Serum neutrophil gelatinase-associated lipocalin levels are correlated with the complexity and the severity of atherosclerosis in acute coronary syndrome

The predictive role of neutrophil gelatinase-associated lipocalin in coronary artery disease

The prognosis holds significant implications for the long-term quality of life among patients suffering from coronary artery disease. However, a pressing challenge lies in the absence of reliable biomarkers that can establish a definitive correlation between these biomarkers and the prognosis of coronary artery heart disease. This review paper delves into the critical role of neutrophil gelatinase-associated lipocalin (NGAL) in predicting outcomes in coronary artery disease. It examines the influence of NGAL on various clinical manifestations, including stable angina, ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction, and isolated coronary artery dilation. Furthermore, this review provides recommendations aimed at enhancing the rigor and impact of future research, thereby serving as a valuable reference for subsequent studies in this domain.

Correlation between neutrophil gelatinase phase lipocalin and cerebral small vessel disease

Background

Cerebral small vessel disease (CSVD) is common in the elderly population. Neutrophil gelatinase-associated lipocalin (NGAL) is closely related to cardiovascular and cerebrovascular diseases. NGAL causes pathological changes, such as damage to the vascular endothelium, by causing inflammation, which results in other related diseases. The purpose of this study was to investigate whether serum NGAL levels could predict disease severity in patients with CSVD.

Methods

The patients with CSVD who visited the Department of Neurology at the First Affiliated Hospital of Zhengzhou University between January 2018 and June 2022 were prospectively included. The total CSVD burden score was calculated using whole-brain magnetic resonance imaging (MRI), and the patients were divided into a mild group (total CSVD burden score < 2 points) and a severe group (total CSVD burden score ≥ 2 points). Age, sex, height, smoking and alcohol consumption history, medical history, and serological results of patients were collected to perform the univariate analysis. Multivariate logistic regression was used to analyze the risk factors that affect CSVD severity. The multiple linear regression method was used to analyze which individual CSVD markers (periventricular white matter hyperintensities, deep white matter hyperintensities, lacune, and cerebral microbleed) play a role in the association between total CSVD burden score and NGAL.

Results

A total of 427 patients with CSVD (140 in the mild group and 287 in the severe group) were included in the study. A multivariate logistic regression analysis showed that the following factors were significantly associated with CSVD severity: male sex [odds ratio(OR), 1.912; 95% confidence interval (CI), 1.150-3.179], age (OR, 1.046; 95% CI, 1.022-1.070), history of cerebrovascular disease (OR, 3.050; 95% CI, 1.764-5.274), serum NGAL level (OR, 1.005; 95% CI, 1.002-1.008), and diabetes (OR, 2.593; 95% CI, 1.424-4.722). A multivariate linear regression shows that periventricular white matter hyperintensities and cerebral microbleed are associated with serum NGAL concentrations (P < 0.05).

Conclusion

Serum NGAL level is closely related to CSVD severity and is a risk factor for the burden of CSVD brain damage. Serum NGAL has high specificity in reflecting the severity of CSVD.

The Review of Current Knowledge on Neutrophil Gelatinase-Associated Lipocalin (NGAL)

Neutrophil gelatinase-associated lipocalin (NGAL) is a 25-kDa protein that is secreted mostly by immune cells such as neutrophils, macrophages, and dendritic cells. Its production is stimulated in response to inflammation. The concentrations of NGAL can be measured in plasma, urine, and biological fluids such as peritoneal effluent. NGAL is known mainly as a biomarker of acute kidney injury and is released after tubular damage and during renal regeneration processes. NGAL is also elevated in chronic kidney disease and dialysis patients. It may play a role as a predictor of the progression of renal function decreases with complications and mortality due to kidney failure. NGAL is also useful in the diagnostic processes of cardiovascular diseases. It is highly expressed in injured heart tissue and atherosclerostic plaque; its serum concentrations correlate with the severity of heart failure and coronary artery disease. NGAL increases inflammatory states and its levels rise in arterial hypertension, obesity, diabetes, and metabolic complications such as insulin resistance, and is also involved in carcinogenesis. In this review, we present the current knowledge on NGAL and its involvement in different pathologies, especially its role in renal and cardiovascular diseases.

