逆转录-多重巢式聚合酶链反应技术在急性单核系白血病M4/M5 MLL基因重排检测中的应用

目的 探讨逆转录-多重巢式聚合酶链反应（多重PCR）技术在初诊M4／M5患者MLL基因重排检测中的价值。方法 采用骨髓直接或短期培养法制备染色体，应用R显带技术进行核型分析。采用多重PCR技术，检测40例初诊M4／M5患者中5种急性髓系白血病常见的MLL融合基因以及MLL部分串联重复。结果 R显带揭示7有涉及11q23的易位，包括t（6；11）（q27；q23）、t（9；11）（p21；q23）、t（11；17）（q23；q21）、t（11；19）（q23；p13．1），14例有其他核型异常，19例为正常核型。多重PCR证实了7例核型分析显示11q23易位标本中的6例，例3核型分析揭示46，XX，t（6；11）（q27；q23），多重PCR检测MLL/AF6为阴性；19例显带分析为正常核型标本中检出2例MLL部分串联重复。结论 多重PCR是对初诊M4／M5患者进行各种MLL重排筛检的有效方法。     

38例儿童急性淋巴细胞白血病染色体结果分析

目的对儿童急性淋巴细胞白血病(ALL)中的染色体核型及融合基因进行分析。方法应用骨髓染色体标本及FISH方法对38例儿童ALL患者做染色体核型分析及融合基因检测。结果 38例检测患儿中发现染色体异常核型7例;融合基因检测阳性者12例,其中7例是TEL/AML1阳性。结论细胞遗传学联合融合基因检测有助于儿童ALL的诊断及预后判断分析。     

Ph1染色体的急性双表型白血病的诊断及其预后的探讨

目的观察Ph^1染色体急性双表型白血病（BAL）生物学特征和治疗预后。方法患者骨髓标本分别进行细胞形态学及细胞化学染色，确定其FAB类型；用流式细胞仪对直接免疫荧光标记的骨髓单个核细胞进行免疫分型；采用改良的热处理姬姆萨（RHG）显带技术进行核型分析，同时应用RT-PCR检测ABL／BCR融合基因和MDR1耐药基因。治疗采用针对AML、ALL或二者兼顾的方案。结果Ph^1染色体急性双表型白血病（BAL）治疗效果差，生存期较短。结论Ph^1染色体急性双表型白血病（BAL）具有独特的临床生物学特征。     

FISH联合multiplex RT-PCR检测MLL基因重排的价值探讨

目的:采用荧光原位杂交(FISH)与逆转录多重巢式聚合酶链反应(multiplexRT-PCR)技术检测急性白血病中MLL基因重排的情况,分析两者联合应用的诊断价值。方法:对2008年1月~2011年5月在我院诊断为急性白血病的201例患者采用MLL双色断裂分离重排探针进行FISH检测,同时用multiplexRT-PCR技术检测11种较常见的MLL融合基因,观察MLL基因异常的检出率。所有患者均进行常规染色体核型分析(CCA),观察11q23重排率作为对照。结果:共有19例患者出现11q23／MLL基因重排,在急性髓细胞白血病(AML)中的检出13例(10.2%),急性淋巴细胞白血病(ALL)的检出6例(8.2%)。FISH联合multiplexRT-PCR对MLL基因重排的检出率为9.45%,CCA对11q23异常的检出率为5.47%。5例正常核型的患者和3例未涉及11号染色体异常的患者中FISH检出了1例MLL倒位和3例扩增信号,multiplexRT-PCR检出了7例dupMLL(11q23)重排。结论:FISH联合multiplexRT-PCR能提高MLL基因重排检出率。     

急性淋巴细胞白血病融合基因表达特点分析

目的:分析初诊急性淋巴细胞白血病（ALL）患者融合基因的表达情况,进一步探讨融合基因阳性患者的实验室检查特点。方法:回顾性分析2016年9月至2020年12月天津见康华美医学诊断中心1 994例初诊ALL患者的融合基因筛查结果,同时对表达不同融合基因患者的基因突变筛查结果、免疫表型特点及染色体核型结果进行系统分析。结果...     

