Plasma Neutrophil Gelatinase-associated Lipocalin Research Articles

#554 Baseline neutrophil gelatinase-associated lipocalin (NGAL) levels for early prediction and ruling out future contrast nephropathy

Abstract Background and aims Neutrophil gelatinase-associated lipocalin (NGAL), is an early marker of acute kidney injury (AKI). There is only limited data, however, on the optimal timing for assessment, the cut-off values and its utilization for ruling out AKI We aimed to investigate the diagnostic utility of sequential NGAL measurements for both prediction and ruling out of AKI among patients with ST segment elevation (STEMI) undergoing primary coronary intervention (PCI). Methods We included 133 patients with STEMI treated with PCI. Blood samples for plasma NGAL were drawn immediately before PCI (NGAL 0) and 24 hours after PCI (NGAL 24). Optimal threshold for the development of AKI were determined using receiver operating characteristic curves (ROC). Patients were also assessed for the dynamics between NGAL 0 and NGAL 24 levels. Results Mean age was 62 ± 13 years and 78% were men, and a total of 20 (15%) developed AKI. Patients with AKI demonstrated higher plasma NGAL 0 levels (164 ± 42 vs. 95 ± 30 ng/mL; p < 0.001) as well as NGAL 24 levels (142 ± 41 vs. 93 ± 36 ng/mL; p < 0.001). There were no significant changes between NGAL 0 & 24 hours within the 2 groups (Fig. 1). According to the ROC curve analysis NGAL 0 performed better than NGAL 24 for AKI prediction (Fig. 2). The optimal NGAL 0 level for AKI prediction was >125 ng/mL (AUC 0.841, 95% CI 0.801–0.961, p < 0.001), with a sensitivity of and specificity of 70% and 84% respectively, while the negative predictive value of NGAL 0<125 ng/mL was 94%. Conclusions Among STEMI patients, NGAL levels before primary PCI may be utilized both for ruling out and for the prediction of AKI.

#668 Combined biomarker testing for the assessment of acute kidney injury among myocardial infarction patients

Abstract Background and aims The utility of different biomarkers for the prediction of acute kidney injury following ST-elevation myocardial infarction (STEMI) has been evaluated in several studies however, very few data exist on the prognostic value of combining biomarkers. Among numerous biomarkers examined, C-reactive protein (CRP) and Neutrophil gelatinase associated Lipocalin (NGAL) stand high in their utility to assess AKI risk. The aim of this study was to assess the prognostic value of combined CRP and NGAL measurement for the assessment of the risk of AKI in reperfused STEMI patients Methods Blood samples for plasma NGAL and CRP were drawn 24 hours after admission. High NGAL and CRP were defined as values within the 4th quartile (>75percentile). Patients were stratified into 4 study groups: Low NGAL/Low CRP, LOW NGAL/high CRO, High NGAL /low CRP and high NGAL/high CRP. Patients were assessed for the occurrence of in-AKI based on the KDIGO criteria. Results A total of 311 patients were included (mean age 66 ± 14 years, 81% males). According to the 4 study groups, there was a stepwise increase in the proportion of AKI (9% vs. 21% vs. 40% vs. 68%; p 0.001; Fig. 1). In a multivariate regression model, compared to patients having low NGAL/low CRP we observed a graded, independent increase in the risk for AKI for low NGAL/high CRP, high NGAL/low CRP and high NGAL/high CRP(OR 2.89, p = 0.02 vs. OR 3.29, p < 0.001 vs. OR 17.6, p < 0.001 respectively, Table 1). Peak concentrations showed significant areas under the curves (AUCs) for the prediction of AKI for both CRP AUC (0.692, 95% CI 0.62-0.76) and NGAL (AUC 0.778, 95% CI 0.72-0.84). The combination of NGAL and CRP yielded a significant increase in AUC to 0.822 (95% CI 0.77 to 0.88) (combined biomarkers vs CRP: p < 0.001 and combined vs. NGAL: p = 0.02; Fig. 2). Conclusions In patients with reperfused STEMI, the combined assessment of NGAL and CRP provided incremental prognostic information for the prediction AKI when compared with single-biomarker measurement.

Plasma proenkephalin andneutrophil gelatinase-associated lipocalin predict mortality in ICU patients with acute kidney injury.

