STR-PCR对造血干细胞移植后植入证据的检测

本研究采用STRPCR检测方法，观察比较15例异基因造血干细胞移植术后患者的植入情况。提取15例异基因造血干细胞移植术患者及其供者移植前的以及患者移植术后的不同时期的外周血或骨髓DNA，PCR扩增5个具有高度多态性的STR位点，通过变性聚丙烯酰胺凝胶电泳和银染，分析其植入情况。结果表明：15例患者均有不同程度植入，其中完全供者植入10例，供受者混合嵌合体5例。持续缓解10例，死亡4例，1例复发但仍存活。混合嵌合体中供者DNA比例的下降预示着早期排斥或复发。Ⅱ度以下急性移植物抗宿主病的发生与混合嵌合体有明显相关性。结论：STRPCR是分析异基因造血干细胞移植后供体是否植入的灵敏、准确度高的方法，混合嵌合状态对白血病复发有预警作用。嵌合状态的变化对疾病的治疗有指导作用。     

间期双色双融合荧光原位杂交监测慢性髓系白血病异基因造血干细胞移植后bcr/abl融合基因

本研究探讨bcr/abl双色双融合荧光原位杂交（DD-FISH）的敏感性及临床应用价值.对19例慢性髓细胞白血病（CML）异基因造血干细胞移植（allo-HSCT）后微小残留病灶（MRD）用DD-FISH进行监测,同时与常规细胞遗传学（CC）、逆转录-聚合酶链反应（RT-PCR）结果相比较.样本取自骨髓,少数来源于骨髓片或外周血.结果表明：14例CML患者在Allo-HSCT后CC显示持续正常供者核型,RT-PCR转为阴性,移植2月后均为完全供者嵌合（DC）,DD-FISH检测结果持续为阴性,平均随访11.25月,MRD无增加.1例CC及RT-PCR阴性,而性染色体FISH为混合嵌合,DD-FISH阳性,监测无MRD增加,临床未治疗,疾病稳定.3例骨髓复发患者的DD-FISH及性染色体FISH均提示MRD明显增加,RT-PCR转为阳性,却只有1例CC异常,供者淋巴细胞输注（DLI）及甲磺酸伊马替尼治疗后均为DC,DD-FISH阴性,RT-PCR阴性.1例骨活检证实髓外复发患者骨髓或外周血样本的DD-FISH、CC及PCR均阴性,供受者完全嵌合.结论：间期双色双融合FISH可应用于CML异基因造血干细胞移植后MRD的监测,其操作简易快速,灵敏度高,且骨髓或外周血均可采用.动态监测能及时发现扩大的白血病细胞克隆.     

荧光标记短串联重复序列复合扩增监测嵌合体的应用研究

本研究采用荧光标记的多重PCR复合扩增短串联重复序列(STR)结合全自动毛细管电泳检测异基因造血干细胞移植后嵌合体水平,并探讨该方法动态监测对移植患者预后判断的作用。采集30例异基因造血干细胞移植患者及其供者移植前后骨髓或外周血的DNA,采用Profiler Plus试剂盒进行PCR扩增,产物经ABI310遗传分析仪进行毛细管电泳,通过供受者基因位点差异和峰面积进行嵌合体的定量检测。结果表明,29例患者在移植后28天形成完全供者嵌合体(complete chimerism,CC),1例形成混合嵌合体(mixed chimerism,MC)。在长期随访中,22例表现为持续完全供者嵌合体,8例混合嵌合体患者中7例原病复发,从完全供者嵌合体转为混合嵌合体。完全供者嵌合体组移植物抗宿主病(GVHD)的发生率明显高于混合嵌合体组。结论 :荧光标记多重复合扩增STR检测嵌合体具有快速、自动化高、可定量及灵敏度高等优点,动态定量监测嵌合体可用于移植动力学研究,对移植物早期植入或被排斥、疾病复发以及GVHD均有预警作用,对实施临床干预治疗有指导价值。     

Comparison of T-cell-depleted BMT and PBPCT with respect to chimerism, graft rejection, and leukemic relapse.

