Delayed neutrophil apoptosis in patients with unstable angina: relation to C-reactive protein and recurrence of instability

Sex-specific circulating unconventional neutrophils determine immunological outcome of auto-inflammatory Behçet's uveitis

Neutrophils are the most abundant immune cells that first respond to insults in circulation. Although associative evidence suggests that differences in neutrophils may be linked to the sex-specific vulnerability of inflammatory diseases, mechanistic links remain elusive. Here, we identified extensive sex-specific heterogeneity in neutrophil composition under normal and auto-inflammatory conditions at single-cell resolution. Using a combination of single-cell RNA sequencing analysis, neutrophil-specific genetic knockouts and transfer experiments, we discovered dysregulation of two unconventional (interferon-α responsive and T cell regulatory) neutrophil subsets leading to male-biased incidence, severity and poor prognosis of auto-inflammatory Behçet's uveitis. Genome-wide association study (GWAS) and exosome study revealed that male-specific negative effects of both genetic factors and circulating exosomes on unconventional neutrophil subsets contributed to male-specific vulnerability to disease. Collectively, our findings identify sex-specifically distinct neutrophil subsets and highlight unconventional neutrophil subsets as sex-specific therapeutic targets to limit inflammatory diseases.

Neutrophil extracellular traps contribute to coagulopathy after traumatic brain injury

Coagulopathy contributes to the majority of deaths and disabilities associated with traumatic brain injury (TBI). Whether neutrophil extracellular traps (NETs) contribute to an abnormal coagulation state in the acute phase of TBI remains unknown. Our objectives were to demonstrate the definitive role of NETs in coagulopathy in TBI. We detected NET markers in 128 TBI patients and 34 healthy individuals. Neutrophil-platelet aggregates were detected in blood samples from TBI patients and healthy individuals using flow cytometry and staining for CD41 and CD66b. Endothelial cells were incubated with isolated NETs and we detected the expression of vascular endothelial cadherin, syndecan-1, thrombomodulin, von Willebrand factor, phosphatidylserine, and tissue factor. In addition, we established a TBI mouse model to determine the potential role of NETs in TBI-associated coagulopathy. NET generation was mediated by high mobility group box 1 (HMGB1) from activated platelets and contributed to procoagulant activity in TBI. Furthermore, coculture experiments indicated that NETs damaged the endothelial barrier and caused these cells to assume a procoagulant phenotype. Moreover, the administration of DNase I before or after brain trauma markedly reduced coagulopathy and improved the survival and clinical outcome of mice with TBI.

The mechanistic role of neutrophil lymphocyte ratio perturbations in the leading non communicable lifestyle diseases

Inflammation plays a critical role in the development and progression of chronic diseases like type 2 diabetes mellitus, coronary artery disease, and chronic obstructive pulmonary disease. Inflammatory responses are indispensable for pathogen control and tissue repair, but they also cause collateral damage. A chronically activated immune system and the resultant immune dysregulation mediated inflammatory surge may cause multiple negative effects, requiring tight regulation and dampening of the immune response to minimize host injury.  While chronic diseases are characterized by systemic inflammation, the mechanistic relationship of neutrophils and lymphocytes to inflammation and its correlation with the clinical outcomes is yet to be elucidated. The neutrophil to lymphocyte ratio (NLR) is an easy-to-measure laboratory marker used to assess systemic inflammation. Understanding the mechanisms of NLR perturbations in chronic diseases is crucial for risk stratification, early intervention, and finding novel therapeutic targets. We investigated the correlation between NLR and prevalent chronic conditions as a measure of systemic inflammation. In addition to predicting the risk of impending chronic conditions, NLR may also provide insight into their progression. This review summarizes the mechanisms of NLR perturbations at cellular and molecular levels, and the key inflammatory signaling pathways involved in the progression of chronic diseases. We have also explored preclinical studies investigating these pathways and the effect of quelling inflammation in chronic disease as reported by a few in vitro, in vivo studies, and clinical trials.

