Association of neutrophil gelatinase-associated lipocalin with the severity of coronary artery disease

Predictive value of elevated neutrophil gelatinase-associated lipocalin levels for assessment of in-hospital adverse outcomes among myocardial infarction patients

BACKGROUND

Inflammatory biomarkers are known to rise and have predictive value for adverse outcomes in patients with acute coronary ischemia. One of those biomarkers is neutrophil gelatinase-associated lipocalin (NGAL). To date, only very few studies have assessed the prognostic value of NGAL in this setting. We investigated the prognostic utility of elevated NGAL levels on clinical outcomes among ST-elevation myocardial infarction patients.

METHODS

High NGAL was defined as values within the 4th quartile. Patients were assessed for major in-hospital adverse clinical events (MACE). Multivariable logistic regression and area under the receiver operating characteristic curve (AUC) were used to further evaluate NGAL association for MACE and discrimination ability.

RESULTS

A total of 273 patients were included. patients with high NGAL were at increased risk for MACE (62% vs. 19%; odds ratio 6.88, 95% confidence interval, 3.77-12.54, P  < 0.001). After propensity score matching, the incidence of MACE was significantly higher in patients with high vs. low NGAL levels (69% vs. 6%, P  = 0.002). In multivariable regression, high NGAL level was independently associated with MACE. The discrimination ability of NGAL to identify MACE (AUC 0.823), is significantly better than that of other inflammatory markers.

CONCLUSION

Among ST-segment elevation myocardial infarction patients undergoing primary percutaneous coronary intervention, high NGAL levels are associated with adverse outcomes, independent of traditional inflammatory markers.

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.

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.

Association of plasma neutrophil gelatinase-associated lipocalin and thoracic aorta calcification in maintenance hemodialysis patients with and without diabetes

Background

Neutrophil gelatinase-associated lipocalin (NGAL) is not only a bone-derived factor involved in metabolism, but also a biomarker of kidney disease and cardiovascular pathophysiology. We conducted this cross-sectional observational study to explore relationships between plasma NGAL and thoracic aorta calcification (TAC) in maintenance hemodialysis (MHD) patients with and without diabetes.

Methods

Plasma NGAL was measured by ELISA, TAC was evaluated via computed tomography scan using a 3D quantification method or chest radiography aortic arch calcification score. Spearman correlation, Logistic regression and Partial correlation analysis were used to describe the correlations between NGAL and TAC.

Results

Plasma NGAL levels were lower in MHD patients with diabetes compared to those without diabetes (49.33(42.37, 55.48) vs 56.78(44.37, 674.13) ng/mL, P = 0.026). In MHD patients without diabetes, lg (NGAL) was positively correlated with ARC value(R = 0.612, P = 0.003) analyzed by Spearman correlation; for partial correlation analysis, lg (NGAL) was positively correlated with ARC value, after adjusting for age and sex (R = 0.550, P = 0.015), adjusting for age, sex and CHD (R = 0.565, P = 0.015), adjusting for age, sex, CHD and Alb (R = 0.536, P = 0.027), or adjusting for age, sex, CHD, Alb, and dialyzer membrane (polysulfone) (R = 0.590, P = 0.016); however, when adjusting for age, sex, CHD, Alb and Ca, the correlation between lg (NGAL) and ARC value disappeared. Positive correlation were found between NGAL and Ca (R = 0.644, P < 0.001), Ca and ACR (R = 0.534, P = 0.013) in Spearman coefficient analysis.

Conclusion

There were positive correlations among plasma NGAL, serum Ca and ARC in MHD patients without diabetes; which suggests that NGAL is possibly a participant in cardiovascular calcification, in non-diabetic MHD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02773-z.

Predictive Value of Elevated Neutrophil Gelatinase-Associated Lipocalin (NGAL) Levels for Assessment of Cardio-Renal Interactions among ST-Segment Elevation Myocardial Infarction Patients

Background: Elevated serum neutrophil gelatinase-associated lipocalin (NGAL) levels reflect both inflammatory reactions and renal tubular injury. Recently, associations with endothelial dysfunction and plaque instability were also proposed. We investigated the prognostic utility of elevated NGAL levels for renal and clinical outcomes among ST-segment elevation myocardial infarction (STEMI) patients treated with primary coronary intervention (PCI). Methods: We performed a prospective, observational, open-label trial. High NGAL was defined as values within the third tertile (>66 percentile). Results: A total of 267 patients were included (mean age 66 ± 14 years, 81% males). Short-term adverse outcomes were consistently increased in the high NGAL group with more acute kidney injury, lower mean left ventricular ejection fraction, higher 30-day mortality, and higher incidence for the composite outcome of major adverse cardiac events (MACE). In a multivariate logistic regression model, high NGAL emerged as a strong and independent predictor for MACE (OR 2.07, 95% CI 1.15−3.73, p = 0.014). Conclusions: Among STEMI patients undergoing primary PCI, elevated NGAL levels are associated with adverse renal and cardiovascular outcomes, independent of traditional inflammatory markers. Further studies are needed to assess the potentially unique role of NGAL in cardio−renal interactions.

The Role of Bone-Derived Hormones in Glucose Metabolism, Diabetic Kidney Disease, and Cardiovascular Disorders

Bone contributes to supporting the body, protecting the central nervous system and other organs, hematopoiesis, the regulation of mineral metabolism (mainly calcium and phosphate), and assists in respiration. Bone has many functions in the body. Recently, it was revealed that bone also works as an endocrine organ and secretes several systemic humoral factors, including fibroblast growth factor 23 (FGF23), osteocalcin (OC), sclerostin, and lipocalin 2. Bone can communicate with other organs via these hormones. In particular, it has been reported that these bone-derived hormones are involved in glucose metabolism and diabetic complications. Some functions of these bone-derived hormones can become useful biomarkers that predict the incidence of diabetes and the progression of diabetic complications. Furthermore, other functions are considered to be targets for the prevention or treatment of diabetes and its complications. As is well known, diabetes is now a worldwide health problem, and many efforts have been made to treat diabetes. Thus, further investigations of the endocrine system through bone-derived hormones may provide us with new perspectives on the prediction, prevention, and treatment of diabetes. In this review, we summarize the role of bone-derived hormones in glucose metabolism, diabetic kidney disease, and cardiovascular disorders.