Acute kidney injury (AKI) is a common complication in patients admitted to intensive care unit (ICU) and mortality rates for this condition are high. To reduce the high incidence of short-term mortality, reliable prognostic indicators are required to facilitate early diagnosis and treatment of AKI. We assessed the ability of plasma proenkephalin (p‑PENK) and plasma neutrophil gelatinase-associated lipocalin (p‑NGAL) to predict 28-day mortality in AKI patients in intensive care. This prospective study, carried out between January 2019 and December 2019, comprised 150 patients (100 male) diagnosed with AKI after excluding 20 patients discharged within 24 h and those with missing hospitalization data. Blood samples were collected to determine admission p-PENK and p-NGAL levels. The study outcome was 28‑day mortality. The mean patient age was 68 years (female, 33%). The average P‑PENK and p‑NGAL levels were 0.24 ng/µL and 223.70 ng/mL, respectively. P‑PENK levels >0.36 ng/µL and p‑NGAL levels >230.30 ng/mL were used as critical values to reliably indicate 28‑day mortality for patients with AKI (adjusted hazard ratios 0.785 [95% confidence interval 0.706-0.865, P<0.001] and 0.700 [95% confidence interval 0.611-0.789, P<0.001], respectively). This association was significant for mortality in patients in intensive care with AKI. Baseline p-PENK (0.36 ng/µL) and p-NGAL (230.30 ng/mL) levels and their respective cut-off values showed clinical value in predicting 28-day mortality. Serum PENK and NGAL levels, when used in conjunction, improved the accuracy of predicting 28-day mortality in patients with AKI while retaining sensitivity and specificity.

Impacts of age, type 2 diabetes, and hypertension on circulating neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 after prolonged work in the heat in men.

Prolonged work in the heat increases the risk of acute kidney injury (AKI) in young men. Whether aging and age-associated chronic disease may exacerbate the risk of AKI remains unclear. We evaluated plasma neutrophil gelatinase-associated lipocalin (NGAL) and serum kidney injury molecule-1 (KIM1) before and after 180min of moderate-intensity work (200W/m2) in temperate (wet-bulb globe temperature [WBGT] 16°C) and hot (32°C) environments in healthy young (n = 13, 22years) and older men (n = 12, 59years), and older men with type 2 diabetes (T2D; n = 9, 60years) or hypertension (HTN; n = 9, 60years). There were no changes in NGAL or KIM1 concentrations following prolonged work in temperate conditions in any group. Despite a similar work tolerance, the relative change in NGAL was greater in the older group when compared to the young group following exercise in the hot condition (mean difference + 82ng/mL; p < 0.001). Baseline concentrations of KIM1 were ~ 22pg/mL higher in the older relative to young group, increasing by ~ 10pg/mL in each group after exercise in the heat (both p ≤ 0.03). Despite a reduced work tolerance in the heat in older men with T2D (120 ± 40min) and HTN (108 ± 42min), elevations in NGAL and KIM1 were similar to their healthy counterparts. Age may be associated with greater renal stress following prolonged work in the heat. The similar biomarker responses in T2D and HTN compared to healthy older men, alongside reduced exercise tolerance in the heat, suggest these individuals may exhibit greater vulnerability to heat-induced AKI if work is prolonged.

Neutrophil gelatinase-associated lipocalin (NGAL) levels for early prediction and ruling out future contrast nephropathy in patients undergoing primary coronary intervention

Abstract Funding Acknowledgements None. Background Neutrophil gelatinase-associated lipocalin (NGAL), is an early marker of acute kidney injury(AKI) . We aimed to investigate the diagnostic utility of sequential NGAL measurements for both prediction and ruling out of contrast induced AKI (CI-AKI) among patients with ST segment elevation (STEMI) undergoing primary coronary intervention (PCI). Methods We included 133 patients with STEMI treated with PCI. Blood samples for plasma NGAL were drawn immediately before PCI (NGAL 0) and 24 hours after PCI (NGAL 24). Optimal threshold for the development of CI-AKI were determined using receiver operating characteristic curves (ROC). Patients were also assessed for the dynamics between NGAL 0 and NGAL 24 levels. Results Mean age was 62 ±13 years and 78% were men, and a total of 20 (15%) developed CI-AKI . Patients with CI-AKI demonstrated higher plasma NGAL 0 levels (164 ± 42 vs. 95 ± 30 ng/mL; p &amp;lt; 0.001) as well as NGAL 24 levels (142 ± 41 vs. 93 ± 36 ng/mL; p &amp;lt; 0.001). There were no significant changes between NGAL 0 &amp; 24 hours within the 2 groups( figure 1). According to the ROC curve analysis (figure 2), the optimal NGAL 0 level for CI-AKI prediction was &amp;gt;125 ng/mL (AUC 0.841, 95% CI 0.801–0.961, p &amp;lt; 0.001), with a sensitivity of and specificity of 70% and 84% respectively, while the negative predictive value of NGAL 0&amp;lt;125 ng/mL was 94%. Conclusions Among STEMI patients, NGAL levels before primary PCI may be utilized both for ruling out and for the prediction of CI-AKI.NGAL 0 vs 24 according to CI-AKINGAL AUC

