How I treat myeloproliferative neoplasms in pregnancy.

ABSTRACT: Although myeloproliferative neoplasms (MPNs) are traditionally considered diseases of adults in their sixth or seventh decade, these conditions do occur in young patients; for example, for essential thrombocythemia, in particular, there is a second peak in women of reproductive age. Therefore, pregnancy is an uncommon but not rare occurrence and clinical challenge in some scenarios. Here, we discuss in detail our local approach to the management of pregnancy in patients with MPN while taking a case-based approach. We include relevant updates in the field and point to a future research strategy that should be internationally focused to obtain as much information in as short a time as possible.

Essential thrombocythemia: challenges in clinical practice and future prospects.

Essential thrombocythemia (ET) was first described in 1934, and subsequently, progress has been made in better understanding the molecular pathogenesis and which patients may have greatest risk of progression or vascular events. However, it has been more than a decade since a new therapy has been approved for ET. We are beginning to understand more comprehensively both the heterogeneity of this disease, which is largely driven by driver mutation status, as well as the effect of disease-related symptoms, such as fatigue, on patients. In this review we provide a practical overview of diagnosis and management of ET with focus on challenging patient scenarios and some consideration of what comprehensive care might entail. Finally, we also discuss newer therapies and how these might be assessed.

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.

Essential Thrombocythemia in Adolescents and Young Adults: Clinical Aspects, Treatment Options and Unmet Medical Needs.

OPINION STATEMENT: Current treatment of essential thrombocythemia (ET) should primarily prevent thrombo-hemorrhagic events, without increasing the rate of fibrotic progression or leukemic evolution, and secondarily control microvascular symptoms. Unlike other classic BCR::ABL1-negative myeloproliferative neoplasms, ET is frequently diagnosed in adolescents and young adults (AYA), defined as individuals aged 15 to 39 years, in up to 20% of patients. However, since the current risk stratification of this disease is based on models, including that of ELN, IPSET-Thrombosis and its revised version, mainly applied to an older patients' population, international guidelines are needed that specifically consider how to evaluate the prognosis of AYAs with ET. Furthermore, although ET is the most frequent MPN among AYA subjects, there is a lack of specific recommendations on how to treat it in this subgroup of patients, as management decisions are typically extrapolated from those for the elderly. Accordingly, since AYAs with ET represent a unique disease subset defined by attenuated genetic risk, more indolent phenotype, and longer survival than their older counterparts, treatment selection requires special attention to specific issues such as the risk of fibrotic/leukemic transformation, carcinogenicity, and fertility. This review article will provide a comprehensive overview of the diagnosis, prognostic stratification, and possible therapeutic approaches for AYA patients with ET, including antiplatelets/anticoagulants and cytoreductive agents, with a focus on pregnancy management in real-life clinical practice.

A review of essential thrombocythemia and its complications.

Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm characterized by an increased platelet count in the peripheral blood and excessive megakaryopoiesis in the bone marrow. In one-third of cases, the disease remains benign and does not lead to complications. In the remaining cases, however, ET may present with thromboembolic and hemorrhagic complications and transform into more aggressive myeloid neoplasms, with a negative effect on morbidity and mortality. Despite extensive research and a better understanding of the pathogenesis and etiology of the complications associated with ET, limited data are available on the management of complications and emergencies. This article highlights the complications and emergencies associated with ET and discusses treatment options and the controversies associated with management.

Low-risk polycythemia vera and essential thrombocythemia: management considerations and future directions.

Thrombotic events are a distinctive feature of the myeloproliferative neoplasms (MPNs) polycythemia vera (PV) and essential thrombocythemia (ET). Patients with these MPNs may also experience a poor quality of life secondary to symptom burden, as well as progression of disease to acute leukemia or myelofibrosis. Over the years, various risk stratification methods have evolved in order to attempt to predict thrombotic risk, which is the largest contributor of morbidity and mortality in these patients. More than half of PV and ET patients are low- or intermediate-risk disease status at the time of diagnosis. While therapeutic development is presently focused on high-risk patients, there is a paucity of therapies, outside of aspirin and therapeutic phlebotomy, which can reduce the thrombotic risk or delay disease progression in low-risk patients. In this review, we first describe the various complications that patients with PV and ET experience, and then detail our evolving understanding of risk stratification in these diseases. We then highlight the available evidence on the management of low-risk PV and ET and include a description of novel therapies currently under investigation in this space. We conclude with recommendations for future directions to advance our understanding and improve the treatment of low-risk PV and ET.

