伴NPM1基因突变的成年人急性髓系白血病临床研究

 目的　探讨我国成年伴NPM1基因突变的急性髓系白血病患者（NPMc+AML）的临床特点,初步探讨定期定性检测该突变在早期判断AML复发中的意义。方法　采用聚合酶链反应（PCR）-毛细管电泳法对95例成年初治AML患者检测NPMl突变情况,并选取其中5例完全缓解患者定期检测该突变。结果　95例成年AML患者NPM1突变发生率为29.5 %（28／95）; ≥40岁患者突变发生率[40.0 %（22／55）]明显高于＜40岁患者[15.0 %（6／40）]（χ2＝6.963,P＝0.012）;正常核型AML患者突变发生率[51.1 %（24／47）]明显高于异常核型患者[8.3 %（4／48）]（χ2＝20.860,P＝0.000）。AML患者发生NPM1突变以M5[72.7 %（16／22）]、M2[36.3 %（8／22）]常见,在具有重现性染色体异常的AML中,未发现该突变。NPMc+AML患者白细胞、血小板计数及乳酸脱氢酶水平均明显高于NPMc-AML组（t值分别为4.132、4.603、4.069,均P＜0.05）。NPMc+AML患者完全缓解率、无复发生存率及总生存率均明显高于NPMc-AML患者（χ2值分别为10.448、4.146、4.384,均P＜0.05）。定期检测的患者血液学复发前1.5～2.0个月重新出现NPM1基因突变。结论　NPM1基因突变在成年AML患者中,尤其是正常核型AML患者中有较高的发生率,临床表现为患者年龄偏大,白细胞计数、血小板计数、乳酸脱氢酶均较高,NPM1基因突变是成年AML患者预后良好的指标。定期定性监测该突变可早期判断AML复发。     

NPM1基因突变的急性髓系白血病免疫表型研究

 【摘要】 目的 研究伴有NPM1基因突变的急性髓系白血病(AML)患者的免疫表型特征。方法 采用流式细胞术检测237例初诊AML患者的免疫表型,并采用实时定量PCR方法对NPM1基因突变进行筛查,比较NPM1突变型和野生型患者的免疫表型差异。结果 NPM1突变型患者占所有AML患者的19.0 %（45／237）,与野生型相比其CD34、CD117、HLA-DR、CD15、CD19表达降低（均P＜0.05）。在正常核型AML患者中,NPM1突变率37.7 %（40／106）,突变型患者CD34、HLA-DR、CD15和CD7表达降低（均P＜0.05）。伴NPM1突变的正常核型AML患者的免疫表型在M1中表现为CD34、HLA-DR、CD7表达降低（均P＜0.05）,在M2中为HLA-DR表达降低和CD9表达升高（均P＜0.05）,在M5中为CD117表达降低（P＜0.05）。结论 NPM1突变能对AML患者的免疫表型特征造成影响,不同FAB分型的AML患者免疫表型改变存在差异。     

TET2合并DNMT3A突变及其他共存基因突变对急性髓系白血病患者预后的影响

  目的  探究TET2合并DNMT3A突变及其他共存基因突变对成人非M3型急性髓系白血病（acute myeloid leukemia,AML）患者预后的影响。  方法  回顾性分析2018年1月至2021年9月于南昌大学第一附属医院确诊的初治且行血液肿瘤相关突变基因外显子二代测序检测的512例成人 AML（非 M3 型）患者的临床资料,分析患者的临床特征、疗效及生存情况。  结果  本研究共纳入110例AML患者,TET2突变组64例,DNMT3A单突变组46例。男性50例（45.5%）,中位年龄54（15～79）岁。TET2基因突变频率为12.5%（64/512）,98.4%（63/64）患者突变基因数≥2个,每例患者平均合并5.2个突变基因。NPM1（43.8%）、DNMT3A（42.2%）、FLT3-ITD/TKD（40.6%）、CEBPA（26.6%）、TTN（20.3%）为TET2突变常见的共存突变基因。TET2合并DNMT3A突变患者初次诱导完全缓解（complete response,CR）率为46.2%,略低于TET2单突变患者的76.9%（P=0.077）,与DNMT3A单突变患者无显著性差异（P=0.952）。TET2合并DNMT3A突变患者的中位总生存（median overall survival,mOS）时间为9.5个月,明显低于TET2单突变患者（P=0.002）,而与DNMT3A单突变患者无显著性差异（P=0.414）。三者的中位无复发生存（median relapse- free survival,mRFS）时间无显著性差异（P>0.05）。在TET2突变背景下,合并K/NRAS突变患者的CR率为28.6%,明显低于无K/NRAS突变患者的75.0%（P=0.030）,合并FLT3-ITD突变患者的mOS明显短于无FLT3-ITD突变患者（P=0.030）。多因素分析显示年龄≥60岁、合并FLT3-ITD突变、初次诱导未达CR是影响TET2突变AML患者总生存时间（overall survival,OS）的独立危险因素,DNMT3A突变不影响TET2突变患者OS。  结论  TET2突变是AML患者常见突变,且常合并共存基因突变。共存基因突变与TET2突变共同影响AML患者预后。基于二代测序的基因突变检测对指导AML精确分层及精准治疗具有重要意义。      

