Lymphocyte-to-C-Reactive Protein Ratio as an Early Sepsis Biomarker for Neonates with Suspected Sepsis

Abstract

Background. Neonatal sepsis is an extremely dangerous and fatal disease among neonates, and its timely diagnosis is critical to treatment. This research is aimed at evaluating the clinical significance of the lymphocyte-to-C-reactive protein ratio (LCR) as an early sepsis indicator in neonates with suspected sepsis. Methods. Between January 2016 and December 2021, 1269 neonates suspected of developing sepsis were included in this research. Among them, sepsis was diagnosed in 819 neonates, with 448 severe cases, as per the International Pediatric Sepsis Consensus. Data related to clinical and laboratory tests were obtained via electronic medical records. LCR was calculated as total lymphocyte (109 cells/L)/C-reactive protein (mg/L). Multivariate logistic regression analysis was employed to evaluate the effectiveness of LCR as an independent indicator for determining sepsis in susceptible sepsis neonates. Receiver operating characteristic (ROC) curve analysis was conducted for investigating the diagnostic significance of LCR in sepsis. When suitable, the statistical tool SPSS 24.0 was used for statistical analyses. Results. LCR decreased significantly in the control, mild, and severe sepsis groups. Further analyses exhibited that there was a substantially greater incidence of sepsis in neonates in the low-LCR group ( $\text{LCR}\le 3.94$ ) as opposed to the higher LCR group ( $\text{LCR}>3.94$ ) (77.6% vs. 51.4%, $p<0.001$ ). Correlation analysis indicated a substantial negative association of LCR with procalcitonin ( $r=-0.519$ , $p<0.001$ ) and hospital stay duration ( $r=-0.258$ , $p<0.001$ ). Multiple logistic regression analysis depicted LCR as an independent indicator for identifying sepsis and severe cases of this disease. ROC curve analysis indicated the optimal cutoff value of LCR in identifying sepsis to be 2.10, with 88% sensitivity and 55% specificity. Conclusions. LCR has proven to be a potentially strong biomarker capable of identifying sepsis in a timely manner in neonates suspected to have the disease.