Thrombocytapheresis for acquired von Willebrand syndrome in a patient with essential thrombocythemia and recent multivisceral transplantation.

BACKGROUND: Essential thrombocythemia (ET) is associated with increased risk of bleeding secondary to acquired von Willebrand syndrome (AVWS). Bleeding in ET requires urgent platelet reduction by cytoreductive therapy such as hydroxyurea or thrombocytapheresis. We report on the efficacy and safety of thrombocytapheresis in managing AVWS in a patient with ET and multivisceral transplantation. CASE REPORT: The patient was a 51-year-old female who underwent multivisceral transplantation. Her postoperative course was complicated by bleeding from oral cavity, IV lines, gastrointestinal and upper respiratory tracts as well as vaginal bleeding, which coincided with ET flare with a platelet count of 1512 × 109 /L. Coagulation studies including von Willebrand factor (vWF) antigen and activity, vWF propeptide antigen, and vWF multimer analysis were consistent with AVWS. Hydroxyurea was initiated. However, due to major bleeding, rapidly increasing platelet count, and uncertainty of response to hydroxyurea being given through the enteral tube, thrombocytapheresis was initiated for rapid platelet reduction. The patient tolerated the procedure well. Platelet count was reduced from 1636 × 109 /L to 275 × 109 /L with rapid cessation of bleeding. The patient's condition stabilized over the next few days; however, bleeding recurred with increasing platelet count, which required a second thrombocytapheresis 8 days after the first one. The patient was maintained on hydroxyurea 500 mg twice/day. At 11-month follow-up, she had a normal platelet count and no recurrence of bleeding. DISCUSSION: Thrombocytapheresis is safe and efficient in managing postoperative bleeding due to ET/AVWS in solid organ transplant patients. The procedure can be an adjunct to bridging therapy before response to hydroxyurea is achieved.

The management, outcome, and postpartum disease course of 41 pregnancies in 20 women with polycythemia vera.

OBJECTIVES: Pregnancies in women with polycythemia vera (PV) are associated with an increased risk of PV-related maternal complications and often result in miscarriage. Recommendations for the management of PV pregnancies are mainly based on studies with a small number of patients. A correlation between pregnancy outcome and postpartum course has been reported for essential thrombocythemia, but corresponding data for PV are lacking so far. METHODS: In 41 PV pregnancies, the pregnancy outcome, the use of PV-specific therapies (ie, acetylsalicylic acid, low-molecular weight heparin and/or interferon-alpha), and the postpartum PV course were investigated. RESULTS: A live birth rate of 51.2% (21/41 pregnancies) was observed. 43.9% of pregnancies ended in spontaneous abortion and 4.9% in stillbirth. A significantly increased live birth rate occurred in pregnancies with PV-specific therapies compared to standard antenatal care (69.0% vs. 8.3%; P < .0019). The use of PV-specific therapy significantly increased the number of maternal hemorrhages (P = .021) without increasing the risk of fetal complications. During the median postpartum follow-up period of 1.2 years (range 0.1-13.7), complicated postpartum PV occurred significantly more often after miscarriages (P = .035). CONCLUSIONS: According to our analysis, PV-specific therapy improved the live birth rate. Significantly more complicated postpartum PV courses were observed after miscarriages.

Hematopoietic expression of a chimeric murine-human CALR oncoprotein allows the assessment of anti-CALR antibody immunotherapies in vivo.

Myeloproliferative neoplasms (MPNs) are characterized by a pathologic expansion of myeloid lineages. Mutations in JAK2, CALR and MPL genes are known to be three prominent MPN disease drivers. Mutant CALR (mutCALR) is an oncoprotein that interacts with and activates the thrombopoietin receptor (MPL) and represents an attractive target for targeted therapy of CALR mutated MPN. We generated a transgenic murine model with conditional expression of the human mutant exon 9 (del52) from the murine endogenous Calr locus. These mice develop essential thrombocythemia like phenotype with marked thrombocytosis and megakaryocytosis. The disease exacerbates with age showing prominent signs of splenomegaly and anemia. The disease is transplantable and mutCALR stem cells show proliferative advantage when compared to wild type stem cells. Transcriptome profiling of hematopoietic stem cells revealed oncogenic and inflammatory gene expression signatures. To demonstrate the applicability of the transgenic animals for immunotherapy, we treated mice with monoclonal antibody raised against the human mutCALR. The antibody treatment lowered platelet and stem cell counts in mutant mice. Secretion of mutCALR did not constitute a significant antibody sink. This animal model not only recapitulates human MPN but also serves as a relevant model for testing immunotherapeutic strategies targeting epitopes of the human mutCALR.