66例血液病患者bcr/abl融合基因、Ph染色体结果分析

CML特异性费城染色体（Philadephia,Ph）是由t（9：22）（q34：11）易位形成。9号染色体原癌基因abl（Abelson protooncogene）易位至22号染色体的断裂点簇集区（breakpoint cluster region,bcr）,发生重排,产生bcr／abl融合基因,引起CML的始动突变。融合基因bcr／abl几乎见于所有的慢性粒细胞性自血病、25％-50％的急性B系淋巴细胞性白血病（ALL）和约5％的急性粒细胞性白血病中,本文统计了进行染色体和ber／abl融合基因检查的初诊血液病66例,对其骨髓细胞染色体核型及bcr／abl融合基因进行分析。     

伴有11q23/MLL重排的儿童急性髓系白血病的临床及实验室分析

目的 分析伴有11q23/混合谱系白血病(mixed lineage leukemia,MLL)基因重排的儿童急性體系白血病(acute myeloid leukemia,AML)的临床和实验室特点.方法 采用骨髓细胞短期培养法和R显带技术对234例初诊AML患儿进行核型分析;采用逆转录-多重巢式聚合酶链反应(多重PCR)技术检测MLL融合基因以及MLL部分串联重复;采用双色MLL基因探针,对其中2例核型分析具有11q23易位而多重PCR检测MLL融合基因呈阴性的患儿样本进行间期双色荧光原位杂交(dual-color fluorescencein situ hybridization,D-FISH)MLL重排检测.结果 R显带提示234例初诊AML患儿中,20例(M5 14例、M4 4例、M2 2例)有涉及11q23的易位,包括t(9;11)(p22;q23)12例,t(1;11)(q21;q23)3例,t(6;11)(q27;q23)2例,t(11;19)(q23;p13)、t(5;11)(q31;q23)和t(X;11)(q24;q23)各1例.多重PCR证实其中18例有MLL的融合转录本,有2例阴性,但D-FISH均检出MLL重排;在其余AML患儿的样本中检出8例(M5 4例、M4 2例、M2和M6各1例)有MLL部分串联重复.本组AML患儿中,11q23/MLL重排的总检出率11.97%(28/234),其中85.7%(24/28)的病例为M4/M5亚型.本组28例伴有11q23/MLL重排患儿,治疗后完全缓解率为53.8%,与对照组(以同期伴有其他异常核型和正常核型的AML-M4/M5患儿共27例作为对照)的90.5%相比,差异有统计学意义(P<0.05).其中2例患儿接受了强烈化疗,分别生存达81和66个月.4例接受了异基因干细胞移植,已分别生存21、20、16和11个月,至今仍在完全缓解中.本组28例伴有11q23/MLL重排患儿的中位生存期为11个月,对照组为15个月,差异无统计学意义(P>0.05).结论 伴有11q23/MLL重排的AML患儿和单核系白血病高度相关.11q23易位和MLL部分串联重复是相互排斥的,二者预后均较差.采用强烈化疗和异基因干细胞移植有望获得较好疗效.多重PCR联合染色体核型分析和D-FISH技术是对初诊AML患者进行各种MLL重排筛检的有效方法.     

八探针荧光原位杂交联合R显带技术诊断儿童急性髓系白血病CSCD

目的探讨将八探针荧光原位杂交（fluorescence in situ hybridization, FISH）联合R显带染色体核型分析应用于儿童急性髓系细胞白血病（acute mydoid leukemia,AML）诊断的价值。方法应用八探针FISH（AML1／ETO、PML—RARa、CBFβ／MYH11、mL、P53、5q-、7／7q-、20q-等8种DNA探针）和R显带染色体核型分析技术,对214例AML患儿进行了联合检测。结果八探针FISH技术在118例患儿中检出了细胞遗传学改变,总体阳性率为55．1％,包括AML1／ETO、PML／RARa、CBFβ／MYH11、MLL、P53、5q-、7／7q-、20q-等8种细胞遗传学异常。R显带核型分析检出染色体异常55例,阳性率为25．7％,其中4例染色体异常FISH未检出。两种方法检出阳性率的差异有统计学意义（P〈0．05）。结论八探针FISH技术较R显带染色体核型分析具有准确、高效、省时、省力等优点,可与染色体核型分析有效互补,并且每种细胞遗传学异常都可为儿童AML的诊断、预后评估和个体化治疗提供重要依据。     