Circulating Biomarkers for Cardiovascular Disease Risk Prediction in Patients With Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of death globally. Risk assessment is crucial for identifying at-risk individuals who require immediate attention as well as to guide the intensity of medical therapy to reduce subsequent risk of CVD. In the past decade, many risk prediction models have been proposed to estimate the risk of developing CVD. However, in patients with a history of CVD, the current models that based on traditional risk factors provide limited power in predicting recurrent cardiovascular events. Several biomarkers from different pathophysiological pathways have been identified to predict cardiovascular events, and the incorporation of biomarkers into risk assessment may contribute to enhance risk stratification in secondary prevention. This review focuses on biomarkers related to cardiovascular and metabolic diseases, including B-type natriuretic peptide, high-sensitivity cardiac troponin I, adiponectin, adipocyte fatty acid-binding protein, heart-type fatty acid-binding protein, lipocalin-2, fibroblast growth factor 19 and 21, retinol-binding protein 4, plasminogen activator inhibitor-1, 25-hydroxyvitamin D, and proprotein convertase subtilisin/kexin type 9, and discusses the potential utility of these biomarkers in cardiovascular risk prediction among patients with CVD. Many of these biomarkers have shown promise in improving risk prediction of CVD. Further research is needed to assess the validity of biomarker and whether the strategy for incorporating biomarker into clinical practice may help to optimize decision-making and therapeutic management.

Lipocalin-2 Variants and Their Relationship With Cardio-Renal Risk Factors

OBJECTIVES

To investigate the serum, plasma and urine levels of lipocalin-2 (LCN2) variants in healthy humans and their associations with risk factors for cardiometabolic (CMD) and chronic kidney (CKD) diseases.

METHODS

Fifty-nine males and 41 females participated in the study. Blood and urine were collected following an overnight fasting. LCN2 variants were analyzed using validated in-house ELISA kits. Heart rate, blood pressure, lipids profile, glucose, adiponectin, high-sensitivity C-reactive protein (hsCRP), creatinine, cystatin C, and biomarkers for kidney function were assessed.

RESULTS

The levels of hLcn2, C87A and R81E in serum and urine, but not plasma, were significantly higher in men than women. Increased levels of LCN2 variants, as well as their relative ratios, in serum and plasma were positively associated with body mass index, blood pressure, triglyceride and hsCRP (P<0.05). No significant correlations were found between these measures and hLcn2, C87A or R81E in urine. However, LCN2 variants in urine, but not plasma or serum, were correlated with biomarkers of kidney function (P<0.05).

CONCLUSIONS

Both the serum and plasma levels of LCN2 variants, as well as their ratios are associated with increased cardiometabolic risk, whereas those in urine are correlated with renal dysfunction. LCN2 variants represent promising biomarkers for CMD and CKD.

Prognostic role of plasma galectin-3 levels in acute coronary syndrome

Aim:

Cystatin C, neutrophil gelatinase-associated lipocalin and galectin-3 have emerged as biomarker candidates to predict cardiovascular outcomes and mortality in the general population as well as in patients with coronary artery or renal disease. However, their predictive role and clinical utility in patients with acute coronary syndromes alone or in combination beyond currently used risk scores remains to be determined.

Methods and results:

Cystatin C, neutrophil gelatinase-associated lipocalin, and galectin-3 were measured in plasmas of 1832 patients at the time of presentation with acute coronary syndromes requiring percutaneous coronary intervention or coronary artery bypass grafting. The primary outcomes were major adverse cardiac and cerebrovascular events (defined as the composite of all-cause mortality, cerebrovascular events, any repeat revascularization or myocardial infarction) and all-cause mortality after 1 year and occurred in 192 (10.5%) and 78 (4.3%) of patients, respectively. All three biomarkers were increased in those with major adverse cardiac and cerebrovascular events compared with those without (p&lt;0.001). However, only galectin-3 (all-cause mortality: hazard ratio=1.027 (95% confidence interval (1.011–1.043); p=0.001), major adverse cardiac and cerebrovascular events: hazard ratio=1.025 (95% confidence interval (1.012–1.037); p&lt;0.001)) but not cystatin C nor neutrophil gelatinase-associated lipocalin emerged as independent predictors of both major adverse cardiac and cerebrovascular events and death. The risks were particularly high in the highest quartile of galectin-3. The integration of galectin-3 into the global registry of acute coronary events (GRACE) score improved the prediction of major adverse cardiac and cerebrovascular events and all-cause mortality significantly. The areas under the receiver operator characteristics curves increased from 0.6701 to 0.6932 for major adverse cardiac and cerebrovascular events (p=0.0474) and from 0.804 to 0.8199 for all-cause mortality (p=0.0197). Finally, we applied net reclassification improvement index using different cut-offs for major adverse cardiac and cerebrovascular events which showed negative results (for the cut-offs of 5% and 15%, net reclassification improvement index 0.028, p=0.586, for the cut-offs of 10% and 20%, net reclassification improvement index 0.072, p=0.1132 and for the cut-offs of 10% and 30% the net reclassification improvement index is 0.0843, p=0.077).

Conclusion:

In acute coronary syndromes patients, galectin-3 has moderate prognostic accuracy, provides statistically significant incremental value in some, but not all models, and that the magnitude of any improvement would seem of questionable clinical value.

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.

Adipokines: New Potential Therapeutic Target for Obesity and Metabolic, Rheumatic, and Cardiovascular Diseases

Besides its role as an energy storage organ, adipose tissue can be viewed as a dynamic and complex endocrine organ, which produces and secretes several adipokines, including hormones, cytokines, extracellular matrix (ECM) proteins, and growth and vasoactive factors. A wide body of evidence showed that adipokines play a critical role in various biological and physiological functions, among which feeding modulation, inflammatory and immune function, glucose and lipid metabolism, and blood pressure control. The aim of this review is to summarize the effects of several adipokines, including leptin, diponectin, resistin, chemerin, lipocalin-2 (LCN2), vaspin, omentin, follistatin-like 1 (FSTL1), secreted protein acidic and rich in cysteine (SPARC), secreted frizzled-related protein 5 (SFRP5), C1q/TNF-related proteins (CTRPs), family with sequence similarity to 19 member A5 (FAM19A5), wingless-type inducible signaling pathway protein-1 (WISP1), progranulin (PGRN), nesfatin-1 (nesfatin), visfatin/PBEF/NAMPT, apelin, retinol binding protein 4 (RPB4), and plasminogen activator inhibitor-1 (PAI-1) in the regulation of insulin resistance and vascular function, as well as many aspects of inflammation and immunity and their potential role in managing obesity-associated diseases, including metabolic, osteoarticular, and cardiovascular diseases.

The Prognostic Utility of Plasma NGAL Levels in ST Segment Elevation in Myocardial Infarction Patients

Introduction

Plasma neutrophil gelatinase-associated lipocalin (NGAL) levels in acute myocardial infarction (AMI) patients are markedly higher. In addition, plasma NGAL levels were increased in patients with acute and chronic heart failure as a complication of myocardial infarction. In this study, we investigated whether there is a difference between the prognostic use of plasma NGAL levels in ST-elevation myocardial infarction (STEMI) patients with preserved and reduced left ventricular ejection fraction (LVEF).