Combined biomarker testing for the assessment of cardio-renal interactions among myocardial infarction patients

Abstract Funding Acknowledgements None. Background The utility of different biomarkers for the prediction of either renal or cardiovascular outcomes following ST-elevation myocardial infarction (STEMI) has been evaluated in several studies however, very few data exist on the prognostic value of combining biomarkers. Among numerous biomarkers examined, C-reactive protein (CRP) and Neutrophil gelatinase associated Lipocalin (NGAL) stand high in their utility to assess the cardiorenal crosstalk. The aim of this study was to assess the prognostic value of combined CRP and NGAL measurement for the assessment of renal and cardiovascular outcomes in reperfused STEMI patients. Methods Blood samples for plasma NGAL and CRP were drawn 24 hours after admission. High NGAL and CRP were defined as values within the 4th quartile (&amp;gt;75percentile). Patients were stratified into 4 study groups: Low NGAL/Low CRP, LOW NGAL/high CRO, High NGAL /low CRP and high NGAL/high CRP. Patients were assessed for the occurrence of in-hospital adverse clinical events (MACE). These included occurrence of acute kidney injury , 30-day mortality and their combination. Results A total of 311 patients were included (mean age 66 ± 14 years, 81% males). According to the 4 study groups, there was a stepwise increase in the proportion of in hospital MACE ( 9% vs. 21% vs. 40% vs. 68% ;p,0.001,figure 1). In a multivariate regression model , compared to patients having low NGAL/low CRP we observed a graded, independent increase in the risk for MACE for low NGAL/high CRP , high NGAL/low CRP and high NGAL/high CRP levels( OR 2.89, p=0.02 vs. OR 3.29,p&amp;lt;0.001 vs. OR 17.6,p&amp;lt;0.001 respectively). Peak concentrations showed significant areas under the curves (AUCs) for the prediction of MACE for both CRP AUC (0.692,95% CI 0.62-0.76) and NGAL ( AUC 0.778,95% CI 0.72-0.84). The combination of NGAL and CRP yielded a significant increase in AUC to 0.822 (95% CI 0.77 to 0.88) (combined biomarkers vs CRP: p&amp;lt;0.001 and combined vs. NGAL :p=0.02,figure 2). Conclusions In patients with reperfused STEMI, the combined assessment of NGAL and CRP provided incremental prognostic information for the prediction of in hospital MACE when compared with single-biomarker measurement.Proportion of in-hospital MACEAUC CR NGAL

Furosemide stress test to predict acute kidney injury progression in critically ill children.

Furosemide stress test (FST) is a novel functional biomarker for predicting severe acute kidney injury (AKI); however, pediatric studies are limited. Children 3months to 18years of age admitted to the intensive care unit (ICU) of a tertiary care hospital from Nov 2019 to July 2021 were screened and those who developed AKI stage 1 or 2 within 7days of admission underwent FST (intravenous furosemide 1mg/kg). Urine output was measured hourly for the next 6h; a value > 2ml/kg within the first 2h was deemed furosemide responsive. Other biomarkers like plasma neutrophil gelatinase-associated lipocalin (NGAL) and proenkephalin (PENK) were also evaluated. Of the 480 admitted patients, 51 developed AKI stage 1 or 2 within 7days of admission and underwent FST. Nine of these patients were furosemide non-responsive. Thirteen (25.5%) patients (eight of nine from FST non-responsive group) developed stage 3 AKI within 7days of FST, nine (17.6%) of whom (seven from non-responsive group) required kidney support therapy (KST). FST emerged as a good biomarker for predicting stage 3 AKI and need for KST with area-under-the-curve (AUC) being 0.93 ± 0.05 (95% CI 0.84-1.0) and 0.96 ± 0.03 (95% CI 0.9-1.0), respectively. FST outperformed NGAL and PENK in predicting AKI stage 3 and KST; however, the combination did not improve the diagnostic accuracy. Furosemide stress test is a simple, inexpensive, and robust biomarker for predicting stage 3 AKI and KST need in critically ill children. Further research is required to identify the best FST cut-off in children.