初诊急性髓系白血病患者十种常见突变基因的突变组分析

目的 探讨初诊急性髓系白血病(AML)患者中最常见的10种突变基因的突变组合规律.方法 选取AML患者129例,基因测序法检测初诊时骨髓样本中ASXL1、CEBPA、DNMT3A、FLT3、IDH1/2、KIT、NPM1、PHF6和TET2基因突变.结果 68.99％(89/129)患者上述基因突变阳性,30.23％(39/129)同时有多种基因突变.激酶类基因FLT3和KIT突变互斥,不同时出现.FLT多与其他基因伴随突变,而KIT突变多单独出现.转录因子基因CEBPA、NPM1和PHF6可相互伴随突变.表观遗传调控基因ASXL1、DNMT3A、IDH1/2和TET2的突变多与上述两组基因突变同时出现,但该组基因之间较少伴随突变.结论 首次对初诊AML中的突变组按基因的功能和分类进行谱型分析,显示基因突变的组合具有一定的规律,与基因的功能和分类相关.     

难治复发急性髓系白血病患者十种常见突变基因的突变组分析

目的 探讨难治复发急性髓系白血病(AML)患者中常见的10种突变基因发生的规律.方法 选取难治复发AML患者148例.基因测序检测并分析患者骨髓样本中10种常见突变基因,包括激酶类基因FLT3和KIT,转录因子基因CEBPA、NPM1和PHF6,以及表观遗传类基因ASXL1、DNMT3A、IDH1、IDH2和TET2.结果 在62.16％(92/148)的患者中检测到上述基因突变阳性,其中10.14％(15/148)的患者同时携带多个基因的突变.FLT3-ITD突变率最高(19.59％,29/148),其次为KIT(12.84％,19/148)和CEBPA(11.49％,17/148)突变.KIT突变常单独出现,而IDH1/2突变常伴随其他基因突变.激酶类基因FLT3和KIT突变互斥,转录因子基因和表观遗传基因也存在同类互斥现象.以35岁为界限分组,≤35岁的患者多携带单个基因的突变[61.77％(63/102)比31.11％(14/45),P＜ 0.05],而＞35岁的患者多个基因突变(≥2个)的携带率高[20.00％(9/45)比4.90％(5/102),P＜ 0.05].＞35岁患者组中NPM1突变率高于≤35岁组[20.00％(9/45)比2.94％(3/102),P＜ 0.05].结论 研究发现难治复发AML患者中常见基因突变的组合具有一定的规律,与基因的功能分类和患者的年龄有关.     