[State-of-the-art management for essential thrombocythemia and polycythemia vera].

Essential thrombocythemia (ET) and polycythemia vera (PV) are myeloproliferative neoplasms (MPN), wherein JAK2 V617F mutation exists as a common driver mutation, and the JAK-STAT pathway is constitutively activated. The treatment goal for ET and PV is the prevention of thrombosis and bleeding. The treatment strategy for ET is careful observation or antiplatelet therapy with or without cytoreductive therapy based on the thrombotic risk. The treatment strategy for all PV patients is phlebotomy with a target hematocrit of <45% in addition to antiplatelet therapy. Moreover, for patients at a high risk of thrombosis, additional cytoreductive therapy is considered beneficial. In this session, we discuss important points for ET diagnosis, thrombotic risk stratification, and the details of treatment strategy and current practice with evidence from clinical trials in ET. Furthermore, current topics in the treatment of ET and PV will be introduced with a focus on clinical data about interferon-α, which is reported to induce not only hematologic response but also molecular and histopathologic response in MPN.

Essential thrombocythemia A retrospective case series.

BACKGROUND: Essential thrombocythemia (ET) is rare in children, and pediatric guidelines are lacking. Therefore, we aimed to evaluate ET diagnosis and treatment in a pediatric cohort. PROCEDURE: Data of patients with ET from three hospitals were reviewed. Molecular diagnosis included JAK2V617F, CALR, and MPL mutations. Patients were evaluated for acquired von Willebrand syndrome (AVWS). Follow-up included clinical symptoms, adverse events, and treatment. RESULTS: Twelve children (median age: 8 years, range 1-14.5) were included. Mean lag period between the first documentation of thrombocytosis until ET diagnosis was 36 months. Six patients were positive for JAK2V617F and two for CALR mutations. In six of nine patients, AVWS was diagnosed. At diagnosis, only 33% of patients started therapy with aspirin (n = 4) and hydroxyurea (n = 2). In three of eight untreated patients, therapy was added during follow-up. The cohort was followed for a median of 32.5 months (range: 4-108 months). Clinical follow-up disclosed vascular complications in 4 of 12 patients (deep vein thrombosis, n = 1; transient ischemic attack, n = 3). Two females experienced excessive bleeding; both were diagnosed with AVWS. Neither leukemia nor myelofibrosis evolved in our cohort. CONCLUSION: Increased awareness to pediatric ET is warranted, as delayed diagnosis is common. Compared to adults, AVWS may be more prevalent among children with ET.

Comparison of Dynamic International Prognostic Scoring System and MYelofibrosis SECondary to PV and ET Prognostic Model for Prediction of Outcome in Polycythemia Vera and Essential Thrombocythemia Myelofibrosis after Allogeneic Stem Cell Transplantation.

