TCR基因重排检测在T细胞淋巴瘤病理诊断中的作用

基因重排现象是每个淋巴细胞在早期经历的一个正常的过程,由于机体每个淋巴细胞的重排基因都是特有的,使每个淋巴细胞都有独特的重排形式。如若机体在某些致瘤因素的作用下失去对某个基因重排细胞的控制,则该细胞就会出现无控制的、单克隆性增生,最终导致淋巴瘤的形成。所以淋巴瘤所具有的是单克隆性重排。因此通过聚合酶链反应（polymerase chain reaction,PCR）技术进行T细胞抗原受体（T cell receptor,TCR）基因克隆性重排分析,尤其在常规HE形态学与免疫组化结果都不能确诊时,显得尤为重要。该文对其在T细胞淋巴瘤病理诊断中的作用作一综述。     

外周血T细胞淋巴瘤的TCR基因分析

外周血Ｔ细胞淋巴瘤的ＴＣＲ基因分析唐恩洁Ｅ．ＨｏｄｇｅｓＪｏｈｎＬ．Ｓｍｉｔｈ外周血Ｔ细胞淋巴瘤（ｐｅｒｉｐｈｅｒａｌＴ－ｃｅｌｌｙｍ－ｐｈｏｍａ，ＰＴＣＬ）是高度异质性的免疫系统恶性肿瘤。因其组织学特征多样性和免疫表型易变性，故难于用形态学和免疫学...     

中线T细胞淋巴瘤的TCR—γ基因重排研究

目的对中线Ｔ细胞淋巴瘤的克隆性进行研究。方法用一组针对Ｔ细胞受体γ链基因Ｖ区片段的家族特异性引物和ＰＣＲ方法,对１１例（２２个标本）中线Ｔ细胞淋巴瘤病例进行了Ｔ细胞受体γ基因重排的检测。结果２２个标本中２１个有Ｔ细胞受体γ链基因的克隆性重排（９４４５％）。在９例原发灶的连续活检和１例原发灶及其转移灶的标本中均未发现增生的克隆家族的改变。结论中线Ｔ细胞淋巴瘤的病变组织中存在Ｔ细胞的单克隆性增生,为该肿瘤的Ｔ细胞起源提供了分子生物学的证据。在中线Ｔ细胞淋巴瘤的疾病过程中（包括转移灶）增生Ｔ细胞的家族未发生变化,支持肿瘤的单克隆起源学说     

BIOMED-2标准化IG/TCR基因重排克隆性分析系统在原发性中枢神经系统淋巴瘤诊断中的应用

目的探讨BIOMED-2标准化基因重排克隆性分析系统对原发性中枢神经系统淋巴瘤(primary central nervous system lymphoma,PCNSL)的检出率及应用价值。方法采用BIOMED-2系统引物对29例PCNSL、10例淋巴结反应性增生病变,进行Ig/TCR基因重排的克隆性分析。结果 29例PCNSL中,BIOMED-2系统引物组合检测出27例克隆性重排,其中Ig克隆性重排26例(B细胞性淋巴瘤),另1例检测出TCR克隆性重排(T细胞性淋巴瘤),检出率为93.1%,10例淋巴结反应性增生病变均未见克隆性重排,其检测特异性为100%。结论 PCNSL是一种少见的高侵袭性结外非霍奇金淋巴瘤,利用BIOMED-2系统的Ig/TCR基因重排分析系统可对PCNSL的定性及分类提供客观性手段。     