Ratlarda Oluşturulan Renal İskemi Reperfüzyon Hasarında Epibatidinin Etkileri

Objective: The attenuation of renal ischemia reperfusion (I/R) injury by stimulating cholinergic antiinflamatory pathway has been demonstrated in the literature. The purpose of this study is to investigate the protective effects of epibatidine, a non selective nicotinic acethycholine receptor agonist, administered before ischemia on renal ischemia-reperfusion injury. Methods: After Ethics Committee approval, 24 Wistar Albino rats were randomly allocated into 4 groups. Group S: Sham (n=6), Group I/R: Ischemia/reperfusion (n=6), Group I/R-E: Ischemia/ reperfusion-Epibatidine (n=6), Group E: Epibatidine (n=6). All groups underwent laparotomy and bilateral renal artery and vein dissection under anesthesia. No further action was taken in Group S. In Group I/R and Group I/R-E, renal ischemia was applied for 25 minutes and then reperfusion for 24 hours. A single dose of 5 μg kg-1 epibatidine was administered subcutaneously before the laparotomy in Group I/R-E and Group E. At the end of the reperfusion period, blood and urine samples were taken for plasma BUN, creatine, plasma and urinary neutrophil gelatinase associated lipocalin (NGAL) and cystatin C, plasma IL-6 and TNF-α assessment. Results: Plasma BUN, creatine, NGAL, cystatin C, IL-6 and TNF-α levels were significantly higher in Group I/R when compared to Group S (p&lt;0.05). All the levels of the above biomarkers were comparable in Group S and Group I/R-E. Conclusion: These results indicate that epibatidine administration before ischemia has a protective effect on kidney in renal I/R injury induced rats. Keywords: Renal ischemia-reperfusion injury, cholinergic antiinflammatory pathway, n7AchR, epibatidine, NGAL

Plasma NGAL (Neutrophil Gelatinase Associated Lipocalin) Levels in Septic Patients With &amp; Without Acute Kidney Injury: A Plausible Biomarker

Introduction: Acute kidney injury is extremely common among septic patients. Its early recognition among critically ill patients can help in better prognosis and decrease the risk of longer hospital stay and dialysis requirement. Creatinine is considered as a gold standard for diagnosis of Acute Kidney Injury but it has its own disadvantages. New biomarkers for Acute Kidney Injury that can help in its early recognition are the need of time. Many plasma and urinary markers including Neutrophil Gelatinase Associated Lipocalin are being studied. Its role in earlier detection of septic Acute Kidney Injury in septic patients in our set of population still needs extensive research where incidence of sepsis associated complications leading to death is extremely high. Aims and Objectives: To measure plasma Neutrophil Gelatinase Associated Lipocalin levels in septic patients with and without acute injury compare pNGAL levels in two groups, and to measure specificity and sensitivity of plasma Neutrophil Gelatinase Associated Lipocalin levels in both sets of patients. Place and Duration of study: A cross sectional analytical study was carried out in National Health Research Complex, Shaikh Zayed Hospital, Lahore over a period of 3 years from 2016-2019 Material and Methods: This is a cross-sectional analytical study carried out in ninety two patients that are divided in two groups on the basis of creatinine levels measured at 72hrs. First group consists of septic patients who developed Acute Kidney Injury (AKI) and second group consists of septic patients Without Acute Kidney Injury(WAKI). Plasma NGAL levels are compared in two groups. SPSS v 20 was used for analysis, p-value ? 0.05 was considered significant. Results: The plasma NGAL level at 24 hours for group without Acute Kidney Injury was 126.4±15.4 ng/ml and for the group which developed Acute kidney Injury was 191.1±15.9 ng/ml and the difference was clearly significant with p- value &lt;0.001. Conclusion: pNGAL levels are significantly raised than the cut-off value of 150ng/ml at 0hrs in septic patients who developed AKI as compared to septic patients who didn’t develop AKI.

Pharmacokinetics and Nephrotoxicity of Polymyxin MRX-8 in Rats: A Novel Agent against Resistant Gram-Negative Bacteria.

MRX-8 is a novel polymyxin for carbapenem-resistant Gram-negative infections that has been recently evaluated in Phase I clinical trials. Herein, its pharmacokinetics (PK) and nephrotoxicity in rats are reported for the first time. This study aimed at pre-clinical PK and safety assessments. An LC-MS/MS method was developed to determine concentrations of MRX-8 and its major deacylation metabolite, MRX-8039, in rat plasma. Animals were administered a single dose of MRX-8 (2, 4, 6, and 8 mg/kg) or comparator polymyxin B (PMB) (4 and 8 mg/kg) to compare the kidney injury known for the polymyxin drug class. Nephrotoxicity was evaluated using serum creatinine, blood urea nitrogen (BUN) biomarkers, and renal histopathology. In rats, MRX-8 displayed linear PK within the range of 2-8 mg/kg, with approximately 4% of MRX-8 converted to MRX-8039. MRX-8 induced only mild increases in serum creatinine and BUN levels, with an apparent decrease in nephrotoxicity within 24 h, in contrast to PMB, which exhibited a significant and more persistent toxicity. Additional nephrotoxicity biomarkers (plasma NGAL and urinary NGAL, KIM-1, and TIMP-1) have confirmed attenuated MRX-8 kidney injury. Histopathology has revealed significantly greater cellular/tissue toxicity for PMB as compared to MRX-8 (variances of p = 0.008 and p = 0.048 vs. saline control, respectively). Thus, MRX-8 induces a mild and reversible kidney injury in rats compared to PMB. These data support a continued evaluation of the novel polymyxin in human trials.

