The usefulness of neutrophil/lymphocyte count ratio in the diagnosis and prognosis of bacterial sepsis – An old parameter with new implications

Abstract

Aims: To analyze the diagnostic role of neutrophil/lymphocyte count ratio (NLCR) in sepsis and to evaluate its usefulness in appreciating the prognosis of septic patients.

Methods : A prospective analysis of patients diagnosed with sepsis between October 2015 and July 2017 was performed. A control group of patients with systemic inflammatory response syndrome (SIRS) with noninfectious causes was recruited. The sensitivity, specificity and AUC of NCLR for sepsis diagnosis were comparatively assessed with other biomarkers including fibrinogen (FIB), C-reactive protein (CRP) and procalcitonin (PCT). The baseline levels of NLCR were correlated with APACHE IV, APS and SOFA scores of severity.

Results : We enrolled 105 patients with sepsis and 37 patients with noninfectious SIRS. NLCR had significantly higher levels in the first group (p---lt---0.05). For an optimal cut-off value of 8.18, the sensitivity, specificity and AUC of NLCR for sepsis diagnosis were 70.5%, 72.2% and 0.766, respectively. A cut-off value of 12.0 led to moderate sensitivity (58.7%) and moderate-to-high specificity (89%). For patients with SOFA score over 2 points, the characteristics did not significantly improve. The correlations between baseline NCLR and the severity scores were not statistically significant.

Conclusion : NLCR levels were significantly higher in sepsis group compared to noninfectious SIRS group. NLCR had moderate sensitivity and specificity regarding sepsis diagnosis. Baseline levels of NLCR did not correlate with the severity scores, so its usefulness in sepsis prognosis was limited.