Lipocalin family proteins and their diverse roles in cardiovascular disease

The lipocalin (LCN) family members, a group of small extracellular proteins with 160-180 amino acids in length, can be detected in all kingdoms of life from bacteria to human beings. They are characterized by low similarity of amino acid sequence but highly conserved tertiary structures with an eight-stranded antiparallel β-barrel which forms a cup-shaped ligand binding pocket. In addition to bind small hydrophobic ligands (i.e., fatty acids, odorants, retinoids, and steroids) and transport them to specific cells, lipocalins (LCNs) can interact with specific cell membrane receptors to activate their downstream signaling pathways, and with soluble macromolecules to form the complex. Consequently, LCNs exhibit great functional diversity. Accumulating evidence has demonstrated that LCN family proteins exert multiple layers of function in the regulation of many physiological processes and human diseases (i.e., cancers, immune disorders, metabolic disease, neurological/psychiatric disorders, and cardiovascular disease). In this review, we firstly introduce the structural and sequence properties of LCNs. Next, six LCNs including apolipoprotein D (ApoD), ApoM, lipocalin 2 (LCN2), LCN10, retinol-binding protein 4 (RBP4), and Lipocalin-type prostaglandin D synthase (L-PGDS) which have been characterized so far are highlighted for their diagnostic/prognostic values and their potential effects on coronary artery disease and myocardial infarction injury. The roles of these 6 LCNs in cardiac hypertrophy, heart failure, diabetes-induced cardiac disorder, and septic cardiomyopathy are also summarized. Finally, their therapeutic potential for cardiovascular disease is discussed in each section.

Adipokines and adipocytokines in men with coronary atherosclerosis and overweight

Aim    To study concentrations of adipokines and their associations with proinflammatory cytokines in overweight men with coronary atherosclerosis. Material and methods    This study included 79 men aged 45–60 years with atherosclerosis who had undergone coronary endarterectomy during a coronary bypass surgery, and were overweight (body weight index (BWI), 25.0–29.9 kg /m2). Based on a histological analysis of plaques, the patients were divided into two subgroups: 43 men with stable atherosclerotic plaques and 36 men with unstable plaques in coronary arteries. The control group consisted of 40 age- and BWI-matched men without clinical manifestations of IHD. Blood concentrations of adipokines, including adiponectin, adipsin, lipocalin-2, resistin, and plasminogen 1 activator inhibitor were measured by a multiplex analysis with a MILLIPLEX MAP Human Adipokine Panel 1. Concentrations of proinflammatory cytokines, including tumor necrosis factor α (TNF- α), interleukin (IL)-1β, IL-6, and C-reactive protein (CRP) were measured by enzyme immunoassay. Results    The blood concentration of lipocalin -2 was higher in patients with coronary atherosclerosis and stable or unstable atherosclerotic plaques than in the control group (p<0.01). Both subgroups of men with coronary atherosclerosis were characterized by significant differences from the control group in concentrations of TNF-α (p<0.05), CRP, and IL-6 (p<0.01). The most significant direct correlations were found between adipokines and TNF-α, IL-6, and CRP (p<0.01). Results of a logistic regression analysis showed that relative odds for the presence of significant coronary stenoses increased with increasing blood concentrations of lipocalin-2 (OR=1.005, 95 % CI: 1.002–1.008, р=0.011) and IL-6 (OR=1.582 , 95 % CI: 1.241–2.017, р=0.001).Conclusion    The changes in blood concentrations of adipokines associated with higher levels of proinflammatory cytokines may represent a factor that increases the probability of clinically significant coronary stenosis in overweight men with coronary atherosclerosis.

