Non-malignant T-cells lacking multiple pan-T markers can be found in lymph nodes

Abstract

In order to observe and ascertain the properties of a sub-group of T cells in the lymph node (LN) from seven patients who did not suffer from T cell lymphoproliferative disorders (T-LPDs), the expression levels of several pan-T markers were evaluated by multiparameter flow cytometry (FC) and the clonality of these T-cells was evaluated by both FC analysis and PCR assessment. It turned out that multiple pan-T-cell markers such as CD2, CD5 and CD7 were found to be lost in these T cells. The majority of them were positive for TCRαβ, only a minority of them being positive for TCRγδ. A subset of these T-cells were positive for CD4 or CD8 or dual-negative for CD4 and CD8. Oligoclonality was detected in one case by FC, while clonal TCR rearrangement was detected in three cases. Absence of multiple pan-T-cell markers could be found in benign T cells in LNs.

Gamma-Delta T-Cell Acute Lymphoblastic Leukemia/Lymphoma: Immunophenotype of Three Adult Cases

“…A total of 5 × 10 5 nucleated cells per tube were incubated with 0.1% bovine serum albumin solution and then stained with monoclonal antibodies (mAbs). Samples were stained as described before [5]. All samples were detected by BD FACSCalibur and analyzed by Cell Quest (all are from BD).…”

Normal or reactive minor cell populations in bone marrow and peripheral blood mimic minimal residual leukemia by flow cytometry

“…Reactive T cells with loss of one or more pan‐T‐cell antigens are always a concern for T‐cell neoplasm, and these cells could be T‐ALL MRD mimickers. CD2− T cells (Loza et al, 2005; Loza & Perussia, 2002; Wang et al, 2018) are commonly seen in most BM and PB samples. They usually form a well‐separated cluster and could be an MRD mimicker for CD2− T‐ALL cases.…”

“…CD7 is present in most T‐ALL cases. In rare CD7− cases, reactive CD7− T cells (Park et al, 2019; Reinhold, Liu, Sesterhenn, & Abken, 1996; Wang et al, 2018) could be an MRD mimicker. These CD7− T cells were present in almost all the BM and PB specimens we studied.…”

“…They are mostly CD4+ with a smeared CD7 expression pattern, not separated from CD7+ T cell population, and no other aberrancy; these features make them easily recognizable. Reactive CD5 dim or negative T cell populations also exist (Park et al, 2019; Wang et al, 2018). A small proportion of gamma delta T cells that lack CD5 but show expression of CD16, (Roden, Morice, & Hanson, 2008) can seem to be quite abnormal.…”