number: 48 (6-11) E2077/076). All the patients with a diagnosis of essential thrombocythemia and willing to give consent were included in the study while the patients with incomplete investigations were excluded. A sample size of 72 patients was taken and convenience sampling was done. Data were entered in Microsoft Excel 2010 and analysis was done by the Statistical Package for the Social Sciences Version 22.0. Point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data along with mean and standard deviation for continuous data. Results: Among 72 patients with myeloproliferative neoplasms, the prevalence of essential thrombocythemia was found to be 17 (23.61%) (13.80-33.42 at a 95% Confidence Interval). The mean age of patients was 55.41±11.20 years with a male to female ratio of 9:8. The mean hemoglobin level and platelet count in patients were found to be 11.20±2.1 g/dl and 677000±262067.70 cells/mm3. Twelve (70.58%) of total patients were under low risk of essential thrombocythemia while 3 (17.64%) of them were at high risk. Conclusions: The prevalence of essential thrombocythemia was similar to other studies done in similar settings.

Essential thrombocythemia and aortic dissection,causal or incidental association?

Only few cases of vascular dissection and essential thrombocythemia association have been reported. To the best of our knowledge, we reported the second case of aortic dissection and essential thrombocythemia association in a 60-year-old man with positive JAK2V617F mutation who had no history of hypertension or connective tissue disorders. Through this case, we discussed the eventual existence of a causal relationship between the two conditions. We also suggested the use of hydroxyurea as a prevention treatment of thrombosis in myeloproliferative neoplasms.

Rebound of platelet count in a patient with type 2 calreticulin-mutant essential thrombocythemia in the postpartum period: A case report

INTRODUCTION

Essential thrombocythemia (ET) is an uncommon myeloproliferative neoplasm. It is more common in females; 20% of them are below 40 years old. The optimal management of ET during pregnancy and postpartum periods is still not well established.

PATIENT CONCERN

We report a case of a young lady with type 2 calreticulin-mutant ET who developed a marked rebound in her platelet count (reaching 2030 × 103/μL) 2 weeks after premature delivery of her baby (24th week of gestation). She was on Pegylated Interferon alfa 2-a during pregnancy (her platelet was around 500 × 103/μL during the second trimester), but she had stopped it on her own from the 20th week of gestation.

DIAGNOSIS

Postpartum rebound of platelet count due to medication non-compliance.

INTERVENTION AND OUTCOME

We resumed her regular Pegylated Interferon, and subsequently, her platelet count reduced dramatically within 4 weeks to an acceptable level (684 × 103 /μL).

CONCLUSION

The guideline is still not well-established regarding the optimal approach for postpartum rebound of platelet count in patients with ET. It is still unclear if the platelet count will fall spontaneously without intervention after the rebound phase. Further research is required to establish the optimal management of ET during the postpartum phase. This case emphasizes the importance of platelet count follow-up during the postpartum period and outlines our management approach in such cases.

Clinical characteristics, prognostic factors, and outcomes of patients with essential thrombocythemia in Japan: the JSH-MPN-R18 study

We conducted a large-scale, nationwide retrospective study of Japanese patients who were diagnosed with essential thrombocythemia based on the diagnostic criteria in the World Health Organization classification. We investigated clinical characteristics, survival rates, and the incidence of thrombohemorrhagic events as well as risk factors for these events. A total of 1152 patients were analyzed in the present study. Median age at diagnosis was 65 years, the median platelet count was 832 × 10⁹/L, and the positive mutation rates of JAK2V617F, CALR, and MPL were 62.8, 25.1, and 4.1%, respectively. Compared with European and American patients, Japanese patients were more likely to have cardiovascular risk factors and less likely to have systemic symptoms including palpable splenomegaly. Thrombocytosis was identified as a risk factor for hemorrhagic events and prognosis, but not for thrombotic events. The prognostic factors and risk classifications reported in Europe and the United States were generally applicable to Japanese patients. Regarding transformations, secondary myelofibrosis progressed in a time-dependent manner, but progression to acute leukemia was low in "true" ET patients. Skin cancers were less common and gastrointestinal cancers more common as secondary malignancies in Japanese patients, suggesting ethnic differences.