Methods

235 consecutive STEMI patients were enrolled in the study. Patients were divided into groups according to LVEF. Plasma NGAL, troponin I, creatine kinase MB (CKMB), and C-reactive protein (CRP) were measured. Finally, the study population examined with 34 reduced LVEF and 34 preserved LVEF consisted of a total of 68 patients (12 females; mean age, 61.5 ± 14.7). All patients were followed up prospectively for 6 months. This study group was divided into two subgroups as the patients who died (n = 14) and survived (n = 34), and plasma NGAL levels of the groups were compared.

Results

The median of NGAL was 190.08 ng/ml. Age, troponin I, CKMB, CRP, glomerular filtration rate, and creatinine were higher in reduced LVEF groups. Plasma NGAL levels were also higher in reduced LVEF than in preserved LVEF, but statistically not significant (p=0.07). Plasma NGAL levels were significantly higher in death patients than in survived patients (p < 0.001). In ROC curve analysis, the level to detect isolated cardiovascular mortality with a sensitivity of 86% and a specificity of 77% was 190 ng/mL for NGAL.

Conclusion

Plasma NGAL levels can be used to predict cardiovascular mortality in STEMI 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.

Roles of bone-derived hormones in type 2 diabetes and cardiovascular pathophysiology

Background

Emerging evidence demonstrates that bone is an endocrine organ capable of influencing multiple physiological and pathological processes through the secretion of hormones. Recent research suggests complex crosstalk between the bone and other metabolic and cardiovascular tissues. It was uncovered that three of these bone-derived hormones—osteocalcin, lipocalin 2, and sclerostin—are involved in the endocrine regulations of cardiometabolic health and play vital roles in the pathophysiological process of developing cardiometabolic syndromes such as type 2 diabetes and cardiovascular disease. Chronic low-grade inflammation is one of the hallmarks of cardiometabolic diseases and a major contributor to disease progression. Novel evidence also implicates important roles of bone-derived hormones in the regulation of chronic inflammation.

Scope of review

In this review, we provide a detailed overview of the physiological and pathological roles of osteocalcin, lipocalin 2, and sclerostin in cardiometabolic health regulation and disease development, with a focus on the modulation of chronic inflammation.

Major conclusions

Evidence supports that osteocalcin has a protective role in cardiometabolic health, and an increase of lipocalin 2 contributes to the development of cardiometabolic diseases partly via pro-inflammatory effects. The roles of sclerostin appear to be complicated: It exerts pro-adiposity and pro-insulin resistance effects in type 2 diabetes and has an anti-calcification effect during cardiovascular disease. A better understanding of the actions of these bone-derived hormones in the pathophysiology of cardiometabolic diseases will provide crucial insights to help further research develop new therapeutic strategies to treat these diseases.

Association Between Plasma Neutrophil Gelatinase-Associated Lipocalin and Cardiac Disease Hospitalizations and Deaths in Older Women

Background

Neutrophil gelatinase‐associated lipocalin (NGAL) or lipocalin 2 may promote atherosclerosis and plaque instability leading to increased risk of cardiac events. We investigated the relationships between plasma NGAL, cardiovascular disease biomarkers, and long‐term cardiac events.

Methods and Results

The study population consisted of 1131 ambulant older white women (mean age 75 years) without clinical coronary heart disease (CHD) and measures of plasma NGAL in the Perth Longitudinal Study of Ageing Women with 14.5‐year CHD and heart failure hospitalizations or death (events) captured using linked records. Over 14.5 years, 256 women had CHD events, while 118 had heart failure events. Per SD increase in log‐transformed NGAL there was a 35% to 37% increase in relative hazards for CHD and heart failure events in unadjusted analyses, which remained significant after adjustment for conventional risk factors for CHD events (hazard ratio 1.29, 95% CI 1.13–1.48, P<0.001) but not heart failure (P>0.05). Women in the highest 2 quartiles of NGAL had higher relative hazards for CHD events compared with women in the lowest quartile hazard ratio 1.61, 95% CI 1.08–2.39, P=0.019 and hazard ratio 1.97, 95% CI 1.33–3.93, P=0.001, respectively. These associations were independent of high‐sensitivity cardiac troponin I, homocysteine, and estimated renal function. NGAL correctly reclassified 1 in 4 women who sustained a CHD event up in risk and 1 in 10 women without CHD events down in risk.

Conclusions

NGAL was associated with increased risk of long‐term CHD events, independent of conventional risk factors and biomarkers. These findings provide mechanistic insight into the role of NGAL with cardiac events.

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.

Prognostic Significance of Serum NGAL and Troponin I against Acute Kidney Injury in Egyptian ICU Patients after Open Heart Surgery: A Pilot Study

Background

Acute kidney injury (AKI) is a common complication following cardiac surgery and percutaneous coronary interventions, with an estimated incidence rate around 30%, depicted by long-term intensive care unit stay and culminating renal dysfunction over time, triggering either perpetual renal damage evolving to chronic kidney disease/end-stage renal disease transitions or high vulnerability for sudden death after surgery. The classical diagnosis of AKI is based on a sharp rise in serum creatinine that takes at least 48 h to be visible and is associated with multiple nonrenal factors.

Objective

We aimed to evaluate the predictive performance of both neutrophil gelatinase-associated lipocalin (NGAL) and Klotho for AKI in patients who underwent cardiothoracic surgery using cardiopulmonary bypass (CPB).

Results

Out of the 182 patients included in the study, 65 had AKI and 117 had non-AKI according to the Kidney Disease: Improving Global Outcomes criteria relying on serum creatinine levels. Baseline serum NGAL was 103.5 ± 41.69 μg/L in the AKI group compared to 79.12 ± 48.02 μg/L in the non-AKI group (p < 0.01) and then manifested a peak-fall-rise pattern until 48 h of CPB, with a more remarkable change in the AKI than in the non-AKI group. ROC curve analysis for all measured biomarkers after 2 h of CPB showed that serum NGAL (0.819, > 75% cutoff, 83.5% accuracy) came after serum creatinine (0.864, > 140% cutoff, 85% accuracy), and troponin I was poorer than both (0.606, > 5.5% cutoff, 60% accuracy). Furthermore, multivariate analysis showed that preoperative serum NGAL, preoperative eGFR ≤60 mL/min/1.73 m², and arterial hypertension were possible risk factors for AKI with adverse outcomes.

Conclusions

Our study suggests the role of preoperative serum NGAL as a prognostic tool for renal consequences after cardiac surgery. Besides, postoperative serum NGAL is a sensitive marker for AKI, but is less specific than serum creatinine. Troponin I is considered to be a risk confirmatory tool and may help in the prediction of AKI. However, its diagnostic utility is restricted due to age-dependent cutoff values and poor standardization and harmonization because of interassay variations.

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.

