Neutrophils to Lymphocyte Ratio: Earliest and Efficacious Markers of Sepsis

Abstract

Background Neutrophil to lymphocyte ratio (NLR) can be easily calculated from the white cell differential count and is considered an auspicious marker for predicting different diseases, including sepsis. In this study, we aimed to compare the efficacy of NLR as a sepsis marker by comparing it with other markers of sepsis, such as C-reactive protein (CRP), procalcitonin, and the Sequential Organ Failure Assessment (SOFA) score. Methods A cross-sectional analytical study was conducted at the Aga Khan University Hospital from July 2019 to December 2019. A total of 168 patients who were admitted to the medicine department with a diagnosis of sepsis on arrival or during the hospital stay were enrolled. The neutrophil to lymphocyte ratio was calculated to form venous samples taken on admission and compared to the level of CRP, procalcitonin, culture reports, and the SOFA score as a predictor of sepsis. Results Out of 168 patients, 55.3% were male. The median age of the participants was 68.40 (interquartile range (IQR): 19.5) years in males and 64.0 (IQR: 18.0) in females. Procalcitonin was performed in 121 (72%) and CRP performed in 61 (36.3%) patients. The NLR showed significant associations with all the tested lab parameters of sepsis, such as CRP (p = 0.02), procalcitonin (p = 0.01), and SOFA score (p = 0.01). Values when analyzed according to culture-positive showed higher values in culture-positive samples but were not statistically significant. Conclusion Neutrophil to lymphocyte ratio is a cheap and rapidly available predictor of sepsis and has shown a significant correlation with other relatively expensive and non-rapidly existing markers of inflammation and sepsis. However, large prospective studies are needed to prove its real effectiveness as a marker of sepsis and its prognosis.

Keywords: c-reactive protein; lymphocyte ratio; neutrophil; procalcitonin; sepsis.