Myeloid malignancies arise in bone marrow microenvironments and shape these microenvironments in favor of malignant development. Immune suppression is one of the most important stages in myeloid leukemia progression. Leukemic clone expansion and immune dysregulation occur simultaneously in bone marrow microenvironments. Complex interactions emerge between normal immune system elements and leukemic clones in the bone marrow. In recent years, researchers have identified several of these pathological interactions. For instance, recent works shows that the secretion of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), from bone marrow stromal cells contributes to immune dysregulation and the selective proliferation of JAK2V617F+ clones in myeloproliferative neoplasms. Moreover, inflammasome activation and sterile inflammation result in inflamed microenvironments and the development of myelodysplastic syndromes. Additional immune dysregulations, such as exhaustion of T and NK cells, an increase in regulatory T cells, and impairments in antigen presentation are common findings in myeloid malignancies. In this review, we discuss the role of altered bone marrow microenvironments in the induction of immune dysregulations that accompany myeloid malignancies. We also consider both current and novel therapeutic strategies to restore normal immune system function in the context of myeloid malignancies.

Recent advances in sequencing technologies have clarified the driver gene landscape in Philadelphia chromosomenegative (Ph-) myeloproliferative neoplasms (MPNs) and progressed understanding of MPN pathogenesis. Beyond mutations in the main three drivers of MPN, namely JAK2, MPL and CALR, somatic mutations in the epigenetic regulators and RNA splicing factors have been identified and their association with transformation to myelofibrosis and acute myeloid leukemia have been determined. Clonal expansion of hematopoietic cells with driver mutations (clonal hematopoiesis) has been detected in healthy individuals, especially in elderly people. In MPN patients, however, initial driver mutations such as those in JAK2 and DNMT3A have been shown to be acquired in utero or during childhood. In this review, I will summarize the recent findings about clonal evolution in MPN and the role of driver mutations.

Identification of driver genes and pathological bone marrow diagnosis were considered essential for subclassification of MPN in the revised 4th edition of the WHO classification, and this remained nearly unchanged in the 5th edition. Pathological diagnosis of primary myelofibrosis/pre-fibrotic stage by biopsy is now feasible and is becoming standardized. Progressive myelofibrosis and blast transformation are the advanced forms of MPN, and various therapeutic interventions for these forms have been devised. Observation of activated megakaryocytes on evaluation of megakaryocyte morphology could predict the progression of myelofibrosis. This paper describes recent progress in pathological diagnosis of MPN and how it is performed in practice.

Philadelphia-Negative Myeloproliferative neoplasms (MPNs) are a diverse group of blood cancers leading to excessive production of mature blood cells. These chronic diseases, including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), can significantly impact patient quality of life and are still incurable in the vast majority of the cases. This review examines the mechanobiology within a bone marrow niche, emphasizing the role of mechanical cues and the primary cilium in the pathophysiology of MPNs. It discusses the influence of extracellular matrix components, cell-cell and cell-matrix interactions, and mechanosensitive structures on hematopoietic stem cell (HSC) behavior and disease progression. Additionally, the potential implications of the primary cilium as a chemo- and mechanosensory organelle in bone marrow cells are explored, highlighting its involvement in signaling pathways crucial for hematopoietic regulation. This review proposes future research directions to better understand the dysregulated bone marrow niche in MPNs and to identify novel therapeutic targets.