Nonvitamin K Antagonist Oral Anticoagulant in Patients With Venous Thromboembolism and Polycythemia Vera or Essential Thrombocythemia: A Cohort Study

ABSTRACT

Thrombosis is the most common adverse event in patients with polycythemia vera (PV) and essential thrombocythemia (ET). Little is known about the use of nonvitamin K antagonist oral anticoagulants (NOACs) in patients with myeloproliferative neoplasms. We sought to evaluate the efficacy and safety of NOAC in a cohort of patients with PV and ET, who experienced venous thromboembolism (VTE). We enrolled 48 consecutive patients with PV (70.8%) and ET [median age 67.0 (interquartile range, 58.5-72.0) years], who experienced VTE. Patients received apixaban (39.6%), rivaroxaban (33.3%), or dabigatran (27.1%). During a median follow-up of 30 (interquartile range, 20.5-41.5) months, recurrent thrombotic events and bleeding were recorded. Four thrombotic events (3.3 per 100 patient-years) were reported. Three deep vein thrombosis episodes (2.5 per 100 patient-years) were experienced by 2 patients with PV, who received apixaban (5 mg bid) and dabigatran (150 mg bid), and 1 patient with ET, who received dabigatran (150 mg bid). One ischemic stroke occurred in a patient with PV on rivaroxaban (20 mg/d). There was 1 major bleeding (0.8 per 100 patient-years) in a patient with ET on dabigatran (150 mg bid) and 3 clinically relevant nonmajor bleeding (2.5 per 100 patient-years): 2 on rivaroxaban (20 mg/d) and 1 on apixaban (5 mg bid). We did not observe significant differences related to the type of NOAC. Three deaths (2.5 per 100 patient-years) unrelated to either VTE or bleeding were recorded. This study shows that NOACs may be effective and safe as secondary prevention of VTE in patients with myeloproliferative neoplasms.

Platelet transcriptome identifies progressive markers and potential therapeutic targets in chronic myeloproliferative neoplasms

Predicting disease progression remains a particularly challenging endeavor in chronic degenerative disorders and cancer, thus limiting early detection, risk stratification, and preventive interventions. Here, profiling the three chronic subtypes of myeloproliferative neoplasms (MPNs), we identify the blood platelet transcriptome as a proxy strategy for highly sensitive progression biomarkers that also enables prediction of advanced disease via machine-learning algorithms. The MPN platelet transcriptome reveals an incremental molecular reprogramming that is independent of patient driver mutation status or therapy. Subtype-specific markers offer mechanistic and therapeutic insights, and highlight impaired proteostasis and a persistent integrated stress response. Using a LASSO model with validation in two independent cohorts, we identify the advanced subtype MF at high accuracy and offer a robust progression signature toward clinical translation. Our platelet transcriptome snapshot of chronic MPNs demonstrates a proof-of-principle for disease risk stratification and progression beyond genetic data alone, with potential utility in other progressive disorders.

Essential thrombocythaemia first presenting as myocardial infarction in a 36-year-old male

Essential thrombocythaemia (ET) is a myeloproliferative neoplasm where there is a clonal proliferation of thrombocytes. Whilst most often diagnosed incidentally, it can uncommonly present with arterial thrombosis. This is a case presentation of a 36-year-old male who was diagnosed with ET following myocardial infarction caused by multiple thrombotic emboli. The patient was initially misdiagnosed with viral myopericarditis based on an atypical history of chest pain with a viral prodrome. Reattendance a month later with further chest pain, dynamically raised troponin and ECG changes raised suspicions of ACS. Analysis of blood markers from both admissions showed consistently elevated platelet counts. A CMR scan revealed focal ischaemic scars in multiple cardiac segments consistent with an acute coronary event or coronary embolisation. A subsequent coronary angiography demonstrated minimal coronary artery disease. JAK2 gene V617F mutation was detected, confirming ET. The patient was commenced on pegylated interferon-alpha and dual antiplatelet therapy, and discharged with follow-up.

The Assessment of the Platelet Function During the Acute Phase of ST-segment Elevation Myocardial Infarction in Essential Thrombocythemia

We encountered a case of ST-segment elevation myocardial infarction (STEMI) as the first clinical manifestation of essential thrombocythemia (ET). Platelet function tests revealed high thrombogenicity during primary percutaneous coronary intervention compared with general cardiovascular patients, whereas the platelet function two weeks after admission was effectively suppressed by dual antiplatelet therapy. The patient, who lacked cytoreduction, suffered from recurrent STEMI because of poor compliance with antiplatelet drugs. The risk of acute coronary occlusion may be high during the acute phase of STEMI in ET patients because of high thrombogenicity. Insufficient antiplatelet therapy and no cytoreduction are also risk factors for recurrent coronary events.