Chimerism analysis by DNA-based methods is a valuable diagnostic tool for monitoring engraftment and leukemic relapse after allogeneic BMT or PBPC transplantation (PBPCT). We investigated the chimerism after T-cell-depleted BMT (n = 32) in comparison with T-cell-depleted PBPCT (n = 39). BM grafts were T-cell depleted using the Campath-IgM antibody plus complement. For T-cell depletion of the PBPC grafts, a selection of CD34+ cells with or without a subsequent CD2/3 depletion was performed. In all patients, the T-cell dose of the transplant was < 10(6)/kg body weight. Between day 13 and day 120 after transplantation, chimerism analysis was done by RFLP or amplified fragment length polymorphism (PCR-AFLP), with a detection limit of 1%-5% recipient cells. In the BMT group, 8 of 32 (25%) patients showed a mixed chimerism, but only one graft rejection and no leukemic relapse occurred after a median follow-up of 41 (3-84) months. All patients with PBPCT revealed a complete chimerism of their granulocytes, and 38 of 39 patients showed complete chimerism of their lymphocytes. Follow-up time in these patients is 7 (2-21) months, with no graft rejection and two leukemic relapses. G-CSF-mobilized PBPC are superior to BM cells for full engraftment even after T-cell-depleted transplantation. The more relevant factor for developing complete chimerism seems to be the quantity and possibly the quality of the stem cells rather than the residual T-cell load of the graft. However, a mixed chimerism of the lymphocytes early after transplantation does not predict a higher rate of graft rejection or leukemic relapse.     

STR峰高与峰下面积在干细胞移植后状态判断的应用探讨

目的 探讨短串联重复序列（STR）信息位点的峰高与峰下面积在异基因造血干细胞移植后嵌合状态判断中的作用,寻找适合于异基因造血干细胞移植状态判断的指标.方法 分别采集两名无关供者及M2患者及其HLA全相合供者两组血标本,以白细胞含量为依据制备不同比例混合血样,提取DNA,使用STR试剂盒,建立PCR扩增体系,在ABI3100仪上检测扩增片段,筛选得到理想的信息位点,获取其峰高及峰面积进行移植嵌合率的计算.结果 各筛选位点以峰高或面积得出的模拟嵌合率间差异均无统计学意义,且各位点模拟嵌合率与制备的浓度梯度之间的相关系数均在0.9965以上.结论 峰高或峰下面积均可作为嵌合状态的定量监控指标.     

Hemopoietic chimerism following stem cell transplantation.

Hematopoietic chimerism is a measure of the number of donor and recipient cells in the host following stem cell transplantation (SCT). The type of conditioning therapy prior to SCT has a major impact on the chimeric status in the recipient. Different techniques of measurement have varying sensitivities. The use of polymerase chain reaction (PCR) of short tandem repeats (STR) using fluorescent amplification permits quantification using Genescan analysis. When SCT is used for malignant haematological disorders, measurement of chimeric status may indicate early relapse and in aplastic anemia graft rejection. Reduced intensity or T-cell depletion is associated with mixed haemopoietic chimerism. SCT for benign haematological disorders does not require complete donor chimerism for a successful outcome.     

