Critical limb ischemia patients clinically improving with medical treatment have lower neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios

A systematic review of the neutrophil to lymphocyte and platelet to lymphocyte ratios in patients with lower extremity arterial disease

Lower extremity arterial disease (LEAD) is caused by atherosclerotic plaque in the arterial supply to the lower limbs. The neutrophil to lymphocyte and platelet to lymphocyte ratios (NLR, PLR) are established markers of systemic inflammation which are related to inferior outcomes in multiple clinical conditions, though remain poorly described in patients with LEAD. This review was carried out in accordance with PRISMA guidelines. The MEDLINE database was interrogated for relevant studies. Primary outcome was the prognostic effect of NLR and PLR on clinical outcomes following treatment, and secondary outcomes were the prognostic effect of NLR and PLR on disease severity and technical success following revascularisation. There were 34 studies included in the final review reporting outcomes on a total of 19870 patients. NLR was investigated in 21 studies, PLR was investigated in two studies, and both NLR & PLR were investigated in 11 studies. Relating to increased levels of systemic inflammation, 20 studies (100%) reported inferior clinical outcomes, 13 (92.9%) studies reported increased disease severity, and seven (87.5%) studies reported inferior technical results from revascularisation. The studies included in this review support the role of elevated NLR and PLR as key components influencing the clinical outcomes, severity, and success of treatment in patients with LEAD. The use of these easily accessible, cost effective and routinely available markers is supported by the present review.

Narrative Review of Biological Markers in Chronic Limb-Threatening Ischemia

BACKGROUND

Chronic limb-threatening ischemia (CLTI), the advanced stage of peripheral arterial disease, is diagnosed in the presence of ischemic rest pain, non-healing ulcers, or gangrene. Several studies have demonstrated that inflammation and endothelial dysfunction are some of the main substrates of CLTI.

METHODS

A narrative review was conducted and reported according to PRISMA guidelines. Three databases were searched-Web of Science, Medline, and EMBASE-for the studies assessing CLTI and the biological markers related to it.

RESULTS

We included 22 studies, and all the markers identified (C-reactive protein, D-dimers, fibrinogen, cytokines, IL-6, TNF-α, ICAM-1 (Intracellular Adhesion Molecule-1), VCAM-1 (Vascular Cell Adhesion Molecule-1), neutrophile-to-lymphocytes ratio (NLR), IL-8, Pentraxin-3, neutrophil gelatinase-associated lipocalin (NGAL), calprotectin, E-selectin, P-selectin, neopterin, High-Mobility Group Box-1 protein (HGMB-1), Osteoprotegerin (OPG) and Sortilin) were positively associated with advanced CLTI, with major limb or major cardiovascular events in these patients.

CONCLUSIONS

All the studied markers had increased values in patients with CLTI, especially when associated with diabetes mellitus, proving a very important association between diabetes and major limb or cardiovascular events in these patients. There is a need for more studies to validate these markers in terms of diagnosis or prognosis in CLTI patients and in trying to find new medical strategies that target inflammation or endothelial dysfunction in these patients.

Predictive Significance of the Preoperative Neutrophil-lymphocyte Ratio for Recurrence in Idiopathic Granulomatous Mastitis Patients

BACKGROUND

To investigate and assess the correlation between inflammatory markers, such as the preoperative neutrophil-lymphocyte ratio (NLR), and the recurrence of idiopathic granulomatous mastitis (IGM).

METHODS

All patients with IGM who were free of malignancy or inflammatory diseases were included in this retrospective analysis between January 2013 and December 2019. On the basis of the presence or absence of recurrence, the patients were split into two groups. After collecting retrospective data, the relationship between patient characteristics, hematological markers such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), NLR, platelet-lymphocyte ratio (PLR), and white blood cell count (WBC), and their connection with postoperative recurrence were assessed utilizing univariate and multivariate analyses, receiver operating characteristic curves (ROC curves), and logistic regression.

RESULTS

Recurrences occurred in 40.0% (32/80) of the 80 patients over a median follow-up duration of 35.5 months (22.0-47.8 months). The recurrent group showed higher NLR and CRP than the non-recurrent group (PNLR = .003, PCRP = .02). Neutrophil-lymphocyte ratio and postoperative recurrence were associated (correlation coefficient r = .436, P = .01). The ROC curve's ideal threshold, which had predictive value for IGM recurrence, was 2.18 (sensitivity: 46.9%; specificity: 14.6%).

CONCLUSION

The preoperative NLR is a simple and affordable way to predict IGM relapse, which is important for directing clinical work.

Sarcopenia is a risk factor for major adverse cardiac events after surgical revascularization for critical limb ischemia

OBJECTIVES

We examined the effect of sarcopenia on early surgical outcomes in patients with critical limb ischemia (CLI) in terms of major adverse cardiac events (MACE) and major adverse limb events (MALE), as well as the value of inflammatory markers of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte ratios (PLR) as indicators of sarcopenia in CLI patients.

METHODS

This was an observational retrospective single-center study. Patients who required surgical revascularization for CLI between October 2015 and December 2020 were identified. Psoas muscle areas were calculated from computed tomography images for psoas muscle index (PMI) calculations. Sarcopenia was defined as PMI < 5.5 cm²/m² for men and PMI < 4.0 cm²/m² for women. Risk factors for 30-day major adverse cardiac events (MACE) and major adverse limb events (MALE) were analyzed. NLR and PLR were compared between sarcopenic and non-sarcopenic patients.

