Real-world status of treatment for lymphoid neoplasms developed during the course of myeloproliferative neoplasms in Japan.

OBJECTIVES: Patients with myeloproliferative neoplasms (MPNs) are at higher risk of developing secondary malignancies. In this study, we focused on patients with MPNs that complicated lymphoid neoplasms. To analyze the real-world status of lymphoid neoplasm treatment in patients with pre-existing MPNs in Japan, we conducted a multicenter retrospective study. METHODS: Questionnaires were sent to collect the data on patients who were first diagnosed with either polycythemia vera, essential thrombocythemia or myelofibrosis and who later were complicated with lymphoid neoplasms defined as malignant lymphoma, multiple myeloma, or chronic lymphocytic leukemia/small cell lymphoma. RESULTS: Twenty-four patients with MPNs complicated by lymphoid neoplasms were enrolled (polycythemia vera, n = 8; essential thrombocythemia, n = 14; and primary myelofibrosis, n = 2). Among these, diffuse large B-cell lymphoma (DLBCL) was the most frequently observed (n = 13, 54.1%). Twelve (92.3%) of the patients with DLBCL received conventional chemotherapy. Among these 12 patients, regarding cytoreductive therapy for MPNs, 8 patients stopped treatment, one continued treatment, and two received a reduced dose. Consequently, most patients were able to receive conventional chemotherapy for DLBCL with a slightly higher dose of granulocyte colony-stimulating factor support than usual without worse outcomes. All 3 patients with multiple myeloma received a standard dose of chemotherapy. CONCLUSION: Our data indicate that if aggressive lymphoid neoplasms develop during the course of treatment in patients with MPNs, it is acceptable to prioritize chemotherapy for lymphoma.

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.

Impact of CALR and JAK2V617F Mutations on Clinical Course and Disease Outcomes in Essential Thrombocythemia: A Multicenter Retrospective Study in Turkish Patients.

Objective: In this study, we investigated the effects of calreticulin (CALR) and JAK2V617F mutational status on clinical course and disease outcomes in Turkish patients with essential thrombocythemia (ET). Materials and Methods: Seventeen centers from Türkiye participated in the study and CALR- and JAK2V617F-mutated ET patients were evaluated retrospectively. Results: A total of 302 patients were included, of whom 203 (67.2%) and 99 (32.8%) were JAK2V617F- and CALR-positive, respectively. CALR-mutated patients were significantly younger (51 years vs. 57.5 years, p=0.03), with higher median platelet counts (987x109/L vs. 709x109/L, p<0.001) and lower median hemoglobin levels (13.1 g/dL vs. 14.1 g/dL, p<0.001) compared to JAK2V617F-mutated patients. Thromboembolic events (TEEs) occurred in 54 patients (17.9%), 77.8% of which were arterial. Compared to CALR mutation, JAK2V617F was associated with a higher risk of thrombosis (8.1% vs. 22.7%, p=0.002). Rates of transformation to myelofibrosis (MF) and leukemia were 4% and 0.7%, respectively, and these rates were comparable between JAK2V617F- and CALR-mutated cases. The estimated overall survival (OS) and MF-free survival of the entire cohort were 265.1 months and 235.7 months, respectively. OS and MF-free survival durations were similar between JAK2V617F- and CALR-mutated patients. Thrombosis-free survival (TFS) was superior in CALR-mutated patients compared to JAK2V617F-positive patients (5-year TFS: 90% vs. 71%, respectively; p=0.001). Age at diagnosis was an independent factor affecting the incidence of TEEs. Conclusion: In our ET cohort, CALR mutations resulted in higher platelet counts and lower hemoglobin levels than JAK2V617F and were associated with younger age at diagnosis. JAK2V617F was strongly associated with thrombosis and worse TFS. Hydroxyurea was the most preferred cytoreductive agent for patients with high thrombosis risk.

Transcription factor 3 is dysregulated in megakaryocytes in myelofibrosis.