High neutrophil to lymphocyte ratio with type 2 diabetes mellitus predicts poor prognosis in patients undergoing percutaneous coronary intervention: a large-scale cohort study

BACKGROUND

Inflammation plays a crucial role in the pathogenesis and progression of coronary artery disease (CAD). The neutrophil to lymphocyte ratio (NLR) is a novel inflammatory biomarker and its association with clinical outcomes in CAD patients with different glycemic metabolism after percutaneous coronary intervention (PCI) remains undetermined. Therefore, this study aimed to investigate the effect of NLR on the prognosis of patients undergoing PCI with or without type 2 diabetes mellitus (T2DM).

METHODS

We consecutively enrolled 8,835 patients with CAD hospitalized for PCI at Fuwai hospital. NLR was calculated using the following formula: neutrophil (*10⁹/L)/lymphocyte (*10⁹/L). According to optimal cut-off value, study patients were categorized as higher level of NLR (NLR-H) and lower level of NLR (NLR-L) and were further stratified as NLR-H with T2DM and non-T2DM, and NLR-L with T2DM and non-T2DM. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCEs), defined as all-cause mortality, myocardial infarction (MI), stroke and target vessel revascularization.

RESULTS

A total of 674 (7.6%) MACCEs were recorded during a median follow-up of 2.4 years. The optimal cut-off value of NLR was 2.85 determined by the surv_cutpoint function. Compared to those in the NLR-H/T2DM groups, patients in the NLR-L/non-T2DM, NLR-H/non-T2DM and NLR-L/T2DM groups were at significantly lower risk of 2-year MACCEs [adjusted hazard ratio (HR): 0.67, 95% confidence interval (CI): 0.52 to 0.87, P = 0.003; adjusted HR: 0.62, 95%CI: 0.45 to 0.85, P = 0.003; adjusted HR: 0.77, 95%CI: 0.61 to 0.97, P = 0.025; respectively]. Remarkably, patients in the NLR-L/non-T2DM group also had significantly lower risk of a composite of all-cause mortality and MI than those in the NLR-H/T2DM group (adjusted HR: 0.57, 95%CI: 0.35 to 0.93, P = 0.024). Multivariable Cox proportional hazards model also indicated the highest risk of MACCEs in diabetic patients with higher level of NLR than others (P for trend = 0.009). Additionally, subgroup analysis indicated consistent impact of NLR on MACCEs across different subgroups.

CONCLUSIONS

Presence of T2DM with elevated NLR is associated with worse clinical outcomes in CAD patients undergoing PCI. Categorization of patients with elevated NLR and T2DM could provide valuable information for risk stratification of CAD patients.

Polymorphonuclear neutrophils promote endothelial apoptosis by enhancing adhesion upon stimulation by intermittent hypoxia

PURPOSE

This study explored the interactive effects between polymorphonuclear neutrophils (PMNs) and vascular endothelial cells under intermittent hypoxia (IH) and investigated the mechanisms underlying these effects.

METHODS

Endothelial cells were co-cultured with PMNs isolated from rats exposed to normoxia or IH. The PMN apoptotic rate was determined using flow cytometry. Expression of apoptosis-related proteins in the endothelial cells were evaluated using Western blotting, and the levels of intercellular adhesion molecules in the co-culture supernatants were measured using enzyme-linked immunosorbent assay.

RESULTS

The PMN apoptotic rate in the IH-exposed rat group was significantly lower than that of the normoxia control group. There was a positive relationship between the PMN apoptotic rate and IH exposure time. In endothelial cells co-cultured with PMNs isolated from IH-exposed rats, a significant increase in the protein expression levels of Bax, Bcl-2, and caspase-3 and a significant decrease in the Bcl-2/Bax ratio were observed. Furthermore, the intercellular cell adhesion molecule-1(ICAM-1) and E-select element (E-S) levels were elevated significantly in the co-cultured supernatants of endothelial cells and PMNs from IH-exposed rats compared to that from controls. The above IH-induced alterations were partially restored by tempol pretreatment.