Neutrophil Gelatinase-Associated Lipocalin as Potential Predictive Biomarker of Melanoma and Non-Melanoma Skin Cancers in Psoriatic Patients: A Pilot Study

Background: Studies have demonstrated a higher risk of nonmelanoma skin cancers (NMSC) and a modestly increased melanoma risk in patients with psoriasis. To date, no biomarkers predictive of evolution have been identified yet. Methods: The aim of this prospective case-control study was to investigate the potential role of neutrophil gelatinase-associated lipocalin (NGAL) as a predictive biomarker of skin cancers in psoriatic patients. Patients with a diagnosis of psoriasis were enrolled, as well as healthy subjects and patients with skin cancers as controls. Plasma protein expression of NGAL, metalloproteinases (MMP)-2, and MMP-9 was performed by an enzyme-linked immunosorbent assay (ELISA). In all the patients who developed skin cancer at follow-up, NGAL, MMP-2, and MMP-9 serum levels were dosed again. Results: Plasma NGAL levels were significantly higher in psoriatic patients with NMSC than without (182.3 ± 36.6 ng/mL vs. 139.9 ± 39.3 ng/mL) (p < 0.001). Plasma NGAL levels were significantly higher (p < 0.00001) in patients with psoriasis and NMSC than in patients with skin tumors without psoriasis (182.3 vs. 122.9). Patients with psoriasis who developed NMSC at follow-up showed increased plasma MMP-9 levels. Conclusion: NGAL seems to play a role in the pathogenesis of NMSC but not melanoma in patients with psoriasis.

Neutrophil gelatinase-associated lipocalin: a potential predictor of embolic events in endocarditis

BACKGROUND

As the complication of infective endocarditis (IE), embolic events (EE) are associated with increased mortality and morbidity. However, there are no reliable indicators to predict embolism. The aim of this study was to evaluate neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker to identify IE patients at high risk of embolism.

METHODS

We conducted a prospective observational study of IE patients from January 2018 to December 2020. Plasma NGAL levels were measured in 88 IE patients (37 patients with EE and 51 patients without EE), 91 noninfectious heart valve disease (HVD) patients, and 20 healthy blood donors by ELISA. Native valve tissue was obtained from 16 IE patients and 16 HVD patients. Western blot and immunohistochemical staining were performed to detect NGAL and matrix metalloproteinas-9 (MMP-9).

RESULTS

Higher levels of NGAL were observed in IE patients than HVD patients (P<0.001) or healthy blood donors (P<0.01). In addition, NGAL levels were higher in IE patients with EE compared to those without EE (P<0.001). Receiver operating characteristic analysis demonstrated that NGAL acted as a potential EE predictor with the cutoff value of 166.78 ng/ml. IE patients with higher NGAL levels were significantly related to more severe native valve morphologic changes. NGAL was co-localized with MMP-9, and their expression in the valves of IE patients was higher than those of HVD patients.

CONCLUSIONS

NGAL is a potential predictor of EE in IE. This may be attributed to its potency of increasing the proteolytic activity of MMP-9, which leads to valve morphologic impairment.

Identification of plaque ruptures using a novel discriminative model comprising biomarkers in patients with acute coronary syndrome

Soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1), neutrophil gelatinase-associated lipocalin (NGAL), and matrix metalloproteinase-9 (MMP-9) are inflammatory biomarkers involved in plaque destabilization resulting in acute coronary syndrome (ACS). This study aimed to investigate the diagnostic value of a combination of biomarkers to discriminate plaque ruptures in the setting of ACS. Eighty-five ACS patients with optical coherence tomography (OCT) images of the culprit plaque were included and categorized into two groups: ACS with plaque rupture (Rupture group, n = 42) or without plaque rupture (Non-rupture group, n = 43) verified by OCT. A discriminative model of plaque rupture using several biomarkers was developed and validated. The Rupture group had higher white blood cell (WBC) counts and peak creatine kinase-myocardial band (CK-MB) levels (13.39 vs. 2.69 ng/mL, p = 0.0016). sLOX-1 (227.9 vs. 51.7 pg/mL, p < 0.0001) and MMP-9 (13.4 vs. 6.45 ng/mL, p = 0.0313) levels were significantly higher in the Rupture group, whereas NGAL showed a trend without statistical significance (59.03 vs. 53.80 ng/mL, p = 0.093). Receiver operating characteristic curves to differentiate Rupture group from Non-rupture group calculated the area under the curve for sLOX-1 (p < 0.001), MMP-9 (p = 0.0274), and NGAL (p = 0.0874) as 0.763, 0.645, and 0.609, respectively. A new combinatorial discriminative model including sLOX-1, MMP-9, WBC count, and the peak CK-MB level showed an area under the curve of 0.8431 (p < 0.001). With a cut-off point of 0.614, the sensitivity and specificity of plaque rupture were 62.2% and 97.6%, respectively. The new discriminative model using sLOX-1, MMP-9, WBC count, and peak CK-MB levels could better identify plaque rupture than each individual biomarker in ACS patients.