Transcription factor 3 (TCF3) is a DNA transcription factor that modulates megakaryocyte development. Although abnormal TCF3 expression has been identified in a range of hematological malignancies, to date, it has not been investigated in myelofibrosis (MF). MF is a Philadelphia-negative myeloproliferative neoplasm (MPN) that can arise de novo or progress from essential thrombocythemia [ET] and polycythemia vera [PV] and where dysfunctional megakaryocytes have a role in driving the fibrotic progression. We aimed to examine whether TCF3 is dysregulated in megakaryocytes in MPN, and specifically in MF. We first assessed TCF3 protein expression in megakaryocytes using an immunohistochemical approach analyses and showed that TCF3 was reduced in MF compared with ET and PV. Further, the TCF3-negative megakaryocytes were primarily located near trabecular bone and had the typical "MF-like" morphology as described by the WHO. Genomic analysis of isolated megakaryocytes showed three mutations, all predicted to result in a loss of function, in patients with MF; none were seen in megakaryocytes isolated from ET or PV marrow samples. We then progressed to transcriptomic sequencing of platelets which showed loss of TCF3 in MF. These proteomic, genomic and transcriptomic analyses appear to indicate that TCF3 is downregulated in megakaryocytes in MF. This infers aberrations in megakaryopoiesis occur in this progressive phase of MPN. Further exploration of this pathway could provide insights into TCF3 and the evolution of fibrosis and potentially lead to new preventative therapeutic targets.

What is the context? We investigated TCF3 (transcription factor 3), a gene that regulates megakaryocyte development, for genomic and proteomic changes in myelofibrosis.Myelofibrosis is the aggressive phase of a group of blood cancers called myeloproliferative neoplasms, and abnormalities in development and maturation of megakaryocytes is thought to drive the development of myelofibrosis.What is new? We report detection of three novel TCF3 mutations in megakaryocytes and decreases in TCF3 protein and gene expression in primary megakaryocytes and platelets from patients with myelofibrosis.This is the first association between loss of TCF3 in megakaryocytes from patients and myelofibrosis.What is the impact? TCF3 dysregulation may be a novel mechanism that is responsible for the development of myelofibrosis and better understanding of this pathway could identify new drug targets.

Red Blood Cell Contribution to Thrombosis in Polycythemia Vera and Essential Thrombocythemia.

Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms (MPN) characterized by clonal erythrocytosis and thrombocytosis, respectively. The main goal of therapy in PV and ET is to prevent thrombohemorrhagic complications. Despite a debated notion that red blood cells (RBCs) play a passive and minor role in thrombosis, there has been increasing evidence over the past decades that RBCs may play a biological and clinical role in PV and ET pathophysiology. This review summarizes the main mechanisms that suggest the involvement of PV and ET RBCs in thrombosis, including quantitative and qualitative RBC abnormalities reported in these pathologies. Among these abnormalities, we discuss increased RBC counts and hematocrit, that modulate blood rheology by increasing viscosity, as well as qualitative changes, such as deformability, aggregation, expression of adhesion proteins and phosphatidylserine and release of extracellular microvesicles. While the direct relationship between a high red cell count and thrombosis is well-known, the intrinsic defects of RBCs from PV and ET patients are new contributors that need to be investigated in depth in order to elucidate their role and pave the way for new therapeutical strategies.

Clinical Features and Long-Term Outcomes of a Pan-Canadian Cohort of Adolescents and Young Adults with Myeloproliferative Neoplasms: A Canadian MPN Group Study.

Myeloproliferative neoplasms (MPNs) are a group of chronic hematologic malignancies that lead to morbidity and early mortality due to thrombotic complications and progression to acute leukemia. Clinical and mutational risk factors have been demonstrated to predict outcomes in patients with MPNs and are used commonly to guide therapeutic decisions, including allogenic stem cell transplant, in myelofibrosis. Adolescents and young adults (AYA, age ≤45 years) comprise less than 10% of all MPN patients and have unique clinical and therapeutic considerations. The prevalence and clinical impact of somatic mutations implicated in myeloid disease has not been extensively examined in this population. We conducted a retrospective review of patients evaluated at eight Canadian centers for MPN patients diagnosed at ≤45 years of age. In total, 609 patients were included in the study, with median overall survival of 36.8 years. Diagnosis of prefibrotic or overt PMF is associated with the lowest OS and highest risk of AP/BP transformation. Thrombotic complications (24%), including splanchnic circulation thrombosis (9%), were frequent in the cohort. Mutations in addition to those in JAK2/MPL/CALR are uncommon in the initial disease phase in our AYA population (12%); but our data indicate they may be predictive of transformation to post-ET/PV myelofibrosis.

