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

A Multimodal Fuzzy Approach in Evaluating Pediatric Chronic Kidney Disease Using Kidney Biomarkers

Chronic kidney disease (CKD) is one of the most important causes of chronic pediatric morbidity and mortality and places an important burden on the medical system. Current diagnosis and progression monitoring techniques have numerous sensitivity and specificity limitations. New biomarkers for monitoring CKD progression have been assessed. Neutrophil gelatinase-associated lipocalin (NGAL) has had some promising results in adults, but in pediatric patients, due to the small number of patients included in the studies, cutoff values are not agreed upon. The small sample size also makes the statistical approach limited. The aim of our study was to develop a fuzzy logic approach to assess the probability of pediatric CKD progression using both NGAL (urinary and plasmatic) and routine blood test parameters (creatinine and erythrocyte sedimentation rate) as input data. In our study, we describe in detail how to configure a fuzzy model that can simulate the correlations between the input variables ESR, NGAL-P, NGAL-U, creatinine, and the output variable Prob regarding the prognosis of the patient's evolution. The results of the simulations on the model, i.e., the correlations between the input and output variables (3D graphic presentations) are explained in detail. We propose this model as a tool for physicians which will allow them to improve diagnosis, follow-up, and interventional decisions relative to the CKD stage. We believe this innovative approach can be a great tool for the clinician and validates the feasibility of using a fuzzy logic approach in interpreting NGAL biomarker results for CKD progression.

Early neutrophil gelatinase-associated lipocalin (NGAL) measurement could rule out future acute kidney injury in patients with acute coronary syndrome-Prospective observational study

Background and Aims

The diagnosis of acute kidney injury (AKI) is of importance among patients with ST segment elevation (STEMI) undergoing primary coronary intervention (PCI). It is often delayed given the need in serial measurements of creatinine or other serum markers. Neutrophil gelatinase-associated lipocalin (NGAL) is a proven marker for AKI, although its role as an early predictor in this setting was scarcely addressed before and was the aim of our study.

Methods

Prospective observational study including 133 patients with STEMI treated with PCI. Plasma NGAL was drawn immediately before PCI (NGAL-0) and 24 h after (NGAL-24). Similar analysis of C-reactive protein (CRP) was performed for additional comparison.

Results

Mean age was 62 ± 13 years, 78% were men, and 20 (15%) developed AKI after admission. Patients with AKI after admission demonstrated higher levels of NGAL-0 (164 vs. 95 ng/mL; p < 0.001) and NGAL-24 (142 vs. 93 ng/mL; p < 0.001). Levels of NGAL-0 and NGAL-24 were similar within the AKI and non-AKI groups. Using ROC curve analysis, NGAL-0 had best predictive ability for AKI development (AUC 0.841, 95% CI 0.80-0.96), compared with NGAL-24 (0.783, 95% CI 0.74-0.85), CRP-0 (0.701, 95% CI 0.58-0.83), and CRP-24 (0.781, 95% CI 0.66-0.90). The optimal NGAL-0 cutoff for AKI prediction was 125 ng/mL, with 70% sensitivity, 84% specificity, and 94% negative predictive value.

Conclusions

Among STEMI patients, NGAL measurement upon admission are associated with AKI and may serve as a reliable marker for early AKI detection. Future studies may direct risk stratification using this single test can direct personalized evaluations during the admission, and focused interventions to prevent AKI.

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.

Systemic reserve dysfunction and contrast-associated acute kidney injury following percutaneous coronary intervention

BACKGROUND

Developing contrast-associated acute kidney injury (CA-AKI) following percutaneous coronary intervention (PCI) is closely related to patient-related risk factors as well as contrast administration. The diagnostic and prognostic roles of neutrophil gelatinase-associated lipocalin (NGAL) in CA-AKI following PCI are not well established.

METHODS

Consecutive patients undergoing PCI were enrolled prospectively. CA-AKI was defined as an increase in the serum creatinine level ≥0.3 mg/dL within 48 hours or ≥1.5 times the baseline within 7 days after PCI. Serum NGAL concentrations were determined immediately before and 6 hours after PCI. The participants were classified into four NGAL groups according to the pre- and post-PCI NGAL values at 75th percentile.

