Clinical Evaluation on Ratio of Neutrophil-to-Lymphocyte in Different Pathogens / 现代检验医学杂志

ABSTRACT

Objective To investigate the clinical value of neutrophil-to-lymphocytc ratio(NLR) in identifying blood stream infection caused by different pathogens and for differentiating coagulase negative staphylococcus(CNS)bloodstream infection and contamination.Methods Medical records of 500 patients who underwent blood culture test and routine blood test at the same time were retrospectively analyzed,blood culture negative group 356 patients,blood culture positive group 144 patients,which included Gram-negative group,Gram positive group,fungi group,CNS bloodstream contamination and mingled group.Collected the results and calculated the NLR at the same time.NLR were applied by t test of each group.ROC curve was used to determine the cut off value of NLR.Results ①Mean values of NLR in negative blood culture,blood stream infection group,CNS bloodstream infection and contamination were 6.12,13.15,10.11 and 6.24.NLR had statistical difference between negative blood culture and blood stream infection group,CNS bloodstream infection group and contamination group (P＜0.05).②Mean values of NLR in and fungi group were 15.33,11.63 and 10.58,respectively.NLR had statistical difference between Gram-positive bacteria group and Gram-negative bacteria group (P＜0.05).NLR had no differences among Gram-positive bacteria (15.33) and Gram negative bacteria (11.63) compared with (10.58) fungi respectively (P＞0.05).③The area under the curve of NLR predicting a positive blood culture,distinguishing Gram-positive bacteria and Gram-negative bacteria,differentiating CNS bloodstream infection and contamination were 0.86,0.60 and 0.75,respectively.The optimal cut off values of NLR for predicting a positive blood culture,distinguishing Gram-positive bacteria and Gramnegative bacteria,differentiating CNS bloodstream infection and contamination were 10.45,7.50 and 8.10 respectively.Conclusion NLR is highly effective in distinguishing blood stream infection and differentiating CNS bloodstream infection and contamination.