CALR-mutated patients with low allele burden represent a specific subtype of essential thrombocythemia: A study on behalf of FIM and GBMHM.

A low allele burden (i.e., <20%) of the CALR driver mutation is found in 10.8% of CALR-mutated MPNs, mostly in essential thrombocythemia, and correlates with a milder phenotype and a more indolent evolution compared to patients with an allele burden ≥20%.

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.

Neutrophil-to-lymphocyte ratio and all-cause mortality with and without myeloproliferative neoplasms-a Danish longitudinal study.

The neutrophil-to-lymphocyte ratio(NLR) is increased in chronic inflammation and myeloproliferative neoplasms (MPN). We hypothesize that NLR is associated with all-cause mortality and mortality by comorbidity burden in the general population and individuals with MPN. We included 835,430 individuals from The Danish General Suburban Population Study, general practitioners, and outpatient clinics. We investigated NLR on mortality stratified by prevalent and incident MPN, essential thrombocythemia (ET), polycythemia vera (PV), myelofibrosis (MF), comorbidity burden (CCI-score), and the Triple-A risk score using hazard ratio (HR) and 95% confidence interval (95%CI). NLR 1-1.9 was the reference level. During a median follow-up of 11.2 years, 197,802 deaths were recorded. All-cause mortality increased for a stepwise increasing NLR with a HR (95%CI) for NLR ≥ 6 of 2.06(2.03-2.09) for the whole population and 2.93(2.44-3.50) in prevalent MPN. ET, PV, and MF had a HR (95%CI) for NLR ≥ 2 of 2.14(1.71-2.69), 2.19(1.89-2.54), and 2.31(1.91-2.80). Results were similar for incident MPN. Mortality was higher for stepwise increasing NLR and CCI-score(pinteraction < 2×10-16), with a HR for NLR ≥ 6 of 2.23(2.17-2.29), 4.10(4.01-4.20), and 7.69(7.50-7.89), for CCI-score 0, 1-2, or ≥3. The Triple-A risk score demonstrated alignment with NLR. Increasing NLR and comorbidity burden were associated with lower survival in individuals without MPN but were even worse in prevalent and incident MPN, ET, PV, and MF.

[Comparison of Clinical Characteristics of JAK2, CALR and Tri-Negative Driving Mutant Type in Patients with Essential Thrombocythemia].

OBJECTIVE: To investigate the relationship between mutated genes and clinical features in patients with essential thrombocythemia (ET). METHODS: The clinical data of 69 patients with ET from October 2018 to March 2022 were retrospectively analyzed. According to driver mutation type, patients were divided into JAK2 group, CALR group and triple-negative group. The sex, age, cardiovascular risk factors, thrombosis, splenomegaly, routine blood test and coagulation status of patients in three groups were analyzed. RESULTS: Among 69 ET patients, 46 cases were associated with JAK2 mutation, 14 cases with CALR mutation, 8 cases with triple-negative mutation, and one with MPL gene mutation. There were no significant differences in age and sex among the three groups (P >0.05). The highest thrombotic rate was 26.09% (12/46) in JAK2 group, then 12.5% (1/8) in triple-negative group, while no thrombotic events occurred in CALR group. The incidence of splenomegaly was the highest in JAK2 group (34.78%), while no splenomegaly occurred in triple-negative group. The white blood cell (WBC) count in JAK2 group was (9.00±4.86)×109/L, which was significantly higher than (6.03±2.32)×109/L in CALR group (P <0.05). The hemoglobin (Hb) and hematocrit (HCT) in JAK2 group were (148.42±18.79) g/L and (0.44±0.06)%, respectively, which were both significantly higher than (131.00±15.17) g/L and (0.39±0.05)% in triple-negative group (P <0.05). The platelet (PLT) in JAK2 group was (584.17±175.77)×109/L, which was significantly lower than (703.07±225.60)×109/L in CALR group (P <0.05). The fibrinogen (Fg) in JAK2 and triple-negative group were (2.64±0.69) g/L and (3.05±0.77) g/L, respectively, which were both significantly higher than (2.24±0.47) g/L in CALR group (P <0.05, P <0.01). The activated partial thromboplastin time (APTT) in triple-negative group was (28.61±1.99) s, which was significantly decreased compared with (31.45±3.35) s in CALR group (P <0.05). CONCLUSIONS: There are differences in blood cell count and coagulation status among ET patients with different driver gene mutations. Among ET patients, JAK2 mutation is most common. Compared with CALR group, the thrombotic rate, WBC and Fg significantly increase in JAK2 group, while PLT decrease. Compared with triple-negative group, the incidence of splenomegaly and HCT significantly increase. Compared with CALR group, Fg significantly increases but APTT decreases in triple-negative group.