多探针荧光原位杂交检测急性髓系白血病常见细胞遗传学异常

目的:评价多探针荧光原位杂交(FISH)在检测急性髓系白血病(AML)常见细胞遗传学异常中的价值,探讨细胞遗传学异常与临床诊断、治疗、预后的关系。方法:采用针对AML/MDS的FISH多探针诊断系统,即以针对AML1/ETO融合基因、PML-RARα融合基因、CBFβ/MYH11融合基因、MLL基因、P53基因、Del(5q)、Del(7q)、Del(20q)8种DNA探针对40例患者进行多探针FISH检测,同时联合染色体核型、临床资料进行研究。结果:40例AML中,共22例多探针FISH检出了细胞遗传学改变,包括:AML1/ETO、PML-RARα、MLL基因断裂重排、Del(5q)、Del(7q)、P53基因缺失、8号染色体三体7种细胞遗传学异常。而常规染色体核型分析仅检出11例遗传学异常。多探针FISH与染色体核型分析的总阳性率分别为57.50%及27.50%。AML1/ETO、PML/RARα阳性者首次诱导化疗效果较理想;而Del(7q)、MLL基因断裂重排阳性、伴复杂细胞遗传学改变者可能预示不良预后。结论:FISH多探针诊断系统检测AML患者常见遗传学异常更省时、准确、高效,有利于完善白血病的分层诊断及指导临床个体化治疗。     

苏州地区1305例儿童遗传咨询者的细胞遗传学分析

目的研究儿童染色体异常核型的主要分布情况以及与临床表型的关系。方法按常规方法制备患者外周血淋巴细胞染色体,G显带,显微镜下进行核型分析。结果1305例遗传咨询者中染色体异常275例,异常检出率21.1%（275/1305）。常染色体异常233例,检出率17.9%（233/1305）,其中数目异常200例,占异常核型的72.7%（200/275）,结构异常33例,占异常核型的12%（33/275）;性染色体异常42例,检出率3.2%（42/1305）,其中数目异常22例,占异常核型的8%（22/275）,结构异常20例,占异常核型的7.3%（20/275）。结论儿童常染色体畸变以21-三体综合征最为多见,性染色体畸变以Turner综合征最为多见;染色体畸变是导致儿童先天畸形、身材矮小、智力低下、性发育异常等疾病的重要原因之一,染色体检查可对患儿明确病因、及早诊治、遗传咨询提供依据。     

Precursor T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma and acute biphenotypic leukemias

Session 4 of the 2005 Society of Hematopathology/European Association for Haematopathology Workshop focused on case presentations of precursor T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma (pre-T ALL/LBL) and acute biphenotypic leukemia. Pre-T ALL represents approximately 15% of childhood and 25% of adult ALL cases. Pre-T LBL comprises 85% to 90% of LBL and frequently manifests as a mediastinal mass. Gene expression studies have shown distinct subtypes of LYL1+, HOX11+, TAL1+, and MLL+ pre-T ALL/LBL. HOX11 overexpression may correlate with a good prognosis in adult pre-T ALL. ABL gene amplification and NOTCH1 gene mutations in subsets of pre-T ALL/LBL suggest patients may benefit from therapy with tyrosine kinase and gamma-secretase inhibitors, respectively. Acute biphenotypic leukemias are characterized by a single population of blasts that express myeloid, T- or B-lineage antigens in various combinations and account for fewer than 4% of all acute leukemias. The blasts have a high incidence of chromosome abnormalities. An accurate diagnosis of pre-T ALL/LBL and acute biphenotypic leukemia requires a multiparametric approach, including examination of morphologic features, immunophenotype, clinical characteristics, and cytogenetic and molecular findings.     