CONCLUSIONS

The apoptotic rate was low in PMNs from IH-exposed rats, which consequently increased the apoptotic signals in endothelial cells in vitro. This may be associated with the increased levels of intercellular adhesion molecules. Further, tempol partially attenuates the PMN-mediated pro-apoptotic effects on endothelial cells under IH.

Association between Neutrophil to Lymphocyte Ratio and the Extent of Coronary Artery Disease in Patients with STEMI Versus Patients With Stable Angina Undergoing PCI: An Idea for Investigation of Other Inflammatory Diseases

Background: Inflammation plays an important role in the pathogenesis of diseases such as atherosclerosis and other inflammatory disorders. The inflammatory markers impose a considerable cost on the health system. Recently, neutrophil to lymphocyte ratio (NLR) has been shown to be involved in the prediction of coronary artery disease (CAD). Objectives: This study was conducted to clarify the potential relationship between NLR and the inflammatory extent of CAD. Materials and Methods: Patients with ST-elevation myocardial infarction (STEMI) or stable angina who underwent primary or elective percutaneous coronary intervention (PCI), respectively, were included in this cross-sectional study. Patients with hematologic disorders, recent or active infectious or inflammatory diseases, history of malignancy, and history of treatment with immunosuppressive drugs were excluded from the study. Gensini and SYNTAX scores were calculated for each patient as an indicator of the extent of CAD. Demographic and clinical characteristics were obtained through a questionnaire and NLR was calculated using laboratory results. Results: A total of 446 patients (223 patients in each group) fulfilled the inclusion criteria. NLR had a significant relationship with Gensini score in both stable angina and STEMI patients. Gensini and SYNTAX scores correlated significantly with NLR; however, the correlation was weaker for SYNTAX score. After adjustment for confounding factors, including age and hypercholesterolemia, only one trend remained for the Gensini scores. Conclusion: NLR showed a stronger correlation with Gensini score than SYNTAX score. Our findings are in accordance with previous studies, which show that NLR has a relationship with the extent of CAD. Further studies are required for reaching a definite conclusion. The idea of this study may be useful for the investigation of other inflammatory diseases.

Clinical utility of circulating interleukin-6 concentrations in the detection of functionally relevant coronary artery disease

BACKGROUND

Inflammation plays a major role in the pathogenesis of coronary artery disease (CAD).

METHODS

We hypothesized, that quantifying inflammation by measuring circulating interleukin-6 concentrations help in the diagnosis and/or prediction of functionally relevant CAD. Among consecutive patients with symptoms suggestive of CAD, functionally relevant CAD was adjudicated in two domains: first, diagnosis according to myocardial perfusion single photon emission tomography (MPI-SPECT) and coronary angiography; second, cardiovascular death and all-cause death during 2-years follow-up. Adjudication was done blinded to the interleukin-6 concentrations.

RESULTS

Among 1553 patients, symptoms were adjudicated to be causally related to CAD in 43% (665/1553). Interleukin-6 concentrations were higher in patients with functionally relevant CAD as compared to those without (1.56 pg/mL versus 1.30 pg/mL, p < 0.001), but overall had only low-to-modest diagnostic accuracy (area under the curve [AUC]: 0.57, 95%CI 0.55-0.61) and were no independent predictor of functionally relevant CAD after multivariable adjustment (p = 0.068). Interleukin-6 concentrations had moderate-to-high accuracy in the prediction of cardiovascular death (AUC 0.75, 95%CI 0.69-0.82) and all-cause death (AUC 0.72, 95%CI 0.66-0.78) at 2-years, and remained a significant predictor after multivariable adjustment (p < 0.001). Compared to patients with interleukin-6 concentrations below the median (1.41 pg/mL), patients with concentrations above the median had a significantly higher cumulative incidence of cardiovascular death (1% vs. 4%, log-rank p < 0.001) and all-cause death (2% vs. 8%, log-rank p < 0.001) at 2 years.

CONCLUSION

Interleukin-6 concentrations are strong and independent predictors of cardiovascular death and all-cause death.