Sex-specific associations of plasma neutrophil gelatinase-associated lipocalin (NGAL) with cognition in patients with drug-naïve schizophrenia

This present study aimed to investigate the sex-specific association of plasma neutrophil gelatinase-associated lipocalin (NGAL) with cognition in drug-naïve schizophrenia patients for the first time. A total of 204 participants in this study, including 137 drug-naïve schizophrenia (DNS) patients and 67 healthy controls (HCs). All participants completed the Measurements and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB), and were collected fasting venous blood for NGAL measurement. DNS patients also complete the Positive and Negative Syndrome Scale (PANSS). Partial correlation analysis and multiple linear regression were used to explore sex-specific associations between NGAL and cognition. All dimensions of MCCB scores were significantly lower in both male and female DNS patients than HCs. Sex differences were significant in cognitive performance in both DNS patients and HCs. Female DNS patients experienced poorer working memory and reason& problem solving than male patients. Female HCs performed a better attention/vigilance and visual learning, a poorer reason& problem solving than male HCs. In patients with DNS, NGAL levels were negatively associated with positive subscale of PANSS and positively associated with working memory and visual learning only in female. However, there was no significant correlation between NGAL levels and all cognitive tests in both male and female HCs. Regression model showed that higher level of NGAL was an independent protective factor for cognitive performance in female patients with DNS, whereas there was no such role in male patients. Our findings suggest sex specificity between NGAL levels and cognitive performance in DNS patients.

Systemic Neutrophil Gelatinase-Associated Lipocalin Alterations in Chronic Pancreatitis: A Multicenter, Cross-Sectional Study.

Chronic pancreatitis (CP) is a progressive fibroinflammatory disorder lacking therapies and biomarkers. Neutrophil gelatinase-associated lipocalin (NGAL) is a proinflammatory cytokine elevated during inflammation that binds fatty acids (FAs) such as linoleic acid. We hypothesized that systemic NGAL could serve as a biomarker for CP and, with FAs, provide insights into inflammatory and metabolic alterations. NGAL was measured by immunoassay, and FA composition was measured by gas chromatography in plasma (n = 171) from a multicenter study, including controls (n = 50), acute and recurrent acute pancreatitis (AP/RAP) (n = 71), and CP (n = 50). Peripheral blood mononuclear cells (PBMCs) from controls (n = 16), AP/RAP (n = 17), and CP (n = 15) were measured by cytometry by time-of-flight. Plasma NGAL was elevated in subjects with CP compared with controls (area under the curve [AUC] = 0.777) or AP/RAP (AUC = 0.754) in univariate and multivariate analyses with sex, age, body mass index, and smoking (control AUC = 0.874; AP/RAP AUC = 0.819). NGAL was elevated in CP and diabetes compared with CP without diabetes ( P < 0.001). NGAL + PBMC populations distinguished CP from controls (AUC = 0.950) or AP/RAP (AUC = 0.941). Linoleic acid was lower, whereas dihomo-γ-linolenic and adrenic acids were elevated in CP ( P < 0.05). Linoleic acid was elevated in CP with diabetes compared with CP subjects without diabetes ( P = 0.0471). Elevated plasma NGAL and differences in NGAL + PBMCs indicate an immune response shift that may serve as biomarkers of CP. The potential interaction of FAs and NGAL levels provide insights into the metabolic pathophysiology and improve diagnostic classification of CP.

