Department of Hematopathology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
J Clin Pathol. 2010 Feb;63(2):141-6. doi: 10.1136/jcp.2009.069336.
T cell large granular lymphocytes (T-LGLs) are commonly increased in reactive conditions as well as T-LGL leukaemia. This differential diagnosis often requires a combined assessment of clonality and tumour burden. In this study we assessed the utility of flow cytometric (FC) analysis of T cell receptor beta chain variable region (TCR-Vbeta) expression by using 24 antibodies reactive to 70% of the TCR-Vbeta repertoire.
Analyses were performed on peripheral blood samples obtained from 20 patients with a confirmed diagnosis of T-LGL leukaemia and 18 patients without known T cell lymphoproliferative diseases.
The results were compared with TCR gene rearrangement status assessed by PCR. By FC analysis, 19/20 T-LGL leukaemia cases were CD3+CD8+ and one case was CD3+CD4+. All the cases demonstrated at least one immunophenotypic aberration, with altered CD5 expression being most frequent. Abnormal Vbeta expression was detected by FC in 19 of 20 (95%) T-LGL leukaemia cases, but in none of the controls; this showed 100% concordance with TCR gene rearrangement studies. In addition to establishing clonality, FC Vbeta analysis enables calculation of absolute numbers of clonal T cells; this is important in monitoring tumour burden after treatment.
It is concluded that FC Vbeta analysis is a fast, reliable and quantitative method that can simultaneously assess T-LGL leukaemia clonality and tumour burden.
T 细胞大颗粒淋巴细胞（T-LGL）在反应性疾病以及 T-LGL 白血病中通常会增加。这种鉴别诊断通常需要对克隆性和肿瘤负担进行综合评估。在这项研究中，我们评估了使用针对 TCR-Vβ 库 70%的反应性的 24 种抗体进行 T 细胞受体β链可变区（TCR-Vβ）表达流式细胞术（FC）分析的效用。
对 20 例经证实的 T-LGL 白血病患者和 18 例无已知 T 细胞淋巴增生性疾病的患者的外周血样本进行了分析。
将结果与通过 PCR 评估的 TCR 基因重排状态进行了比较。通过 FC 分析，20 例 T-LGL 白血病病例中有 19 例为 CD3+CD8+，1 例为 CD3+CD4+。所有病例均表现出至少一种免疫表型异常，最常见的是 CD5 表达异常。FC 在 20 例 T-LGL 白血病病例中的 19 例（95%）中检测到异常的 Vβ 表达，但在对照组中均未检测到；这与 TCR 基因重排研究具有 100%的一致性。除了确定克隆性外，FC Vβ 分析还可以计算克隆 T 细胞的绝对数量；这对于治疗后监测肿瘤负担非常重要。
综上所述，FC Vβ 分析是一种快速、可靠且定量的方法，可同时评估 T-LGL 白血病的克隆性和肿瘤负担。
