Association of Neutrophil/Lymphocyte Ratio with Plaque Morphology in Patients with Asymptomatic Intermediate Carotid Artery Stenosis

Prognostic markers for ischemic stroke - are they truly reliable?

Background

Stroke is one of the leading causes of mortality and morbidity worldwide. Despite extensive research, to this date there is no panel of biomarkers for the prevention and prognosis of ischemic stroke and there is still much incomplete and insufficiently researched information.

Aim

We conducted a prospective, observational study between January and June 2020. The main objective of this study was to clarify the role of inflammation markers, i.e. neutrophil/ lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), high-sensitivity C - reactive protein (hsCRP) in ischemic stroke and whether there is or not a correlation between these markers and carotid stenosis.

Study design

In the study we included 150 subjects divided in two groups: study group - 100 subjects and control group - 50 subjects.

Methods

Data collected during the research (at the time of patient admission): 1) biological sample: 5 ml of peripheral blood were collected in a vial with clot activator and separating gel, from which the following laboratory tests were performed: hsCRP, neutrophils, lymphocytes, platelets. NLR and PLR were subsequently calculated as the ratio of neutrophils to lymphocytes, respectively platelets and lymphocytes), 2) paraclinical examinations: extracranial carotid Doppler ultrasound examination.

Results

The results were impressive: high-sensitivity C reactive protein (hsCRP), neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) were strongly, respectively moderately correlated with the severity of stroke (the severity being established with the NIHS (National Institute of Health Stroke) score. None of the inflammation markers included in the present study was correlated with carotid stenosis.

Conclusion

hsCRP, NLR and PLR may potentially be prognostic markers for ischemic stroke, being of major help in preventing its possible complications.

Leukocyte subtypes, gelatinases, and their tissue inhibitors in a group of subjects with asymptomatic carotid atherosclerosis

In a cohort of subjects with asymptomatic carotid atherosclerosis (ACA), we have evaluated the neutrophil and lymphocyte count and their ratio (NLR), the gelatinases (MMP-2 and MMP-9) and their tissue inhibitors (TIMP-1 and TIMP-2). At baseline, no difference was observed between ACA subjects and subject control group regarding neutrophil and lymphocyte count while was evident in ACA subjects a significant increase in MMP-2, MMP-9 and TIMP-2 associated to a significant decrease in TIMP-1. Dividing the ACA according to the number of cardiovascular risk factors (CRFs) we have observed an increase in lymphocyte count in the subgroup with 3-5 CRFs. Evaluating the leukocyte subtypes according to all the surrogate markers of insulin resistance has been noted, in the subgroups that exceed the medians of these markers, a significant increase in neutrophil and lymphocyte count without any variation of the NLR. Effecting the same evaluation for the MMP/TIMP pattern we observed, instead, that the same subgroups tend to show a decrease in MMP-2 and an increase in MMP-9. No difference instead for TIMP-1 and TIMP-2. The abnormality of the MMP/TIMP pattern, bearing in mind the cardiometabolic clustering present in this cohort of ACA subjects, would induce to use drugs able not only to cure the cardiometabolic risk factors but also to influence the MMP/TIMP profile.

Correlation between neutrophil-to-lymphocyte ratio and stability of carotid plaques

OBJECTIVE

The neutrophil-to-lymphocyte ratio (NLR) has been proved to be a strong predictor of carotid atherosclerotic plaque, but the correlation between NLR and the stability of carotid plaque is not clear. Thus we conducted a study to evaluate the correlation between NLR and the stability of carotid atherosclerotic plaque, and to develop a new evaluation scale for rapid clinical evaluation of carotid plaque stability.

METHODS

We recruited 528 patients with acute anterior circulation ischemic stroke who were in accordance with extracranial and intracranial large artery atherosclerosis of Chinese ischemic stroke subtype. Blood routine examination and carotid ultrasound examination were performed on admission. According to the ultrasonic characteristics, the patients were divided into plaque stabilization group and plaque instability group.

RESULTS

There was significant difference in NLR between plaque stability and instability groups (P < 0.001). The risk of plaque instability increased with the increase of NLR (odds ratio (OR), 4.737; 95% confidence interval (CI), 3.404-6.592; P < 0.001). Receiver operating characteristic (ROC) curve showed that the critical point of NLR is 2.55 and the area under the curve (AUC) was 0.782 (95%CI, 0.740-0.823; P < 0.001). The best cut-off value of the evaluation scale was ≥ 4 points (sensitivity, 0.77; specificity, 0.75; accuracy, 0.76).