Serial measurements of neutrophil gelatinase-associated lipocalin: prognostic value in patients with ST-segment elevation myocardial infarction treated with a primary percutaneous coronary intervention

BACKGROUND

There are no previous data on serial changes in neutrophil gelatinase-associated lipocalin (NGAL) levels in ST-segment elevation myocardial infarction (STEMI) patients before and after a primary percutaneous coronary intervention (pPCI). The aim of the present study was to evaluate the prognostic value of serial NGAL measurements in patients with STEMI treated by pPCI.

MATERIALS AND METHODS

We identified 169 STEMI patients who underwent pPCI within 12 h of symptom onset and had plasma NGAL measurements before (pre-NGAL) and 6 h after (post-NGAL) pPCI. The primary endpoint was 30-day all-cause mortality, including cardiac death, whereas the secondary endpoint was the change in NGAL levels from before to after pPCI.

RESULTS

The mean pre-NGAL and post-NGAL levels were 109.2±76.1 and 93.3±83.8 ng/ml, respectively. Thirty-day mortality occurred in 12 (7.1%) patients. In terms of changes in serial NGAL levels, post-NGAL levels were decreased in 132 (79%) patients. Patients with elevated post-NGAL levels showed increased mortality compared with patients with decreased post-NGAL levels (P=0.005). Multivariate analyses indicated that old age and high post-NGAL levels were independent risk factors for 30-day mortality.

CONCLUSION

In a large percentage of STEMI patients, plasma post-pPCI NGAL levels were decreased compared with pre-pPCI NGAL levels, even with the administration of potentially nephrotoxic contrast medium. Post-NGAL levels seemed to be superior to pre-NGAL levels for the prediction of 30-day mortality outcome.

Lipocalin-2 contributes to experimental atherosclerosis in a stage-dependent manner

BACKGROUND AND AIMS

Lipocalin-2 (Lcn2) is a glycoprotein which can be secreted by immune cells. Several studies in humans have suggested Lcn2 can be used as a biomarker for the detection of unstable atherosclerotic lesions, partly as it is known to interact with MMP-9.

METHODS

In this study, we generated Ldlr^-/-Lcn2^-/- mice to assess the functional role of Lcn2 in different stages of atherosclerosis. Atherosclerotic lesions were characterized through histological analysis and myeloid cell populations were examined using flow cytometry.

RESULTS

We show that Ldlr^-/-Lcn2^-/- mice developed larger atherosclerotic lesions during earlier stages of atherosclerosis and had increased circulating Ly6C^hi inflammatory monocytes compared to Ldlr^-/- mice. Advanced atherosclerotic lesions from Ldlr^-/-Lcn2^-/- mice had decreased necrotic core area, suggesting Lcn2 deficiency may affect lesion stability. Furthermore, MMP-9 activity was diminished in plaques from Ldlr^-/-Lcn2^-/- mice.

CONCLUSIONS

Altogether, these findings suggest that Lcn2 deficiency promotes lesion growth in earlier stages of the disease while it decreases MMP-9 activity and necrotic core size in advanced atherosclerosis.

Early prediction of contrast-induced acute kidney injury by a "bedside" assessment of Neutrophil Gelatinase-Associated Lipocalin during elective percutaneous coronary interventions

Contrast-induced acute kidney injury (CI-AKI) is a serious complication during percutaneous coronary interventions (PCI). Currently, the diagnosis of CI-AKI relies on serum creatinine (SCr) that is however affected by several limitations potentially leading to delayed or missed diagnoses. In this study we examined the diagnostic accuracy of a “bedside” measurement of plasma Neutrophil Gelatinase-Associated Lipocalin (NGAL) in the early detection of CI-AKI in 97 patients undergoing elective PCI. The overall incidence of CI-AKI was 3%. A significant positive correlation was observed between 6-hours NGAL and post-PCI SCr (r = 0.339, p = 0.004) and a significant negative correlation between 6-hours NGAL and post-PCI CrCl (r = -0.303, p = 0.010). In patients with post-PCI SCr increase > 0.24 mg/dl (median SCr absolute increase), delta NGAL 0–6 hours and 6-hours NGAL values were higher compared with patients with SCr elevation below the defined threshold (p = 0.049 and p = 0.056). The ROC analysis showed that a 6 hours NGAL value > 96 ng/ml significantly predicted an absolute SCr increase > 0.24 mg/dl after contrast exposure with sensitivity of 53% and specificity of 74% (AUC 0.819, 95% CI: 0.656 to 0.983, p = 0.005). The use of bedside NGAL assessment may significantly hasten diagnosis and treatment of CI-AKI, with remarkable clinical prognostic consequences.

Neutrophil Gelatinase-Associated Lipocalin from immune cells is mandatory for aldosterone-induced cardiac remodeling and inflammation

Immune system activation is involved in cardiovascular (CV) inflammation and fibrosis, following activation of the mineralocorticoid receptor (MR). We previously showed that Neutrophil Gelatinase-Associated Lipocalin (NGAL) is a novel target of MR signaling in CV tissue and plays a critical role in aldosterone/MR-dependent hypertension and fibrosis. We hypothesized that the production of NGAL by immune cells may play an important part in the mediation of these deleterious mineralocorticoid-induced effects. We analyzed the effect of aldosterone on immune cell recruitment and NGAL expression in vivo. We then studied the role of NGAL produced by immune cells in aldosterone-mediated cardiac inflammation and remodeling using mice depleted for NGAL in their immune cells by bone marrow transplantation and subjected to mineralocorticoid challenge NAS (Nephrectomy, Aldosterone 200μg/kg/day, Salt 1%). NAS treatment induced the recruitment of various immune cell populations to lymph nodes (granulocytes, B lymphocytes, activated CD8⁺ T lymphocytes) and the induction of NGAL expression in macrophages, dendritic cells, and PBMCs. Mice depleted for NGAL in their immune cells were protected against NAS-induced cardiac remodeling and inflammation. We conclude that NGAL produced by immune cells plays a pivotal role in cardiac damage under mineralocorticoid excess. Our data further stressed a pathogenic role of NGAL in cardiac damages, besides its relevance as a biomarker of renal injury.

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.

Urinary neutrophil gelatinase-associated lipocalin and cystatin C compared to the estimated glomerular filtration rate to predict risk in patients with suspected acute myocardial infarction

INTRODUCTION

Impaired renal function, reflected by estimated glomerular filtration rate (eGFR) or cystatin C, is a strong risk predictor in the presence of acute myocardial infarction (AMI). Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is an early marker of acute kidney injury. uNGAL might also be a good predictor of outcome in patients with cardiovascular disease. Aim of the present study was to evaluate the prognostic value of uNGAL compared to eGFR and cystatin C in patients with suspected AMI.

METHODS

1818 patients were enrolled with suspected AMI. Follow-up information on the combined endpoint of death or non-fatal myocardial infarction was obtained 6months after enrolment and was available in 1804 patients. 63 events (3.5%) were registered.

