The goal of this study was to conduct a systematic review of the literature on the relationship between peripheral blood platelet to lymphocyte ratio (PLR) and mortality in sepsis and to integrate the findings in a meta‐analysis. An electronic search of three main databases was performed: PubMed, Embase, and Scopus on 19 December 2021. Finally, 16 studies comprising 2403 septic patients, including 1249 survivors and 1154 nonsurvivors, were included in this meta‐analysis. We found that PLR levels were significantly higher in nonsurvivors than in survivors (random effect model: SMD = 0.72, 95% CI; 0.35–1.10, p < 0.001). However, significant heterogeneity was observed across the studies (I² = 94.1%, p < 0.01). So, we used random effect model in our meta‐analysis. In the subgroup analysis, according to mortality time, patients deceased during one month after sepsis had elevated levels of PLR compared to survivors (SMD = 1.03, 95% CI = 0.15‐1.92, p = 0.22). However, in‐hospital mortality was not associated with PLR level (SMD = 0.41, 95% CI = −0.18‐0.99, p = 0.175). Our findings support PLR to be a promising biomarker that can be readily integrated into clinical settings to aid in the prediction and prevention of sepsis mortality.

Background: The present study aims to review the existing scientific literature on the role of neutrophil to lymphocyte ratio (NLR) in diabetic peripheral neuropathy (DPN) to perform a meta-analysis on the available data. Methods: The electronic repositories Web of Science, PubMed, and Scopus were systematically explored starting from their establishment up until June 9, 2022. Results: Fifteen articles were included in the meta‐analysis after multiple screening according to the PRISMA guidelines. The combined findings indicated that individuals with DPN had higher levels of NLR in comparison to those without DPN (SMD = 0.61; CI 95% = 0.40–0.81, p < 0.001). In the subgroup assessment based on ethnicity, it was observed that diabetic patients with DPN exhibited increased NLR levels in contrast to those without DPN in studies conducted in India (SMD = 1.30; CI 95% = 0.37–2.24, p = 0.006) and East Asia (SMD = 0.53; CI 95% = 0.34–0.73, p < 0.001) but not in studies conducted in Turkey (SMD = 0.30; CI 95% = − 0.06–0.67, p = 0.104) and Egypt (SMD = 0.34; CI 95% = -0.14–0.82, p = 0.165). The pooled sensitivity of NLR was 0.67 (95% CI = 0.49–0.81), and the pooled specificity was 0.70 (95% CI, 0.56–0.81). The pooled positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR) of NLR were 2.30 (95% CI = 1.71–3.09), 0.45 (95%CI = 0.30–0.67), and 5.06 (95% CI = 3.16–8.12), respectively. Conclusion: NLR serves as a distinct marker of inflammation, and its rise in cases of DPN suggests an immune system imbalance playing a role in the development of the disease.

Background: The goal of this research was to explore the role of Neutrophil to lymphocyte ratio (NLR) in Parkinson’s disease (PD). Methods: From inception to 4 June 2023, PubMed, Web of Science, and ProQuest were searched for papers comparing NLR in PD to healthy individuals. Standardized mean difference (SMD) with a confidence interval (CI) of 95% were calculated. Results: A random-effect model revealed that PD patients had elevated NLR values compared to healthy individuals (SMD = 0.81, 95% CI = 0.47 to 1.14, P < 0.001). The results of subgroup analysis were as follows: (1) study design: We observed that patients with PD had higher levels of NLR than healthy controls in either retrospective (SMD = 1.12, 95% CI = 0.58 to 1.66, P < 0.001) or prospective (SMD = 0.43, 95% CI = 0.18 to 0.68, P = 0.001) studies. (2) Ethnicity: We noticed that individuals with PD had higher levels of NLR than healthy controls, whether they were East Asian (SMD = 0.93, 95% CI = 0.22 to 1.63, P = 0.010) or Caucasian (SMD = 0.75, 95% CI = 0.40 to 1.10, P < 0.001).The pooled sensitivity of NLR in the prediction of PD was 0.67 (95% CI = 0.61–0.73), and the pooled specificity was 0.66 (95% CI, 0.61–0.70). Conclusions: Increased levels of NLR is highly related with the presence of PD. Further research is needed to determine the potential clinical benefits of this simple and low-cost biomarker in the PD diagnosis.