BIOMED-2系统引物用于检测T细胞淋巴瘤石蜡样本T细胞受体γ基因重排的研究

目的 了解BIOMED-2系统T细胞受体(TCR)γ引物组合对T细胞淋巴瘤的常规石蜡包埋组织样本中TCR基因重排的检出情况及其实用性.方法 用酚/氯仿法提取55例各种组织类型的T细胞淋巴瘤石蜡包埋组织样本的DNA并通过扩增看家基因β-globin检测其质量,利用BIOMED-2系统TCR-γ引物组合和TCR-γ基因通用型引物(TVG/TJX)对55例进行TCR基因重排检测,比较二者的检出率并进行统计学分析.结果 BIOMED-2系统TCR-γ引物组合和TCRγ基因通用型引物(TVG/TJX)的TCR基因重排检出率分别为76.4%和60.0%,前者高于后者,二者的差异无统计学意义(P>0.05).结论 BIOMED-2系统TCRγ引物组合适用于本组T细胞淋巴瘤石蜡包埋组织样本的TCR基因重排检测.     

非霍奇金淋巴瘤的IgH和TCRδ基因重排

目的：探讨非霍奇金淋巴瘤（NHL）免疫球蛋白重链（IgH）和T细胞受体δ链（TCRδ）基因重排情况。方法：用半重叠式聚合酶链反应（PCR）方法检测IgH及TCRδ基因重排。结果：57例NHL中41例（72％）发生IgH基因重排，30例（53％）出现TCRδ基因重排。结论：检测克隆性基因重排可以作为诊断NHL有效基因标志，NHL中存在系列不忠实现象。     

正常人T细胞和胸腺细胞中多种新的TCRδRec基因重排

利用巢式或半巢式PCR扩增10例正常人外周血单个核细胞(PBMC)、4例分选CD3~+细胞和7例正常胸腺细胞DNA中TCR δRec区与Jδ1、Dδ3和Ja重排的基因片段,分析正常人外周血T细胞和胸腺细胞中TCR δRec基因重排情况。克隆性PCR产物进一步进行核苷酸序列分析确定其重排位置。结果发现了4种新的TCR δRec重排,包括TCR δRec_(149321)-Jδ1、TCRδRec_(149820)-Jδ1、TCR δRec_(151657)(Nx)-Ja和TCR δRec_(153199)-Jδ1等,其中以TCR δNx的重排最多见,通过利用不同模板DNA的PCR分析发现δRec重排在外周血和胸腺细胞中有所不同。结果显示TCR δNx-Jδ1重排在成熟和不成熟T细胞发生频率均较高,而TCR δNx-Dδ3重排在不成熟T细胞中发生率较高。但所有重排均不表达于mRNA中。本研究结果为TCR δ基因重排的研究补充了一些新的数据。     

利用Fine-tiling aCGH分析TCR基因重排鉴定T细胞白血病克隆

目的:建立基于分析T细胞受体(TCR)基因重排而确定T细胞-急性淋巴细胞白血病(T-ALL)克隆的新方法,为研究T-ALL中涉及TCR基因位点的染色体易位提供基础。方法:提取1例T-ALL患者外周血单个核细胞(PBMC)的总DNA,利用精细定位的寡核苷酸阵列比较基因组杂交(fine-tiling aCGH)分析样本与对照组基因组DNA的差异,了解不同染色体上可能的断裂点和具体的位点,根据所提供的初步结果,从断裂点涉及的基因序列设计特异引物,采用连接介导PCR(LM-PCR)和序列分析等方法去找出与之发生重排的基因序列。并进一步通过RT-PCR检测TCR基因表达。结果:该例T-ALL患者fine-tiling aCGH结果显示14染色体TCRα/δ基因座出现4个断裂点,分别对应TCR Vδ1、Vδ2、Jδ1和Jδ2基因位点。通过LM-PCR、测序及序列分析,该例T-ALL患者的PBMC中TCR基因涉及Vδ1Dδ2Dδ3 Jδ1、Vδ2Dδ3 Jδ2重排。RT-PCR的结果也验证T-ALL表达该TCR基因重排。结论:结果表明,利用fine-tiling aCGH及LM-PCR技术可以找出TCR基因重排,并且该方法是可靠的,也是发现一些涉及TCR位点的融合基因的一条途径。     

