JAK2 V617F mutation is uncommon in non-Hodgkin lymphomas

Recently, the JAK2 V617F mutation has been reported in high proportions of chronic myeloproliferative disorders, including polycythemia vera. To see whether the JAK2 V617F is important in the pathogenesis of lymphoid malignancies, this study analysed the occurrence of the JAK2 V617F mutation in 117 non-Hodgkin lymphomas (NHLs) by a single strand conformation polymorphism assay. However, there was no JAK2 V617F mutation in the NHLs and the data suggest that the JAK2 V617F mutation may not play a role in the development of NHL.     

原发血小板增多症患者 JAK2 V617F 突变与凝血功能的相关性

目的：探讨原发血小板增多症（ET）患者 JAK2 V617F 突变及其突变负荷与血常规及凝血功能之间的相关性。方法回顾性分析2008年1月至2015年12月收治的90例 ET 患者临床及实验室资料,用等位基因特异性聚合酶链反应行 JAK2 V617F 点突变检测,实时定量特异性聚合酶链反应行JAK2 V617F 检测突变负荷,分析 JAK2 V617F 突变及突变负荷与血常规及凝血功能的相关性。结果90例ET 患者中,50例患者检出 JAK2 V617F 突变,突变率为55.6%。 JAK2 V617F 突变组红细胞计数[（4.67±0.89）×109／L 比（4.04±0.99）×109／L, P＝0.003]、白细胞计数[（11.64±5.20）×109／L 比（9.11±4.11）×109／L, P＝0.014]、血细胞比容[（0.41±0.07）比（0.36±0.07）,P＝0.005]均较野生型组高,凝血酶原时间较野生型组长[（13.18±1.63） s 比（12.02±1.24） s,P＝0.000]。 JAK2 V617F 突变负荷为（29.91±18.63）%,JAK2 V617F 突变负荷与血常规之间未见相关性（均 P＞0.05）,与纤维蛋白降解产物（FDP）之间存在相关性（r＝0.456,P＝0.001）。结论 ET 患者存在较高的 JAK2 V617F 突变率,临床早期检测JAK2 V617F 突变及突变负荷可能对 ET 患者血管性事件早期预防具有重要的临床价值。     

JAK2V617F mutation and spontaneous megakaryocytic or erythroid colony formation in patients with essential thrombocythaemia (ET) or polycythaemia vera (PV)

The in vitro cultures of erythroid (BFU-E) and megakaryocytic (CFU-Meg) progenitors have been useful diagnostic tools in myeloproliferative disorders (MPD). However, after the discovery of the JAK2V617F mutation, their diagnostic role has been uncertain. In this single-centre retrospective study we analyzed JAK2V617F mutation in 58 ET and 42 PV patients diagnosed according to WHO criteria and compared the results with those of colony forming assays with special emphasis on CFU-Meg growth. 91% of PV and 57% of ET patients had JAK2V617F mutation and they all showed spontaneous BFU-E growth. However, endogenous BFU-E formation was also seen in nine JAK2V617F mutation negative patients displaying also a normal JAK2 exon 12 allele. Endogeneous CFU-Meg colony formation was found in 59% of PV and 53% of the ET patients. A subgroup of ET patients (n=7) displayed sole spontaneous CFU-Meg growth without spontaneous BFU-E growth. They all were JAK2 mutation negative, but one of them had MPL mutation. In conclusion, in vitro cultures of haematopoietic progenitors are sensitive diagnostic tools in the present group of 100 MPD patients revealing also JAK2 mutation negative ET and PV patients displaying sole spontaneous CFU-Meg or BFU-E growth.     

