Elevated circulating myeloid-derived suppressor cells associated with poor prognosis in B-cell non-Hodgkin's lymphoma patients

Introduction: Myeloid-derived suppressor cells (MDSCs) are a heterogeneous cell population with the ability to suppress immune responses. MDSCs usually cluster in cancer, inflammation, and autoimmune diseases. Although there have been some studies on MDSCs in non-Hodgkin lymphoma (NHL), the correlation between the peripheral levels of MDSCs in patients with various subtypes of B cell NHL and clinical features and prognosis remains inconclusive. This study aimed at the issue. Methods: 101 patients with B cell NHL and 15 age-matched healthy controls were included in this study. Flow cytometric detection of monocytic-MDSCs (M-MDSCs) and granulocytic-MDSCs (G-MDSCs) was done. Results: In this study, we found that counts of circulating M-MDSCs and G-MDSCs were significantly increased in different clinical statuses of B-NHL patients compared to healthy controls. Similarly, a significant increase in the levels of M-MDSCs and G-MDSCs was found among the diverse types of B-NHL compared with healthy donors. Stratification studies indicated MDSCs expansion was closely associated with disease progression (tumor stage, LDH levels and B syndromes). Moreover, the overall survival time of patients with G-MDSCs (%) >= 98.70% was shorter than patients with G-MDSCs (%) < 98.70% in newly diagnosed B-NHL subgroup, meanwhile, there was a significant difference in survival of patients with M-MDSCs (%) >= 7.19% compared to patients with M-MDSCs (%) < 7.19% in relapsed B-NHL subgroup. Conclusion: Our results suggested that M-MDSCs and G-MDSCs may be a potential and efficient index to evaluate the prognosis of B-NHL patients.