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

Area of Science:

• Immunology
• Cell Biology

Background:

• T cells are crucial immune cells residing in lymph nodes.
• T-cell lymphoproliferative disorders (T-LPDs) involve abnormal T-cell proliferation.
• Understanding normal T-cell properties is vital for distinguishing benign from malignant conditions.

Purpose of the Study:

• To investigate the characteristics of a T-cell subpopulation in lymph nodes of patients without T-LPDs.
• To evaluate the expression of pan-T cell markers and assess T-cell clonality in this subgroup.

Main Methods:

• Multiparameter flow cytometry (FC) was used to analyze pan-T cell marker expression (CD2, CD5, CD7).
• T-cell receptor (TCR) expression (TCRαβ, TCRγδ) and CD4/CD8 profiles were assessed via FC.
• T-cell clonality was evaluated using FC and Polymerase Chain Reaction (PCR) for TCR gene rearrangement.

Main Results:

• A significant loss of multiple pan-T cell markers (CD2, CD5, CD7) was observed in the studied T cells.
• The majority of these T cells expressed TCRαβ, with a minority expressing TCRγδ.
• Subsets exhibited CD4+, CD8+, or CD4-CD8- (double-negative) phenotypes.
• Oligoclonality was detected in one case by FC, and clonal TCR rearrangement was confirmed in three cases via PCR.

Conclusions:

• The absence of multiple pan-T cell markers can occur in benign T cells within lymph nodes.
• These findings highlight the importance of comprehensive marker analysis for accurate T-cell subset characterization and diagnosis.