Comparison of JAK2V617F‐positive essential thrombocythaemia and early primary myelofibrosis: The impact of mutation burden and histology

An accurate histological diagnosis may distinguish essential thrombocythaemia (ET) from early primary myelofibrosis (early‐PMF), which is associated with worse outcome. Outcome of ET is also negatively affected by the presence of the JAK2^V617F mutation. To investigate the impact of JAK2^V617F mutation burden and histology on outcome, we collected 475 WHO‐diagnosed ET (69.2%) or early‐PMF JAK2^V617F‐positive patients followed in 4 Italian haematology centers. JAK2^V617F allele burden was ≤50% in 90% and 87% of ET and early‐PMF patients, respectively (P = .34). During follow‐up, 32 (9.7%) ET and 18 (12.3%) early‐PMF patients experienced 59 thrombotic events, and 27 patients (5.6%) and 6 (1.2%) patients evolved to myelofibrosis and acute leukemia, respectively. At last contact, 28 (5.8%) patients had died. In early‐PMF compared to ET, the 10‐year mortality rates (6.7% and 4.3%, P = .73), leukemic transformation rates (1.4% and 1.2%, P = .45), and thrombosis rates (16.7% and 12.2%, P = .12) were comparable. Only progression to overt myelofibrosis at 10 years was significantly worse (11.4% and 1.5%, P = .004). In multivariate analysis, a higher (>50%) JAK2^V617F burden was significantly correlated with fibrotic progression and histology. Considering JAK2^V617F‐positive disease, a higher (>50%) JAK2^V617F burden and histological classification are independent prognostic risk factors for disease progression. These findings reinforce the need for standardized detection of this mutation.     

bcr-abl阴性骨髓增生性疾病患者JAK2V617F点突变检测的临床意义

目的 探索Janus Kinase 2V617F基因突变(JAK2V617F)在bcr-abl阴性骨髓增生性疾病(MPD)的发生率和临床意义.方法 基因组DNA从患者骨髓或外周血粒细胞中提取.采用等位基因特异性PCR(AS-PCR)、限制性内切酶消化和PCR产物测序的方法检测JAK2V617F突变.共检测患者110例,其中bcr-abl阴性MPD 41例、bcr-abl阳性慢性粒细胞白血病(CML)25例和急性白血病44例.结果 JAK2V617F阳性结果分别为真性红细胞增多症(PV)11例(91.7%)、原发性血小板增多症(ET)8例(53.3%)、特发性骨髓纤维化(IMF)4例(57.1%),而高嗜酸粒细胞增多症(HES)7例、bcr-abl阳性CML 25例和急性白血病44例[包括急性髓细胞白血病(AML)24例、急性淋巴细胞白血病(ALL)18例、急性混合细胞白血病2例1均未检测到JAK2V617F基因突变.在所有JAK2V617F阳性的标本和10份阴性标本中,AS-PCR和限制性内切酶消化方法的测定结果都可经测序进一步证实.结论 90%以上的PV、50%以上的ET和IMF可检测到JAK2V617F基因突变;JAK2V617F基因突变在PV、ET和IMF的诊断和鉴别诊断中有重要意义,可以作为诊断的分子标志,也可能是治疗的新靶点.     

BCR-ABL阴性骨髓增殖性肿瘤JAK2 V617F基因突变状态及负荷的临床意义

目的探讨JAK2 V617F基因突变状态及负荷对BCR-ABL阴性骨髓增殖性肿瘤(MPN)的影响。方法回顾性分析2015年9月至2020年1月河北省沧州市中心医院199例MPN患者的临床资料。分析JAK2 V617F突变负荷与MPN患者临床病理特征及预后评分的关系。结果199例BCR-ABL阴性MPN患者中JAK2 V617F突变阳性138例(69.4%);其中,72例真性红细胞增多症(PV)患者中突变阳性64例(88.9%),101例原发性血小板增多症(ET)患者中突变阳性54例(53.5%),25例骨髓纤维化(MF)患者中突变阳性20例(80.0%),1例嗜酸粒细胞增多症(HES)患者突变阳性。JAK2 V617F突变高负荷者占55.1%(76/138)。突变负荷最高的类型为PV,MF次之,ET最低,3组突变负荷分别为(73.9±18.3)%、(59.9±25.2)%、(25.0±16.5)%。JAK2 V617F突变负荷与PV、ET、MF患者的白细胞计数均呈正相关(r值分别为0.626、0.675、0.796,均P<0.01)。JAK2 V617F突变负荷与PV、ET患者的预后评分均呈正相关(r值分别为0.296、0.404,均P<0.05)。结论BCR-ABL阴性MPN患者JAK2 V617F突变负荷与临床病理因素相关,JAK2 V617F突变高负荷患者预后不良。     