Apolipoprotein L Expression Correlates with Neutrophil Cell Death in Critically Ill Patients

Delayed neutrophil apoptosis has been demonstrated in sepsis and may contribute to organ damage. It has recently been proposed that apolipoprotein L (ApoL) may be involved in programmed cell death, but the expression and functions of ApoLs in leukocytes (especially neutrophils) during sepsis and other inflammatory conditions are currently unknown. In this prospective observational study in a 36-bed university hospital medicosurgical intensive care unit (ICU), we included 78 adult ICU patients with (n = 41) or without (n = 37) sepsis and 47 healthy volunteers. We analyzed ApoL mRNA expression using quantitative polymerase chain reaction in whole blood leukocytes and protein expression in CD15 isolated neutrophils using Western blotting. Neutrophil apoptosis was assessed using the APO-BRDU method. Apolipoprotein L mRNA was downregulated in whole blood leukocytes and neutrophils in ICU patients compared with in healthy volunteers, and this effect translated at the protein level as indicated by Western blot analysis of neutrophils. There was a negative correlation between ApoL expression in neutrophils and C-reactive protein levels and a positive correlation between the number of apoptotic neutrophils and mRNA levels of ApoL1 and ApoL2. The degree of neutrophil apoptosis in critically ill patients is therefore correlated with modified expression profiles of ApoLs.

Platelet-derived PF4 reduces neutrophil apoptosis following arterial occlusion

Note: The editorial process for this manuscript was fully handled by Gregory Y. H. Lip, Editor in Chief.

Delayed neutrophil apoptosis mediates intermittent hypoxia-induced progressive heart failure in pressure-overloaded rats

BACKGROUND AND OBJECTIVE

Obstructive sleep apnea (OSA) and heart failure (HF) are common coexisting diseases. Intermittent hypoxia (IH), caused by repeated apnea/hypopnea events, accompanied by increased systemic inflammation, might contribute to the promotion of HF.

METHODS

To assess the hypothesis, rats were exposed to IH or normal air condition 4 weeks on the basis of normal heart function or pre-existing HF, which was induced by pressure overload caused by abdominal aortic constriction surgery performed 12 weeks earlier. Echocardiography was performed before and after IH exposure to evaluate left ventricular (LV) function. Serum concentrations of pro-inflammatory cytokines TNF-α and IL-6 were detected by enzyme-linked immunosorbent assay. Flow cytometric analysis was used to determine the apoptotic rate of polymorphonuclear neutrophils (PMNs).

RESULTS

The echocardiographic study showed a significant decrease in LV fractional shortening (FS) and ejection fraction (EF) as well as an increase in the LV relative wall thickness (RWT) index in HF rats, which was aggravated by further exposure to IH compared with single-handed HF-only and sham-IH and sham-control groups. A reduced PMN apoptotic rate was observed in HF-IH rats compared with HF-only, sham-IH, and sham-control rats. Serum concentrations of TNF-α and IL-6 were also increased in HF-IH rats, accompanied by delayed PMN apoptosis, indicating significant systemic inflammation induced by IH.

CONCLUSION

The results of this study demonstrated that IH aggravates LV remodeling and heart dysfunction in rats with pre-existing HF. Delayed neutrophil apoptosis, which was revealed in HF rats following exposure to IH, contributed to the exacerbation of myocardial damage and progression of heart dysfunction.

CXCR4 blockade induces atherosclerosis by affecting neutrophil function

AIMS

The SDF-1α/CXCR4 dyad was previously shown by us and others to be instrumental in intimal hyperplasia as well as early stage atherosclerosis. We here sought to investigate its impact on clinically relevant stages of atherosclerosis in mouse and man.