急性髓细胞白血病NPM1和FLT3-ITD突变检测临床意义分析

目的:研究核仁磷酸蛋白1(NPM1)FMS样酪氨酸激酶3(FLT3)基因内部串联重复(ITD)突变在急性髓细胞白血病(AML)中发生的情况,并了解其临床特征及预后意义.方法:分别应用高分辨熔解曲线(HRM)和变性高效液相色谱技术(DHPLC)检测103例初诊AML患者NPM1和FLT3-ITD突变情况,并结合临床资料进行分析.结果:103例初诊AML患者中,31例发现NPM1基因突变,20例发现FLT3-ITD突变,阳性率分别为30.1％和19.4％,而在核型正常组中所占的比例分别为47.6％(20/42)和26.2％(11/42).FLT3-ITD突变型外周血白细胞计数高,t=2.21,P=0.037;骨髓原始细胞比例高,t=2.44,P=0.023;NPM1突变型亦表现为高外周血白细胞计数,t=2.24,P=0.034.在非M3患者中,NPM1突变型的CR与野生型差异无统计学意义,但第1次化疗的CR(76.9％)明显高于野生型患者(35.0％),x2=12.78,P=0.000 35;FLT3-ITD突变型患者的CR为58.8％,野生型患者为82.6％,两者比较,x2=4.48,P=0.034;FLT3-ITD突变型患者第1次化疗的CR为17.6％,而野生型患者为55.1％,两者比较,x2=6.23,P=0.012.31例NPM1基因突变中有6例合并FLT3-ITD突变,NPM1+/FLT3-ITD-组的CR最高(85.0％),1年内RR率最低(17.6％);NPM1-/FLT3-ITD+组的CR最低(54.5％),1年内RR率最高(50.0％).结论:NPM1和FLT3-ITD突变是AML患者常见的分子遗传学异常,与预后密切相关,可成为目前细胞遗传学预后分组的重要补充,对于指导AML患者的个体化治疗具有重要的临床价值.     

急性髓系白血病患者骨髓涂片FMS样酪氨酸激酶3、NPM1和c-kit基因检测及临床研究

目的：探讨提取贮存骨髓涂片DNA的方法,通过对急性髓系白血病（AML）患者FMS样酪氨酸激酶3（FLT3）、NPM1及c-kit基因突变进行检测,分析三种基因突变与AML临床特征之间的关系。方法收集55例AML患者骨髓涂片,采用聚合酶链反应（PCR）、DNA测序和分子克隆方法对FLT3-内部串联重复（ITD）、NPM1和c-kit基因突变进行检测及分析,记录患者疾病缓解、进展及生存时间。结果实验证实对于低温冻存、未经瑞特染色、未用化学方法固定的骨髓涂片标本及室温贮存、经瑞特染色脱色后的标本均能用苯酚∶氯仿∶异戊醇法成功提取DNA。从骨髓涂片中提取的DNA可用于PCR、直接测序和分子克隆测序分析。在55例AML患者中,FLT3-ITD阳性10例（18.2%）,其中9例为杂合型突变,1例为纯合型突变。FLT3-ITD阳性组较阴性组完全缓解（CR）率低,无事件生存（EFS）和总生存（OS）时间短（P＜0.05）。NPM1基因杂合型突变9例（16.4%）,全部为A型突变。10个月以内NPM1突变组患者EFS率比野生组高（P＜0.05）,19个月以内NPM1突变组OS率比野生组高（P＜0.05）。9例NPM1突变患者中FLT3-ITD阳性3例,CR率由高到低依次为NPM1+ FLT3-ITD-、NPM1- FLT3-ITD-、NPM1- FLT3-ITD+、NPM1+ FLT3-ITD+（P＜0.05）,且NPM1- FLT3-ITD+是影响OS的危险因素（RR＝1.250,P＝0.005）。55例患者中,c-kit基因突变2例（3.6%）,分别为D816H突变型和D816V突变型;c-kit基因突变患者与FLT3-ITD阳性及NPM1突变患者无重叠。结论 FLT3-ITD突变为AML患者预后不良的分子标志,NPM1基因突变可能提示预后较好,NPM1- FLT3-ITD+是影响OS的危险因素。AML中c-kit基因突变率低,未见其与FLT3、NPM1基因突变重叠。     

正常核型急性髓系白血病NPM1基因突变的临床分析

目的：分析具有正常核型的急性髓系白血病（CN-AML）患者 NPM1基因突变情况及其临床意义。方法回顾性分析2008年1月至2015年6月年同济医院血液内科收治的190例初发 CN-AML患者的临床资料。对比研究 NPM1突变型与野生型 CN-AML 患者之间临床特征和治疗效果的差异。结果190例 CN-AML 患者中44例（23.16%）出现 NPM1基因突变。与野生组比较,突变组患者外周血白细胞计数高（60.0×109／L 比75.7×109／L,P＜0.05）,骨髓中原始细胞比例高（63.87%比75.82%,P＜0.05）,初次化疗缓解（完全缓解+部分缓解）率高[56.91%（45／79）比70.09%（22／31）,P＜0.05]。结论NPM1基因突变与 CN-AML 高肿瘤负荷以及高诱导化疗缓解率具有相关性。     