NGAL Correlates with Femoral and Carotid Plaque Volume Assessed by Sonographic 3D Plaque Volumetry

Background/Objectives: Inflammation represents a cornerstone in the development of atherosclerosis and early detection is essential to avoid cardiovascular events. Biomarkers like interleukin-1 beta, interleukin-6, or high sensitivity CRP (hs-CRP) have been investigated intensively in this field. Since they have several limitations, additional biomarkers are needed for cardiovascular risk stratification. The acute phase protein, neutrophil gelatinase-associated lipocalin (NGAL), modulates inflammation and is elevated in cardiovascular disease (CVD). Moreover, it contributes to plaque destabilization. Methods: In this prospective, single-center study, we included 323 asymptomatic patients with at least one cardiovascular risk factor or established CVD. NGAL levels were measured in plasma samples using a commercially available ELISA. Carotid, femoral, and total atherosclerotic plaque volumes (PV) were measured using a 3D ultrasound system (Philips iU22). Patients were separated into a low (n = 243) and high (n = 80) total PV group. Results: NGAL was significantly higher in patients with high total PV versus patients with low total PV. The NGAL amplitude for the prediction of high total PV was significantly higher when compared with hs-CRP. A high predictive value could also be observed for patients without established CVD. Conclusion: NGAL seems to be a promising biomarker for the identification of asymptomatic patients with atherosclerotic disease.

Plasma neutrophil gelatinase-associated lipocalin levels are associated with the presence and severity of coronary heart disease

OBJECTIVE

This study aimed to compare the levels of plasma neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinase (MMP)-9, high-sensitivity C-reactive protein (hs-CRP), and interleukin (IL)-1β across different clinical presentations of coronary artery disease and to evaluate the relationship between those biomarkers and the severity of coronary artery lesions in patients without kidney disease.

METHODS

We examined 365 eligible patients who underwent coronary angiography. A total of 124 ST-segment elevation myocardial infarction (STEMI) patients, 117 stable angina pectoris (SAP) patients and 124 patients without atherosclerotic plaques were enrolled in the study. Plasma NGAL, MMP-9, hs-CRP, and IL-1β were measured in all patients using the enzyme-linked immunosorbent assay (ELISA) method. According to the SYNTAX score, the STEMI patients and SAP patients were divided into another set of 2 groups: a high score group (≥ 33, n = 29) and a low score group (<33, n = 212). The relationship between those biomarkers and the severity of coronary stenosis was examined by Spearman correlation analysis; the ability for NGAL to discriminate severe coronary stenosis was examined by receiver operating characteristic (ROC) curve; the influencing factors for the SYNTAX score were determined by logistic regression analysis.

