Low-density neutrophils and myeloid-derived suppressor cell subsets as immune indicators of early diagnosis and prognosis in patients with sepsis

Abstract

Abstract Background: Immunosuppression is a leading cause of septic death. Therefore, it is necessary to search for biomarkers that can evaluate the immune status of patients with sepsis. We assessed the diagnostic and prognostic value of low-density neutrophils (LDNs) and myeloid-derived suppressor cells (MDSCs) subsets in the peripheral blood mononuclear cells (PBMCs) of patients with sepsis. Methods: LDNs and MDSCs subsets were compared among 52 inpatients with sepsis, 33 inpatients with infection, and 32 healthy controls to investigate their potential as immune indicators of sepsis. The percentages of LDNs, monocytic MDSCs (M-MDSCs), and polymorphonuclear MDSCs (PMN-MDSCs) in PBMCs were analyzed. Sequential organ failure assessment (SOFA) scores, C-reactive protein (CRP), and procalcitonin (PCT) levels were measured concurrently. Results: The percentages of LDNs and MDSCs subsets were significantly increased in the healthy controls, infection, and sepsis groups. MDSCs performed similarly to CRP and PCT in the diagnosis of infection or sepsis. LDNs and MDSCs subsets significantly correlated with PCT and CRP levels and showed an upward trend with the number of dysfunctional organs and SOFA score. Non-survivors had elevated M-MDSCs compared with that of patients who survived sepsis within 28 days after enrollment. Conclusions: LDNs and MDSCs subsets were promising diagnostic biomarkers in infection and sepsis, even in distinguishing sepsis from infection. M-MDSCs are potential prognostic biomarkers of sepsis and can be used to predict 28-day hospital mortality in patients with sepsis.