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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. [ABSTRACT FROM AUTHOR]

Patients with polycythemia vera (PV) or essential thrombocythemia (ET) presenting with splanchnic vein thrombosis (SVT) might have a specific clinico-biological profile. To investigate this hypothesis, 3705 PV/ET patients from three national registers, 118 of them presenting with SVT, were reviewed. After correction for age and sex, PV/ET patients with SVT showed an increased risk of death (HR 2.47, 95% CI 1.5-4.01, p < 0.001), venous thrombosis (IRR 3.4, 95%CI 2.1-5.5, p < 0.001), major bleeding (IRR 3.6, 95%CI 2.3-5.5, p < 0.001), and second cancer (IRR 2.37, 95%CI 1.4-4.1, p = 0.002). No case of acute leukemia was documented among patients with PV/ET presenting with SVT and seven of them (6%) progressed to myelofibrosis. SVT was not associated with lower risk of MF after correction by age and sex. Patients with SVT more frequently died from complications related to hepatic disease, major bleeding, or second cancer, resulting in a 5-year reduction of age- and sex-adjusted median survival. In conclusion, PV and ET patients presenting with SVT have shorter survival than patients with PV and ET of the same age and sex. This excess mortality is related to liver disease, major bleeding, and second cancer rather than to the natural evolution of the MPN. [ABSTRACT FROM AUTHOR]

It is unclear whether anticoagulation guidelines intended for the general population are applicable to patients with polycythemia vera (PV) and essential thrombocythemia (ET). In the present study, the risk of thrombotic recurrence was analyzed in 150 patients with PV and ET treated with vitamin K antagonists (VKA) because of an arterial or venous thrombosis. After an observation period of 963 patient-years, the incidence of re-thrombosis was 4.5 and 12 per 100 patient-years under VKA therapy and after stopping it, respectively ( P < 0.0005). After a multivariate adjustment for other prognostic factors, VKA treatment was associated with a 2.8-fold reduction in the risk of thrombotic recurrence. Notably, VKA therapy offset the increased risk of re-thrombosis associated with a prior history of remote thrombosis. Both the protective effect of VKA therapy and the predisposing factors for recurrence were independent of the anatomical site involved in the index thrombosis. Treatment periods with VKA did not result in a higher incidence of major bleeding as compared with those without VKA. These findings support the use of long-term anticoagulation for the secondary prevention of thrombosis in patients with PV and ET, particularly in those with history of remote thrombosis. [ABSTRACT FROM AUTHOR]

This study investigates whether the response criteria proposed by the European LeukemiaNet (ELN) to evaluate cytoreductive therapies in essential thrombocythemia (ET) correlate with clinically relevant outcomes in patients receiving anagrelide. We evaluated 154 ET patients treated with anagrelide (upfront in 87) for a median of 2.9 years. Complete response (CR), partial response, and no response were observed in 56, 30.5, and 13.5 % patients, respectively. Only 38 patients (25 %) achieved a sustained CR. Overall, the aggregated time on CR and without CR was 200.1 and 333.6 person-years, respectively. The incidence rate of thrombosis and hemorrhage was independent of the CR status. The only factor associated with shorter survival after anagrelide start was the patient's age, whereas achieving a CR with anagrelide had no predictive value for subsequent survival. In conclusion, CR according to the ELN definition is not associated with any measurable clinical benefit in ET patients treated with anagrelide. [ABSTRACT FROM AUTHOR]

Platelet and leukocyte activation has been demonstrated in polycythemia vera (PV) and essential thrombocythemia (ET), but such information is limited in primary myelofibrosis (PMF). Platelet, leukocyte, endothelial, and coagulation activation status was assessed in 26 PMF patients and compared with data from 22 age- and sex-matched healthy individuals. Study included flow cytometry assessment of platelet P-selectin expression [at baseline and after adenosine diphosphate (ADP), thrombin and arachidonic acid stimulation], platelet–neutrophil and platelet–monocyte complexes, and CD11b expression in neutrophils and monocytes. Additionally, soluble P-selectin, sCD40L, tissue factor, thrombomodulin, prothrombin fragment 1 + 2 (F1 + 2), and D-dimer were measured by enzyme-linked immunosorbent assays. The above parameters were correlated with the patients’ clinical data and presence of the JAK2 V617F mutation. Compared with controls, PMF patients had increased baseline platelet activation, as shown by significantly higher levels of soluble and platelet P-selectin expression, and also higher percentages of platelet–monocyte complexes. Neutrophil and monocyte CD11b expression was significantly higher in patients with the JAK2 mutation than in those with wild-type allele or the controls. Endothelial and coagulation activation, as demonstrated by increased plasma levels of thrombomodulin and F1 + 2, was also found in PMF, with patients with the JAK2 mutation showing significantly higher values of F1 + 2 than those with wild-type allele. In conclusion, PMF patients have platelet, leukocyte, endothelial, and coagulation activation similar to that in PV and ET. CD11b overexpression and F1 + 2 are correlated with the presence of the JAK2 mutation. [ABSTRACT FROM AUTHOR]