RESULTS

While cystatin C and eGFR were strong risk predictors for the primary endpoint even adjusted for several variables, uNGAL was not independently associated with outcome: When applied continuously uNGAL was associated with outcome but did not remain a statistically significant predictor after several adjustments (i.e. eGFR). By adding cystatin C or uNGAL to GRACE risk score variables, only cystatin C could improve the predictive value while uNGAL showed no improvement.

CONCLUSION

We could show that cystatin C is an independent risk predictor in patients with suspected AMI and cystatin C can add improvement to the commonly used GRACE risk score. In contrast uNGAL is not independently associated with outcome and seems not to add further prognostic information to GRACE risk score.

Immediate postoperative plasma neutrophil gelatinase-associated lipocalin to predict acute kidney injury after major open abdominal aortic surgery: A prospective observational study

INTRODUCTION

Plasma neutrophil gelatinase-associated lipocalin (pNGAL) has been used as a biomarker in acute kidney injury (AKI). AKI is a common postoperative complication of aortic surgery. We sought to evaluate the performance of the immediately postoperative pNGAL level in comparison with the serum creatinine (SCr) level in predicting AKI and the need for renal replacement therapy (RRT).

PATIENTS AND METHODS

Prospective non-interventional study in a university hospital. Fifty patients undergoing elective or emergent major intra-abdominal aortic surgery were included. Comparisons between groups of patients with or without postoperative AKI, according to KDIGO staging, were made. Performance of NGAL was determined by examining the area under receiver operating characteristic (AUROC) curve.

RESULTS

The incidence of AKI was 36%. At H+2, pNGAL values in AKI and non-AKI patients, respectively, were 221 [133-278] versus 50 [50-90] ng/mL (P<0.0001), and SCr values were 115 [96-178] versus 90 [72-99] μmol/L (P<0.0008). The AUROC of pNGAL for prediction of AKI was 0.90 (95% CI: 0.81-0.98) with an optimal cutoff of 112ng/mL, a sensitivity of 83%, specificity of 84%, and positive and negative predictive values of 75% and 90%, respectively. SCr produced an AUROC curve of 0.79 (0.65-0.92) at a cutoff of 110μmol/L. The diagnostic performance of pNGAL was significantly better than that of SCr (P=0.039). PNGAL at H+2 better predicted the RRT requirement [0.96 (0.90-1.0)] compared to SCr [0.86 (0.73-0.98)], but this difference was not statistically significant.

CONCLUSIONS

A 2-hour postoperative determination of pNGAL outperformed SCr level in predicting postoperative AKI after major aortic surgery.

Altered human neutrophil FcγRI and FcγRIII but not FcγRII expression is associated with the acute coronary event in patients with coronary artery disease

OBJECTIVE

Neutrophils enhancing atherosclerotic plaque instability have been observed in patients with acute coronary syndrome (ACS). Generally, activation of neutrophils in lesions depends on the interaction of Fcγ receptors (FcγRs) with immunoglobulin G antibodies in immune complexes. However, altered FcγR expression on neutrophils of patients with ACS is unknown. We aimed to evaluate changes in FcγR expression on neutrophils of patients with ACS.

METHODS

We enrolled 106 patients who were divided into four groups: acute myocardial infarction (AMI), unstable angina (UA), stable angina, and normal coronary arteries. The expressions of FcγRI, FcγRII, and FcγRIII on neutrophils and related upstream ligand and downstream molecules were measured by flow cytometry and enzyme-linked immunosorbent assay.

RESULTS

The expression of unbound FcγRI was significantly decreased in AMI and UA patients and that of unbound FcγRIII was significantly decreased in AMI patients, with no difference in the expression of unbound FcγRII among the four groups. In contrast, plasma levels of antioxidized LDL antibody, myeloperoxidase, matrix metalloproteinase-9, and neutrophil gelatinase-associated lipocalin were significantly greater in AMI and UA than in stable angina and normal coronary arteries patients.

CONCLUSION

Unbound FcγRI and FcγRIII expression was decreased on neutrophils of patients with ACS, which reflects a potential role of disturbed FcγRI and FcγRIII expression in the destabilization of atherosclerotic plaque. Our findings may provide insight into the mechanism underlying culprit plaque-relevant activation of neutrophil FcγRs in ACS patients.

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.

Plasma neutrophil gelatinase-associated lipocalin levels are positively associated with diabetic retinopathy in patients with Type 2 diabetes

AIM

To assess the relationship between plasma neutrophil gelatinase-associated lipocalin (NGAL) levels and diabetic retinopathy in patients with Type 2 diabetes.

METHODS

In total, 204 patients with Type 2 diabetes were investigated in this cross-sectional study. They were classified as having no diabetic retinopathy, non-proliferative diabetic retinopathy (NPDR) or proliferative retinopathy (PDR), according to the degree of diabetic retinopathy. Thus, diabetic retinopathy in the patients in this study was either NPDR or PDR.

RESULTS

Plasma NGAL concentrations were significantly higher in patients with diabetic retinopathy than in those without. The mean plasma NGAL levels differed significantly according to the severity of diabetic retinopathy (no diabetic retinopathy, 120.8 ng/ml; NPDR, 217.8 ng/ml; PDR, 372.4 ng/ml; P for trend = 0.002) after adjustment for other covariates. In multivariable analysis, plasma NGAL levels were significantly associated with diabetic retinopathy (odds ratio for each standard deviation increase in the logarithmic value, 7.75; 95% confidence interval, 2.04-29.41, P = 0.003).

CONCLUSION

Plasma NGAL levels were positively associated with diabetic retinopathy in patients with Type 2 diabetes.

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.

Renal biomarkers for the prediction of cardiovascular disease

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is a well-known risk factor for cardiovascular disease (CVD). Renal biomarkers might be valuable in predicting CVD. Investigation of these biomarkers may uncover some of the poorly understood mechanisms that link renal and CVD as well as aid in the modification of disease and serve as a useful tool in diagnosing early disease and monitoring therapeutic responses. In this review we discuss the clinical utility of emerging and known renal biomarkers in predicting CVD.

RECENT FINDINGS

Prior to adopting a biomarker into routine clinical practice, evidence-based laboratory medicine requires optimal technical and analytical performance, which is a prerequisite to have confidence in the result. Furthermore, an ideal biomarker should have evidence of its utility in predicting clinical, therapeutic and other health outcomes as well as proving its organizational impact and cost-effectiveness. The renal biomarkers that have been associated with CVD include cystatin C as a better marker of glomerular filtration than creatinine, albuminuria, neutrophil gelatinase associated lipocalin, a marker of acute kidney injury, fibroblast growth factor-23 and parathyroid hormone. Only urine albumin has been adopted into routine clinical practice.

SUMMARY

Of all the renal biomarkers, only albumin is clearly associated with CVD. The other biomarkers are earlier in clinical development and the evidence base for their clinical utility needs to be expanded substantially before they can be adopted into routine practice.