RESULTS

CA-AKI occurred in 38 (6.4%) of 590 patients. With chronic kidney disease status (hazard ratio [HR] 1.63, 95% confidence interval [CI]: 1.06-2.52), NGAL groups defined by the combination of pre- and 6 h post-PCI values were independently associated with the occurrence of CA-AKI (HR 1.69, 95% CI: 1.16-2.45). All-cause mortality for 29-month follow-ups was different among NGAL groups (log-rank p<0.001). Pre-PCI NGAL levels significantly correlated with baseline cardiac, inflammatory, and renal markers. Although post-PCI NGAL levels increased in patients with larger contrast administration, contrast media made a relatively limited contribution to the development of CA-AKI.

CONCLUSION

In patients undergoing PCI, the combination of pre- and post-PCI NGAL values may be a useful adjunct to current risk-stratification of CA-AKI and long-term mortality. CA-AKI is likely caused by systemic reserve deficiency rather than contrast administration itself.

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.

Plasma Neutrophil Gelatinase-Associated Lipocalin Associates with New-Onset Chronic Kidney Disease in the General Population

Circulating levels of neutrophil gelatinase-associated lipocalin (NGAL) have been associated with acute kidney injury and the severity and progression of chronic kidney disease (CKD). This study investigated its potential utility as a biomarker for the risk of new-onset CKD in a population-based cohort study. Individuals without CKD at baseline (n = 4660) who participated in the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) prospective population-based cohort study in the Netherlands were included. Baseline plasma NGAL concentrations were investigated for their associations with new-onset CKD, defined as a composite outcome of an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m², urinary albumin excretion (UAE) > 30 mg/24-h, or both. Mean (±SD) plasma NGAL concentrations were 104.0 (±34.7) μg/L and median eGFR was 96 [IQR: 85.3-105.8] mL/min/1.73 m². After median follow-up of 8.3 [IQR: 7.8-8.9] years, 467 participants developed new-onset CKD. Plasma NGAL concentrations were significantly associated with an increased risk of new-onset CKD (hazard ratio [HR] per doubling 1.35 [95% CI: 1.11-1.63], p = 0.002), even after adjustment for potentially confounding factors (1.37 [1.09-1.73], p = 0.007) except baseline eGFR (1.09 [0.86-1.37], p = 0.490). In secondary analyses, plasma NGAL concentrations were significantly associated with new-onset CKD as defined by eGFR < 60 mL/min/1.73 m² alone (adjusted HR per doubling 2.54 [1.69-3.80], p < 0.001), which was abrogated after adjustment for eGFR (1.05 [0.69-1.59], p = 0.828), also when UAE > 30 mg/24-h was set as individual outcome (1.05 [0.82-1.35], p = 0.705). Higher plasma NGAL concentrations are associated with an increased risk of developing CKD in the general population. This association is dependent on renal function, and mainly driven by new-onset CKD as defined by renal function decline.

MR-proANP measured at admission is associated with incident atrial fibrillation in STEMI patients

Atrial fibrillation (AF) is common following ST-segment elevation myocardial infarction (STEMI). Increased blood levels of mid regional pro atrial natriuretic peptide (MR-proANP) have been associated with a greater risk of incident AF. However, knowledge of the value of MR-proANP in predicting incident AF after STEMI is sparse. To assess whether MR-proANP measured at admission is associated with development of incident AF in patients with STEMI. 673 STEMI patients with no history of AF treated with primary percutaneous coronary intervention (pPCI) were prospectively enrolled from September 2006 to December 2008. Blood samples were drawn before the procedure. MR-proANP was measured by an automated processing assay. End point was incident AF. Median follow-up time was 5.5 years (interquartile-range 4.7-6.0), during which 63 patients developed AF. In a multivariable Cox regression model adjusted for relevant clinical and biochemical variables, MR-proANP was significantly associated with the development of AF (HR 1.18 per 100 pmol, 95% CI 1.11-1.28, p < 0.001). In a subgroup of patients who underwent echocardiography (N = 360), MR-proANP remained significantly associated with the development of AF (HR 1.39 per 100 pmol, 95% CI 1.13-1.71, p = 0.002) after adjusting for clinical and biochemical variables and left ventricular ejection fraction. When stratifying patients according to tertiles of MR-proANP, patients in the upper tertile displayed an 11 times greater risk of developing AF during follow-up as compared to patients in the lower tertile (HR 11.1, 95% CI 4.4-28.2, p < 0.001). Plasma MR-proANP measured at admission is an independent predictor of incident AF after STEMI.