OBJECTIVE: To observe the genetic variation of SH2B3 in patients with myeloid neoplasms.
METHODS: The results of targeted DNA sequencing associated with myeloid neoplasms in the Department of Hematology, Xuanwu Hospital, Capital Medical University from November 2017 to November 2022 were retrospectively analyzed, and the patients with SH2B3 gene mutations were identified. The demographic and clinical data of these patients were collected, and characteristics of SH2B3 gene mutation, co-mutated genes and their correlations with diseases were analyzed.
RESULTS: The sequencing results were obtained from 1 005 patients, in which 19 patients were detected with SH2B3 gene mutation, including 18 missense mutations (94.74%), 1 nonsense mutation (5.26%), and 10 patients with co-mutated genes (52.63%). Variant allele frequency (VAF) ranged from 0.03 to 0.66. The highest frequency mutation was p.Ile568Thr (5/19, 26.32%), with an average VAF of 0.49, involving 1 case of MDS/MPN-RS (with SF3B1 mutation), 1 case of MDS-U (with SF3B1 mutation), 1 case of aplastic anemia with PNH clone (with PIGA and KMT2A mutations), 2 cases of MDS-MLD (1 case with SETBP1 mutation). The other mutations included p.Ala567Thr in 2 cases (10.53%), p.Arg566Trp, p.Glu533Lys, p.Met437Arg, p.Arg425Cys, p.Glu314Lys, p.Arg308*, p.Gln294Glu, p.Arg282Gln, p.Arg175Gln, p.Gly86Cys, p.His55Asn and p.Gln54Pro in 1 case each.
CONCLUSIONS: A wide distribution of genetic mutation sites and low recurrence of SH2B3 is observed in myeloid neoplasms, among of them, p.Ile568Thr mutation is detected with a higher incidence and often coexists with characteristic mutations of other diseases.
UNASSIGNED: SH2B3 基因在髓系肿瘤中的突变位点及频率分析.
UNASSIGNED: 分析SH2B接头蛋白3（SH2B3 ）基因在髓系肿瘤中的突变位点及频率。.
UNASSIGNED: 回顾性分析2017年11月至2022年11月首都医科大学宣武医院血液内科髓系肿瘤相关基因靶向DNA测序结果，筛选出携带SH2B3 基因突变的患者，收集患者人口学资料及临床资料，分析SH2B3 基因突变类型、突变位点、发生频率、共突变基因以及与疾病间的关系。.
UNASSIGNED: 测序结果来自1 005例患者，有19例患者检测到SH2B3 基因突变，其中错义突变18例（94.74%），无义突变1例（5.26%），10例患者同时伴发其他突变（52.63%），突变等位基因频率（VAF）分布于0.03-0.66；发生频率最高的突变为p.Ile568Thr（5/19，26.32%），平均VAF为0.49，涉及1例MDS/MPN-RS（伴 SF3B1突变）、1例MDS-U（伴 SF3B1突变）、1例再生障碍性贫血伴PNH克隆（伴PIGA和KMT2A 突变）、2例MDS-MLD（其中1例伴SETBP1 突变）；其余突变包括2例p.Ala567Thr（10.53%），p.Arg566Trp、p.Glu533Lys、p.Met437Arg、p.Arg425Cys、p.Glu314Lys、p.Arg308*、p.Gln294Glu、p.Arg282Gln、p.Arg175Gln、p.Gly86Cys、p.His55Asn和p.Gln54Pro各1例。.
UNASSIGNED: SH2B3 基因在髓系肿瘤中突变位点分布较广，重现性低，其中p.Ile568Thr突变发生率较高，常与其他疾病特征性突变共存。.

OBJECTIVE: To analyze the clinical characteristics and occurrence of thrombotic/bleeding events of patients with myeloproliferative neoplasm (MPN), and explore the main influencing factors, and create a risk prediction.
METHODS: The clinical data of 126 MPN patients with BCR-ABL fusion gene negative in the Department of Hematology of Gansu Provincial Hospital from January 2016 to September 2021 were collected, and their clinical characteristics, occurrence of thrombotic/bleeding events and main influencing factors were analyzed and summarized retrospectively. Then, a risk prediction model for thrombotic/bleeding events in MPN patients was constructed.
RESULTS: Among 126 MPN patients, 50 patients (39.7%) had experienced thrombotic/bleeding events, including 44 patients (34.9%) with thrombotic events and 6 patients (4.8%) with bleeding events. Among thrombotic diseases, cerebral thrombosis was the most common (23/44, 52.3%), followed by 9 cases of limb artery thrombosis mainly characterized by finger and toe tip artery ischemia, occlusion and gangrene (9/44, 20.5%). Bleeding events included intracerebral hemorrhage and gastrointestinal hemorrhage. Univariate analysis showed that hypertension, hyperhomocysteinemia, white blood cell (WBC) ≥10×109/L, hematocrit (HCT) ≥49%, platelet (PLT) ≥600×109/L and JAK2V617F gene mutation were risk factors for thrombotic/bleeding events in MPN patients, while CALR gene mutation was a protective factor. Multivariate analysis showed that hypertension and PLT≥600×109/L were independent risk factors for thrombotic/bleeding events in MPN patients. The goodness of fit of the constructed risk prediction model was 0.872, and the area under the ROC curve was 0.838. The model was validated with clinical data, the sensitivity, specificity and accuracy was 78.85%, 87.83% and 84.13%, respectively .
CONCLUSIONS: The risk of thrombotic/bleeding events in MPN patients with high WBC count, hypertension and hyperhomocysteinemia is higher. Controlling hypertension and hyperhomocysteinemia and reducing WBC and PLT counts are helpful to prevent thrombotic/bleeding events and improve the life quality of patients.
UNASSIGNED: 骨髓增殖性肿瘤患者血栓/出血事件的影响因素分析及其风险预测.
UNASSIGNED: 分析骨髓增殖性肿瘤(MPN)患者的临床特征、血栓/出血事件的发生情况，探讨其影响因素并进行风险预测。.
UNASSIGNED: 收集2016年1月至2021年9月就诊于甘肃省人民医院血液科的126例BCR-ABL融合基因阴性的MPN患者的临床资料，对其临床特征、血栓/出血事件发生情况及影响因素进行回顾性分析和总结，并构建风险预测模型。.
UNASSIGNED: 在126例MPN患者中，50例（39.7%）发生过血栓/出血事件，其中发生血栓事件44例（34.9%），出血事件6例（4.8%）。血栓性疾病中以脑血栓最常见（23/44，52.3%），其次是以指端和趾端动脉缺血、闭塞和坏疽为主要表现的四肢动脉血栓，共9例（9/44，20.5%）；出血事件包括脑出血和胃肠道出血。单因素分析结果表明，高血压病史、高同型半胱氨酸血症、白细胞计数≥10×109/L、血细胞比容≥49%、血小板计数≥600×109/L以及JAK2V617F基因突变是MPN患者发生血栓/出血事件的危险因素，而CALR基因突变是保护性因素。多因素分析结果表明，高血压病史和血小板计数≥600×109/L为MPN患者发生血栓/出血事件的独立危险因素。构建的风险预测模型拟合优度P =0.872，ROC曲线下面积为0.838。临床验证模型预测的灵敏度为78.85%，特异度为87.83%，准确率为84.13%。.
UNASSIGNED: 高白细胞计数伴有高血压和高同型半胱氨酸血症的MPN患者发生血栓/出血事件的风险更高，控制高血压及高同型半胱氨酸血症，降低白细胞和血小板数，有助于预防血栓/出血事件的发生，从而提高患者生存质量。.