We aimed to validate the MYelofibrosis SECondary to PV and ET prognostic model (MYSEC-PM) in 159 patients with myelofibrosis secondary to polycythemia vera (PV) and essential thrombocythemia (ET) from the European Society for Blood and Marrow Transplantation registry undergoing transplantation from matched siblings or unrelated donors. Furthermore, we aimed to test its prognostic performance in comparison with the Dynamic International Prognostic Scoring System (DIPSS). Score performance was analyzed using the concordance index (C): the probability that a patient who experienced an event had a higher risk score than a patient who did not (C > .5 suggesting predictive ability). Median follow-up of the total cohort was 41 months (range, 34 to 54), 45 months in post-PV and 38 months in post-ET myelofibrosis. Survival at 1, 2, and 4 years was 70% (95% CI, 63% to 77%), 61% (95% CI, 53% to 69%), and 52% (95% CI, 43% to 61%) for the total cohort; 70% (95% CI, 59% to 80%), 61% (95% CI, 49% to 73%), and 51% (95% CI, 38% to 64%) for post-PV; and 71% (95% CI, 61% to 81%), 61% (95% CI, 50% to 72%), and 54% (95% CI, 42% to 66%) for post-ET myelofibrosis (P = .78). Overall, the DIPSS was not significantly predictive of outcome (P = .28). With respect to the MYSEC-PM, overall survival at 4 years was 69% for the low-risk, 55% for the intermediate 1-risk, 47% for the intermediate 2-risk, and 22% (0% to 45%) for the high-risk groups. The prognostic model was predictive of survival overall (P = .05), whereas groups with intermediate 2 and high risk showed no significant difference (P = .44). Assessment of prognostic utility yielded a C-index of .575 (95% CI, .502 to .648) for the DIPSS, whereas assessment of the MYSEC-PM resulted in a C-statistics of .636 (95% CI, .563 to .708), indicating improvement in prediction of post-transplant survival using the new MYSEC-PM. In addition, transplantations from an unrelated donor in comparison with an HLA-identical sibling showed worse outcome (P = .04), and transplant recipients seropositive for cytomegalovirus in comparison with seronegative recipients (P = .01) showed worse survival. In conclusion, incorporating transplant-specific and clinical and mutational information together with the MYSEC-PM may enhance risk stratification.

Polycythemia vera and essential thrombocythemia: 2019 update on diagnosis, risk-stratification and management.

Disease Overview: Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms respectively characterized by erythrocytosis and thrombocytosis; other disease features include leukocytosis, splenomegaly, thrombosis, bleeding, microcirculatory symptoms, pruritus, and risk of leukemic or fibrotic transformation. Diagnosis: Bone marrow morphology remains the cornerstone of diagnosis. In addition, the presence of JAK2 mutation is expected in PV while approximately 90% of patients with ET express mutually exclusive JAK2, CALR, or myeloproliferative leukemia mutations. In ET, it is most important to exclude the possibility of prefibrotic myelofibrosis. Survival: Median survivals are 14 years for PV and 20 years for ET; the corresponding values for younger patients are 24 and 33 years. Certain mutations (mostly spliceosome) and abnormal karyotype might compromise survival in PV and ET. Life-expectancy in ET is inferior to the control population. Driver mutations have not been shown to affect survival in ET. Risk of thrombosis is higher in JAK2-mutated ET. Leukemic transformation rates at 10 years are estimated at <1% for ET and 3% for PV. Thrombosis Risk: In PV, 2 risk categories are considered: high (age > 60 years or thrombosis history present) and low (absence of both risk factors); in ET, 4 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 (age > 60 years, no thrombosis history, JAK2 wild-type) and high (thrombosis history present or age > 60 years with JAK2 mutation). Risk-Adapted Therapy: The main goal of therapy in both PV and ET is to prevent thrombohemorrhagic complications. All patients with PV require phlebotomy to keep hematocrit below 45% and once- or twice-daily aspirin (81 mg), in the absence of contraindications. Very low-risk ET might not require therapy while aspirin therapy is advised for low-risk disease. Cytoreductive therapy is recommended for high-risk ET and PV but it is not mandatory for intermediate-risk ET. First-line drug of choice for cytoreductive therapy, in both ET and PV, is hydroxyurea and second-line drugs of choice are interferon-α and busulfan. We do not recommend treatment with ruxolutinib in PV, unless in the presence of severe and protracted pruritus or marked splenomegaly that is not responding to the aforementioned drugs.

Polycythemia vera and essential thrombocythemia: algorithmic approach.

PURPOSE OF REVIEW: To describe an algorithm-based approach, whenever available, to the diagnosis, the risk stratification criteria informing therapy and the current management of polycythemia vera and essential thrombocythemia. RECENT FINDINGS: Description of recurrent genetic abnormalities in driver genes, including Janus Kinase 2 (JAK2), myeloproliferative leukemia and calreticulin, a better appreciation of the key diagnostic role of bone marrow features, results of large epidemiologic studies and a few but landmark controlled clinical trials produced in the last decade, all resulted in a reappraisal of the approach to polycythemia vera and essential thrombocythemia. SUMMARY: The revised 2017 WHO classification of polycythemia vera and essential thrombocythemia allows early diagnosis and accurate distinction from other chronic myeloproliferative neoplasms, particulary prefibrotic myelofibrosis. The prognostic value of selected mutations is being appreciated and JAK2V617F mutation is currently incorporated as risk variable in prognostic system for essential thrombocythemia. Risk-adjusted stratification is used to select therapeutic approaches that include target agents. However, there is not yet a curative approach to these hematologic neoplasms, and although their management has much improved in the last decades, the associated morbidity and mortality remains significant and may be worsened by toxicities of therapeutic agents. Therefore, several clinically relevant endpoints remain unmet.