Neutrophil degranulation and myocardial infarction

Myocardial infarction (MI) is one of the most common cardiac emergencies with high morbidity and is a leading cause of death worldwide. Since MI could develop into a life-threatening emergency and could also seriously affect the life quality of patients, continuous efforts have been made to create an effective strategy to prevent the occurrence of MI and reduce MI-related mortality. Numerous studies have confirmed that neutrophils play important roles in inflammation and innate immunity, which provide the first line of defense against microorganisms by producing inflammatory cytokines and chemokines, releasing reactive oxygen species, and degranulating components of neutrophil cytoplasmic granules to kill pathogens. Recently, researchers reported that neutrophils are closely related to the severity and prognosis of patients with MI, and neutrophil to lymphocyte ratio in post-MI patients had predictive value for major adverse cardiac events. Neutrophils have been increasingly recognized to exert important functions in MI. Especially, granule proteins released by neutrophil degranulation after neutrophil activation have been suggested to involve in the process of MI. This article reviewed the current research progress of neutrophil granules in MI and discusses neutrophil degranulation associated diagnosis and treatment strategies.

Comparative Evaluation of Two NGAL Automated Immunoassays in Urine and Plasma

BACKGROUND

Acute kidney injury (AKI), a frequent and serious complication of hospitalized patients, is associated with increased mortality and morbidity. Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker for the early identification of AKI. We report a comparative laboratory verification of the Abbott Diagnostics (ARCHITECT® urine NGAL) and BioPorto Diagnostics (NGAL TestTM) assays including an assessment of the Abbott assay's performance in EDTA plasma.

METHODS

Intra-/interbatch imprecision, linearity, recovery, and limit of quantitation (LoQ) were assessed and an interassay comparison performed (n = 51). Between-laboratory agreement was assessed against other laboratories using the Abbott (n = 48) and BioPorto (n = 94) assays. Plasma NGAL (pNGAL) levels were measured in non-AKI patients with a range of estimated glomerular filtration rates (n = 80).

RESULTS

Coefficients of variation (CVs) for intra- and interbatch imprecision were 0.7%-12.4% and 1.9%-27.5% for the BioPorto assay, respectively, and 1.4%-6.3%/3.4%-6.8%, respectively, for the Abbott assay. The BioPorto assay exhibited a higher LoQ (27.5 ng/mL vs 1.2 ng/mL). Both assays were linear over the range 5-6000 ng/mL. Recovery of recombinant NGAL was 113.1 ± 7.1% and 96.5 ± 7.8% for the Abbott and BioPorto assays, respectively. On average, the Abbott assay gave results 9.2% lower than the BioPorto assay. Mean differences of 0.2% (Abbott) and 20.2% (BioPorto) were observed in the between-laboratory comparison. In patients without AKI, pNGAL levels were inversely proportional to eGFR.

CONCLUSIONS

Performance of the Abbott and BioPorto assays was similar although the latter performed less well at lower NGAL concentrations. The Abbott assay tended to yield lower results, exhibited a lower LoQ and over-recovered NGAL. Although only Conformité Européenne-marked and marketed for use in urine, the Abbott assay demonstrated equivalent performance to the BioPorto assay with EDTA plasma.

Detection of Renal Injury Following Primary Coronary Intervention among ST-Segment Elevation Myocardial Infarction Patients: Doubling the Incidence Using Neutrophil Gelatinase-Associated Lipocalin as a Renal Biomarker

Background: A subgroup of patients with acute kidney injury (AKI) do not fulfil the functional criteria for AKI diagnosis but show elevated levels of new biomarkers reflecting tubular injury, suggesting that these patients suffer “subclinical AKI”. We investigated the incidence and possible implications of “subclinical AKI”, compared to no and clinical AKI among ST elevation myocardial infarction patients (STEMI) treated with primary coronary intervention (PCI). Methods: We included 223 patients with STEMI treated with PCI. Neutrophil gelatinase-associated lipocalin (NGAL) was used as a marker of renal tubular damage in the absence of functional AKI, with NGAL levels ≥100 ng/mL suggesting subclinical AKI. Patients were assessed for the occurrence of in-hospital adverse outcomes. Results: Of the study patients, 45 (25%) had subclinical AKI. These patients were more likely to have left ventricular ejection fraction ≤45% (33% vs. 23%. p = 0.01), in-hospital adverse outcomes (73% vs. 48%; p = 0.005), and a combination of the two. The multivariate regression model demonstrated that subclinical AKI was independently associated with in-hospital adverse outcomes (OR 3.71, 95% CI 1.30–10.62, p = 0.02). Conclusions: Subclinical AKI is common among STEMI patients and is independently associated with adverse outcomes, even in the absence of functional AKI.

