Investigation of CD4+CD25+FoxP3+PD-1+ Regulatory T-cells and PD-1, PD-L1 mRNA Expression in the Bone Marrow in Newly Diagnosed Multiple Myeloma Patients

Multiple myeloma (MM) is a cancer that plasma cells. Increased regulatory T-cells (Tregs) have been associated with poor clinical outcomes in both newly diagnosed and treated MM patients. Treg cells are a T-cell subgroup that suppresses immune response. Programmed cell death protein 1 (PD-1) signaling pathway plays an essential role in Treg function and development. In literature, there is insufficient knowledge about the distribution of Treg cells in the bone marrow microenvironment despite the presence of these clinical studies in MM. In this study, we aimed to investigate PD-1+ Treg cell distribution and PD-1/PD-ligand 1 (PD-L1) gene expression levels in MM patients' bone marrow.