Soluble Interleukin-7 receptor levels and risk of acute graft-versus-host disease after allogeneic haematopoietic stem cell transplantation.

Interleukin-7 is a cytokine essential for T cell homeostasis. IL-7 binds to cellular IL-7 receptors in competition with a soluble form of the receptor (sIL-7Rα). We hypothesized that altered sIL-7Rα levels may cause adverse outcomes in patients undergoing HSCT. In parallel, we investigated the impact of the IL-7Rα SNP rs6897932, which has been associated with release of IL-7R. The sIL-7Rα levels decreased during HSCT (from 114ng/ml before to 48ng/ml at day +14 (P<0.0001)). This pattern was inversely mirrored by IL-7. The IL-7/sIL-7Rα ratio at day +14 was significantly higher in patients developing grades II-IV aGVHD (OR=4.3, P=0.026). Furthermore, donor carriage of the rs6897932 T allele was associated with reduced sIL-7Rα levels, increased risk of grades II-IV aGVHD (OR=2.4, P=0.055) and increased transplant-related mortality (CC=4.5%, CT=21.4% and TT=27.3%, P=0.0037). In conclusion, this study suggests an impact of sIL-7Rα levels and rs6897932 donor genotype on alloreactivity and outcome after HSCT.

How I treat essential thrombocythemia.

Essential thrombocythemia (ET) is an indolent myeloproliferative neoplasm that may be complicated by vascular events, including both thrombosis and bleeding. This disorder may also transform into more aggressive myeloid neoplasms, in particular into myelofibrosis. The identification of somatic mutations of JAK2, CALR, or MPL, found in about 90% of patients, has considerably improved the diagnostic approach to this disorder. Genomic profiling also holds the potential to improve prognostication and, more generally, clinical decision-making because the different driver mutations are associated with distinct clinical features. Prevention of vascular events has been so far the main objective of therapy, and continues to be extremely important in the management of patients with ET. Low-dose aspirin and cytoreductive drugs can be administered to this purpose, with cytoreductive treatment being primarily given to patients at high risk of vascular complications. Currently used cytoreductive drugs include hydroxyurea, mainly used in older patients, and interferon α, primarily given to younger patients. There is a need for disease-modifying drugs that can eradicate clonal hematopoiesis and/or prevent progression to more aggressive myeloid neoplasms, especially in younger patients. In this article, we use a case-based discussion format to illustrate our approach to diagnosis and treatment of ET.

Treatment of essential thrombocythemia in Europe: a prospective long-term observational study of 3649 high-risk patients in the Evaluation of Anagrelide Efficacy and Long-term Safety study.

Evaluation of Anagrelide (Xagrid®) Efficacy and Long-term Safety, a phase IV, prospective, non-interventional study performed in 13 European countries enrolled high-risk essential thrombocythemia patients treated with cytoreductive therapy. The primary objectives were safety and pregnancy outcomes. Of 3721 registered patients, 3649 received cytoreductive therapy. At registration, 3611 were receiving: anagrelide (Xagrid®) (n=804), other cytoreductive therapy (n=2666), or anagrelide + other cytoreductive therapy (n=141). The median age was 56 vs. 70 years for anagrelide vs. other cytoreductive therapy. Event rates (patients with events/100 patient-years) were 1.62 vs. 2.06 for total thrombosis and 0.15 vs. 0.53 for venous thrombosis. Anagrelide was more commonly associated with hemorrhage (0.89 vs. 0.43), especially with anti-aggregatory therapy (1.35 vs. 0.33) and myelofibrosis (1.04 vs. 0.30). Other cytoreductive therapies were more associated with acute leukemia (0.28 vs. 0.07) and other malignancies (1.29 vs. 0.44). Post hoc multivariate analyses identified increased risk for thrombosis with prior thrombohemorrhagic events, age ≥65, cardiovascular risk factors, or hypertension. Risk factors for transformation were prior thrombohemorrhagic events, age ≥65, time since diagnosis, and platelet count increase. Safety analysis reflected published data, and no new safety concerns for anagrelide were found. Live births occurred in 41/54 pregnancies (76%). clinicaltrials.gov Identifier: 00567502.