暂无摘要。

BCR::ABL1-negative myeloproliferative neoplasms (MPNs) are clonal haematopoietic stem cell disorders characterized by specific driver mutations and an increased risk of both macrothrombosis and microthrombosis. Serotonin receptor type 1B (HTR1B) was found to be expressed by various solid tumours, and also primary bone marrow mononuclear cells from myelodysplastic neoplasm and acute myeloid leukaemia patients, representing a potential therapeutic target. In this study we assessed for the first time the expression levels of HTR1B mRNA in the peripheral blood mononuclear cells (PBMC) of 85 newly diagnosed MPN patients, consisting of 28 polycythemia vera, 25 essential thrombocythemia and 32 primary myelofibrosis cases. Levels of HTR1B expression between MPN subtypes and control group were not significantly different. However, at clinical data examination, it was observed that MPN patients with a recent history of major thrombosis and/or signs of impaired microcirculation exhibited significantly higher HTR1B expression levels compared to non-thrombotic MPNs and control group. Moreover, thrombotic MPN patients had significantly higher HTR1B expression than patients with recent thrombosis and absence of MPN diagnostic criteria. These findings suggest that increased levels of HTR1B expression in PBMC might be associated with thrombosis in MPN patients, but larger studies are needed for confirmation, including testing of the receptor protein expression level.

Plasma cell neoplasms (PCN) have infrequently been reported in patients with myelodysplastic syndrome (MDS) and even more rarely in those with myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN). We report the clinicopathologic features of 26 patients with bone marrow myelodysplasia accompanied by PCN, including 21 patients with MDS and 5 with MDS/MPN. The clinicopathologic features of the MDS/MPN-PCN were compared to those of the MDS-PCN group and 68 cases of MDS/MPN without PCN, respectively. The MDS/MPN-PCN group was notable for increased reticulin fibrosis > grade 1 when compared to both the MDS/MPN (p = 0.007) and MDS-PCN (p = 0.02) groups. MDS/MPN-PCN was associated with worse overall survival when compared with MDS-PCN (p = 0.03) and but not with MDS/MPN. Notably, hemoglobin level <8 g/dl (p = 0.008), and IDH2 somatic mutation (p = 0.003) were independent predictors of poor overall survival in all patients with MDS/MPN. Analysis of larger cohorts is required to confirm these associations and provide an insight into the pathogenesis.

We investigated the role of toll-like receptors (TLRs) in inflammatory pathways in Philadelphia chromosome-negative myeloproliferative neoplasms (Ph(-)MPNs). TLR2 expression was increased in ET, PV, and MPN (grouped as (PV + (ET) + MF)), whereas TLR4 was elevated only in MPN. TLR3, 7, and 9 were not elevated. Cultured monocyte-derived dendritic cells and plasma assays in TLR2-elevated patients were found to secrete more cytokines than those from TLR2-normal patients. These facts suggest that TLR2 is the major inflammatory pathways in MPN. We also measured S100A9 and reactive oxygen species (ROS), revealing increased S100A9 in PV, MF, and MPN, while ROS were only increased in MF. These data suggests that MPNs initially involve TLR2, with minor contributions from TLR4, and with S100A9, leading to ROS formation, JAK2 mutation, and progression to MF or leukemia. Furthermore, patients with JAK2 mutations or leukocytosis exhibited higher TLR2 expression. In leukocyte-platelet interactions, cells from MPN patients displayed a stronger response to a TLR2 agonist than TLR4 agonist. A TLR2 inhibitor (but not a TLR4 inhibitor) attenuated this response. Thrombosis incidence was higher in TLR2-elevated patients (29%) than in TLR2-normal patients (19%). These findings suggest that TLR2 likely contributes to thrombosis in MPN.