METHODS AND RESULTS

Immunohistochemical analysis of CXCR4 expression in human atherosclerotic lesions revealed a progressive accumulation of CXCR4(+) cells during plaque progression. To address causal involvement of CXCR4 in advanced stages of atherosclerosis we reconstituted LDLr(-/-) mice with autologous bone marrow infected with lentivirus encoding SDF-1α antagonist or CXCR4 degrakine, which effects proteasomal degradation of CXCR4. Functional CXCR4 blockade led to progressive plaque expansion with disease progression, while also promoting intraplaque haemorrhage. Moreover, CXCR4 knockdown was seen to augment endothelial adhesion of neutrophils. Concordant with this finding, inhibition of CXCR4 function increased adhesive capacity and reduced apoptosis of neutrophils and resulted in hyperactivation of circulating neutrophils. Compatible with a role of the neutrophil CXCR4 in end-stage atherosclerosis, CXCR4 expression by circulating neutrophils was lowered in patients with acute cardiovascular syndromes.

CONCLUSION

In conclusion, CXCR4 contributes to later stages of plaque progression by perturbing neutrophil function.

Impact of inflammation on adverse cardiovascular events in patients with acute coronary syndromes

AIMS

Inflammation is a key factor in the long-term outcome of acute coronary syndromes (ACS). The aim of the present study was to evaluate inflammatory markers in patients with ACS as predictors for major adverse cardiovascular events (MACE) and hard events.

METHODS

This study included 1548 patients with ACS. C-reactive protein (CRP), white blood count (WBC), and their subtypes were analyzed during hospitalization. Receiver operator characteristic (ROC) and Kaplan-Meier survival curves were used to assess the predictive value and hard events (nonfatal myocardial infarction and cardiac death) and MACE (hard events, hospitalization for cardiac causes, late revascularization and stroke) were obtained during 30 days.

RESULTS

ROC analysis of CRP and WBC to predict adverse events revealed cut-offs of 47.5 ng/l and 16.6 × 10/μl for MACE and 93.5 ng/l and 16.6 × 10/μl for hard events. The cumulative adverse event rates were significantly higher in patients with increased CRP (≥47.5 ng/l; 17 versus 4%, P < 0.001) and WBC (≥16.6 × 10/μl; 21 versus 5%, P < 0.001) for MACE and with elevated CRP (≥93.5 ng/l; 16 versus 2%, P < 0.001) and WBC (≥16.6 × 10/μl; 18 versus 2%, P < 0.001) for hard events, demonstrating highest event rates with elevation of both inflammatory markers: (28 versus 5%, P < 0.001) for MACE and (26 versus 2%, P < 0.001) for hard events. Analysis of CRP and WBC further revealed a substantial negative correlation with left ventricular function (P < 0.001). Moreover, markers of myocardial damage were significantly elevated in patients with abnormal CRP or WBC (P < 0.001).

CONCLUSION

Inflammatory markers such as CRP and WBC alone and, particularly, in combination are strong and independent predictors of outcome in patients with ACS.

Targeting inflammation: impact on atherothrombosis

Atherothrombosis is a worldwide epidemic accounting for an unacceptable toll of deaths and disabilities. Its pathophysiology is complex and hardly referable to a specific mechanism; however, in the last 20 years, a growing amount of evidence has demonstrated that inflammatory processes play a major role from the very beginning to the ultimate complication of atherothrombosis. These evidences are addressing a growing interest toward anti-inflammatory agents as preventive or curative treatments of atherothrombosis. At present, accumulated data are not conclusive, but strong evidence exists in favor of an anti-inflammatory positive effect for several drugs as statins or renin-angiotensin inhibitors. More conclusive data are expected from ongoing trials directly exploring the role of specific cytokines antagonists.

Elevated levels of circulating DNA and chromatin are independently associated with severe coronary atherosclerosis and a prothrombotic state

OBJECTIVE

Aberrant neutrophil activation occurs during the advanced stages of atherosclerosis. Once primed, neutrophils can undergo apoptosis or release neutrophil extracellular traps. This extracellular DNA exerts potent proinflammatory, prothrombotic, and cytotoxic properties. The goal of this study was to examine the relationships among extracellular DNA formation, coronary atherosclerosis, and the presence of a prothrombotic state.