孕妇外周血胎儿ABO血型基因分型技术的建立

本研究目的是建立孕妇外周血胎儿ABO血型基因分型技术,用于ABO血型不合引起的新生儿溶血病的产前诊断。根据ABO血型基因DNA全序列和mRNA序列设计4对引物,选择20例健康供者血浆,提取血浆中DNA进行扩增,探索最佳的血浆DNA提取及PCR扩增条件,初步建立单人ABO血型基因分型技术。将O型血浆DNA与A型或B型血浆DNA按1：1、2：1、4：1、8：1、10：1、20：1、40：1、100：1进行混合,模拟孕妇外周血胎儿与孕妇自身ABO基因混合状态,建立混合ABO血型基因分型技术。选取14例孕30周以上的孕妇外周血标本,进行胎儿ABO血型基因型鉴定,并对孕妇进行追踪,尽量获取胎儿出生以后的外周血标本进行ABO血型鉴定,以评价孕妇外周血胎儿ABO血型基因分型技术的灵敏度与准确性。结果表明：单人血浆进行准确血型鉴定的最少模板DNA量约为0．625ng,500μl血浆提取的DNA量即可达到PCR扩增要求;当混合血浆中O型DNA所占比例≤10时,可以准确检测出非0基因的存在;14名O型孕妇外周血标本中9例标本扩增出非O型基因,5例未扩增出非0基因;通过血清学方法对5例胎儿出生后外周血进行ABO血型鉴定,其中A型3例,B型1例,O型1例,与其基因分型结果一致,符合率100％。结论：本研究建立的孕妇外周血胎儿ABO血型基因提取、分型技术,可以对妊娠中晚期胎儿ABO血型基因型进行准确鉴定,从而为新生儿溶血病的产前诊断与预防提供指导意见。     

Validation of human monoclonal HLA Class I antibodies to evaluate the kinetics of donor chimerism in different cell subsets after double‐cord‐blood transplantation in the NOD/SCID model

BACKGROUND: Double‐cord‐blood transplantation (DCBT) in patients is typically accompanied by predominance of a single unit. The causative mechanism, however, is unknown. Identifying the dynamics of mixed donor chimerism in general and in specific subpopulations may help to resolve this question. We conducted studies in a mouse model to develop a new analytic method using anti‐human HLA Class I allele–specific monoclonal antibodies (HLA‐MoAbs) in flow cytometry. STUDY DESIGN AND METHODS: Single‐cord‐blood transplantation or DCBT from HLA‐mismatched donors was performed in NOD/SCID mice. Bone marrow (BM) and peripheral blood were collected from 3 to 20 weeks after transplantation. Donor chimerism was determined quantitatively within human platelets (hPLTs), human CD45+ (hCD45+) cells, and human myeloid and lymphocyte subsets by flow cytometry. RESULTS: Both cord donors stably engrafted in NOD/SCID. The sensitivity to detect chimerism measured with all HLA‐MoAbs was 1% (>10 cells/µL). In mouse BM, the percentage of human cells measured with hCD45+ versus HLA‐MoAbs correlated excellently (r = 0.999). Donor origin could be defined with HLA‐MoAbs for nearly all (>93.6%) human cells in mouse peripheral blood and BM in all lineages. Chimerism of hPLTs in peripheral blood correlated well with hCD45+ cells in BM enabling frequent measurement of chimerism from early after transplantation onward. CONCLUSION: This approach using HLA‐MoAbs enables longitudinal analysis of double‐mixed human chimeric populations despite low absolute concentrations of human hematopoietic cell subsets in peripheral blood and BM in mice. Lacking reactivity with mouse cells, the HLA‐MoAbs are suitable for use in other mouse models and in humans to identify the mechanisms involved in DCBT.     

Polymerase chain reaction: amplification of DNA from fixed tissue

The polymerase chain reaction (PCR) allows the analysis of DNA from biologic samples containing only nanogram quantities of DNA. We used DNA purified from fresh or frozen peripheral blood (PB) leukocytes and formalin, or B-5 fixed bone marrow aspirate clots (BM). A sequence of the beta-globin gene was amplified via the PCR then hybridized with allele specific oligonucleotide probes for hemoglobin A, S, and C. All DNA preparations, including formalin and B-5 fixed BMs, were successfully amplified; the hybridization of the amplified products resulted in patterns consistent with the hemoglobin phenotype for all patients. PCR can be used on DNA from many sources; retrospective studies using paraffin embedded fixed tissue are possible because extremely small amounts of DNA present in fixed tissue can be successfully amplified.     

