Diagnostic and Prognostic values of delta neutrophil index in patients with sepsis

Abstract

Background: A reproducible measurement of immature granulocytes might be a useful parameter to predict the presence of sepsis. Delta neutrophil index (DN) is the immature granulocyte fraction provided by a blood cell analyzer (ADVIA 2120; Siemens Healthcare Diagnostics, IL), which is determined by subtracting the fraction of mature polymorphonuclear leukocytes from the sum of myeloperoxidase (MPO)-reactive cells. The purpose of this study is to define the role of DN in differential diagnosis and predicting prognosis of patients with systemic inflammatory response syndrome (SIRS), sepsis, and severe sepsis.Methods: Hospital records of 273 patients were retrospectively collected: 47 with SIRS (SIRS group), 78 with sepsis (sepsis group), 51 with severe sepsis (severe sepsis group), and 97 controls (control group). DN and C-reactive protein (CRP) data on the day of the first blood culture were compared among the groups and 28-day mortality associated with sepsis was assessed.Results: Median values of DN were 0.0% (interqurtile range [IQR], 0.0-0.0) in the control group, 0.8% (0.0-1.7) in the SIRS group, 3.4% (1.5-5.3) in the sepsis group, and 18.6% (9.3-24.7) in the severe sepsis group. Furthermore, there were significant differences among the groups. The receiver operating characteristic curves showed that DN was a better predictor of sepsis than CRP. The best cut-off value for DN for predicting sepsis was 2.7%. DN was significantly higher in those who died than in the survivors (median [IQR]: 11.5% [3.5-25.0] vs 4.7% [2.2-10.6], p=0.008) and was identified to be an independent predictor for 28-day mortality in patients with sepsis by the Cox proportional hazards model.Conclusions: These data indicate that DN may serve as a facile and useful marker for early diagnosis and prognostic assessment of patients with sepsis as it is included in a routine complete blood count. Daily monitoring of DN may be helpful in the follow-up of patients with suspected sepsis