RESULTS

Plasma NGAL, MMP-9, and hs-CRP levels in STEMI patients were higher than in the SAP patients and control subjects (P<0.05, respectively), and plasma NGAL and hs-CRP levels were significantly higher in the SAP patients than in control subjects (P<0.05, respectively), while plasma IL-1β was similar among the 3 groups (P>0.05, respectively). The SYNTAX score was positively related to NGAL (r = 0.363, P<0.001), MMP-9 (r = 0.377, P<0.001), and hs-CRP (r = 0.163, P<0.011); the SYNTAX score was not related to IL-1β (r = -0.043, P = 0.510). Plasma NGAL was positively related to MMP-9 (r = 0.601, P<0.001) and IL-1β (r = 0.159, P = 0.014). The area under the ROC curve for NGAL discriminating severe coronary stenosis was 0.838 (95% CI: 0.752-0.923, P<0.001), which was greater than that for MMP-9 [0.818, (95% CI: 0.724-0.912, P<0.001)], IL-1β [0.485, (95% CI: 0.369-0.601, P = 0.791)], and hs-CRP [0.607, (95% CI: 0.492-0.722, P = 0.061)]. Multivariate regression analysis showed that plasma NGAL levels were independently related to high SYNTAX scores [OR = 1.109, (95% CI: 1.104-1.114), P<0.001].

CONCLUSION

Plasma NGAL, MMP-9, and hs-CRP levels in STEMI patients were higher than those in the SAP patients and control subjects. NGAL had a better ability to discriminate severe coronary stenosis than MMP-9, IL-1β, and hs-CRP. NGAL may be a novel biomarker to aid in risk stratification in coronary heart disease patients.

Neutrophil gelatinase-associated lipocalin (NGAL) and cardiovascular events in patients with stable coronary artery disease

Inflammation is an important mediator in the pathogenesis of atherosclerosis. Neutrophil gelatinase-associated lipocalin (NGAL) is a small glycoprotein secreted by neutrophils. NGAL regulates the activity of matrix metalloproteinase-9, which plays a role in plaque instability. It has therefore been hypothesised that NGAL may modulate inflammation and promote the development and progression of atherosclerosis. Our aim was to assess the predictive value of plasma NGAL in a prospective cohort study of 876 high-risk patients with stable coronary artery disease (CAD). NGAL levels were measured using the NGAL Test^TM from BioPorto Diagnostics. Clinical follow-up was performed after a median of 3.1 years. The endpoint was a combination of non-fatal acute myocardial infarction (MI), cardiovascular death (CVD), or ischaemic stroke. The NGAL concentration was (median [25;75%]: 64.3 µg/L [51.3;81.4]). The area under the receiver operating characteristic curve (AUC) was 0.56 (95% confidence interval (CI): 0.49;0.64) for the diagnosis of the composite endpoint and 0.66 (95% CI: 0.56;0.75) after adding NGAL to high-sensitive C-reactive protein (hs-CRP), leucocyte count, interleukin-6 (IL-6), calprotectin, age, sex, body mass index (BMI), diabetes mellitus, smoking and creatinine. However, the AUC for hs-CRP, leucocyte count, IL-6, calprotectin, age, sex, BMI, diabetes mellitus, smoking and creatinine without NGAL was similar at 0.66 (95% CI: 0.56;0.76). NGAL alone had no predictive value with respect to the composite endpoint of non-fatal AMI, ischaemic stroke, or CVD in stable CAD patients. NGAL did not add any predictive value to the endpoint compared with existing inflammatory biomarkers and cardiovascular risk factors.

More than a simple biomarker: the role of NGAL in cardiovascular and renal diseases

Neutrophil gelatinase-associated lipocalin (NGAL) is a small circulating protein that is highly modulated in a wide variety of pathological situations, making it a useful biomarker of various disease states. It is one of the best markers of acute kidney injury, as it is rapidly released after tubular damage. However, a growing body of evidence highlights an important role for NGAL beyond that of a biomarker of renal dysfunction. Indeed, numerous studies have demonstrated a role for NGAL in both cardiovascular and renal diseases. In the present review, we summarize current knowledge concerning the involvement of NGAL in cardiovascular and renal diseases and discuss the various mechanisms underlying its pathological implications.