Introduction: The neutrophil to lymphocyte ratio (NLR), an inflammatory biomarker, measures innate-adaptive immune system balance. In this systematic review and meta-analysis, we aim to analyze the current literature to evaluate the diagnostic role of NLR in neonatal sepsis. Methods: PubMed, Web of Science, and Scopus were used to conduct a systematic search for relevant publications published before May 14, 2022. Results: Thirty studies, including 2328 neonates with sepsis and 1800 neonates in the control group, were included in our meta-analysis. The results indicated that NLR is higher in neonates with sepsis compared to healthy controls (SMD = 1.81, 95% CI = 1.14–2.48, P-value < 0.001) in either prospective (SMD = 2.38, 95% CI = 1.40–3.35, P-value < 0.001) or retrospective studies (SMD = 0.87, 95% CI = 0.63–1.12, P-value < 0.001) with a pooled sensitivity of 79% (95% CI = 62–90%), and a pooled specificity of 91% (95% CI = 73–97%). Also, we found that NLR is higher in neonates with sepsis compared to those who were suspected of sepsis but eventually had negative blood cultures (SMD =1.99, 95% CI = 0.76–3.22, P-value = 0.002) with a pooled sensitivity of 0.79% (95% CI = 0.69–0.86%), and a pooled specificity of 73% (95% CI = 54–85%). In addition, neonates with sepsis had elevated levels of NLR compared to other ICU admitted neonates (SMD = 0.73, 95% CI = 0.63–0.84, P < 0.001). The pooled sensitivity was 0.65 (95% CI, 0.55–0.80), and the pooled specificity was 0.80 (95% CI, 0.68–0.88). Conclusion: Our findings support NLR as a promising biomarker that can be readily integrated into clinical settings to aid in diagnosing neonatal sepsis. As evidenced by our results, restoring balance to the innate and adaptive immune system may serve as attractive therapeutic targets. Theoretically, a reduction in NLR values could be used to measure therapeutic efficacy, reflecting the restoration of balance within these systems.

This study systematically reviewed the evidence regarding differences in the neutrophil to lymphocyte ratio (NLR) level between hypertensive and normotensive individuals as well as between patients with dipper and non-dipper hypertension (HTN). PubMed, Scopus, and Web of Science databases were systematically searched up to 20 December 2021. This was done without any limitation with regard to date, publication, or language. Pooled weighted mean differences (WMD) with 95% confidence intervals (95% CI) were reported. We assessed the quality of studies based on the Newcastle–Ottawa Scale (NOS). In total, 21 studies were included in our study. There was a significant increase in NLR levels for the hypertensive group in comparison to the control group (WMD = 0.40, 95%CI = 0.22–0.57, P < 0.0001). In addition, the NLR levels were higher in the non-dipper than in the dipper group (WMD = 0.58, 95%CI = 0.19–0.97, P = 0.003). Our findings showed that hypertensive patients had higher level of NLR than normotensive individuals.

The neutrophil to lymphocyte ratio (NLR) reflects a dynamic relationship between the innate (neutrophils) and adaptive (lymphocytes) cellular immune response. This systematic review and meta‐analysis was conducted to critically evaluate the literature regarding the use of the NLR as a reliable means to detect several ocular disorders. Our study was registered with the PROSPERO (ID: CRD42022314850). Three databases, including PubMed, Embase, Scopus, and the Web of Science, were searched on September 9, 2022, with no restrictions on the article’s language. Finally, 32 articles were recognized as eligible for our meta‐analysis. We found that patients with eye diseases had significantly elevated levels of NLR in comparison to healthy controls (SMD =0.53, 95% CI =0.35‐0.71, P < 0.001). In subgroup analysis, patients with keratoconus (SMD =0.69; 95% CI =0.33‐1.05, P < 0.001), glaucoma (SMD =0.56, 95% CI =0.25‐0.87, P < 0.001), pterygium (SMD =0.14; 95% CI =0.01‐0.26, P < 0.001), and idiopathic epiretinal membrane (SMD =0.14; 95% CI =0.01‐0.26, P < 0.001) had higher levels of NLR compared to healthy controls. However, NLR levels of patients with dry eye disease were similar to healthy controls (SMD =0.32, 95% CI = ‐0.49‐1.13, P = 0.435). It can be said that NLR is a valuable marker of systemic inflammation, which is significantly increased in many eye disorders, suggesting that inflammation plays a key role in the pathophysiology of these diseases.