Plasma Neutrophil Gelatinase-Associated Lipocalin Reflects Both Inflammation and Kidney Function in Patients with Myocardial Infarction

BACKGROUND/AIMS

Neutrophil gelatinase-associated lipocalin (NGAL) has emerged as a marker for acute kidney injury and cardiovascular outcome. However, the relative importance of inflammation versus kidney function on plasma NGAL levels is uncertain, making the interpretation of plasma NGAL unclear. Accordingly, we investigated the relationship between plasma NGAL, inflammation and kidney function in patients with myocardial infarction (MI).

METHODS

We prospectively included 584 patients with acute ST-segment elevation MI (STEMI) treated with primary percutaneous coronary intervention (PCI) from 2006 to 2008. Blood samples were drawn immediately before PCI. Additionally, we included 42 patients who had 4 blood samples drawn before and after PCI. Plasma NGAL was measured using a time-resolved immunofluorometric assay. Cross-sectional analyses were performed in these two single-center, prospective study cohorts.

RESULTS

Estimated glomerular filtration rate (eGFR) was associated significantly more strongly with plasma NGAL when eGFR was abnormal compared to normal eGFR: a decrease in eGFR of 10 ml/min was associated with an increase in NGAL of 27% (18-36%) versus 4% (1-7%), respectively (p < 0.001). Leukocyte count and C-reactive protein were the main determinants of plasma NGAL in patients with normal eGFR, whereas eGFR was the main determinant at reduced kidney function.

CONCLUSIONS

eGFR determines the association of NGAL with either inflammation or kidney function; in patients with normal eGFR, plasma NGAL reflects inflammation but when eGFR is reduced, plasma NGAL reflects kidney function, highlighting the dual perception of plasma NGAL. From a clinical perspective, eGFR may be used to guide the interpretation of elevated NGAL levels in patients with STEMI.

Serum neutrophil gelatinase-associated lipocalin concentration reflects severity of coronary artery disease in patients without heart failure and chronic kidney disease

Serum neutrophil gelatinase-associated lipocalin (NGAL) is recognized as a useful biomarker for acute kidney injury. Recently, elevated NGAL levels were reported in patients with heart failure and cardiac events, but the association between serum NGAL and severity of coronary artery disease (CAD) has not been investigated adequately. This study aimed to evaluate the association between serum NGAL concentration and CAD severity in patients without heart failure and chronic kidney disease. Two-hundred thirteen patients [mean age: 66.2 ± 9.2 (SD)] without heart failure and chronic kidney disease (estimated glomerular filtration rate >60 mL/min/1.73 m(2)) who underwent coronary angiography were retrospectively analyzed using the SYNTAX score. The mean concentration of serum NGAL was 134.3 ± 111.3 ng/mL. A statistically significant correlation was observed between serum NGAL levels and the SYNTAX score (R = 0.18, P = 0.0091). Multivariable analysis also showed elevated serum NGAL as an independent risk factor for a high SYNTAX score (P < 0.01). Moreover, we evaluated the association of serum NGAL and brain natriuretic peptide (BNP) with the SYNTAX score. Patients with high levels of serum NGAL (>100 ng/mL) and high levels of BNP (>25 pg/mL) had a higher SYNTAX score (low-low vs. high-high: 13.8 ± 13.4 vs. 20.8 ± 18.9, P < 0.05). Serum NGAL levels were positively and significantly associated with CAD severity, and the evaluation of both serum NGAL and BNP was useful for predicting CAD in patients without renal dysfunction and heart failure. Serum NGAL might be a biomarker for CAD severity.

Lipocalin (LCN) 2 Mediates Pro-Atherosclerotic Processes and Is Elevated in Patients with Coronary Artery Disease

Background

Lipocalin (LCN) 2 is associated with multiple acute and chronic inflammatory diseases but the underlying molecular and cellular mechanisms remain unclear. Here, we investigated whether LCN2 is released from macrophages and contributes to pro-atherosclerotic processes and whether LCN2 plasma levels are associated with the severity of coronary artery disease progression in humans.

Methods and Results

In an autocrine-paracrine loop, tumor necrosis factor (TNF)-α promoted the release of LCN2 from murine bone-marrow derived macrophages (BMDM) and vice versa. Moreover, LCN2 stimulation of BMDM led to up-regulation of M1 macrophage markers. In addition, enhanced migration of monocytic J774A.1 cells towards LCN2 was observed. Furthermore, LCN2 increased the expression of the scavenger receptors Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) as well as scavenger receptor class A-1 (SRA-1) and induced the conversion of macrophages to foam cells. In atherosclerotic lesions of low density lipoprotein receptor-deficient (ldlr^−/−) mice fed a high fat, high cholesterol diet, LCN2 was found to be co-localized with macrophages in the shoulder region of the atherosclerotic plaque. In addition, LCN2 plasma levels were significantly increased in plasma samples of these mice. Finally, LCN2 plasma levels correlated with the severity of coronary artery disease (CAD) in patients as determined by coronary angiography.

Conclusions

Here we demonstrated that LCN2 plays a pivotal role in processes involved in atherogenesis by promoting polarization and migration of monocytic cells and development of macrophages towards foam cells. Moreover, LCN2 may be used as a prognostic marker to determine the status of CAD progression.

Plasma neutrophil gelatinase-associated lipocalin predicts major adverse cardiovascular events after cardiac care unit discharge

BACKGROUND

Emerging acute kidney injury biomarkers, including neutrophil gelatinase-associated lipocalin (NGAL), have a high potential for predicting worsening renal function. Acute exacerbation of renal dysfunction has a great impact on the outcomes of cardiovascular patients in critical conditions. This study aimed to evaluate whether plasma NGAL can predict the mortality and major adverse cardiovascular events (MACEs) after discharge from the cardiac care unit (CCU).

METHODS

Patients who were admitted to the CCU of the Tokyo University Hospital were prospectively enrolled (101 patients). Blood and urinary markers, including the blood NGAL, brain natriuretic peptide, creatinine, cystatin C, urinary albumin, N-acetyl-β-d-glucosaminidase, and L-type fatty acid-binding protein, were measured at CCU discharge. The primary outcome was MACEs until at least 6 months after CCU discharge.

RESULTS

Thirty-five patients experienced MACEs (35%). Multivariate logistic analysis revealed that the plasma NGAL, length of CCU stay, and existence of diabetes and heart failure were independent predicting factors for MACEs. Patients with the highest NGAL at discharge (>75th percentile) showed a significantly higher risk of MACEs than those with the lowest NGAL (<25th percentile) (log-rank test; hazard ratio, 5.15; 95% confidence interval 1.84-18.20; p<0.01).

CONCLUSION

Plasma NGAL at CCU discharge is a significant prognostic indicator of outcomes at 6 months in critically ill cardiac patients treated in a CCU.