CONCLUSION

There is a correlation between NLR and carotid plaque instability. NLR may be useful as a potential inflammation biomarker indicating the risk of unstable carotid plaques. The new scoring scale is a reliable index to predict the stability of carotid plaque.

NETosis in ischemic/reperfusion injuries: An organ-based review

Neutrophil extracellular trap (NETosis), the web-like structures induced by neutrophil death, is an important inflammatory mechanism of the immune system leading to reactive oxygen species production/coagulopathy, endothelial dysfunction, atherosclerosis, and ischemia. NETosis exerts its role through different mechanisms such as triggering Toll-like receptors, inflammatory cytokines, platelet aggregation, neutrophil activation/infiltration, and vascular impairment. NETosis plays a key role in the prognosis of coronary artery disease, ischemic injury of kidney, lung, gastrointestinal tract and skeletal muscles. In this review, we explored the molecular mechanisms involved in NETosis, and ischemic/reperfusion injuries in body organs.

Panoramic imaged carotid atheromas are associated with increased neutrophil count: both validated, independent predictors of near-term myocardial infarction

OBJECTIVES

Panoramic images (PXs) demonstrating calcified carotid artery atheromas (CCAAs) are associated with heightened risk of near-term myocardial infarction (MI). Elevated neutrophil counts (NC) within normal range 2,500-6,000 per mm³ are likewise associated with future MI signaling the role neutrophils play in the chronic inflammation process underlying coronary artery atherogenesis. We determined if CCAAs on PXs are associated with increased NC.

METHODS

Investigators implemented a retrospective study of PXs and accompanying medical records of white males ≥ 65 years treated by a VA dental service. Two groups (N = 60 each) were constituted, one with atheromas (CCAA+) and one without (CCAA-). Predictor variable was CCAA + and outcome variable was NC. Bootstrapping analysis determined the difference in mean NCs between two groups, significance set at ≤0.05.

RESULTS

The study group of (CCAA+) (mean age 75.9; range 69-91 years) demonstrated a mean NC of 4,843 per mm³ and control group (CCAA-) (mean age 75.3; range; 66-94) a mean NC of 4,108 per mm³. The difference between the groups was significant (p = 0.0008) (95% CI of difference of mean: -432, 431; observed effect size 736).

CONCLUSIONS

CCAAs on PXs of elderly white males are associated with elevated NC; amplifying need for medical consultation prior to invasive dental procedures.

Associations of the neutrophil to lymphocyte ratio with intracranial artery stenosis and ischemic stroke

Background

The neutrophil-to-lymphocyte ratio (NLR) has emerged as an inflammatory marker. However, the associations of NLR with intracranial artery stenosis (ICAS) and ischemic stroke remain unclear. This study aimed to examine the associations of NLR with ICAS and ischemic stroke among a large and high-risk population.

Methods

Participants with records of clinical characteristics were prospectively recruited from the Neurology Department and Health & Physical Examination Center of Qingdao Municipal Hospital. Logistic regression analysis was used to examine the associations of NLR with ICAS and ischemic stroke. Moreover, we also conducted parametric mediation analysis to estimate the effect of NLR on the risk of ischemic stroke mediated through ICAS.

Results

A total of 2989 participants were enrolled in this study. After adjusting for covariates, NLR (OR = 1.125, 95%CI 1.070–1.183) and ICAS (OR = 1.638, 95%CI 1.364–1.967) were significantly associated with ischemic stroke. Compared with the first quartile NLR, the second, third and fourth quartiles NLR were independent risk predictors for ischemic stroke (P for trend < 0.001); the third and fourth quartiles were independent predictors for ICAS (P for trend < 0.001). The mediation analysis showed that ICAS partially mediated the association between NLR and ischemic stroke, accounting for 14.4% of the total effect (P < 0.001).

Conclusions

NLR was significantly associated with ICAS and ischemic stroke. Besides, ICAS partially mediated the association between NLR and ischemic stroke.

Predicting Motor and Cognitive Improvement Through Machine Learning Algorithm in Human Subject that Underwent a Rehabilitation Treatment in the Early Stage of Stroke

BACKGROUND

The objective of this study was to investigate, in subject with stroke, the exact role as prognostic factor of common inflammatory biomarkers and other markers in predicting motor and/or cognitive improvement after rehabilitation treatment from early stage of stroke.