Urine Liver-Type Fatty Acid Binding Protein; Biomarker for Diagnosing Acute Kidney Injury and Predicting Mortality in Cirrhotic Patients

Objective: To determine impact of urine liver-type fatty acid binding protein (uL-FABP) and urine neutrophil gelatinase-associated lipocalin (uNGAL), which were biomarkers linked to acute kidney injury (AKI), in AKI diagnosis and prediction of 28-day mortality among hospitalized cirrhotic patients. Materials and Methods: We prospectively enrolled hospitalized cirrhotic patients at a tertiary care university hospital between June 2018 and November 2019. The uL-FABP, uNGAL, and plasma NGAL (pNGAL) were collected within 48 hours of admission. Cutoff values of biomarkers for diagnosing AKI derived from receiver operating characteristic (ROC) curve. Logistic regression analysis was used to identify independent factors for 28-day mortality. Results: We enrolled 109 cirrhotic patients in derivative cohort, 41.3% had AKI. Median uL-FABP, uNGAL, and pNGAL levels in AKI group were higher than non-AKI group: 8.1 vs. 2.8 ng/mL (p=0.002), 40.5 vs. 10.1 ng/mL (p&lt;0.001), and 195.7 vs 81.4 ng/mL (p=0.001), respectively. Areas under the ROC curve of uL-FABP, uNGAL, and pNGAL for AKI diagnosis were 0.68, 0.73 and 0.68, respectively. Also, all biomarkers were significantly higher in mortality group. Multivariate analysis showed that the only independent predictor for 28-day mortality was uL-FABP ≥ 4.68 ng/mL (odd ratio 4.15, p=0.02). Conclusion: UL-FABP, uNGAL, and pNGAL are associated with AKI in hospitalized cirrhotic patients. Moreover, uL-FABP ≥ 4.68 ng/mL was a significant independent predictor for 28-day mortality.

Plasma neutrophil gelatinase-associated lipocalin independently predicts dialysis need and mortality in critical COVID-19

Neutrophil gelatinase-associated lipocalin (NGAL) is a novel kidney injury and inflammation biomarker. We investigated whether NGAL could be used to predict continuous renal replacement therapy (CRRT) and mortality in critical coronavirus disease 2019 (COVID-19). This prospective multicenter cohort study included adult COVID-19 patients in six intensive care units (ICUs) in Sweden between May 11, 2020 and May 10, 2021. Blood was sampled at admission, days two and seven in the ICU. The samples were batch analyzed for NGAL, creatinine, and cystatin c after the end of the study period. Initiation of CRRT and 90-day survival were used as dependent variables in regression models. Of 498 included patients, 494 were analyzed regarding CRRT and 399 were analyzed regarding survival. Seventy patients received CRRT and 154 patients did not survive past 90 days. NGAL, in combination with creatinine and cystatin c, predicted the subsequent initiation of CRRT with an area under the curve (AUC) of 0.95. For mortality, NGAL, in combination with age and sex, had an AUC of 0.83. In conclusion, NGAL is a valuable biomarker for predicting subsequent initiation of CRRT and 90-day mortality in critical COVID-19. NGAL should be considered when developing future clinical scoring systems.

Longitudinal NGAL and cystatin C plasma profiles present a high level of heterogeneity in a mixed ICU population

BackgroundNGAL and Cystatin C (CysC) as biomarkers for the early detection of AKI are subject to both pathophysiological, as well as patient related heterogeneity. The aim of this study was to investigate the timeline of plasma levels of NGAL and CysC during the first seven days of ICU admission in a mixed ICU population and to relate these to AKI severity during ICU stay. Via these means we aimed to bring clarity to the previously reported heterogeneity of these renal biomarkers.MethodsProspective Observation Cohort. Consecutive patients admitted to adult ICU at an academic hospital in the Netherlands between 18-02-2014 and 31-03-2014 were included. Urine output, serum creatinine, plasma NGAL and CysC were recorded during the first seven days of ICU admission. Biomarker expression was analyzed based on KDIGO score and time of AKI diagnosis.Results335 patients were included, 110 met KDIGO criteria for AKI. NGAL and CysC plasma levels were higher in AKI patients compared to non-AKI, high variability in individual values resulted in 56% of AKI patients having a false negative, and 32% of non-AKI patients having a false positive. Individual biomarker levels were variable, and no pattern based on KDIGO score was observed.ConclusionsPlasma NGAL and CysC as biomarkers for the early AKI detection may be subject to pathophysiological, and patient related heterogeneity. Further understanding of individual biomarker profiles may help in their application amongst mixed ICU populations.Trial RegistrationThe need for informed consent was waived by the Institutional Ethical Review Board of the University Medical Center Groningen (METc 2013 − 174) by Prof. dr. W.A. Kamps on May 17th 2013.