PCR技术检测IgH和TCRγ基因重排及其在淋巴瘤诊断中的初步应用

应用半重叠ＰＣＲ扩增ＩｇＨ、混合引物ＰＣＲ增ＴＣＲγ基因重排片段，并初步用于淋巴瘤的诊断，发现７７％的Ｂ细胞性非何杰金淋巴瘤出现ＩｇＨ基因重排的单克隆条带，９１％的Ｔ细胞性非何杰金淋巴瘤出现ＴＣＲγ基因重排条带。提示ＰＲＣ对鉴定淋巴细胞增生的克隆性和细胞源性具有重要价值。与Ｓｏｕｔｈｅｒｎ印迹杂交相比，ＰＣＲ具有简便，快速等特点，更具有临床实用性。     

TCRαβ基因结构与重排

ＴＣＲαβ基因是由Ｖ，（Ｄ），Ｊ，Ｃ等不同基因片段组成的，α和β链编码基因在结构上各有其特点，ＴＣＲαβ基因的重排与分子表达是在胸腺内完成的，这一过程受等位基排斥等机制的严格调控，从而确保了Ｔ细胞只能产生来自一个等位基因重排编码的克隆特异的αβＴＣＲ分子。     

Ig/TCR基因重排分析联合EBER原位杂交检测在原发性胃肠道淋巴瘤诊断中的应用

目的 探讨Ig/TCR基因重排分析联合EBER原位杂交检测在原发性胃肠道淋巴瘤(gastrointestinal lymphomas,GIL)中的诊断价值.方法 选取常规石蜡包埋的GIL病理标本35例(包括成熟B淋巴细胞肿瘤29例,成熟T淋巴细胞和NK细胞肿瘤6例),淋巴结反应性增生病变10例,提取DNA,应用BIOMED-2引物系统进行Ig/TCR基因重排的克隆性分析,并采用原位杂交方法检测EB病毒编码的小RNA(EBER).结果 35例GIL中,共检测出34例克隆性重排.其中29例成熟B细胞淋巴瘤均扩增出Ig克隆性重排,敏感性为100%,且联合应用IgH与IgK引物Ig单克隆性重排的检出率最高;6例成熟T淋巴细胞和NK细胞肿瘤中5例扩增出TCR克隆性重排,敏感性为83.3%;10例淋巴结反应性增生病例均未检测到Ig及TCR克隆性重排条带,其检测特异性为100%.29例成熟B细胞淋巴瘤及10例淋巴结反应性增生组织经EBER原位杂交检测均为阴性,6例成熟T淋巴细胞和NK细胞肿瘤中2例EBER原位杂交检测阳性,且均为鼻型NK/T细胞淋巴瘤.结论 BIOMED-2标准化的基因重排分析系统检测石蜡包埋组织中Ig基因和TCR基因克隆性重排的敏感性和特异性均很高,对GIL的诊断和鉴别诊断具有重要的临床应用价值,EBER原位杂交检测对基因克隆性重排阴性的淋巴瘤也具有一定的辅助诊断作用.     

Gene rearrangements in T-cell lymphoblastic lymphoma

This study presents an examination of the Ig heavy chain (IgH) and T-cell receptor gamma (TCRγ) genes in a series of 39 CD3-positive T-cell acute lymphoblastic leukaemia (ALL) cases with and without co-expression of CD79a; 30/39 cases had a rearrangement of the TCRγ genes and two of these 30 cases also demonstrated an IgH rearrangement. No cases had solely an IgH rearrangement. The conclusion of the study is that lymphoblastic lymphoma cases that are positive for CD3 are of T-cell lineage, regardless of CD79a expression. Copyright © 1999 John Wiley & Sons, Ltd.     

T-cell receptor variable (V) gene usage by lymphoid populations in T-cell lymphoma.