NPM1突变及H3K79甲基化的研究进展

白血病是一种常见的血液系统恶性肿瘤,其中急性髓系白血病（acute myeloid leukemia,AML）约占所有白血病的59%,其发病机理尚不十分清楚,现认为多种因素在多个层面、多个阶段的相互作用导致白血病的发生。NPM1蛋白可以穿梭于胞浆与胞核之间,并主要定位于细胞核内,与多种蛋白结合。NPM1突变在急性髓系白血病中占25～30%,产生的突变的NPM1蛋白因缺乏核定位肽段而滞留于细胞浆,对细胞核的稳定性以及某些癌基因的表达产生负面影响。在含有NPM1基因突变的AML中,约70%的病人同时含有DNA甲基化调节基因的突变（DNMT3A、IDH1、IDH2、TET2等）,并且已知表观遗传学的异常可以直接破坏核稳定性,上调某些白血病相关基因的高表达。NPM1突变基因的白血病细胞具有特殊的基因表达特征,如HOX家族基因、MEIS1基因在突变系统中显著高表达,这些基因不仅是引发白血病的关键调节子,而且是MLL融合蛋白的下游靶点。在携带有MLL融合蛋白的AML中,MLL的融合伴侣可以募集DOT1L,对MLL靶点基因上的H3K79位点进行甲基化,造成这些基因过度活化。同MLL基因的异常相比,NPM1突变保持着相似的转录特点,然而NPM1突变是否能够影响组蛋白H3K79甲基化的变化还不是很清楚。本综述着重探讨NPM1突变与H3K79甲基化的关系,以及H3K79甲基化转移酶DOT1L抑制剂对NPM1突变的AML的作用,从而为白血病发病寻求新的分子机制和治疗策略。     

CCAAT/增强子结合蛋白α基因突变急性髓系白血病患者临床特征及预后

目的 分析CCAAT/增强子结合蛋白α（CEBPA）基因突变急性髓系白血病（AML）患者临床特征及预后.方法 回顾分析208例初诊AML患者CEBPA基因突变发生率、临床特征、治疗效果及预后.结果 208患者中,CEBPA突变患者37例（17.8％）,其中29例为双突变,8例为单突变.1 17例正常核型患者中CEBPA突变28例（23.9％）.CEBPA双突变患者具有以下临床特征：初诊时年龄小,大部分（82.8％,24/29）患者为M1型与M2型,初诊时表现为外周血白细胞数高、血红蛋白水平高、血小板数低,白血病细胞高表达CD7、CD34及HLA-DR.CEBPA双突变患者总生存率优于无突变者（2年总生存率：100％比75.1％,P=0.045）.结论 CEBPA双突变为AML预后良好标志之一.     

Landscape of TET2 mutations in acute myeloid leukemia

We investigated ten-eleven translocation 2 (TET2) mutations in acute myeloid leukemia (AML), their correlation with other gene mutations and prognostic value. By deep-sequencing, 131 somatic TET2 mutations were identified in 87/318 (27.4%) patients. Of 87 mutated cases, 44 (50.6%) carried two mutations. TET2 mutations were concomitantly observed with mutations in NPM1, FLT3-ITD, FLT3-TKD, JAK2, RUNX1, CEBPA, CBL and KRAS. However, TET2 mutations rarely concomitantly occurred with IDH1mut or IDH2mut (2/251 or 0/184; P=0.046 and P=0.003, respectively). TET2 mutations were associated with normal karyotype AML (CN-AML) (62/206 (30.1%) CN-AML vs 20/107 (18.7%) aberrant karyotype; P=0.031), higher white blood cell count (mean 65.3 vs 40.3 × 10(9)/l, P=0.023), lower platelet count (mean 68.6 vs 92.4 × 10(9)/l, P=0.03) and higher age (67.5 vs 65.2 years, P<0.001). Survival analyses were restricted to de novo CN-AML patients (n=165) and showed inferior event-free survival (EFS) of TET2 mutations compared with TET2wt (median: 6.7 vs 18.7 months, P=0.009). This negative effect of TET2 mutation on EFS was particularly observed in patients 65 years (median: 8.9 months vs not reached (n.r.), P=0.027) as well as in patients of the European LeukemiaNet favorable-risk subgroup, that is, patients harboring mutated CEBPA and/or mutated NPM1 without FLT3-ITD (median: 10.3 vs 41.3 months, P=0.048). These data support a role for TET2 as an important prognostic biomarker in AML.     

