Cytoplasmic Expression of CD3ε Heterodimers by Flow Cytometry Rapidly Distinguishes Between Mature T-Cell and Natural Killer–Cell Neoplasms. Issue 5 (26th June 2020)

• Record Type: Journal Article
• Authors: Shi, Min; Nguyen, Phuong; Timm, Michael M; Otteson, Gregory E; Horna, Pedro; Olteanu, Horatiu; Jevremovic, Dragan
• Is Part Of: American journal of clinical pathology. Volume 154:Issue 5(2020)
• Page Start: 683
• Page End: 691
• Publication Date: 2020-06-26
• Subjects: Cytoplasmic CD3 -- T-cell neoplasm -- NK-cell neoplasm -- Flow cytometry; Diagnosis, Laboratory -- Periodicals; Pathology -- Periodicals; 616.07
• DOI: 10.1093/ajcp/aqaa086
• Languages: English
• ISSNs: 0002-9173

Abstract

Abstract: Objectives: Distinguishing between T-cell and natural killer (NK)–cell neoplasms could be difficult given their overlapping immunophenotype. In this study, we investigated whether a flow cytometry assay with cytoplasmic staining for CD3 could be used for this purpose. Methods: Flow cytometry immunophenotyping was performed on 19 surface CD3 (sCD3)–negative mature T-cell neoplasms, 10 sCD3-positive mature T-cell neoplasms, 13 mature NK-cell neoplasms, and 19 normal controls. In addition to routine antibody panels (CD2, sCD3, CD4, CD5, CD7, CD8, CD16, CD45, CD56, CD57, CD94, CD158a, CD158b, CD158e, NKG2A TCRγ/δ), cytoplasmic staining for a monoclonal CD3 antibody (clone SK7/Leu-4) was assessed in all cases. A molecular study for T-cell receptor ( TCR ) gene rearrangement and an immunohistochemical study for TCRβ were performed. Results: Our data showed all T-cell neoplasms were uniformly positive for cytoplasmic CD3 (cCD3) regardless of sCD3 expression, whereas 85% of NK-cell neoplasms completely lacked cCD3 expression. The 2 cases with classic NK-cell immunophenotype but partial cCD3 expression showed no molecular genetic features of T-cell lineage by TCR gene rearrangement studies. Conclusions: Uniform cCD3 positivity and homogeneous cCD3 negativity highly suggest T-cell and NK lineage, respectively. When partial cCD3 expression is encountered, additional confirmatory studies should be pursued for the most accurate lineage assignment.