A panel of monoclonal antibodies specific for TcR V gene families was used to study TcR V region expression in 28 cases of malignant and reactive T-cell expansions including four cases of mixed cellularity Hodgkin's disease (HD) and five reactive cases. TcR V beta 5 gene products were represented in three cases of lymphoblastic malignancy (V beta 5.1, V beta 5.2) and two cases of peripheral T-cell lymphoma (PTCL) (V beta 5.1). In the PTCL cases, the expanded family was found in the absence of clonal TcR gene rearrangements and in one of these cases with Ig JH and Ck clonal gene rearrangements consistent with the presence of a phenotypically and histologically undetectable clonal B-cell population. In a third PTCL case not investigated for genotype, the TCR V alpha 12 family was overrepresented. Expanded TcR V alpha 2 and V beta 5.1 families were identified in HD and V beta 8 and V beta 5.2/V beta 5.3 families in a reactive lymph node and CD3 and CD8-positive blood lymphocytosis respectively. Further study of PTCL and related entities are needed to establish whether expanded TcR families are common in those cases that fail to exhibit clonal TcR gene rearrangement.     

Real-time PCR method for the quantitative analysis of human T-cell receptor gamma and beta gene rearrangements

Analyzing the status of T-cell receptor (TCR) gene rearrangements has been an essential part of deciphering the stages of thymocyte development, understanding the β vs. γδ lineage decision, and characterizing T-cell leukemias. Methods such as PCR and quantitative Southern blotting provide useful information, but also have significant shortcomings such as lack of quantitation in the case of PCR and technical challenges in the case of Southern blotting. Here we describe a real-time PCR method that overcomes many of these shortcomings. This new method shows comparable results for the fraction of unrearranged TCRγ and TCRβ genes in human thymocytes and peripheral blood T cells as Southern blotting, and has the advantages of being simple to perform, highly quantitative, and requiring nanogram quantities of DNA. We also describe a real-time PCR method to quantitate T-cell receptor excision circles formed during TCRβ rearrangements.     

Recombination pattern of the TCR γ locus in human peripheral T-cell lymphomas

The recombination events of the γ and β T-cell receptor (TCR) loci were analysed in a series of 39 peripheral T-cell lymphomas (PTCLs) in association with the expression of TCR chains. In TCR αβ PTCLs, 22/23 cases showed a γ-gene rearrangement while only 18/23 showed a concomitant β-gene rearrangement. The germline configuration of the β locus was found in angioimmunoblastic lymphadenopathy and lymphoepithelioid lymphomas. Three γδ PTCLs rearranged both γ and β genes. TCR silent PTCLs showed three different patterns of γ- and β-gene rearrangements. Three cases were in germline configuration for both loci; five cases had a rearranged γ and a germline β locus; and five cases had the two loci rearranged. Regarding the variable genes in the γ-rearranged alleles, members of the VγI subgroup were the most frequently presented (39/50), followed by VγII, VγIII, and VγIV (9/50, 1/50, and 1/50, respectively). Joining segment usage was as follows: J1 or J2 (32/50), JP1 or JP2 (17/50), and JP (1/50). Taken together, these data demonstrate that the γ locus is more frequently rearranged whatever the TCR expression. The γ-locus analysis provides a better diagnostic yield than the β locus in the study of PTCL clonality.     

Frequent detection of Epstein–Barr virus-infected B cells in peripheral T-cell lymphomas

