Delta neutrophil index: could it predict mortality in patients with bacteraemia?

Despite advances in therapy, sepsis still has a high mortality rate. To improve the treatment outcome, early diagnosis and treatment is essential, as reflected in many publications about biomarkers for sepsis. Recent models of automatic cell analyzers provide the delta neutrophil index (DN), which corresponds to the fraction of immature granulocytes in circulating blood. This study investigated DN as a prognostic marker in patients with bacteraemia.

We retrospectively collected data on adult patients with bacteraemia admitted to an urban hospital between November 2009 and April 2010. The DN was measured at the onset of bacteraemia and at 24 and 72 h later. Factors associated with 28-day mortality were assessed using logistic regression.

A total of 102 patients were included in the analysis, and 24 patients died within 28 days. In the univariate analysis, appropriate antibiotic treatment, multidrug-resistant bacterial infection, history of intensive care unit (ICU) stay before the onset of bacteraemia, healthcare-associated infection, DN at 72 h after the onset of bacteraemia (DN-72 h), and platelet count at the onset of bacteraemia were significantly associated with survival. In multivariate analysis, DN-72 h (odds ratio (OR) 1.246, 95% confidence interval (CI) 1.030-1.508; p = 0.023), platelet count at the onset of bacteraemia (OR 0.986, 95% CI 0.977-0.995; p = 0.003), and history of ICU stay before the onset of bacteraemia (OR 4.907, 95% CI 1.045-23.051; p = 0.044) were the independent factors associated with survival.

DN at 72 h after bacteraemia may be valuable to assess the prognosis of patients with bacteraemia.