The role of monocytosis and neutrophilia in atherosclerosis

Monocytosis and neutrophilia are frequent events in atherosclerosis. These phenomena arise from the increased proliferation of hematopoietic stem and multipotential progenitor cells (HSPCs) and HSPC mobilization from the bone marrow to other immune organs and circulation. High cholesterol and inflammatory signals promote HSPC proliferation and preferential differentiation to the myeloid precursors (i.e., myelopoiesis) that than give rise to pro-inflammatory immune cells. These cells accumulate in the plaques thereby enhancing vascular inflammation and contributing to further lesion progression. Studies in animal models of atherosclerosis showed that manipulation with HSPC proliferation and differentiation through the activation of LXR-dependent mechanisms and restoration of cholesterol efflux may have a significant therapeutic potential.

Neutrophil gelatinase-associated lipocalin as a risk marker in cardiovascular disease

Neutrophil gelatinase-associated lipocalin (NGAL) is a promising diagnostic biomarker of early acute kidney injury. Increasing evidence suggests that NGAL may also be involved in inflammatory processes in cardiovascular disease. NGAL modulates the enzymatic activity of matrix metalloproteinase-9 (MMP-9), which is an important mediator of plaque instability in atherosclerosis. The complex formation between NGAL and MMP-9 therefore suggests that NGAL might play a role in progression of atherothrombotic disease. This review summarises current data on NGAL in atherosclerosis, acute myocardial infarction, and heart failure.

Effect of curcumin on inhibiting atherogenesis by down-regulating lipocalin-2 expression in apolipoprotein E knockout mice

BACKGROUND

Curcumin possesses significant anti-atherosclerosis properties. Lipocalin-2 (LCN2) is already known as one of the most promising biomarkers of atherosclerosis. However, research on the effect of curcumin on regulating LCN2 expression in atherogenesis is very limited. The aim of the study was to investigate whether curcumin could alleviate atherosclerosis in ApoE-/- mice by down-regulating LCN2 expression.

METHODS

Fifty apolipoprotein E knockout (ApoE-/-) mice were fed with a western diet for 12 weeks and randomly divided into five groups: model group (Mod), positive control group (Lov, with 30 mg/kg/d lovastatin), three curcumin groups (CurL, CurM and CurH, with 40, 60 and 80 mg/kg/d curcumin), while 10 C57BL/6J mice were fed with a standard mouse chow diet as a control group (Con). LCN2 in serum and aorta, biomarkers of serum lipid and inflammation were determined and the plaque area of the atherosclerosis lesions was quantified.

RESULTS

CurM and CurH group were significantly lower than Mod group in terms of serum LCN2, lipid and inflammatory cytokine levels, plaque area and LCN2 expression in atherosclerotic lesions, similar to lovastatin treatment.

CONCLUSIONS

Our findings indicate that dietary curcumin ameliorates western diet-induced atherosclerosis in ApoE-/- mice, which is related to LCN2 down-regulation, anti-hyperlipidemia effect as well as the inhibition of inflammation.

Neutrophil gelatinase-associated lipocalin levels are U-shaped in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study-Impact for mortality

INTRODUCTION

Neutrophil gelatinase-associated lipocalin (NGAL) is a glycoprotein released by damaged renal tubular cells and mature neutrophils. It is elevated in kidney injury, but also in patients with coronary artery disease (CAD) and myocardial infarction. We investigated the prognostic value of NGAL for total and cardiovascular mortality in patients undergoing coronary angiography without history of renal insufficiency at inclusion into the study.

PARTICIPANTS

The LURIC study is an ongoing prospective cohort study of patients referred for coronary angiography and is designed to evaluate determinants of cardiovascular health.