JAK2V617F drives gut microbiota differences in patients with myeloproliferative neoplasms.

BACKGROUND: Essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (MF) are myeloproliferative neoplasms (MPN). Inflammation is involved in the initiation, progression, and symptomology of the diseases. The gut microbiota impacts the immune system, infection control, and steady-state hematopoiesis. METHODS: We analyzed the gut microbiota of 227 MPN patients and healthy controls (HCs) using next-generation sequencing. We expanded our previous results in PV and ET patients with additional PV, pre-MF, and MF patients which allowed us to compare MPN patients collectively, MPN sub-diagnoses, and MPN mutations (separately and combined) vs. HCs (N = 42) and compare within MPN sub-diagnoses and MPN mutation. RESULTS: MPN patients had a higher observed richness (median, 245 [range, 49-659]) compared with HCs (191.5 [range, 111-300; p = .003]) and a lower relative abundance of taxa within the Firmicutes phylum; for example, Faecalibacterium (6% vs. 14%, p < .001). The microbiota of CALR-positive patients (N = 30) resembled that of HCs more than that of patients with JAK2V617F (N = 177). In JAK2V617F-positive patients, only minor differences in the gut microbiota were observed between MPN sub-diagnoses, illustrating the importance of this mutation. CONCLUSION: The gut microbiota in MPN patients differs from HCs and is driven by JAK2V617F, whereas the gut microbiota in CALR patients resembles HCs more.

Newly identified roles for PIEZO1 mechanosensor in controlling normal megakaryocyte development and in primary myelofibrosis.

Mechanisms through which mature megakaryocytes (Mks) and their progenitors sense the bone marrow extracellular matrix to promote lineage differentiation in health and disease are still partially understood. We found PIEZO1, a mechanosensitive cation channel, to be expressed in mouse and human Mks. Human mutations in PIEZO1 have been described to be associated with blood cell disorders. Yet, a role for PIEZO1 in megakaryopoiesis and proplatelet formation has never been investigated. Here, we show that activation of PIEZO1 increases the number of immature Mks in mice, while the number of mature Mks and Mk ploidy level are reduced. Piezo1/2 knockout mice show an increase in Mk size and platelet count, both at basal state and upon marrow regeneration. Similarly, in human samples, PIEZO1 is expressed during megakaryopoiesis. Its activation reduces Mk size, ploidy, maturation, and proplatelet extension. Resulting effects of PIEZO1 activation on Mks resemble the profile in Primary Myelofibrosis (PMF). Intriguingly, Mks derived from Jak2V617F PMF mice show significantly elevated PIEZO1 expression, compared to wild-type controls. Accordingly, Mks isolated from bone marrow aspirates of JAK2V617F PMF patients show increased PIEZO1 expression compared to Essential Thrombocythemia. Most importantly, PIEZO1 expression in bone marrow Mks is inversely correlated with patient platelet count. The ploidy, maturation, and proplatelet formation of Mks from JAK2V617F PMF patients are rescued upon PIEZO1 inhibition. Together, our data suggest that PIEZO1 places a brake on Mk maturation and platelet formation in physiology, and its upregulation in PMF Mks might contribute to aggravating some hallmarks of the disease.

CALR mutation burden in essential thrombocythemia and disease outcome.

ABSTRACT: Among 281 patients with essential thrombocythemia and calreticulin (CALR) mutation, we found a variant allele frequency of ≥60% to be associated with significantly shortened myelofibrosis-free survival, mostly apparent with CALR type-1 and CALR type-indeterminate mutations.

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.

Prolonged Proton Pump Inhibitor Use and Thrombohemorrhagic Risk in Essential Thrombocythemia and Polycythemia Vera Patients Treated with Long-Term Aspirin: A Pilot Study.