BCR-ABL阴性骨髓增殖性疾病患者

目的：检测BCRABL融合基因阴性的骨髓增殖性疾病（myeloproliferative disorders,MPD）患者的JAK2 V617F突变率,探讨其与MPD患者临床特征间的关系。方法：选择山东大学附属省立医院确诊的56例BCRABL阴性的MPD患者为研究对象,其中真性红细胞增多症（polycythaemia vera,PV）20例、原发性血小板增多症（essential thrombocythaemia,ET）26例,特发性骨髓纤维化（idiopathic myelofibrosis,IMF）10例。应用等位基因特异性PCR（allelespecific polymerase chain reaction,ASPCR）和基因测序检测MPD患者JAK2 V617F突变情况,分析各组MPD患者JAK2 V617F突变与MPD临床特征间的关系。结果：56例MPD患者中36例检出JAK2 V617F突变,突变率分别为ET患者53.8%（14/26）,PV患者85%（17/20）,IMF患者50%（5/10）。JAK2 V617F突变阳性的MPD患者与突变阴性者相比,在血象方面：PV患者的白细胞（P= 0.018）、血小板计数（P= 0.021）;ET患者的白细胞计数（P= 0.001）、血红蛋白（P= 0.007）;IMF患者的白细胞计数（P= 0.026）差异均有统计学意义。在并发症方面：ET组中JAK2 V617F突变阳性的患者出血、血栓并发症的发生率更高（P= 0.016）,PV及IMF组中差异无统计学意义。结论：ASPCR可有效检测JAK2 V617F突变的发生,JAK2 V617F突变阳性的MPD患者与突变阴性者在临床特征上有较明显的差异。     

骨髓增殖性肿瘤JAK2V617F基因突变与疾病临床特征相关性的分析※

 摘要：目的：研究我区骨髓增殖性肿瘤（MPN）中JAK2V617F基因突变与疾病临床特征的相关性。方法：回顾性分析我区134例MPN患者JAK2V617F基因突变与患者性别、年龄、民族、外周血白细胞、血小板计数、血红蛋白、血清乳酸脱氢酶（LDH）水平及是否合并血栓、出血及心血管疾病并发症等临床特征的相关性进行统计分析。结果：134例MPN患者中PV 51例,ET 66例,IMF17例,存在JAK2V617F突变98例（73.1%）。年龄60岁以上者发生突变率较60岁以下者明显增高（p＜0.05）,MPD患者中JAK2V617F突变阳性者外周血白细胞计数、血红蛋白水平与血栓、心血管疾病的发生率均高于突变阴性者（p＜0.05）,而性别、民族、血小板计数及LDH水平在JAK2V617F基因突变阳性与阴性患者间无显著性差异（p＞0.05）。结论：MPN患者JAK2V617F基因突变与MPN患者年龄、外周血白细胞计数、血红蛋白水平、血栓及心血管疾病并发症相关。     

Translocation t(1;9) is a recurrent cytogenetic abnormality associated with progression of essential thrombocythemia patients displaying the JAK2 V617F mutation

A cohort of 338 patients diagnosed with myeloproliferative neoplasms was investigated by conventional cytogenetics and evaluated for the presence of the JAK2 V617F mutation. A t(1;9)(p10;q10) in addition to two extra der(1;9)(q10;p10) chromosomes was observed in two patients of essential thrombocythemia that transformed to acute myelogenous leukemia or to myelofibrosis. These findings suggest that the presence of extra derivative chromosomes der(1q;9p) in combination with the JAK2 V617F mutation may play a role in the progression of myeloproliferative neoplasms and supports the use of cytogenetics in the follow-up of the disease.