Although Epstein–Barr virus (EBV) positivity has been described in peripheral T-cell lymphomas (PTCLs) in Chinese patients, the cellular lineage of EBV-harbouring cells is unknown. Forty-four cases of PTCL were therefore studied by in situhybridization (ISH) for EBV-encoded small non-polyadenylated RNA 1 and 2 (EBER), and the lineage of the EBER+ cells was determined by double labelling. The findings were further correlated with the clonality of EBV and the genotype of these EBER+ tumours. The results for the detection of EBV by ISH show that 23 of the 44 cases were EBER+. In 5/23 of the EBER+ cases, EBER was found in around 50 per cent of atypical cells and in 18/23 cases, EBER was found in a subpopulation of atypical cells. Amongst the EBER+ cases, all 15 tested showed clonal T-cell receptor gene rearrangement by Southern blot hybridization. Double labelling was successfully done in 11 EBER+ cases, and by comparison, EBER+/CD20+ B cells outnumbered the EBER+/CD3+ T cells in all these cases. EBV clonality analysis revealed that EBV was monoclonal in six EBER+ cases and biclonal in three cases. With the predominance of EBV+ B cells over EBV+ neoplastic T cells being observed in most of these cases, it is possible that the EBV-infected clonal population may be of B-cell lineage. This was supported in some cases where a faint clonal band was seen over a background smear in the gene rearrangement study of immunoglobulin heavy chain gene by polymerase chain reaction (PCR), indicating a minor B-cell clone. It is concluded that in EBV+ PTCL, EBV is preferentially localized in B cells rather than neoplastic T cells. The neoplastic T cells may support the clonal proliferation of a subpopulation of EBV+ B cells in PTCLs. © 1998 John Wiley & Sons, Ltd.     

Angioimmunoblastic T-cell lymphoma with dual genotype of TCR and IgH genes

A 70-year-old man complained of fever and sore throat accompanied by hoarseness of voice. On physical examination, there was no systemic abnormality but a mild lymphadenopathy of cervical lymph nodes. With laryngoscopy, there was a marked outgrowth of the bilateral palatine tonsils proximal to the vocal cord. The histology of the resected tumor was compatible with angioimmunoblastic T cell lymphoma (AITL), revealing the effacement of normal tonsillar architecture and small to medium-sized neoplastic cell proliferation around marked vascular proliferation and atrophic lymphoid follicles. Tumor cells were positive for conventional T-cell antigens as well as for the follicular helper T-cell marker, PD-1, and CXCL13. Large hodgkinoid cells, but no tumor cells, were positive for latent membrane protein-1 and Epstein-Barr virus-encoded small RNA (EBER)-1 (in situ hybridization). Non-neoplastic, double positive cells for EBER-1 and CD20 were also scattered. Southern blot analysis revealed dual TCR-Cβ1 and IGH-JH gene rearrangements. Although the swelling of bilateral inguinal and perigastric lymph nodes developed later, the radical resection of tumor and chemotherapy appeared to be effective for the treatment of AITL with clinical stage IIIa. We here report a rare case of AITL involving palatine tonsil as primary site and give a review of the literature.     

T-cell lymphomas in adults: a clinicopathological study of eighteen cases

Eighteen cases of adult T-cell lymphoma have been studied with respect to clinical presentation, response to treatment, histology, enzyme histochemistry, immunocytochemistry, and gene rearrangement. Seven cases (39 per cent) presented at extra-nodal sites, and the age range was from 18 to 79. Treatment was with combination chemotherapy in most cases, and 11 of the 18 patients died within the three year follow-up period. The lymphomas were classified morphologically into six types; T-lymphoblastic lymphoma (TLL), angioimmunoblastic lymphadenopathy (AIL)-like T-cell lymphoma, T-zone lymphoma, pleomorphic mixed medium and large cell T-cell lymphoma (PMMLC), pleomorphic large cell T-cell lymphoma (PLC), and monomorphic large cell T-cell lymphoma (MLC). Enzyme histochemistry was found to be of limited value in the identification of T-cell lymphomas. Immunocytochemistry showed a degree of correlation between the immunological profile and morphology, with cases in the PLC and MLC groups showing limited expression of T-cell antigens. Re-arrangement of the beta chain of the T-cell receptor gene was detected in 12 of the 14 cases studied, and all showed germ-line immunoglobulin genes. The study emphasizes the varied morphological and clinical appearances of adult T-cell lymphoma.