Urinary vanin-1, tubular injury, and graft failure in kidney transplant recipients

We investigated whether urinary vascular non-inflammatory molecule-1 (vanin-1), a promising early-onset tubular injury marker, correlates with other established tubular injury markers and is associated with graft failure in kidney transplant recipients (KTR). We measured 24 h urinary vanin-1 excretion in 656 KTR (age 53 ± 13 years, 43% female, estimated glomerular filtration rate (eGFR) 53 ± 21 mL/min/1.73 m2) who had undergone kidney transplantation ≥ 1 year. The median 24 h urinary vanin-1 excretion was 145 [51–331] pmol/24 h. 24 h urinary vanin-1 excretion correlated weakly but significantly with other tubular injury markers (ρ = 0.14, p < 0.001 with urinary liver-type fatty acid binding protein, ρ = 0.13, p = 0.001 with urinary post-translationally modified fetuin-A protein, and ρ = 0.10, p = 0.011 with plasma neutrophil gelatinase-associated lipocalin) and with eGFR (ρ = − 0.13, p = 0.001). During a median follow-up of 7.4 [4.9–8.0] years, 94 (14%) KTR developed death-censored graft failure. In multivariable Cox regression analyses, 24 h urinary vanin-1 excretion was not associated with an increased risk of death-censored graft failure (adjusted hazard ratio [95% confidence interval] = 0.96 [0.86–1.07], p = 0.5). In conclusion, our findings do not support the role of urinary vanin-1 as a biomarker of graft failure after kidney transplantation.

Relationship between difference of preoperative and cardiopulmonary bypass mean arterial pressure, and acute kidney injury in cardiac surgical patients undergoing valve surgery.

Modifiable and non-modifiable factors contribute to development and progression of acute kidney injury (AKI) during cardiac surgery. We hypothesized that, the difference between preoperative mean arterial pressure (MAP) and the average mean arterial pressure maintained on cardiopulmonary bypass (CPB) would be strongly predictive of AKI. We also measured plasma Neutrophil gelatinase-associated lipocalin (NGAL), to establish its association with cardiac surgery associated-AKI (CSA-AKI). One hundred and twelve high-risk patients undergoing valve, and valve plus coronary artery bypass grafting (CABG) surgery under cardiopulmonary bypass (CPB) were included in this study. Delta mean arterial pressure (MAP) was calculated as the difference between the average of pre-operative and on-bypass MAP, and blood was sampled for NGAL levels, at baseline, and 6-h after CPB. Detailed data collection was done, tabulating most of the factors which might influence development of post-operative cardiac surgery associated-AKI (CSA-AKI). To define CSA-AKI within the first 24-h post-operatively, the Kidney Disease Improving Global Outcomes (KDIGO) classification was used. Out of 112 patients, 44 (39.3%) developed CSA-AKI postoperatively. With an ROC analysis cut-off of delta MAP of more than 25.67 mmHg, 46.4% patients developed post-operative AKI, and the average CPB flows which were 1.8 ± 0.2 were not contributory to the development of early CSA-AKI. In our study, ELISA test for human NGAL was performed on serum samples, and the estimated cut-off value of 1661ng/mL was found to be significantly associated with early CSA-AKI. Delta MAP and CPB flows are not related to early post-surgical CSA-AKI in cases with prior high-risk elements. However, baseline serum NGAL, as well as its percent change during the early post-surgical period independently predicted the development of CSA-AKI. This implies that, there may be patients with a higher pre-operative preponderance to develop this complication, which could actually be delineated by the use of serum NGAL estimations at baseline.

J147 affects cognition and anxiety after surgery in Zucker rats

Vulnerable patients are at risk for neuroinflammation-mediated post-operative complications, including depression (POD) and cognitive dysfunction (POCD). Zucker rats, expressing multiple risk factors for post-operative complications in humans, may provide a clinically relevant model to study pathophysiology and explore potential interventions. J147, a newly developed anti-dementia drug, was shown to prevent POCD in young healthy rats, and improved early post-surgical recovery in Zucker rats. Aim of the present study was to investigate POCD and the therapeutic potential of J147 in male Zucker rats.Risk factors in the Zucker rat strain were evaluated by comparison with lean littermates. Zucker rats were subjected to major abdominal surgery. Acute J147 treatment was provided by a single iv injection (10 mg/kg) at the start of surgery, while chronic J147 treatment was provided in the food (aimed at 30 mg/kg/day), starting one week before surgery and up to end of protocol. Effects on behavior were assessed, and plasma, urine and brain tissue were collected and processed for immunohistochemistry and molecular analyses.Indeed, Zucker rats displayed increased risk factors for POCD, including obesity, high plasma triglycerides, low grade systemic inflammation, impaired spatial learning and decreased neurogenesis. Surgery in Zucker rats reduced exploration and increased anxiety in the Open Field test, impaired short-term spatial memory, induced a shift in circadian rhythm and increased plasma neutrophil gelatinase-associated lipocalin (NGAL), microglia activity in the CA1 and blood brain barrier leakage. Chronic, but not acute J147 treatment reduced anxiety in the Open Field test and protected against the spatial memory decline. Moreover, chronic J147 increased glucose sensitivity. Acute J147 treatment improved long-term spatial memory and reversed the circadian rhythm shift. No anti-inflammatory effects were seen for J147.Although Zucker rats displayed risk factors, surgery did not induce extensive POCD. However, increased anxiety may indicate POD. Treatment with J147 showed positive effects on behavioral and metabolic parameters, but did not affect (neuro)inflammation. The mixed effect of acute and chronic treatment may suggest a combination for optimal treatment.