人感染田鼠巴贝斯虫的实验室诊断一例

目的通过回顾1例人感染巴贝斯虫的实验室资料,以积累经验,提高诊断水平。方法研究红细胞(RBC)、血小板(PLT)直方图,白细胞(WBC)VCS散点图;观察外周血、骨髓涂片中虫体的形态;从患者外周血中提取的DNA核酸用疟原虫、巴贝斯虫种、巴贝斯虫属特异性引物进行聚合酶链反应(PCR)。结果 RBC直方图波峰降低,宽度增加,PLT直方图无异常,WBC VCS散点图非WBC区有颗粒团;外周血、骨髓涂片见大量拟似恶性疟原虫虫体;PCR产物测序结果经BLAST比对,结果显示与巴贝斯虫和田鼠巴贝斯虫18s核糖体DNA序列分别有96%和99%的同源性。结论感染的虫体为田鼠巴贝斯虫。     

异基因造血干细胞移植后细胞嵌合状态动态监测的临床意义

目的 研究异基因造血干细胞移植(allo-HSCT)后各系细胞嵌合状态与移植物植入、急性移植物抗宿主病(aGVHD)、移植物被排斥和疾病复发的关系.方法 对65例患者进行allo-HSCT,在移植后定期采集所有患者的外周血和骨髓.用流式细胞术分选了65例患者的CD3+T淋巴细胞,52例分选了CD3-CD56+CD16+NK细胞,32例分选了CD15+粒细胞,20例分选了CD19+B淋巴细胞.进行PCR扩增短串联重复序列检测各系细胞嵌合状态.结果 移植后NK细胞早期植入比例(55.5%)最高,T细胞最晚(+21 d)达到完全供者嵌合状态.+7 d T淋巴细胞供者嵌合比例(DC)≥70%和+14 d T淋巴细胞DC≥95%属aGVHD发生的高危患者.除急性淋巴细胞白血病外,出现移植物被排斥的分子生物学征象者和疾病复发者,都以T淋巴细胞供者嵌合状态下降为主.在过继免疫治疗中,动态检测嵌合状态可以判断疗效和指导进一步的治疗.结论 allo-HSCT后T淋巴细胞嵌合状态动态检测可以早期预测发生aGVHD的高危患者、判断移植物植入、发现移植物被排斥和疾病复发并指导免疫调节治疗的时机和疗效.     

STR-PCR定量检测嵌合体供者嵌合率准确性探讨

目的探讨用荧光标记复合扩增短串联重复序列(STR-PCR)结合序列分析仪毛细管电泳法检测嵌合体供者细胞嵌合率的准确性。方法采集健康献血者外周血按白细胞比例两两混合制备不同供受者比例的体外嵌合体模型,对15个STR位点进行荧光标记复合扩增,扩增产物进行序列分析仪毛细管电泳,计算嵌合率。结果实验测得嵌合率与扩增前样本嵌合率呈显著直线相关,r=0.999 7,最小检出供者细胞嵌合率<1%。供者嵌合率≥5%的嵌合体模型嵌合率的检测值与理论值差别无统计学意义(P>0.05),<5%的模型嵌合率检测值与理论值差别有统计学意义(P<0.05)。结论荧光标记复合扩增STR基因结合序列分析仪毛细管电泳检测嵌合率方法个体识别力高、特异、敏感,当供者嵌合率≥5%时能准确反映异基因造血干细胞移植后患者的嵌合状态。     

Single cell PCR from archival stained bone marrow slides: a method for molecular diagnosis and characterization

Molecular analysis of isolated single cells is a powerful tool for clarifying issues of cell origin and clonality. Previous reports have described PCR amplifications from total DNA and RNA extracted from archival bone marrow and peripheral blood smears and have also shown the feasibility of amplifications from single cells, microdissected from stained histological sections. In this study, a method is described for performing PCR from morphologically defined single cells isolated from archival May-Gruenwald-Giemsa-stained bone-marrow and blood smears. Using three DNA extraction procedures, the organic lysis showed reproducible high efficiencies of amplifications. With this method, we were able to amplify long range amplicons up to 14.5 kb from mitochondrial DNA as well as PCR products of conventional length. The usability of such products for molecular diagnosis is demonstrated by restriction fragment length polymorphism (RFLP)characterization of a mitochondrial disorder. In conclusion, this method has the power to perform molecular diagnosis and characterization of diseases on the single cell level, and should provide valuable information to aid disease treatment and prognosis of hematological disorders.     