Neutrophil Gelatinase-Associated Lipocalin for the Assessment of Reversible versus Persistent Renal Tubular Damage in ST-Segment Myocardial Infarction Patients

BACKGROUND

Most studies investigated the value of neutrophil gelatinase-associated lipocalin (NGAL) as a marker of renal tubular injury only at a single time point. We investigated the possible utilization of NGAL level dynamics for the identification of different renal injury patterns in ST-elevation myocardial infarction (STEMI) patients.

METHODS

Blood samples for plasma NGAL in 132 STEMI patients were drawn immediately before and 24 h following primary coronary intervention. Abnormal elevation of NGAL levels was defined using the cardiac surgery-associated NGAL score with NGAL levels ≥100 ng/mL suggesting renal tubular damage. According to NGAL levels at 0 and 24 h, patients were stratified into 3 groups: no tubular damage (NGAL <100 ng/mL in both exams), reversible tubular damage (NGAL >100 ng/mL at 0 h but <100 ng/mL at 24 h), and persistent tubular damage (NGAL >100 ng/mL at both 0 and 24 h).

RESULTS

Mean age was 62 ± 13 years, and 78% were men. Of these patients, 29/132 (22%) demonstrated reversible tubular damage, and 36/132 (27%) persistent tubular damage. Only 13/132 patients (10%) progressed to clinical acute kidney injury during hospitalization, all of whom had persistent tubular injury. In multivariate regression model, symptom duration was independently associated with persistent tubular damage, both as continues variable (odds ratio [OR] 1.02, 95% confidence interval [CI] 1.01-1.04; p = 0.04) and for symptom duration >360 min (OR 2.66, 95% CI 1.07-6.63; p = 0.03).

CONCLUSIONS

Renal tubular damage is common among STEMI patients. Dynamic NGAL measurement may differentiate between reversible and persistent tubular damage. Further trials are needed in order to assess the complex cardiorenal interactions.

Left Atrial Function Determined by Echocardiography Predicts Incident Heart Failure in Patients With STEMI treated by Primary Percutaneous Coronary Intervention

OBJECTIVES

To assess the comparative effectiveness of left atrial (LA) functional parameters (left atrial emptying fraction (LAEF), left atrial expansion index (LAi) and minimal left atrial volume index (MinLAVI)) with that of LA volume index (LAVI) in predicting heart failure (HF) and death following ST-elevated myocardial infarction (STEMI).

BACKGROUND

HF is common following STEMI. Enlarged LA volume as determined by echocardiography predicts adverse outcome following STEMI. However, whether echocardiographic parameters of LA function, such as LAEF, LAi and MinLAVI, are superior to LAVI for predicting prognosis following STEMI is unknown.

METHODS AND RESULTS

A total of 369 patients with STEMI but without atrial fibrillation or HF who were treated with primary percutaneous coronary intervention were prospectively enrolled in the period between September 2006 and December 2008. Patients underwent echocardiography shortly after STEMI. The maximal and minimal LA volumes were measured using the biplane area-length method. LAVI, MinLAVI (minimal LA volume indexed to body surface area), LAEF ((maximal LA volume-minimal LA volume)/maximal LA volume), and LAi ((maximal LA volume-minimal LA volume)/minimal LA volume) were calculated. The endpoint was a composite consisting of HF or death from any cause. During a median follow-up of 66 months (interquartile range: 50-73 months), 112 patients reached the endpoint (68 HFs, 44 deaths). Following adjustment for clinical, biochemical and echocardiographic variables, only LAEF remained an independent predictor of the composite outcome, whereas LAVI did not (LAEF: HR 1.25, P = 0.043, per 1 SD decrease) (LAVI: HR 1.01, P = 0.91, per 1 SD increase).

CONCLUSION

In patients with STEMI who were treated with primary percutaneous coronary intervention, LAEF, as measured by echocardiography shortly after infarction, was superior to LAVI in predicting incident HF and death.

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.

