Increase of CD4+CD25+FoxP3+Regulatory T Cells in Myeloma.

BACKGROUND

In the tumor microenvironment, regulatory T cells (Treg cells), a small subset of CD4+ T cells, can interrupt antitumor immune reactions by interacting with various other immune cells. The present study aimed to determine the expression level of Treg cells in myeloma compared with that in normal control.

METHODS

Peripheral blood samples from 90 healthy adults and marrow aspiration samples from 13 patients newly diagnosed with myeloma were collected. Eight-color flow cytometry was performed using a Duraclone IM Treg tube kit. A gating strategy was established based on immunophenotypic characteristics of Treg cells identified as CD3+CD4+CD25+FoxP3+CD39+Helios+ cells.

RESULTS

A 2.5-fold increase in Treg cells, based on the CD4+CD25+FoxP3+ combination, was confirmed in the ini-tial myeloma diagnosis compared with the normal control. Additionally, increased Treg cells had a weak positive correlation with urine M-protein levels (r = 0.619, p < 0.05).

CONCLUSIONS

Thus, an increase in Treg cells appears to potentially predict a worse complication of myeloma based on microenvironmental-related biomarkers.