Yoko Edahiro

Hemorrhagic events are a rare but potentially fatal complication in patients with polycythemia vera (PV). We analyzed the characteristics of hemorrhagic events in 267 patients with PV. A median follow-up of 4.8 years revealed that 23 (8.6%) hemorrhagic events occurred. Significantly more hemorrhagic events occurred in younger patients aged below 60 years (n = 72) than in older patients aged 60 years or above (n = 191) (n = 12 [16.7%] vs. n = 11 [5.8%], respectively, P = 0.012). In univariate analysis among the younger patients, white blood cell (WBC) count ≥ 15 × 10⁹/L (hazard ratio [HR] = 7.746, 95% confidence interval [CI] 2.082-28.830, P = 0.002), palpable splenomegaly (HR = 5.629, 95% CI 1.193-26.550, P = 0.029), and JAK2V617F allele burden ≥ 80% (HR = 22.850, 95% CI 2.885-181.00, P = 0.003) were associated with an increased risk of hemorrhagic events. In multivariate analysis, JAK2V617F allele burden ≥ 80% (HR = 9.394, 95% CI 1.046-84.380, P = 0.046) was a significant risk factor. There is an increased risk of hemorrhagic events after diagnosis in younger PV patients with a high JAK2V617F allele burden, high WBC count or palpable splenomegaly. It is important to consider treatment options that aim to avoid hemorrhagic events by reducing the JAK2V617F allele burden in younger PV patients.

Polycythemia vera (PV) is a myeloproliferative neoplasm that is associated with an elevated risk of thrombosis. Treatment strategies are based on thrombosis risk classification. Phlebotomy is a commonly recommended treatment for all patients with PV, regardless of their risk classification, and reduces the incidence of thrombosis by lowering hematocrit levels. However, patients with PV frequently present with iron deficiency at diagnosis due to increased erythropoiesis, which repeated phlebotomy can exacerbate. This can produce symptoms that diminish quality of life, such as fatigue, lethargy, and impaired concentration. Recently, hepcidin mimetics have been developed to suppress iron utilization in erythropoiesis. Among them, rusfertide has been shown to control hematocrit levels without requiring phlebotomy. Further studies are needed to identify new treatment strategies for PV that also consider iron deficiency.

Patients with Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), a classification of chronic hematologic neoplasms characterized by overproduction of hematopoietic stem/progenito...

Summary: Risk‐adapted therapy is recommended to prevent major clinical complications, such as thrombo‐haemorrhagic events, in patients with essential thrombocythaemia (ET). In this study, we analysed the association between non‐driver gene mutations and thrombo‐haemorrhagic events in 579 patients with ET. ASXL1 and TP53 mutations were frequently identified in patients with ET complicated by thrombosis (22.7% and 23.1%, respectively), and the DNMT3A mutation was frequently identified in patients who experienced haemorrhage (15.2%). Multivariate analyses of thrombosis‐free survival (TFS) revealed that ASXL1 and TP53 mutations are associated with thrombosis (hazard ratio [HR] = 3.140 and 3.752 respectively). Patients harbouring the ASXL1 or TP53 mutation had significantly worse TFS rates than those without mutation (p = 0.002 and p < 0.001 respectively). Furthermore, JAK2V617F‐mutated patients with accompanying ASXL1 mutations showed significantly shorter TFS compared with those without ASXL1 mutations (p = 0.003). Multivariate analyses of haemorrhage‐free survival (HFS) revealed that the DNMT3A mutation (HR = 2.784) is associated with haemorrhage. DNMT3A‐mutated patients showed significantly shorter HFS than those without the mutation (p = 0.026). Non‐driver gene mutations should be considered in treatment strategies and may provide important information for personalised treatment approaches.

Since MPL mutation is a rare driver gene mutation found in a small number of essential thrombocythemia (ET) patients, the clinical characteristics of patients with MPL mutations and their association with thrombotic events have not yet been elucidated in Japan. We enrolled 579 Japanese ET patients based on the diagnostic criteria of the WHO classification 2017 and compared clinical characteristics of MPL-mutated patients (n = 22; 3.8%) to JAK2V617F-mutated (n = 299; 51.6%), CALR-mutated (n = 144; 24.9%), and triple-negative (TN) (n = 114; 19.7%) patients. Thrombosis during follow up was observed in 4 out of 22 (18.2%) in the MPL-mutated group, which was the highest among all driver gene mutation groups (JAK2V617F-mutated, 8.7%; CALR-mutated, 3.5%; TN,1.8%). The MPL- and JAK2V617F-mutated groups had worse thrombosis-free survival (TFS) than the CALR-mutated (p = 0.043) and TN groups (p = 0.006). Univariable analysis revealed that a history of thrombosis was a possible risk factor for thrombosis among MPL-mutated patients (hazard ratio: 9.572, p = 0.032). MPL-mutated ET patients should require more intensive management to prevent recurrence of thrombosis.

Myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) is a rare disease, which presents with features of myelodysplastic syndromes with ring sideroblasts and essential thrombocythemia, as well as anemia and marked thrombocytosis. SF3B1 and JAK2 mutations are often found in patients, and are associated with their specific clinical features. This study was a retrospective analysis of 34 Japanese patients with MDS/MPN-RS-T. Median age at diagnosis was 77 (range, 51–88) years, and patients had anemia (median hemoglobin: 9.0 g/dL) and thrombocytosis (median platelet count: 642 × 109/L). Median overall survival was 70 (95% confidence interval: 68-not applicable) months during the median follow-up period of 26 (range: 0–91) months. A JAK2V617F mutation was detected in 46.2% (n = 12) of analyzed patients (n = 26), while an SF3B1 mutation was detected in 87.5% (n = 7) of analyzed patients (n = 8). Like those with myelodysplastic syndromes or myeloproliferative neoplasms, patients often received erythropoiesis-stimulating agents and aspirin to improve anemia and prevent thrombosis. This study, which was the largest to describe the real-world characteristics of Japanese patients with MDS/MPN-RS-T, showed that the patients had similar characteristics to those in western countries.

Risk-adapted therapy is recommended to prevent thrombosis in essential thrombocythemia (ET) patients. An advanced age, a history of thrombosis, and the presence of the JAK2V617F mutation are well-defined risk factors for thrombosis in ET; however, the impact of cardiovascular risk (CVR) factors on thrombosis in ET remains elusive. Therefore, we herein investigated the impact of CVR factors on thrombosis in 580 ET patients who met the 2017 World Health Organization Classification diagnostic criteria. A univariate analysis identified hypertriglyceridemia and multiple CVR factors as strong risk factors for thrombosis (hazard ratio [HR] 3.530, 95% confidence interval [CI] 1.630–7.643, P = 0.001 and HR 3.368, 95% CI 1.284–8.833, P = 0.014, respectively) and hyper-LDL cholesterolemia as a potential risk factor (HR 2.191, 95% CI 0.966–4.971, P = 0.061). A multivariate analysis revealed that hypertriglyceridemia was an independent risk factor for thrombosis (HR 3.364, 95% CI 1.541–7.346, P = 0.002). Furthermore, poor thrombosis-free survival was observed in patients with a serum triglyceride level ≥ 1.2 mmol/L (HR = 2.592, P = 0.026 vs. < 1.2 mmol/L) or two or more CVR factors (P = 0.011 vs. no CVR factors and P = 0.005 vs. one CVR factor). These results revealed the impact of CVR factors on thrombosis in ET. Since CVR factors are manageable, lifestyle interventions, such as the control of serum triglyceride levels, may effectively prevent thrombosis in ET patients.

Objective Thrombocytosis can occur as a primary event accompanying hematological diseases or as a secondary event. Since the publication of the World Health Organization classification in 2008, thrombocytosis is now generally defined as a platelet count above 450×109/L. Furthermore, the discovery of driver-gene mutations in myeloproliferative neoplasms (MPNs) has simplified the diagnostic approach for thrombocytosis. To identify the causes of thrombocytosis using this new definition, we conducted a retrospective study. Methods We identified outpatients and inpatients aged 20 years or older with platelet counts >450×109/L in a half-year period at a single institute and analyzed the causes of thrombocytosis and associated clinical characteristics. Results Among 1,202 patients with thrombocytosis, 150 (12.5%) had primary and 999 (83.1%) had secondary thrombocytosis. Of these patients with primary thrombocytosis, 129 (86%) had at least 1 molecular marker indicative of MPNs. The major causes of secondary thrombocytosis were tissue injury (32.2%), infection (17.1%), chronic inflammatory disorders (11.7%) and iron deficiency anemia (11.1%). The median platelet count and the incidence of thrombosis were significantly higher in patients with primary thrombocytosis than in those with secondary thrombocytosis. Conclusion Thrombocytosis mainly occurs as a secondary event; however, it is important to determine the cause of and prevent thrombosis, particularly in cases of primary thrombocytosis.

Objectives: A proportion of patients with polycythemia vera (PV) and essential thrombocythemia (ET) harbor non‐driver mutations associated with poor prognosis. In this study, we analyzed the frequency of non‐driver mutations in a large Japanese PV and ET cohort. Furthermore, we studied the relationship of these mutations and prognosis in Japanese patients.Methods: We enrolled 843 Japanese patients with PV or ET. Non‐driver mutations were analyzed by target resequencing using next‐generation sequencing. The association of the mutations with the prognosis was estimated using multivariable logistic regression analysis and log‐rank test.Results: Non‐driver mutations were detected in 31.1% and 24.5% patients with PV and ET, respectively. Among them, ASXL1 mutations were identified as a risk factor for leukemic/myelofibrotic transformation in PV and ET patients (hazard ratio: 4.68, p = .006). The higher‐risk groups of the mutation‐enhanced international prognostic system (MIPSS)‐PV and MIPSS‐ET incorporating non‐driver mutations exhibited significantly shorter overall survival compared with the low‐risk group (p < .001).Conclusions: These results implicate the importance of studying non‐driver mutations for predicting the prognosis and survival of Japanese PV and ET patients.