Nephroprotective effects of diminazene on doxorubicin-induced acute kidney injury in rats

This study aimed to investigate the potential protective effects of diminazene, an activator of angiotensin II converting enzyme (ACE2), on kidney function and structure in rats with acute kidney injury (AKI) induced by the anticancer drug doxorubicin (DOX). The impact of diminazene was compared to that of two other drugs: the ACE inhibitor lisinopril and the angiotensin II type 1 (AT1) receptor blocker valsartan. Rats were subjected to a single intraperitoneal injection of DOX (13.5 mg/kg) on the 5th day, either alone or in combination with diminazene (15 mg/kg/day), lisinopril (10 mg/kg/day), or valsartan (30 mg/kg/day) for 8 consecutive days. Various markers related to kidney function, oxidative stress, and inflammation were measured in plasma and urine. Additionally, kidney tissues were assessed histopathologically. DOX-induced nephrotoxicity was confirmed by elevated levels of plasma urea, creatinine, and neutrophil gelatinase-associated lipocalin (NGAL). DOX also led to increased urinary N-acetyl-β-D-glucosaminidase (NAG) activity and decreased creatinine clearance, albumin levels, and osmolality. Moreover, DOX caused a reduction in renal oxidative stress markers, including superoxide dismutase (SOD), glutathione reductase (GR), and catalase activities, while increasing malondialdehyde (MDA) levels. It also raised plasma inflammatory markers, tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β). Concurrently administering diminazene significantly mitigated these DOX-induced changes, including histopathological alterations like renal tubule necrosis, tubular casts, shrunken glomeruli, and increased renal fibrosis. Similar protective effects were observed with lisinopril and valsartan. These protective effects, at least in part, appear to result from the anti-inflammatory and antioxidant properties of these drugs. In summary, this study suggests that the administration of diminazene, lisinopril, or valsartan had comparable effects in ameliorating the biochemical and histopathological aspects of DOX-induced acute kidney injury in rats.

Plasma neutrophil gelatinase-associated lipocalin predicts renal tubulointerstitial injury in patients with IgA nephropathy.

To investigate the relationship of plasma neutrophil gelatinase-associated lipocalin (pNGAL) and urine neutrophil gelatinase-associated lipocalin (uNGAL) with clinical indicators and pathology in patients with IgA nephropathy (IgAN). Clinical and pathological data of 36 patients with primary IgAN diagnosed by kidney biopsy were selected. The Oxford and Lee classifications were used to rank the pathology of IgAN patients and the particle-enhanced immunoturbidimetric method was adopted to measure pNGAL and uNGAL. Subsequently, the correlations of pNGAL and uNGAL levels with clinical indices and pathology were analyzed to evaluate the diagnostic value. Referring to the comparison group, pNGAL levels were elevated in the women, 24-hour proteinuria ≥1g/day, Lee classification IV - V, and tubular atrophy/interstitial fibrosis (T) score of 1 subgroup of Oxford classification (p&lt;0.05). The pNGAL was positively correlated with 24-hour proteinuria, urine microalbumin, urine α1 microglobulin, and the score of T (p<0.05), while uNGAL was negatively correlated with serum albumin (p< 0.05). The occurrence of T1 was evaluated by pNGAL, serum creatinine (Scr), 24-hour proteinuria, and estimated glomerular filtration rate (eGFR), and it was shown that the area under the curve of 24-hour proteinuria, pNGAL, Scr, and eGFR were 0.629, 0.817, 0.919, and 0.799, respectively; in addition, the sensitivity of both pNGAL and eGFR are 100%. The pNGAL levels in patients with IgAN are positively correlated with the Lee and Oxford classifications of T scores. The level of pNGAL in IgAN patients is found to be a prominent indicator for identification of renal tubulointerstitial injury and perhaps this feature may make it a non-invasive predictor for progression of IgAN.