RESULTS

NGAL was determined in plasma of 2997 persons (mean age: 62.7 years; 69.7% men) with a follow up for 10 years. 2358 patients suffered from CAD and 638 did not-these patients served as controls. Stable CAD was found in 1408 and unstable CAD in 950 patients. Death rate from cardiovascular events and all causes was highest in patients within the 4th quartile of NGAL (≥56 ng/ml, p<0.001 vs third quartile), even after adjustment for age and gender. According to multivariable-adjusted Cox analysis adjusting for well-known cardiovascular risk factors, as well as lipid lowering therapy, angiographic CAD, and C-reactive protein we found patients in the highest NGAL quartile being at increased risk for cardiovascular (hazard ratio (HR) 1.33, 95%CI 1.05-1.67, p = 0.016) and all cause mortality (HR 1.29 95%CI 1.07-1.55, p = 0.007) compared to those in the third quartile. The lowest risk was seen in the third quartile of NGAL (41-56 ng/ml) suggesting a U-shaped relationship between NGAL and mortality. Further adjustment for creatinine abrogated the predictive effect of NGAL. However, the 3rd and 4th quartiles of NGAL were significantly associated with higher neutrophil counts, which were associated with CAD, non-ST elevation and ST-elevation myocardial infarction (p<0.05).

CONCLUSIONS

Plasma NGAL concentrations are mainly derived from neutrophils and do not predict mortality independent of renal function.

Serum cystatin C and neutrophil gelatinase-associated lipocalin in predicting the severity of coronary artery disease in diabetic patients

Objective:

Cystatin C and neutrophil gelatinase-associated lipocalin (NGAL) are biomarkers of renal functions. We evaluated their roles in predicting the severity of coronary artery disease (CAD).

Methods:

Fifty-two consecutive type 2 diabetic patients (32 males, 65.7±8.6 years) who underwent coronary angiography (CAG) for stable CAD were included in this single-center, prospective, cross-sectional study. Patients with an estimated glomerular filtration rate <60 mL/min/1.73 m² and with a history of by-pass surgery and/or coronary stent implantation were excluded. The vessel score and Gensini score were calculated to assess the presence and severity of CAD. Mann–Whitney U test, Spearman test, and multiple linear regression analysis were used for the main statistical analyses.

Results:

Serum cystatin C levels were higher in patients with multivessel disease than in those with single vessel disease [1260 ng/mL (953–1640) vs. 977 ng/mL (599–1114), p=0.017]. According to the median Gensini score, the higher score group also had higher cystatin C levels than the lower score group [1114 ng/mL (948–1567) vs. 929 ng/mL (569–1156), p=0.009]. However, serum NGAL levels were similar between these subgroups. There was a positive correlation between cystatin C and Gensini score (r=0.334, p=0.016). Multiple linear regression analysis revealed serum cystatin C as an independent predictor of the Gensini score (b=0.360, t=2.311, p=0.026). These results may aid in defining cystatin C as a surrogate marker of the extent of CAD in further clinical trials.

Conclusion:

Serum Cystatin C, but not NGAL levels, could predict the severity of CAD in diabetic patients.

Neutrophil's weapons in atherosclerosis

Neutrophils are important components of immunity associated with inflammatory responses against a broad spectrum of pathogens. These cells could be rapidly activated by proinflammatory stimuli and migrate to the inflamed and infected sites where they release a variety of cytotoxic molecules with antimicrobial activity. Neutrophil antibacterial factors include extracellular proteases, redox enzymes, antimicrobial peptides, and small bioactive molecules. In resting neutrophils, these factors are stored in granules and released upon activation during degranulation. These factors could be also secreted in a neutrophil-derived microparticle-dependent fashion. Neutrophils exhibit a unique property to produce neutrophil extracellular traps (NETs) composed of decondensed chromatin and granular proteins to catch and kill bacteria. Neutrophil-released factors are efficient in inactivation and elimination of pathogens through oxidation-dependent or independent damage of bacterial cells, inactivation and neutralization of virulence factors and other mechanisms. However, in chronic atherosclerosis-associated inflammation, protective function of neutrophils could be impaired and misdirected against own cells. This could lead to deleterious effects and progressive vascular injury. In atherogenesis, a pathogenic role of neutrophils could be especially seen in early stages associated with endothelial dysfunction and induction of vascular inflammation and in late atherosclerosis associated with plaque rupture and atherothrombosis. Assuming a prominent impact of neutrophils in cardiovascular pathology, developing therapeutic strategies targeting neutrophil-specific antigens could have a promising clinical potential.