Single Antibody Detection of T-Cell Receptor αβ Clonality by Flow Cytometry Rapidly Identifies Mature T-Cell Neoplasms and Monotypic Small CD8-Positive Subsets of Uncertain Significance

Min Shi, Dragan Jevremovic, Gregory E. Otteson, Michael M. Timm, Horatiu Olteanu, Pedro Horna

Research output: Contribution to journalArticle

Abstract

Background: The diagnosis of T-cell neoplasms is often challenging, due to overlapping features with reactive T-cells and limitations of currently available T-cell clonality assays. The description of an antibody specific for one of two mutually exclusive T-cell receptor (TCR) β-chain constant regions (TRBC1) provide an opportunity to facilitate the detection of clonal TCRαβ T-cells based on TRBC-restriction. Methods: Twenty patients with mature T-cell neoplasms and 44 patients without evidence of T-cell neoplasia were studied. Peripheral blood (51), bone marrow (10), and lymph node (3) specimens were evaluated by 9-color flow cytometry including TRBC1 (CD2/CD3/CD4/CD5/CD7/CD8/CD45/TCRγδ/TRBC1 and/or CD2/CD3/CD4/CD5/CD7/CD8/CD26/CD45/TRBC1). Monophasic TRBC1 expression on any immunophenotypically distinct CD4-positive or CD8-positive/TCRγδ-negative T-cell subset was considered indicative of clonality. Results: Monophasic (clonal) TRBC1 expression was identified on immunophenotypically abnormal T-cells from all 20 patients with T-cell malignancies (100% sensitivity), including 17 cases with either >97% or <3% TRBC1-positive events, and three cases with monophasic homogenous TRBC1-dim expression. All immunophenotypically distinct CD4-positive and CD8-positive/TCRγδ-negative T-cell subsets from 44 patients without T-cell malignancies showed the expected mixture of TRBC1-positive and TRBC-1-negative subpopulations (non-clonal), except for seven patients (16%) with very small CD8-positive T-cell subsets exhibiting a monophasic (clonal) pattern. Conclusion: Inclusion of a single anti-TRBC1 antibody into a diagnostic T-cell flow cytometry panel facilitates the rapid identification of T-cell neoplasms, in addition to small monotypic CD8-positive subsets of uncertain significance.

Original languageEnglish (US)
JournalCytometry Part B - Clinical Cytometry
DOIs
StatePublished - Jan 1 2019

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Keywords

  • flow cytometry
  • T-cell clonality
  • TRBC1

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Histology
  • Cell Biology

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