The 2014 BCSH criteria and the 2016 WHO criteria for essential thrombocythemia: A comparison in a large-scale cohort.

OBJECTIVE: There are currently 2 representative diagnostic criteria for essential thrombocythemia (ET), the 2014 British Committee for Standards in Hematology Guidelines (BCSH) criteria and the 2016 World Health Organization (WHO) criteria. We compare and discuss the advantages and disadvantages of the 2 criteria. METHOD: We applied the 2 criteria to 403 patients with thrombocytosis and suspected myeloproliferative neoplasms (MPN) and compared patient populations. RESULTS: The BCSH criteria diagnosed ET in 279 patients (BCSH-ET) whereas the WHO criteria diagnosed ET in 203 patients (WHO-ET). There were 83 patients diagnosable only by the BCSH criteria (BCSH-only-ET), of which under the WHO classification, 69 patients fell under the category of MPN, unclassifiable (MPN-u), 12 patients were PMF, prefibrotic/early stage (pre-PMF), and 2 patients were polycythemia vera. Patient characteristics such as age, hemoglobin, hematocrit, platelet counts, lactate dehydrogenase levels, JAK2V617F allele burdens, prevalence of myelofibrosis and splenomegaly, and frequencies of thrombotic events and treatment did not differ between WHO-ET and BCSH-only-ET, but BCSH-only-ET patients showed higher WBC counts and higher JAK2V617F mutation frequencies. CONCLUSION: The BCSH criteria diagnosed ET in a broader range of patients encompassing a significant number of patients who would otherwise be diagnosed as pre-PMF or MPN-u.

Significance of thrombocytopenia in patients with primary and postessential thrombocythemia/polycythemia vera myelofibrosis.

Severe thrombocytopenia (platelets <50 × 109 /L) is associated with very poor outcome of patients with myelofibrosis (MF). As patients with primary myelofibrosis (PMF) differ from patients with postessential thrombocythemia (PET-MF) and postpolycythemia vera myelofibrosis (PPV-MF), we aimed to evaluate the significance of low platelets among these patients. We present clinical characteristics and outcome of patients with either PMF, PPV-MF, or PET-MF, and thrombocytopenia who presented to our institution between 1984 and 2015. Of 1269 patients (877 PMF, 212 PPV-MF, 180 PET-MF), 11% and 14% had platelets either <50 × 109 /L or between 50-100 × 109 /L, respectively. Patients with platelets <50 × 109 /L were most anemic and transfusion dependent, had highest blast count and unfavorable karyotype. In general, their overall and leukemia-free survival was the shortest with median time of 15 and 13 months, respectively; with incidence of acute leukemia almost twice as high as in the remaining patients (6.9 vs 3.6 cases per 100 person-years). Nevertheless, this observation remains mostly significant for patients with PMF, as those with PEV/PVT-MF have already significantly inferior prognosis with platelets <100 × 109 /L.

[Myeloproliferative neoplasms: recent progresses in therapy].

The expected survival duration of polycythemia vera (PV) and essential thrombocythemia (ET) patients is not substantially lower than that of the general population. The current goal of therapy is to prevent thrombohemorrhagic events associated with PV and ET. The current first line therapy for PV is phlebotomy, hydroxyurea (HU), and aspirin, while that for ET was HU or anagrelide. The follow-up phase 3 randomized trial wherein the hematological response was evaluated in PV patients treated with ropeginterferon alfa-2b, a next-generation monopegylated IFN-α-2b, or HU, demonstrated a superior hematological effect and a lower incidence of adverse events in patients who were treated with ropeginterferon. The prognosis of primary myelofibrosis (PMF) is poorer than that of PV or ET. The only curative therapeutic option for PMF patients is allogeneic hematopoietic stem cell transplantation (HSCT). Other than HSCT options, ruxolitinib ameliorates splenomegaly and MF-associated symptoms and provides an overall survival benefit in PMF patients with intermediate-2 or high risk. Several different JAK inhibitors have been developed; however, many of them were discontinued because of toxicity concerns. Recently, promising results have been demonstrated for the effect of different JAK inhibitors as well as the drugs that directly target anemia and bone marrow fibrosis.