Predictive value of plasma neutrophil gelatinase-associated lipocalin in acute charcoal-burning carbon monoxide poisoning

This study aimed to assess the feasibility of using the plasma neutrophil gelatinase-associated lipocalin (NGAL) level at the time of presentation in the emergency department (ED) to predict acute kidney injury (AKI) and the long-term neurological outcomes of acute charcoal-burning carbon monoxide (CO) poisoning. This retrospective study included 260 patients who suffered acute charcoal-burning CO poisoning. The median plasma NGAL concentration at the time of presentation in the ED after acute charcoal-burning CO poisoning was 78 (54–115) ng/ml. The NGAL level was an independent predictor of AKI development and could be used to stratify the severity of AKI. However, the area under the receiver operating characteristic curve (AUC) of the predictive model for AKI that included both the plasma NGAL level and clinical parameters was comparable to that of the predictive model including only the clinical parameters. The plasma NGAL level at the time of presentation in the ED was an independent factor predicting long-term neurological outcomes in patients who did not develop AKI. In these patients, the plasma NGAL level significantly improved the predictive accuracy of the model when used in combination with clinical parameters. In contrast, the plasma NGAL level was not associated with long-term neurological outcomes in patients who developed AKI. Measurement of the plasma NGAL level at the time ED presentation might improve the prediction of long-term neurological outcomes in patients who do not develop AKI after acute charcoal-burning CO poisoning. However, it might not offer additional benefit for AKI prediction compared to previously used markers.

Elevated neutrophil gelatinase-associated lipocalin levels before contrast media administration among ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is a glycoprotein released by renal tubular cells upon nephrotoxic or ischemic events and is considered an early marker of tubular damage. We aimed to demonstrate the presence of early renal injury detected by elevated NGAL levels taken before contrast administration in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI).

PATIENTS AND METHODS

We prospectively included 88 patients with STEMI treated with PCI. Blood samples for plasma NGAL were drawn immediately before PCI (baseline NGAL; NGAL1) and 24 h after PCI (NGAL2). Abnormal elevations in NGAL levels were defined using the cardiac surgery associated NGAL score (NGAL score) with NGAL levels at least 100 ng/ml, suggesting renal tubular damage. Patients were also assessed for the dynamics between NGAL2 and NGAL1 levels.

RESULTS

The mean age of the patients was 62 ± 13 years and 78% were men. A total of 50/88 (56%) patients had baseline NGAL level of at least 100, suggesting possible tubular damage before PCI. Only 10 patients progressed to clinical acute kidney injury during hospitalization, all of whom had baseline NGAL level of at least 100 (P < 0.001). Among patients with baseline NGAL at least 100, 28/50 (56%) showed a decrease in the NGAL level within 24 h, whereas only 9/50 (18%) showed an elevation in the NGAL level. In contrast, only 7/38 (19%) patients with baseline NGAL level less than 100 showed an elevation in NGAL levels within 24 h.

CONCLUSION

Elevated NGAL levels before primary PCI suggesting renal tubular damage are common among STEMI patients. Further trials are needed to assess the complex cardio-renal interactions.

Improvement of neutrophil gelatinase-associated lipocalin sensitivity and specificity by two plasma measurements in predicting acute kidney injury after cardiac surgery

Introduction

Acute kidney injury (AKI) remains among the most severe complication after cardiac surgery. The aim of this study was to evaluate the neutrophil gelatinase-associated lipocalin (NGAL) as possible biomarker for the prediction of AKI in an adult cardiac population.

Materials and methods

Sixty-nine consecutive patients who underwent cardiac surgeries in our hospital were prospectively evaluated. In the intensive care unit (ICU) NGAL was measured as a new biomarker of AKI besides serum creatinine (sCrea). Patients with at least two factors of AKI risk were selected and samples collected before the intervention and soon after the patient's arrival in ICU. As reference standard, sCrea measurements and urine outputs were evaluated to define the clinical AKI. A Triage Meter for plasma NGAL fluorescence immunoassay was used.

Results

Acute kidney injury occurred in 24 of the 69 patients (35%). Analysis of post-operative NGAL values demonstrated an AUC of 0.71, 95% CI (0.60 - 0.82) with a cut-off = 154 ng/mL (sensitivity = 76%, specificity = 59%). Moreover, NGAL after surgery had a good correlation with the AKI stage severity (P ≤ 0.001). Better diagnostic results were obtained with two consecutive tests: sensitivity 86% with a negative predictive value (NPV) of 87%. At 10-18 h after surgery sCrea measurement, as confirmatory test, allowed to reach a more sensitivity and specificity with a NPV of 96%.

Conclusions

The assay results showed an improvement of NGAL diagnostic accuracy evaluating two tests. Consequently, NGAL may be useful for a timely treatment or for the AKI rule out in ICU patients.

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.

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.