NEUTROPHIL-TO-LYMPHOCYTE RATIO AS AN INFECTIOUS COMPLICATIONS BIOMARKER IN COLORECTAL SURGERY (own data, systematic review and meta-analysis)

Abstract

BACKGROUND: biological markers of inflammation belong to the main tool for predicting the risk of infectious complications at the preclinical stage. One of such biomarkers is the neutrophil-to-lymphocyte ratio (NLR), but an insufficient number of studies does not allow us to estimate its value as a predictor of infectious complications in colorectal surgery. AIM : to determine the predictive value of NLR as a predictor of infectious complications after colorectal surgery. PATIENTS AND METHODS: from January 2018 to December 2019 192 patients after colorectal surgery were included in the study. The rate of infectious complications, NLR levels differences in patients with and without infectious complications were determined, the area under the curve (AUC), sensitivity, specificity, negative and positive prognostic value of NLR on the 3rd (POD) and the 6th (POD) postoperative days were assessed. A literature search and meta-analysis of the data in accordance with the preferred reporting items for systematic reviews and meta-analyses checklist (PRISMA) were conducted. The information was taken from the Medline electronic database and the E-library, scientific electronic library, among the English and Russian literature without publication date restrictions by the keywords: “neutrophil/lymphocyteratio”, “neutrophil-to-lymphocyte ratio”, “neutrophil lymphocyte ratio”, “neutrophil ratio”, “lymphocyte ratio”, “colorectal”, “colon”, “rectum”. The systematic review included all the studies related to assessing the prognostic value of NLR as a predictor of infectious complications in colorectal surgery. RESULTS: infectious complications were detected in 29 (15.1%) of 192 patients. On the 3rd and the 6th POD, the patients with infectious complications had higher median NLR values than the patients without complications (p=0.0017 for the 3rd POD; p=0.018 for the 6th POD). On the 3rd POD, the area under the curve at the NLR cut-off point 5.13 was 0.644, sensitivity – 69.7%, specificity – 60.7% (p=0.019). On the 6th POD, similar indicators at an NLR cut-off point of 3.94 were 0.75, 75.9% and 70.6%, respectively (p<0,001). Four studies, which included 1,152 observations, were added in the meta-analysis. On the 3th POD, the summarized AUC was 0.671, sensitivity – 86.3%, specificity – 60.3% (p=0.014). The risk of infection with a biomarker above the threshold increased by more than 10 times (OR=10.2; 95% CI: 1.4-72). On the 4th POD, the above indicators were 0.711, 75.4%, 87.5%, respectively (p=0.002). Odds ratio was 51 (95% CI: 20-128). CONCLUSION : the neutrophil-to-lymphocyte ratio is a reliable indicator for predicting the risk of developing infectious complications in colorectal surgery. In addition, the low values of this biomarker are an important criterion for the safe discharge of patients from hospital. The prevalence and availability of this test makes it easily feasible in clinical practice.