The correlation between T regulatory cells and autologous peripheral blood stem cell transplantation in multiple myeloma.
OBJECTIVE
Multiple myeloma (MM) is characterized by malignant proliferation of plasmocytes and their precursors. T regulatory cells (Tregs) have a role in immunosuppression and control of autoimmunity, and are currently an important topic in the study of immune response to tumor cells. The correlation between Tregs and autologous peripheral blood stem cell transplantation (APBSCT) in MM has not been studied. The aim of this study was to compare CD4+CD25+FOXP3+ Treg, CD200, and PD-1 levels in MM patients that did and did not undergo APBSCT.


METHODS
Peripheral blood samples were collected from 28 MM patients ranging in age from 41 to 78 years for analysis of CD4CD25+ FOXP3+ Tregs, PD-1 (CD279), and CD200. Peripheral blood mononuclear cells were isolated via density gradient centrifugation. Four-color flow cytometry was performed. Using a sequential gating strategy, Tregs were identified as CD4+CD25+FOXP3+ T-cells. Results were analyzed using the Mann Whitney U non-parametric test and a compare means test. p values <0.05 were considered statistically significant.


RESULTS
The study included 28 MM patients (10 female and 18 male). In all, 11 of the patients underwent APBSCT. The level of Tregs identified as CD4+CD25+FOXP3+ T-cells was higher in the patients that underwent APBSCT (p=0.042). CD200 and PD-1 levels did not significantly differ between the 2 groups (p=0.711 and p=0.404, respectively). There weren't any statistically significant differences in CD200, PD-1, or CD4+CD25+FOXP3+ T-cell levels between the patients that did and did not undergo APBSCT (p>0.05).


CONCLUSIONS
Treg levels were higher in the patients that underwent APBSCT. Tregs are crucial for the induction and maintenance of peripheral tolerance to self-antigens. In addition, Tregs can suppress immune responses to tumor antigens; however, APBSCT and Treg levels were not correlated with CD200 or PD-1 expression. Relationship of Tregs with prognosis needs to be determined by studies that include larger cohorts.
Department of Institute of Oncology, Faculty of Medicine, Dokuz Eylul University, İzmir, Turkey, Phone: +90 232 412 58 73 E-mail: pinarercetin@gmail.com.
Ayşe Pınar
AP
Erçetin
Safiye
S
Aktaş
Özden
Ö
Pişkin
Halil
H
Ateş
Zeynep Filiz
ZF
Zadeoğluları
Nur Hilal
NH
Turgut
Mehmet Ali
MA
Özcan