The Influence of Simvastatin on NGAL, Matrix Metalloproteinases and Their Tissue Inhibitors in Human Intraluminal Thrombus and Abdominal Aortic Aneurysm Tissue

OBJECTIVE/BACKGROUND

Matrix metalloproteinases (MMPs) play a pivotal role in the development and progression of abdominal aortic aneurysms (AAAs). The action of MMPs depends on a balance between tissue inhibitors of MMPs (TIMPs) and compounds that may prolong protease activity, such as neutrophil gelatinase-associated lipocalin (NGAL).

METHODS

The study was designed to analyse gene expression and protein concentration of MMPs, TIMPs, and NGAL in AAA walls and intraluminal thrombi (ILTs) of patients on simvastatin (n = 10) and not on statins (n = 10). The patients were matched by age, sex, and AAA diameter. Expression of MMP2, MMP9, TIMP1, TIMP2, and NGAL was investigated by real time polymerase chain reaction, and MMP2, MMP9, MMP9/TIMP1, MMP9/TIMP2, and MMP9/NGAL protein levels by enzyme-linked immunosorbent assay.

RESULTS

MMP2 and MMP9 protein and mRNA levels were comparable in the simvastatin and non-statin groups (p > .05); however, there was a significant decrease in TIMP1 mRNA in AAA tissue (p = .04). Moreover, a significant increase in MMP9/TIMP2 complex concentration in ILTs of patients on simvastatin was noted (median 94.71 ng/mL in the simvastatin group vs. 36.80 ng/mL in the non-statin group; p = .01). No significant difference was observed for NGAL mRNA or protein content in AAA and ILT.

CONCLUSION

Simvastatin treatment in patients with AAAs may influence the concentration of proteases and their inhibitors (TIMPs) in aneurysmal wall tissue and ILTs. Thus, further studies should be undertaken to understand the different influence of statin therapy on the components of the MMP/TIMP system in AAAs and ILTs.

Serum neutrophil gelatinase-associated lipocalin levels and aortic stiffness in noncritical coronary artery disease

AIM

The aim of this study was to establish the degree of aortic stiffness and levels of neutrophil gelatinase-associated lipocalin (NGAL) in patients with stable ischemic heart disease.

MATERIALS AND METHODS

Patients who were found to have stable, noncritical lesions on coronary angiography were included in the study [noncritical coronary artery disease (CAD)]. The control group consisted of those patients who had similar risk profiles and metabolic parameters without atherosclerosis on angiography.

RESULTS

A total of 101 patients were included in the study of which 56 had noncritical CAD. Whereas the aortic strain (9.11 ± 3.4 vs. 14.01 ± 4.1%, p < 0.001) and aortic distensibility (3.98 ± 1.9 10(-6) cm(2)/dyn vs. 6.33 ± 2.3 10(-6) cm(2)/dyn, p < 0.001) were lower in the noncritical CAD group, the aortic stiffness index was higher (6.34 ± 3.9 vs. 3.37 ± 2.4, p < 0.001) as compared to controls. Serum NGAL levels were higher in the noncritical CAD group (79.29 ± 38.8 vs. 48.05 ± 21.4 ng/ml, p < 0.001). NGAL levels were negatively correlated with aortic strain (p < 0.01, r = 0.57) and distensibility (p < 0.001, r = 0.62), but positively correlated with the aortic stiffness index (p < 0.001, r = 0.72).

CONCLUSION

We show that in patients with noncritical CAD, the degree of aortic stiffness and NGAL levels are higher. These markers can be used as tools for further risk stratification of patients with noncritical CAD.

Neutrophil gelatinase-associated lipocalin (NGAL) in heart transplant recipients after conversion to everolimus therapy

BACKGROUND

Due to the lack of nephrotoxic activity, proliferation signal inhibitors (PSI) such as everolimus are recommended for immunosuppression after heart transplantation, but the assessment of renal function in patients receiving PSI has led to conflicting results. We examined renal integrity and function using neutrophil gelatinase-associated lipocalin (NGAL) and conventional markers [plasma creatinine, cystatin C, urine albumin, α1-microglobulin (α1M)] in heart transplant patients, who underwent conversion to everolimus due to allograft vasculopathy, graft rejection episodes, or renal function deterioration, and in patients maintained on calcineurin inhibitors (CNI).

METHODS

This cross-sectional study included 121 consecutive heart transplant recipients: 44 patients received CNI-free immunosuppressive therapy with everolimus and 77 patients received CNI. Renal parameters were determined in plasma and urine samples using standard enzymatic or immunochemical methods.

RESULTS

Heart transplant recipients receiving everolimus therapy had significantly lower NGAL concentrations in plasma [median (95% CI): 128 (97-176)ng/mL vs. 252 (224-283)ng/mL, p<0.001] and urine [median (95% CI): 6.4 (4.5-7.6)ng/g vs. 15.7 (10.2-25.9)ng/g creatinine, p<0.001]. In contrast, no significant differences were observed between everolimus- and CNI-treated groups with regard to creatinine and cystatin C, as well as urine albumin and α1M levels. Significant correlations were noted between plasma NGAL and creatinine (r=0.42, p<0.001), cystatin C (r=0.44, p<0.001), N-terminal brain natriuretic propeptide (r=0.31, p<0.01) and indicators of chronic inflammation [lipoprotein-associated phospholipase A2 (Lp-PLA2), r=0.31, p<0.01] and soluble CD40 ligand (sCD40L, r=0.22, p<0.05), and between urinary NGAL and α1M (r=0.21, p<0.05). Multiple regression analysis indicated that cystatin C and Lp-PLA2 were the best predictors of plasma NGAL.

CONCLUSION

The present study documents reduced plasma and urinary NGAL levels in the absence of differences in conventional renal parameters in patients on CNI-free immunosuppressive therapy with everolimus. These results support favorable effects of everolimus on renal integrity in heart transplant recipients.

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

Objective:

Neutrophil gelatinase-associated lipocalin (NGAL) is a novel inflammatory marker that is released from neutrophils. In this study, we evaluated the correlation between serum NGAL level and clinical and angiographic risk scores in patients diagnosed with non-ST elevation acute coronary syndrome (NSTE-ACS).

Methods:

Forty-seven random NSTE-ACS patients and 45 patients with normal coronary arteries (NCA) who underwent coronary angiography were enrolled in the study. GRACE risk score and SYNTAX and Gensini risk scores were used, respectively, for the purpose of clinical risk assessment and angiographic risk scoring. Serum NGAL level was measured via ELISA in peripheral blood samples obtained from the patients at the time of admission.