METHODS

In this longitudinal cohort study on stroke patients undergoing inpatient rehabilitation, data from 55 participants were analyzed. Functional and clinical data were collected after admission to the rehabilitation unit. Biochemical and hematological parameters were obtained from peripheral venous blood samples on all individuals who participated in the study within 24hours from the admission at the rehabilitative treatment. Data regarding the health status were collected at the end of rehabilitative treatment. First, a feature selection has been performed to estimate the mutual dependence between input and output variables. More specifically, the so called Mutual Information criterion has been exploited. In the second stage of the analysis, the Support Vector Machines (SVMs), a non-probabilistic binary machine learning algorithm widely used for classification and regression, has been used to predict the output of the rehabilitation process. Performances of the linear SVM regression algorithm have been evaluated considering a different number of input features (ranging from 4 to 14). The performance evaluation of the model proposed has been investigated in terms of correlation, Root Mean Square Error (RMSE) and Mean Absolute Deviation Percentage (MADP).

RESULTS

Results on the test samples show a good correlation between all the predicted and measured outputs (i.e. T1 Barthel Index (BI), T1 Motor Functional Independence Measure (FIM), T1 Cognitive FIM and T1 Total FIM) ranging from 0.75 to 0.81. While the MADP is high (i.e., 83.96%) for T1 BI, the other predicted responses (i.e., T1 Motor FIM, T1 Cognitive FIM, T1 Total FIM) disclose a smaller MADP of 30%. Accordingly, the RMSE ranges from 4.28 for T1 Cognitive FIM to 22.6 for T1 BI.

CONCLUSIONS

In conclusion, the authors developed a new predictive model using SVM regression starting from common inflammatory biomarkers and other ratio markers. The main efforts of our model have been accomplished in regard to the evidence that the type of stroke has not shown itself to be a critical input variable to predict the discharge data, furthermore, among the four selected indicators, Barthel at T1 is the less predictable (MADP > 80%), while it is possible to predict T1 Cognitive FIM with an MADP less than 18%.

Neutrophil-to-Lymphocyte Ratio is a strong predictor of atherosclerotic carotid plaques in older adults

BACKGROUND AND AIMS

The Neutrophil-to-Lymphocyte Ratio (NLR), an index of systemic inflammation, has been reported to be associated with subclinical atherosclerosis, but its predictive role of the presence of carotid atherosclerotic plaques remains undefined. This study aims to assess this association which gives additional value to this biomarker, with respect to the main risk factors, in the prediction of carotid atherosclerosis in older adults.

METHODS AND RESULTS

We recruited 324 patients, aged ≥65 years, without hematopoietic disorders, and/or history of malignancies, evidence of acute infections, chronic inflammatory status, and history of glucocorticoid therapy within the past three months, hospitalized in the Unit of Internal Medicine, University of Catania, Catania, Italy from January 2014 to December 2016. All patients underwent blood sampling for white blood cell, neutrophil, lymphocyte and platelet counts, and for measurements of inflammatory markers, NLR was calculated as the ratio of the absolute neutrophil count to the absolute lymphocyte count. Patients also underwent carotid scan by ultrasonography (US) to evaluate abnormalities of carotid wall. NLR resulted a strong predictor of the presence of carotid plaques. NLR > 2.4 predicted with 80% probability carotid plaques (p < 0.01), while NLR > 3.68 gave 97% probability (p = 0.013). Furthermore, NLR > 2.4 was associated with an average presence of 2.86 carotid plaques (p < 0.001). Fibrinogen and CRP performed well, but with lesser significance, as predictors of the presence of carotid plaques (p = 0.002).

CONCLUSION

NLR is a strong predictor of the presence and the number of carotid atherosclerotic plaques. Its use could be useful to identify the risk of harboring carotid plaques.

Thrombosis, Neuroinflammation, and Poststroke Infection: The Multifaceted Role of Neutrophils in Stroke

Immune cells can significantly predict and affect the clinical outcome of stroke. In particular, the neutrophil-to-lymphocyte ratio was shown to predict hemorrhagic transformation and the clinical outcome of stroke; however, the immunological mechanisms underlying these effects are poorly understood. Neutrophils are the first cells to invade injured tissue following focal brain ischemia. In these conditions, their proinflammatory properties enhance tissue damage and may promote ischemic incidences by inducing thrombus formation. Therefore, they constitute a potential target for therapeutic approaches and prevention of stroke. Indeed, in animal models of focal brain ischemia, neutrophils have been targeted with successful results. However, even in brain lesions, neutrophils also exert beneficial effects, because they are involved in triggering immunological removal of cell debris. Furthermore, intact neutrophil function is essential for maintaining immunological defense against bacterial infections. Several studies have demonstrated that stroke-derived neutrophils displayed impaired bacterial defense capacity. Because infections are known to impair the clinical course of stroke, therapeutic interventions that target neutrophils should preserve or even restore their function outside the central nervous system (CNS). This complex situation requires well-tailored therapeutic approaches that can effectively tackle immune cell invasion in the brain but avoid increasing poststroke infections.