利用红细胞Kidd血型基因实时荧光定量PCR法监测个体嵌合状态

本研究建立红细胞Kidd血型基因实时荧光定量PCR(RT-qPCR)技术以监测个体嵌合状态。根据红细胞Kidd血型等位基因的差异设计TaqMan MGB探针和特异性引物,进行实时荧光定量PCR检测个体嵌合状态,利用倍比稀释的方法模拟个体DNA嵌合状态并进行敏感性分析。结果表明,实时荧光定量PCR法可有效区分JK*A和JK*B等位基因。人工嵌合JK*A和JK*B的DNA标本实测值与理论值无显著差异(P>0.05)。在104个嵌合型细胞中存在156个供者型细胞时,该方法可有效检出供者型细胞。结论:建立的红细胞Kidd血型基因实时荧光定量PCR法检测嵌合体具有可行性,可以在一定范围内用于定量监测嵌合样本。     

STR-PCR分析嵌合体在同种异基因造血干细胞移植中的应用

利用荧光标记的多重PCR扩增短串联重复序列（STR-PCR）结合毛细管电泳检测供者细胞嵌合率（DC）,以探讨该方法的连续检测对异基因造血干细胞移植（allo-HSCT）后转归的预警作用,采集27例清髓性外周血干细胞移植患者移植前、移植后不同时段的外周血或骨髓,DNA样本用Profiler Plus和Cofiler Plus商品化试剂盒扩增后,用ABI310遗传分析仪进行毛细管电泳,确定基因位点及峰面积,根据基因型的差异选择嵌合率计算公式。结果表明：两种试剂盒测得的DC嵌合率一致;在27对中能区别出供受差别的STR位点,Profiler Plus为6.3（4-9）个,Cofiler Plus为4.9（2-6）个。26例患者均在移植后28天出现供者细胞,1例患者未出现供者细胞。14例患者DC100%,均获得持久植入,至今仍无白血病生存;另有9例患者出现不稳定混合嵌合（MC）状态（DC为0%-90.2%）,其中5例为血液学复发。27例病人中有6例死亡。上述5例复发患者均在出现临床症状前发生DC量下降;供者细胞完全嵌合组移植物抗宿主病（GVHD）的发生率高于MC组。结论：动态检测DC可用于移植动力学研究,对移植物早期植入或被排斥、疾病复发以及GVHD的发生均有预警作用,对早期实施临床干预治疗有重要的指导意义。     

荧光标记复合扩增短串联重复序列基因分析骨髓移植物的植入

目的 为了准确地识别骨髓移植物的植入状态,探讨PCR扩增短串联重复序列（short tandem repeat,RCR－STR）在亲缘或无关供者骨髓移植的预后及白血病复发中的预警作用。方法 建立荧光标记PCR－STR等位基因分析技术,采用单克隆磁珠提取DNA,四色荧光标记,于移植前、移植后7天－6个月不等,采集供、受者血液（2例回顾性研究患者刮取口腔粘膜脱落细胞作为术前样本）DNA作PCR－STR分析。结果 ①12例患者骨髓移植后10例为完全供者型,其中同胞损髓8例,HLA全相合77例,半相合1例;无关供者损髓1例,HLA全相合,母亲供髓1例,HLA-Ⅰ全相合,HLA－Ⅱ半相合。10例受者术后出现Ⅰ度移植物抗宿主病（GVHD）,STR均完全和持续表达供者基因型,追求观察3－25个月,预后良好。②12例中1例由嵌合型转变为完全供者型,系同胞损髓,HLA－Ⅰ半相合,HLA－Ⅱ全相合;术后第30天PCR－STR表达供、受者双方基因型,第60天完全转变为供者基因型,而自身的基因在外周血中消失,预后良好。③12例中1例为持续未植入,HLA半相合同胞捐髓,术后虽然有血液学和临床情况的改善,但移植后7,14,21天STR分析始终仅显示受者基因型,移植后4个月死亡。结论 基于分子水平的移位点PCR－STR分析是骨髓移植后供者植入的精确标志。研究表明,PCR－STR植入分析的准确性优于任何传统技术,对移植效果有预警作用。     

Evaluation of chimerism in DNA samples by PCR amplification of D1S80 with detection by capillary electrophoresis.