APPROACH AND RESULTS

In a prospective, observational, cross-sectional cohort of 282 individuals with suspected coronary artery disease, we examined the severity, extent, and phenotype of coronary atherosclerosis using coronary computed tomographic angiography. Double-stranded DNA, nucleosomes, citrullinated histone H4, and myeloperoxidase-DNA complexes, considered in vivo markers of cell death and NETosis, respectively, were established. We further measured various plasma markers of coagulation activation and inflammation. Plasma double-stranded DNA, nucleosomes, and myeloperoxidase-DNA complexes were positively associated with thrombin generation and significantly elevated in patients with severe coronary atherosclerosis or extremely calcified coronary arteries. Multinomial regression analysis, adjusted for confounding factors, identified high plasma nucleosome levels as an independent risk factor of severe coronary stenosis (odds ratio, 2.14; 95% confidence interval, 1.26-3.63; P=0.005). Markers of neutrophil extracellular traps, such as myeloperoxidase-DNA complexes, predicted the number of atherosclerotic coronary vessels and the occurrence of major adverse cardiac events.

CONCLUSIONS

Our report provides evidence demonstrating that markers of cell death and neutrophil extracellular trap formation are independently associated with coronary artery disease, prothrombotic state, and occurrence of adverse cardiac events. These biomarkers could potentially aid in the prediction of cardiovascular risk in patients with chest discomfort.

Pathophysiological role of neutrophils in acute myocardial infarction

The pathogenesis of acute myocardial infarction is known to be mediated by systemic, intraplaque and myocardial inflammatory processes. Among different immune cell subsets, compelling evidence now indicates a pivotal role for neutrophils in acute coronary syndromes. Neutrophils infiltrate coronary plaques and the infarcted myocardium and mediate tissue damage by releasing matrix-degrading enzymes and reactive oxygen species. In addition, neutrophils are also involved in post-infarction adverse cardiac remodelling and neointima formation after angioplasty. The promising results obtained in preclinical modelswith pharmacological approaches interfering with neutrophil recruitment or function have confirmed the pathophysiological relevance of these immune cells in acute coronary syndromes and prompted further studies of these therapeutic interventions. This narrative review will provide an update on the role of neutrophils in acute myocardial infarction and on the pharmacological means that were devised to prevent neutrophil-mediated tissue damage and to reduce post-ischaemic outcomes.

Myeloperoxidase may help to differentiate coronary plaque erosion from plaque rupture in patients with acute coronary syndromes

Coronary thrombosis is the most frequent final event leading to an acute coronary syndrome. In approximately two-thirds of cases, the thrombus overlies a ruptured plaque, whereas in one-third of cases it overlies an intact plaque with superficial endothelial erosion, a finding showed initially by histopathological postmortem studies and more recently confirmed by in vivo optical coherence tomography imaging. Interestingly, recent observations suggest that mechanisms leading to plaque rupture or erosion are different. In fact, in a recent study, we showed that myeloperoxidase levels in peripheral blood and expression within thrombi overlying the culprit plaque are much higher in patients with plaque erosion than in those with plaque rupture. These observations suggest that innate immunity activation is likely to play a key role, in particular, in plaque erosion and might become a therapeutic target in this subset of patients.

T-cell proliferation by surface molecules expression on polymorphonuclear neutrophils stimulated with IL-4 in superantigen presence

BACKGROUND

Polymorphonuclear neutrophils (PMNs) were originally described as short lived and terminally differentiated phagocytes that contribute only to the innate immune response. Some studies of PMNs cytokine production and expression of numerous cell surface proteins has suggested that PMNs are likely to influence adaptive responses and may satisfy the criteria of antigen presenting cells.

AIM OF THE STUDY

This work aimed to study the effect of IL-4 in the function of PMNs as antigen presenting cells.

METHODS

Flow cytometry was used in the present study for the detection of cell surface human leukocyte antigen (HLA) class II, CD80 and CD86 required for antigen presentation and subsequent T-cell activation in the presence of Staphylococcus aureus enterotoxin (A). Human peripheral blood neutrophils were used for this purpose.