Acute lymphoblastic leukemia. Survey of immunophenotype, French-American-British classification, frequency of myeloid antigen expression, and karyotypic abnormalities in 210 pediatric and adult cases

Immunophenotypic studies are essential to distinguish acute lymphoblastic leukemia (ALL) from minimally differentiated acute myeloid leukemia (AMLM0) and to classify ALL into immunologic subtypes. Frequently, immunophenotyping identifies myeloid antigen expression in ALL, causing a potential diagnostic problem. To evaluate the immunophenotype of ALL, we studied 210 cases of pediatric and adult ALL by flow cytometry and compared the results with the French-American-British (FAB) Cooperative Group classification and the karyotypic findings. Myeloid-associated antigens were expressed in 78 (45.6%) of precursor B-cell ALL cases. Pediatric precursor B ALLs had a higher frequency of myeloid antigen expression than did adult cases. All mature B-cell ALL cases were negative for TdT and myeloid antigens. Myeloid antigen expression was less frequent in T-cell ALL cases compared with precursor B-cell ALL cases. Of the 192 cases submitted for cytogenetic analysis, 147 were abnormal. The most common chromosomal translocation was the Philadelphia chromosome, which was more likely to have L2 blast morphology and a precursor B immunophenotype. Myeloid antigen expression was present in 70.8% of Ph-positive cases (P = .008). Chromosome rearrangements involving 11q23 also showed an increased frequency of myeloid antigen expression. Chromosome translocations involving regions of T-cell receptor genes were present in 24% of T-cell ALL cases. A high percentage of ALL cases, however, had various other cytogenetic abnormalities, many of which involved less well-studied chromosomal regions.     

Analysis of t(9;11) chromosomal breakpoint sequences in childhood acute leukemia: almost identical MLL breakpoints in therapy-related AML after treatment without etoposides

The translocation t(9;11)(p22;q23) is a recurring chromosomal abnormality in acute myeloid leukemia (AML) fusing two genes designated as MLL and AF9. Within MLL, almost all rearrangements cluster in an 8.3-kb restricted region and fuse 5' portions of MLL to a variety of heterologous genes in various 11q23 translocations. AF9 is one of the most common fusion partners of MLL. It spans more than 100 kb, and two breakpoint cluster regions (BCRs) have been identified in a telomeric region of intron 4 (BCR1) and within introns 7 and 8 (BCR2). We investigated 11 children's bone marrow or peripheral blood samples (3 AML, 5 t-AML, 2 ALL, 1 ALL relapse) and two cell lines (THP-1 and Mono-Mac-6) with cytogenetically diagnosed translocations t(9;11). By use of an optimized multiplex nested long-range PCR assay, a breakpoint-spanning DNA fragment from each sample was amplified and directly sequenced. In four patients and two cell lines, the AF9 breakpoints were located within BCR1 and in two patients within BCR2, respectively. However, in five patients the AF9 breakpoints were found outside the previously described BCRs within the centromeric region of intron 4 and even within intron 3 in one case. All five patients with a secondary AML, who had not received etoposides during treatment of the primary malignant disease, revealed almost identical MLL breakpoints very close to a breakage hot spot inducible by topoisomerase II inhibitors or apoptotic triggers in vitro. Sequence patterns around the breakpoints indicated involvement of a "damage-repair mechanism" in the development of t(9;11) similar to t(4;11) in infants' acute leukemia.     

FISH analysis of an AML-M5a with segmental rearrangements involving 11q23-MLL region

A 66-year-old man was diagnosed 10 years ago with thrombocytosis and treated with hydroxyurea. Recently, his condition deteriorated and he was found to have 68% blasts in the blood and AML-M5a. Conventional cytogenetic analysis and fluorescence in situ hybridization studies using 11-painting and MLL probes showed that chromosome 11 had duplications or triplications; the markers were also derived from the chromosome 11-MLL region. Therefore, we have demonstrated segmental rearrangement of chromosome 11 involving the MLL region resulting in multiple copies of the MLL gene.