The frequency of vascular events and evolution to myelofibrosis (MF) in young individuals with essential thrombocythemia (ET) is not well known. The incidence and predisposing factors to such complications was studied in 126 subjects diagnosed with ET at a median age of 31 years (range: 5–40). Overall survival and probability of survival free of thrombosis, bleeding and MF were analyzed by the Kaplan–Meier method and the presence of the Janus Kinase 2 (JAK2) V617F mutation correlated with the appearance of such complications. The JAK2 mutation (present in 43% of patients) was associated with higher hemoglobin (Hb) (P<0.001) and lower platelets at diagnosis. With a median follow-up of 10 years (range: 4–25), 31 thrombotic events were registered (incidence rate: 2.2 thromboses/100 patients/year). When compared with the general population, young ET patients showed a significant increase in stroke (odds ratio 50, 95% CI: 21.5–115) and venous thromboses (odds ratio 5.3, 95% CI: 3.9–10.6). Thrombosis-free survival was 84% at 10 years, with tobacco use being associated with higher risk of thrombosis. Actuarial freedom from evolution to MF was 97% at 10 years. In conclusion, young ET patients have thrombotic events, especially stroke and venous thrombosis, more frequently than generally considered, whereas they rarely transform to MF.Leukemia (2007) 21, 1218–1223. doi:10.1038/sj.leu.2404693; published online 12 April 2007 [ABSTRACT FROM AUTHOR]

Thrombosis is a frequent complication of polycythemia vera and essential thrombocythemia, but its incidence and predisposing factors in idiopathic myelofibrosis (IM) are unknown. In 18 (11.6%) of 155 patients diagnosed with IM in a single institution, 31 thrombotic events (19 arterial, 12 venous) were registered after a mean follow-up of 4.2 (s.d.: 4.5) years. In six patients, the thrombosis was simultaneous to or appeared a few months before IM diagnosis and 14 had one or more thrombotic episodes. When compared with the general population, a significant increase was observed in the incidence of venous thrombosis (odds ratio 17.5, 95% confidence interval: 10.3–31.4). At multivariate analysis, the initial variables associated with an increased risk of thrombosis were thrombocytosis (platelets >450 × 109/l, P=0.001), presence of one cardiovascular risk factor (arterial hypertension, smoking, hypercholesterolemia, or diabetes, P=0.003), cellular phase of myelofibrosis (P=0.005), and Hb >11 g/dl (P=0.02). Considering post-diagnosis events, the 5-year thrombosis-free survival probability was 90.4% in the series, 80.6% for patients with platelets >450 × 109/l, 82.6% for patients with one cardiovascular risk factor, and 85.1% for those in cellular phase. These results indicate an increased thrombotic risk for IM patients with hyperproliferative features and/or coexistent cardiovascular risk factors.Leukemia (2006) 20, 55–60. doi:10.1038/sj.leu.2404048; published online 24 November 2005 [ABSTRACT FROM AUTHOR]

Severe retroperitoneal hemorrhage represents an infrequent and serious complication of bone marrow biopsy. A 53-year-old man, diagnosed with polycythemia vera 12 years earlier, was submitted to a bone marrow biopsy due to the appearance of anemia with clinical and hematological features suggesting myelofibrotic transformation, a diagnosis that was confirmed by the marrow study. At 2 h of a right anterior iliac bone marrow trephine biopsy, the patient suddenly developed severe pain in the area of the biopsy, with antialgic flexion of the right leg. Computed tomographic (CT) scan of the abdomen showed a 5 x 9.5 cm hematoma in the right iliac and psoas muscles. The patient was initially managed with analgesics and transfusional support, but the pain persisted and a continuous fall in the hematocrit was observed in the following days. Angiographic examination of the right external iliac artery showed contrast extravasation arising from the circumflex iliac branch, which was embolized using polivinyl alcohol particles and one coil. Following such procedure, the patient recovered uneventfully and was discharged in good condition a few days later. This case illustrates the effectiveness of an endovascular approach in providing a fast and minimally invasive treatment for this life-threatening complication of bone marrow trephine biopsy. [ABSTRACT FROM AUTHOR]