RESULTS

The mean age of 217 study patients was 61.5 ± 10.9, and 16 (7.4%) patients were female. 82 (37.8%) patients were sarcopenic. Patients with sarcopenia were older (65.1 ± 9.3 vs 59.4 ± 11.2, p < .001) and history of myocardial infarction was more frequent (23.2% vs 12.6%, p = 0.042) among sarcopenic patients. Sarcopenic patients more frequently encountered MACE (9.8% vs 0.7%, p = 0.002), but not MALE. Sarcopenia increased early postoperative MACE in our cohort with an odds ratio of 11.925. NLR was not different between the two groups, while PLR was higher (127.16 vs 104.06, p = 0.010) among sarcopenic patients. The platelet-to-lymphocyte ratio of 125.11 had a sensitivity of 53.7% and a specificity of 68.1% for differentiating sarcopenia.

CONCLUSIONS

Sarcopenia was associated with more frequent 30-day MACE and perioperative mortality after revascularization for CLI. 30-day MALE was not increased in patients with sarcopenia. The use of PLR as a simple marker of sarcopenia is limited by its low sensitivity and specificity.

The Role of Neutrophils in Lower Limb Peripheral Artery Disease: State of the Art and Future Perspectives

In recent years, increasing attention has been paid to the role of neutrophils in cardiovascular (CV) disease (CVD) with evidence supporting their role in the initiation, progression, and rupture of atherosclerotic plaque. Although these cells have long been considered as terminally differentiated cells with a relatively limited spectrum of action, recent research has revealed intriguing novel cellular functions, including neutrophil extracellular trap (NET) generation and inflammasome activation, which have been linked to several human diseases, including CVD. While most research to date has focused on the role of neutrophils in coronary artery and cerebrovascular diseases, much less information is available on lower limb peripheral artery disease (PAD). PAD is a widespread condition associated with great morbidity and mortality, though physician and patient awareness of the disease remains low. To date, several studies have produced some evidence on the role of certain biomarkers of neutrophil activation in this clinical setting. However, the etiopathogenetic role of neutrophils, and in particular of some of the newly discovered mechanisms, has yet to be fully elucidated. In the future, complementary assessment of neutrophil activity should improve CV risk stratification and provide personalized treatments to patients with PAD. This review aims to summarize the basic principles and recent advances in the understanding of neutrophil biology, current knowledge about the role of neutrophils in atherosclerosis, as well as available evidence on their role of PAD.

S100A8 and S100A9 are elevated in chronically threatened ischemic limb muscle and induce ischemic mitochondrial pathology in mice

Objective

The objective of the present study was to determine whether elevated levels of S100A8 and S100A9 (S100A8/A9) alarmins contribute to ischemic limb pathology.

Methods

Gastrocnemius muscle was collected from control patients without peripheral arterial disease (PAD; n = 14) and patients with chronic limb threatening limb ischemia (CLTI; n = 14). Mitochondrial function was assessed in permeabilized muscle fibers, and RNA and protein analyses were used to quantify the S100A8/A9 levels. Additionally, a mouse model of hindlimb ischemia with and without exogenous delivery of S100A8/A9 was used.

Results

Compared with the non-PAD control muscles, CLTI muscles displayed significant increases in the abundance of S100A8 and S100A9 at both mRNA and protein levels (P < .01). The CLTI muscles also displayed significant impairment in mitochondrial oxidative phosphorylation and increased mitochondrial hydrogen peroxide production compared with the non-PAD controls. The S100A8/A9 levels correlated significantly with the degree of muscle mitochondrial dysfunction (P < .05 for all). C57BL6J mice treated with recombinant S100A8/A9 displayed impaired perfusion recovery and muscle mitochondrial impairment compared with the placebo-treated mice after hindlimb ischemia surgery. These mitochondrial deficits observed after S100A8/A9 treatment were confirmed in the muscle cell culture system under normoxic conditions.

Conclusions

The S100A8/A9 levels were increased in CLTI limb muscle specimens compared with the non-PAD control muscle specimens, and the level of accumulation was associated with muscle mitochondrial impairment. Elevated S100A8/A9 levels in mice subjected to hindlimb ischemia impaired perfusion recovery and mitochondrial function. Together, these findings suggest that the inflammatory mediators S100A8/A9 might be directly involved in ischemic limb pathology.

Despite improvements in the surgical management of chronic limb threatening limb ischemia (CLTI), the rates of major adverse limb events have remained high. Skeletal muscle has emerged as a strong predictor of outcomes in peripheral arterial disease (PAD)/CLTI; however, a complete understanding of muscle pathology in CLTI is lacking. This study identified elevated S100A8 and S100A9 alarmin proteins as a characteristic of CLTI muscle specimens and that the S100A8/A9 levels are associated with the degree of mitochondrial impairment in patient limb muscle specimens. Using a mouse model of PAD, treatment with S100A8/A9 exacerbated ischemic limb pathology, including impaired limb perfusion recovery and muscle mitochondrial impairment. Taken together, these findings connect the inflammatory milieu in the CLTI limb to exacerbated limb muscle outcomes via mitochondrial alterations.