Objectives: Multiple myeloma (MM) is a plasma cell malignancy that still remains incurable. Programmed cell death(PD)-1 and programmed cell death ligand (PDL-1) pathway are immune checkpoint molecules. They play a role in the immune escape of tumor cells. Methods: We measured serum soluble PD-1(sPD-1) and soluble PDL-1 (sPDL1) in 24 newly dignosed patients and 22 healthy controls (HC). Results: We determined significantly increased serum sPDL-1 levels in MM patients when compared to HC. Moreover, sPDL-1 levels correlated positively with a p53 positive mutation status, elevated lactate dehydrogenase, C-reactive protein, calcium levels and poor performance status. A significant difference is detected between sPDL-1 level and PFS; but not OS. The sPDL-1 cut-off value for predicting survival outcomes was 1.03 ng/mL that was detected median value in MM patients. Patients with high serum sPDL-1 level were associated with a significantly decreased progression free survival (p<0.045). Conclusion: We conclude that sPDL-1 level is a probable prognostic biomarker for a poor outcome in MM patients. PD-1/PDL-1 pathway blockage may be one of the new strategies for MM patients. However, there is still a need for future studies enrolling more patients in order to clarify the prognostic significance of PDL-1. Keywords: Immune checkpoint, multiple myeloma, programmed cell death (pd)-1, programmed cell death ligand (pdl-1), survival outcomes
Corresponding Author: Terzi Demirsoy E.