Results:

Serum NGAL level was significantly higher in the NSTE-ACS group compared to the control group (112.3±49.6 ng/mL vs. 58.1±24.3 ng/mL, p<0.001). There was a significant positive correlation between serum NGAL levels and the GRACE (r=0.533 and p<0.001), SYNTAX (r=0.395 and p=0.006), and Gensini risk scores (r=0.575 and p<0.001). The intermediate-high SYNTAX (>22) group had statistically significantly higher serum NGAL levels compared to the low SYNTAX (≤22) group (143±29.5 ng/mL vs. 98.7±43.2 ng/mL, p=0.001).

Conclusion:

NGAL level was positively correlated with lesion complexity and severity of coronary artery disease in patients with NSTE-ACS. Serum NGAL levels on admission are associated with increased burden of atherosclerosis in patients with NSTE-ACS.

Plasma neutrophil gelatinase-associated lipocalinin in the general population: association with inflammation and prognosis

OBJECTIVE

Neutrophil gelatinase-associated lipocalin (NGAL) is a glycoprotein stored in granules of neutrophil leukocytes participating in inflammatory and atherosclerotic processes and possibly plaque rupture. Despite the putative role of NGAL in atherosclerosis and acute myocardial infarction, human studies of plasma NGAL are still limited.

APPROACH AND RESULTS

We prospectively followed 5599 randomly selected men and women from the community in the fourth Copenhagen Heart Study. Plasma NGAL was measured at study entry. Participants were followed for 10 years. During follow-up, 20% died (n=1120) and 15% (n=884) developed a major adverse cardiovascular event. Plasma NGAL associated strongly with all inflammatory markers (high-sensitivity C-reactive protein, total leukocyte count, neutrophil count) and inversely with estimated glomerular filtration rate (all, P<0.001). Multivariate analysis identified neutrophil leukocyte count as the main determinant of plasma NGAL. During follow-up, participants with increasing NGAL had increased risk of all-cause mortality and major adverse cardiovascular event (both, P<0.001). Even after adjustment for confounding risk factors by Cox regression analysis, NGAL remained an independent predictor of both all-cause mortality and major adverse cardiovascular event. When added to the Framingham risk score, NGAL improved c-statistics and correctly reclassified ≈15% into more appropriate risk groups. In comparison with high-sensitivity C-reactive protein, when both markers were added to the Framingham risk score, NGAL conferred 3× to 4× the risk.

CONCLUSIONS

Plasma NGAL is strongly associated with inflammation in the general population. NGAL independently associated with 10-year outcome, and when added to the Framingham risk score, NGAL both improves c-statistics and correctly reclassifies participants into more accurate risk categories.

Epicardial adipose tissue thickness and NGAL levels in women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with an increased cardiovascular disease (CVD) risk and early atherosclerosis. Epicardial adipose tissue thickness (EATT) is clinically related to subclinical atherosclerosis. In the present study, considering the major role of neutrophil gelatinase-associated lipocalin (NGAL) which is an acute phase protein rapidly releasing upon inflammation and tissue injury, we aimed to evaluate NGAL levels and EATT in PCOS patients and assess their relationship with cardiometabolic factors.

METHODS

64 patients with PCOS and 50 age- and body mass index-matched healthy controls were included in the study. We evaluated anthropometric, hormonal and metabolic parameters. EATT was measured by echocardiography above the free wall of the right ventricle. Serum NGAL and high-sensitive C- reactive protein (hsCRP) levels were measured by ELISA.

RESULTS

Mean EATT was 0,38 +/-0,16 mm in the PCOS group and 0,34 +/-0,36 mm in the control group (p = 0,144). In the obese PCOS group (n = 44) EAT was thicker compared to the obese control group (n = 41) (p = 0.026). Mean NGAL levels of the patients with PCOS were 101,98 +/-21,53 pg/ml, while mean NGAL levels were 107,40 +/-26,44 pg/ml in the control group (p = 0,228). We found a significant positive correlation between EATT and age, BMI, waist circumference, fasting insulin, HOMA-IR, triglyceride and hsCRP levels in PCOS group.

CONCLUSIONS

Thickness of the epicardial adipose tissue can be used to follow the risk of CVD development in obese PCOS cases. However serum NGAL levels do not differ in patients with PCOS and control group.

Epicardial adipose tissue thickness and NGAL levels in women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with an increased cardiovascular disease (CVD) risk and early atherosclerosis. Epicardial adipose tissue thickness (EATT) is clinically related to subclinical atherosclerosis. In the present study, considering the major role of neutrophil gelatinase-associated lipocalin (NGAL) which is an acute phase protein rapidly releasing upon inflammation and tissue injury, we aimed to evaluate NGAL levels and EATT in PCOS patients and assess their relationship with cardiometabolic factors.

METHODS

64 patients with PCOS and 50 age- and body mass index-matched healthy controls were included in the study. We evaluated anthropometric, hormonal and metabolic parameters. EATT was measured by echocardiography above the free wall of the right ventricle. Serum NGAL and high-sensitive C- reactive protein (hsCRP) levels were measured by ELISA.

RESULTS

Mean EATT was 0,38 +/-0,16 mm in the PCOS group and 0,34 +/-0,36 mm in the control group (p = 0,144). In the obese PCOS group (n = 44) EAT was thicker compared to the obese control group (n = 41) (p = 0.026). Mean NGAL levels of the patients with PCOS were 101,98 +/-21,53 pg/ml, while mean NGAL levels were 107,40 +/-26,44 pg/ml in the control group (p = 0,228). We found a significant positive correlation between EATT and age, BMI, waist circumference, fasting insulin, HOMA-IR, triglyceride and hsCRP levels in PCOS group.

CONCLUSIONS

Thickness of the epicardial adipose tissue can be used to follow the risk of CVD development in obese PCOS cases. However serum NGAL levels do not differ in patients with PCOS and control group.

Neutrophil gelatinase associated lipocalin in acute kidney injury

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is a member of the lipocalin family of proteins. Usually, NGAL is produced and secreted by kidney tubule cells at low levels, but the amount produced and secreted into the urine and serum increases dramatically after ischemic, septic, or nephrotoxic injury of the kidneys. The purpose of our review article is to summarize the role of NGAL in acute kidney injury (AKI), emergent, and intensive care.

METHODS

A PubMed search was performed (only English-language articles concerning human subjects were considered) using each of the following search term combinations: neutrophil gelatinase-associated lipocalin OR NGAL and acute kidney injury OR AKI; cardiac surgery; heart failure OR cardiology; intensive care; emergency department OR emergency medicine; nephropathy OR nephrotoxicity and transplantation.

RESULTS

The results of our search yielded 339 articles. Of the 339 articles, 160 were eligible for review based on the predefined criteria for inclusion.

CONCLUSION

Based on the evidence reviewed, it is clear that patient NGAL level is an appropriate, sensitive, and specific early biomarker of AKI caused by a variety of different etiologies. It is advised that a multidisciplinary group of experts come together to make recommendations and propose a consensus of clinical procedures to advance the most efficacious NGAL monitoring protocol for early detection and treatment of patients with AKI.