Systematic review of the significance of neutrophil to lymphocyte ratio in anastomotic leak after gastrointestinal surgeries.

INTRODUCTION: The inflammatory response is thought to be a critical initiator of epigenetic alterations. The neutrophil to lymphocyte ratio (NLR), a biomarker of inflammation, is computed by dividing the number of neutrophils by the number of lymphocytes. The primary goal of this systematic review and meta-analysis was to evaluate the pre-operative NLR of gastrointestinal surgery patients who had an anastomotic leak (AL) in comparison to those who did not AL. METHODS: We performed a comprehensive search for relevant papers published before May 4, 2022, using PubMed, Scopus, and Web of Science. Standardized mean difference (SMD) with a 95% confidence interval (CI) was pooled in meta-analysis to yield a summary estimate. We utilized the random-effects model to create pooled effects since we discovered a substantial heterogeneity level. For evaluating quality, the Newcastle-Ottawa scale (NOS) was implemented. RESULTS: The research comprised 12 studies with a total of 2940 individuals who had GI operations, 353 of whom went on to develop AL. We discovered that patients who had GI surgeries and acquired AL had significantly higher NLR levels than those who did not (random-effects model: SMD = 0.75, 95% CI = 0.11-1.38, p = 0.02). Patients with AL showed significantly higher NLR levels than control group in retrospective studies (SMD = 0.93, 95% CI = 0.20-1.66, p=0.01) but not in prospective studies (SMD = - 0.11, 95% CI = - 0.65-0.43, p = 0.69), according to the subgroup analysis based on research design. Subgroup analysis based on ethnicity yielded that white patients with AL exhibited significantly higher NLR values than the control group (SMD = 1.35, 95% CI = 0.01-2.68, p = 0.04) but this result was not applied to East Asian patients (SMD = 0.14, 95% CI = -0.13-0.41, p = 0.29). CONCLUSION: Our research suggests a potential association between preoperative NLR and postoperative AL. However, it is essential to acknowledge the variability in the findings, with significantly higher NLR levels observed in retrospective studies and among white patients, but not consistently replicated in prospective studies and among East Asian patients. Further investigations with larger and more diverse cohorts are warranted to validate these findings and explore potential factors contributing to the observed discrepancies.

Neutrophil-to-Lymphocyte Ratio and Early Neurological Deterioration in Stroke Patients: A Systematic Review and Meta-Analysis.

In light of the growing emphasis on classifying stroke patients for different levels of monitoring intensity and emergency treatments, we conducted a systematic review of a wide range of clinical studies, according to the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines, with no restrictions on the language or publication date, to analyze the potential of the neutrophil-to-lymphocyte ratio (NLR) as an early neurological deterioration (END) risk predictor. A comprehensive search was carried out in PubMed, Scopus, and Web of Science databases from the inception to March 13, 2022. Nine articles were included in our study. Stroke patients with END had significantly higher NLR levels than the those without END (SMD = 0.73; CI 95% = 0.42-1.05, P value < 0.001). In the subgroup analysis, according to ethnicity, East Asian patients with END had elevated levels of NLR compared to those without END (SMD = 0.79; CI 95% = 0.52-1.06, P value < 0.001). However, the difference in the Caucasian group was not significant (SMD = 0.60; CI 95% = -0.50-1.70, P value = 0.28). In the subgroup analysis according to the type of stroke, the NLR levels in patients with hemorrhagic stroke who developed END were similar to those without END (SMD = 0.84, CI 95% = -0.10-1.77, P value = 0.07). Vice versa, in the ischemic stroke group, patients with END had elevated levels of NLR compared to those without END (SMD = 0.67, CI 95% = 0.38-0.96, P value < 0.001). NLR is a unique inflammatory biomarker whose increase in END suggests an immune system dysfunction in the pathogenesis of the disease.