BACKGROUND: Analysis of the relative amounts of donor and recipient DNA in bone marrow after bone marrow transplantation is frequently used to determine the status of the transplant. We studied the performance of an assay to quantify chimerism based on amplification of the D1S80 variable number tandem repeat marker by PCR with detection of PCR products by capillary electrophoresis (CE). METHODS AND RESULTS: Samples from potential bone marrow donors and recipients were analyzed separately and in mixtures to simulate various degrees of chimerism from 10% to 90% and subjected to PCR/CE analysis. There was excellent agreement between the measured and known relative proportions of DNA components in chimeric samples. The lower limit of sensitivity for detection of chimerism was 1%; between-runs coefficients of variation were <5%. CONCLUSIONS: Amplification of the D1S80 minisatellite by PCR with CE detection is a reliable method for determination of the relative contribution of different DNAs in mixed samples. This method is fast, quantitative, and extremely reproducible.     

适合移植后嵌合物定量分析的信息STR位点谱的建立及其应用

本研究选取8个STR位点作为嵌合物定量分析的信息STR位点谱,评估其作为异基因造血干细胞移植（HSCT）后移植物嵌合状态的定量监控指标的作用。采集15对移植供受者血样,提取DNA,分别合成标记D3S3045、D4S2366、D4S2639、D5S818、D13S317、D18S1002、D20S481、D22S689的引物,建立PCR扩增体系,在ABI3100仪上检测这些位点的扩增片段．筛选得到理想的信息位点;制备梯度供者／受者DNA混合品和移植后不同日期采集的标本,进行信息位点的检测;获取峰高或峰面积进行移植嵌舍率的计算。结果显示,根据梯度混合DNA的结果获得标准曲线,计算得到的嵌合率和配制浓度中的嵌合比例基本一致;用峰高和峰面积同时计算,两者基本一致;成功获得了15例移植后病人的嵌舍状态变化数据,并帮助诊断了1例复发病人。结论：本研究建立的信息STR位点谱及检测方法,可以较准确地定量监控嵌合状态,成功用于临床干细胞移植工作,与商品化试剂相比,更便宜,在使用上更灵活。     

Symmetric vs asymmetric PCR and molecular beacon probe in the detection of a target gene of adenovirus

A DNA fragment (307 bp) from the conserved region of an adenovirus gene (hexon) was amplified by symmetric and by asymmetric polymerase chain reaction (PCR). Two amplifications, one in the absence other in the presence of a molecular beacon probe were conducted by both symmetric and asymmetric PCR. The probe sequence was complementary to an internal segment of the amplified fragment. The product amplified in the absence and presence of the probe was detected by agarose gel and fluorescence analysis, respectively. A symmetric PCR results in exponentially grown double stranded DNA. An asymmetric PCR generates one of the strands by linear ampIlification and a fraction of its total product as double-stranded DNA limited by the concentration ratio of the primers used. Thus asymmetric PCR provided lower intensity signal hence less sensitivity than symmetric PCR by agarose gel analysis as expected. However, signal from a beacon probe based PCR assay is generated only from the probe fraction that hybridizes successfully competing against the strand complementary to the target strand of the product generated by PCR. The symmetric PCR has so far been used for the molecular beacon based fluorescent signal detection. The present study compared the level of fluorescent signal detectable from a symmetric PCR with that from an asymmetric PCR. The fluorescent data analysis demonstrated that a significant higher level of fluorescent signal hence higher sensitivity of detection is obtainable using asymmetric PCR than symmetric PCR performed in presence of the molecular beacon probe.