Aims 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 β chain variable region (TCR-Vβ) expression by using 24 antibodies reactive to 70% of the TCR-Vβ repertoire.
Methods 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.
Results 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 Vβ 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 Vβ analysis enables calculation of absolute numbers of clonal T cells; this is important in monitoring tumour burden after treatment.
Conclusions It is concluded that FC Vβ analysis is a fast, reliable and quantitative method that can simultaneously assess T-LGL leukaemia clonality and tumour burden.
Statistics from Altmetric.com
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.