RESULTS

This study has shown that IL-4 stimulated PMNs for 24h expressed HLA class II, CD80 and CD86 that involved in antigen presentation. It also indicated that co-cultivation of IL-4 stimulated PMNs with autologous T-cells and in the presence of S. aureus enterotoxin (A) induced T-cell proliferation.

CONCLUSIONS

In vitro stimulation of PMNs with IL-4 showed expression of surface molecules involved in antigen presentation. In addition, the co-culture of T-Cells and stimulated PMNs showed high T-Cells proliferation in the presence of superantigens.

Neutrophils and clinical outcomes in patients with acute coronary syndromes and/or cardiac revascularisation. A systematic review on more than 34,000 subjects

Some studies have suggested that high levels of total white blood cell (WBC) count and C-reactive protein (CRP) may be considered as independent prognostic factors in patients with acute coronary syndromes (ACS) and/or after cardiac revascularisation by percutaneous coronary intervention or coronary artery bypass grafting surgery. Evidence on the role of neutrophils in cardiovascular disease is less compelling. Therefore, we conducted a systematic review of the literature with the aim of identifying all the available evidence to clarify the role of neutrophils (absolute or relative count, neutrophil/lymphocyte ratio) as a prognostic risk factor in patients with ACS and/or cardiac revascularisation. All published studies evaluating the role of neutrophils as a risk factor for clinical outcomes were assessed using the MEDLINE and EMBASE databases. Study selection, data extraction and validity assessment was performed independently by two reviewers. Twenty-one studies (17 of which had positive results) for a total of more than 34,000 patients were included. Ten of 13 studies in ACS patients found that neutrophils measured on-admission are related to mortality rate and/or to major adverse clinical events. A predictive value of neutrophils after cardiac revascularisation procedures was reported in seven out of eight studies. Most of the studies showed that neutrophils were independent predictors of cardiovascular outcomes when analysed concomitantly with other markers of inflammation (WBC, CRP). The findings of our systematic review highlight the potential application of this inexpensive and readily available inflammatory marker for risk stratification in patients with ACS and/or cardiac revascularisation.

Cardiovascular risk in obesity: different activation of inflammation and immune system between obese and morbidly obese subjects

BACKGROUND

Both inflammation and immunity are involved in the development and progression of atherosclerosis. Obesity is considered a major modifiable cardiovascular risk factor, however, the correlation between increasing degrees of obesity and cardiovascular risk is not clear yet. Aim of our study was to investigate how different degrees of obesity are associated with inflammation and immune system responses.

METHODS

One-hundred healthy individuals were divided into 3 groups according to body mass index (BMI): 22 overweight (OW), 26 obese (O) and 52 morbidly obese (MO). High-sensitivity C-Reactive Protein (hs-CRP, immunonephelometry), leptin (radio-immunoassay) and CD4+CD28nullT-lymphocytes (flow-cytometry), a particular subset of T-lymphocytes with pro-atherogenic and plaque-destabilizing properties, were assessed.

RESULTS

hs-CRP levels were significantly higher in O vs OW (p=0.036), in MO vs OW (p<0.001) and in MO vs O (p=0.012). Similarly, leptin levels were higher in O vs OW (p=0.02), in MO vs OW (p<0.001) and in MO vs O (p<0.001). CD4+CD28nullT-lymphocytes were higher in O vs OW (p<0.001), in O vs MO (p=0.03) and in MO vs OW (p=0.01). hs-CRP and leptin levels significantly correlated each other (r=0.39; p<0.001) and with waist circumference (r=0.52; p<0.001; r=0.64; p<0.001) and BMI (r=0.60; p<0.001; r=0.74; p<0.001).

CONCLUSIONS

Our study demonstrates that, notwithstanding higher levels of inflammation, MO are characterized by less detrimental immune activation, as shown by the reduced CD4+CD28nullT-cells expansion as compared to OW and O, which might translate in less immune vascular injury. These findings suggest that MO might represent a particular population, in which different pathophysiological mechanisms take part if compared with "classic" obesity.