INTRODUCTION: Proton pump inhibitors (PPIs) are known to decrease the risk of gastrointestinal (GI) bleeding. However, concerns have been raised regarding the potential pharmacodynamic interactions of PPIs and antiplatelet drugs with respect to cardiovascular risk. Patients with BCR::ABL1-negative myeloproliferative neoplasms (MPNs), essential thrombocythemia (ET), and polycythemia vera (PV) often suffer from peptic ulcer disease (PUD) and frequently receive low-dose aspirin due to an intrinsically high thrombotic risk. METHOD: This retrospective multicenter study from a community setting investigated whether continuous PPI use may affect thrombohemorrhagic risk in ET and PV patients treated with long-term aspirin. RESULTS: Ninety-four aspirin-treated MPN patients (ET = 36, PV = 58) were included; median age was 69.5 years (range 21-92) and 40 (42.6%) were males. Nineteen (20.2%) patients continuously received PPIs and pantoprazole (n = 15, 78.9%) was the most frequently received PPI. PV phenotype (p = 0.085), male sex (p = 0.011), and prior thrombosis (p = 0.005) were associated with PPI use, whereas no correlations were found with respect to age, disease risk, splenomegaly, mutational status, constitutional symptoms, cardiovascular risk factors, cytoreductive treatment, or any of the blood cell counts (p > 0.050 for all analyses). The median follow-up time was 55.5 months; 19 (20.2%) thrombotic and 13 (13.8%) bleeding events occurred during this time. The use of PPIs was not associated with an increased risk of thrombosis (p = 0.158) or overall bleeding (p = 0.229) and none of the patients treated with PPIs experienced GI bleeding. CONCLUSIONS: Considering that Helicobacter pylori infection and PUD are quite frequent in ET and PV patients, these preliminary results may provide some reassurance to physicians regarding the absence of thrombohemorrhagic risk associated with prolonged PPI use in MPN patients treated with long-term aspirin. Our observations may be even more important in the light of recent evidence suggesting suboptimal platelet inhibition in ET with once-daily when compared to twice- or triple-daily aspirin which may also cause more abdominal discomfort. Limitations of this study are its retrospective design, limited number of patients included, and the lack of pharmacodynamic and pharmacokinetic assessments.

One thousand patients with essential thrombocythemia: the Florence-CRIMM experience.

We describe 1000 patients with essential thrombocythemia seen at the Center Research and Innovation of Myeloproliferative Neoplasms (CRIMM), Florence, Italy, between 1980 and 2023: median age 59 years (18-95), females 65%, JAK2/CALR/MPL-mutated 66%/19%/4%, triple-negative (TN) 11%. Extreme thrombocytosis (ExT, platelets ≥1000 × 109/L) in 16%, leukocytosis (leukocytes >11 × 109/L) in 16%, and at least one cardiovascular risk factor in 52% of cases. JAK2-mutated patients were older (median 62 years) and CALR-mutated and TN (53 years for both) younger (p < 0.001). Female gender clustered with TN (76%) and JAK2 (67%) vs CALR (46%) mutations (p < 0.001). ExT clustered with CALR (type-2 more than type-1), TN and MPL, and leukocytosis with JAK2 mutation (p < 0.001). In multivariable analysis, risk factors for arterial thrombosis-free survival were age ≥60 years (HR 2.0; p < 0.001) and JAK2 mutation (HR 1.3; p = 0.02) with borderline significance for male gender (p = 0.08) and cardiovascular risk factors (p = 0.08); for venous thrombosis-free survival, JAK2 mutation (HR 1.9; p = 0.03) with borderline significance for venous thrombosis history (p = 0.07); for overall survival, older age (p < 0.001), male gender (HR 1.9; p < 0.001), absolute neutrophil count (ANC) ≥ 8 × 109/L (HR 1.8; p = 0.01), absolute lymphocyte count (ALC) < 1.7 × 109/L (HR 1.2; p = 0.03); for myelofibrosis-free survival, CALR mutation (HR 2.7; p < 0.001, particularly for CALR type 1/1-like, HR 3.3) and MPL mutation (HR 3.9; p = 0.001); for leukemia-free survival, older age (p = 0.03). Cytoreductive therapy appeared to mitigate both venous (HR 0.3; p = 0.01) and arterial thrombosis (HR 4; p = 0.04); there was a trend for aspirin in preventing arterial thrombosis recurrence. The current study provides real-world observations in essential thrombocythemia, representing a valid source document for interpreting current literature and planning future studies.