Clinical outcomes of interferon therapy for polycythemia vera and essential thrombocythemia: a systematic review and meta-analysis

Interferon therapy has been used in clinical practice for more than three decades to treat polycythemia vera (PV) and essential thrombocythemia (ET). However, there has been no systematic investigation of its expected outcomes and potential risks. We performed a systematic review and single-arm meta-analysis to assess the clinical outcomes (hematological response, molecular response, vascular events, hematological transformation, and adverse events) after interferon therapy for patients with PV and ET. A systematic search identified 37 reports, including data from 1794 patients that were published before March 2021. The pooled overall hematological response (OHR) rate was 86%, with better OHR rates observed in studies using long-acting interferon (p < 0.001) and studies with younger patients (p = 0.038). The pooled overall molecular response rate was 48%, and inter-study heterogeneity was also related to patient age (p = 0.009). The overall incidence was 0.42/100 person-years for thrombosis, 0.01/100 person-years for hemorrhage, 0.21/100 person-years for myelofibrotic transformation, and 0.08/100 person-years for leukemic transformation. Compared with hydroxyurea, interferon produced a non-inferior hematological response and a superior molecular response. In conclusion, interferon therapy provided high rates of hematological and molecular response for patients with PV and ET and was associated with a favorable prognosis.

Foot ischemia related to essential thrombocytemia and atherosclerosis

We report two cases of foot ischemia combining microvascular thrombosis related to essential thrombocytemia (ET) and a proximal ulcerating atherosclerotic plaque. This suggests that myeloproliferative neoplasms could also trigger distal embolism from an unstable atherosclerotic plaque by creating a prothrombotic status. These distal ischemic events were the first ET manifestation and therefore lead to myeloproliferative neoplasm diagnosis. In ET, thrombosis event can occur with a normal platelet count. Furthermore, hemogram should be regularly controlled among JAK2 muted patients considering the frequent evolution from isolated JAK2 mutation to ET.

Clinical and Prognostic Features of Essential Thrombocythemia: Comparison of 2001 WHO Versus 2008/2016 WHO Criteria in a Large Single-center Cohort

BACKGROUND

According to 2008/2016 classification of the World Health Organization (WHO), a platelet (PLT) count ≥ 450 × 10⁹/L, reduced from the previously published WHO 2001 indicated level ≥ 600 × 10⁹/L, was considered the new PLT threshold for the diagnosis of essential thrombocythemia (ET).

PATIENTS AND METHODS

To validate this important diagnostic change in a setting of current clinical practice, we retrospectively analyzed clinical and hematologic features at diagnosis and during follow-up of 162 patients with ET, diagnosed in our center from January 2008 to December 2017. We subdivided patients according to PLT value at baseline into Group A (PLT ≥ 600 × 10⁹/L) (124 patients; 76.5%) and Group B (PLT ≥ 450 × 10⁹/L < 600 × 10⁹/L) (38 patients; 23.5%).

RESULTS

Among clinical features, only the median value of leukocytes (P < .001) was significantly higher in Group A. Cytostatic treatment was administered in 103 patients, with a significantly higher rate in patients of group A (P < .001). After a median follow-up of 42.4 months (interquartile range, 22.1-70.6 months), 8 thrombotic events were recorded in the entire cohort, without differences between the 2 groups (P = .336). The 5-year overall survival (OS) of the entire cohort was 96.9% (95% confidence interval, 92.6%-100%), without differences between the 2 groups (P = .255).

CONCLUSIONS

Our data indicate a substantial homogeneity among patients with ET regardless of the PLT count at diagnosis, thus confirming the usefulness of the 2008/2016 WHO diagnostic criteria.

The Current Status of Screening for Essential Thrombocythemia and Polycythemia Vera in Clinical Practice-Report from a Single Institution

OBJECTIVE

We investigate the current status of screening for essential thrombocythemia(ET)and polycythemia vera(PV), at our hospital.

METHODS

According to the World Health Organization(WHO)diagnostic criteria.

PATIENTS

All patients who visited Juntendo University Urayasu Hospital between May 1984(when the hospital opened)and January 2019.

RESULT

More than 90% of patients with elevated platelet counts(PLT)(n=25,062)and more than 90% of patients with elevated hemoglobin( Hb)or hematocrit(Ht)levels(n=16,422)did not visit the department of hematology, suggesting that there could be a high percentage of patients with potentially latent ET and PV visiting the hospital. In addition, a large number of patients fulfilling the laboratory criteria for ET/PV visited various departments of the hospital other than the department of hematology.

CONCLUSION

Because ET/PV manifests with diverse symptoms, including non-specific symptoms and symptoms pertaining to other organ systems. Based on the findings, we consider that it is essential to disseminate information about the WHO diagnostic criteria/clinical symptoms and possibility of latent ET/PV to all departments of the hospital, and to establish cooperation between the department of hematology and other departments.