Adverse impact of IDH1 and IDH2 mutations in primary AML: experience of the Spanish CETLAM group

The study of genetic lesions in AML cells is helpful to define the prognosis of patients with this disease. This study analyzed the frequency and clinical impact of recently described gene alterations, isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2) mutations, in a series of homogeneously treated patients with primary (de novo) AML. Two-hundred and seventy-five patients enrolled in the CETLAM 2003 protocol were analyzed. IDH1 and IDH2 mutations were investigated by well-established melting curve-analysis and direct sequencing (R140 IDH2 mutations). To establish the percentage of the mutated allele a pyrosequencing method was used. Patients were also studied for NPM, FLT3, MLL, CEBPA, TET2 and WT1 mutations. IDH1 or IDH2 mutations were identified in 23.3% AML cases and in 22.5% of those with a normal karyotype. In this latter group, mutations were associated with short overall survival. This adverse effect was even more evident in patients with the NPM or CEBPA mutated/FLT3 wt genotype. In all the cases analyzed, the normal allele was detected, suggesting that both mutations act as dominant oncogenes. No adverse clinical impact was observed in cases with TET2 mutations. IDH1 and IDH2 mutations are common genetic alterations in normal karyotype AML. Favourable genotype NPM or CEBPA mutated/FLT3 wt can be further categorized according to the IDH1 and IDH2 mutational status.     

Mutation Analysis of IDH1/2 Genes in Unselected De novo Acute Myeloid Leukaemia Patients in India - Identification of A Novel IDH2 Mutation

IDH1/2 mutations which result in alternation in DNA methylation pattern are one of the most commonmethylation associated mutations in Acute myeloid leukaemia. IDH1/2 mutations frequently associated withhigher platelet level, normal cytogentics and NPM1 mutations. Here we analyzed IDH1/2 mutations in 200 newlydiagnosed unselected Indian adult AML patients and investigated their correlation with clinical, cytogeneticparameters along with cooperating NPM1 mutation. We detected 5.5% and 4% mutations in IDH1/2 genes,respectively. Except IDH2 c.515_516GG>AA mutation, all the other identified mutations were reported mutations.Similar to reported c.515G>A mutation, the novel c.515_516GG>AA mutation replaces 172nd arginine to lysinein the active site of the enzyme. Even though there was a preponderance of IDH1/2 mutations in NK-AML,cytogenetically abnormal patients also harboured IDH1/2 mutations. IDH1 mutations showed significant higherplatelet count and NPM1 mutations. IDH2 mutated patients displayed infrequent NPM1 mutations and lowerWBC count. All the NPM1 mutations in the IDH1/2 mutated cases showed type A mutation. The present datasuggest that IDH1/2 mutations are associated with normal cytogenetics and type A NPM1 mutations in adultIndian AML patients.     

IDH Mutations in AML Patients; A higher Association with Intermediate Risk Cytogenetics

Objective: IDH mutations diversely affect the prognosis of cyogenetically normal acute myeloid leukemia (CN-AML) adult patients. The aim of this study is to assess the frequency of IDH mutations and to evaluate its role in AML prognosis. Methods: We have analyzed IDH1 and 2 mutations using High Resolution Melting curve analysis (HRM) in 70 denovo AML patients. Results: The median age of AML patients is 40 years (16-75). Incidence of IDH mutations is 10/70 (14.3%); 2 (2.9%) IDH1 mutant and 8 (11.4%) IDH2 mutant. Median PB blasts of mutant IDH patients was 67.5% (25-96) vs. 44% (0-98) for wild type (p=0.065). Eight/10 (80%) mutant IDH patients had B.M blasts ≥50% vs. 2/10 (20%) <50% (p<0.001) and were classified as intermediate risk cytogenetics (p=0.020) with wild FLT3-ITD (p=0.001). Ten/10 (100%) mutant IDH patients showed wild NPM1 (p=0.049). Median OS of mutant IDH in the intermediate risk cytogenetics was 1.8 years (0.7-3.1) vs. 3.1 years (1.1-5.5) for wild IDH (p=0.05). Conclusion: IDH mutation is mainly associated with intermediate risk AML and when integrated in this specific subgroup displays a lower survival and can be considered an additional integrated molecular risk marker for AML prognosis.