Serum NGAL and FGF23 may have certain value in early diagnosis of CIN

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.

Novel mechanism of the COVID-19 associated coagulopathy (CAC) and vascular thromboembolism

Previous studies from our laboratory revealed that SARS-CoV-2 spike protein (SP) administration to a genetically engineered model expressing the human angiotensin-converting enzyme 2; ACE2 receptor (i.e., hACE2 humanized mouse) mimicked the coronavirus disease-19 (COVID-19) pathology. In humans the cause of high morbidity, and mortality is due to 'cytokine-storm' led thromboembolism; however, the exact mechanisms of COVID-19 associated coagulopathy (CAC) have yet to be discovered. Current knowledge suggests that CAC is distinct from the standard coagulopathy, in that the intrinsic and extrinsic thrombin-dependent coagulation factors, and the pathway(s) that are common to coagulopathy, are not recruited by SARS-CoV-2. Findings from patients revealed that there is little change in their partial thromboplastin, or the prothrombin time coupled with a significant decline in platelets. Further, there appears to be an endothelial dysfunction during COVID-19 suggesting an interaction of the endothelia with immune cells including neutrophils. There are also reports that inflammatory NGAL is elevated during COVID-19. Furthermore, the levels of NPT are also increased indicating an increase in inflammatory M1 macrophage iNOS which sequesters BH4; an essential enzyme co-factor that acts as a potent antioxidant thus causing damage to endothelia. SARS-CoV-2 entry into the host cells is facilitated by a co-operative action between TMPRSS2 and the main ACE2 receptor. Interestingly, after infection ADAMTS13; a von Willebrand factor; VWF cleaving enzyme is found to be decreased. Based on these facts, we hypothesize that vascular thromboembolism is associated with serine and metalloproteinase, and in that context, we opine that inhibition of iNOS might help mitigate COVID-19 harmful effects. To test this hypothesis, we administered SP to the hACE2 mice that were subsequently treated with amino guanidine (AG; a potent inhibitor of glycoxidation, lipoxidation and oxidative vicious cycles). Our results revealed increase in TMPRSS2, and NGAL by SP but treatment with AG mitigated their levels. Similarly, levels of MMP-2, and -9 were increased; however, AG treatment normalized these levels. Our findings suggest that occurrence of CAC is influenced by TMPRSS2, ADAMTS13, NGAL and MMP- 2, and -9 factors, and an intervention with iNOS blocker helped mitigate the CAC condition in experimental settings.

NGAL as Biomarker of Clinical and Subclinical Damage of Kidney Function after Coronary Angiography

Contrast-induced acute kidney injury (CI-AKI) is a serious complication after angiographic examinations in cardiology. Diagnosis may be delayed based on standard serum creatinine, and subclinical forms of kidney damage may not be detected at all. In our study, we investigate the clinical use in these directions of a “damage”-type biomarker—neutrophil gelatinase-associated lipocalin (NGAL). Among patients with a high-risk profile undergoing scheduled coronary angiography and/or angioplasty, plasma NGAL was determined at baseline and at 4th and 24th h after contrast administration. In the CI-AKI group, NGAL increased significantly at the 4th hour (Me 109.3 (IQR 92.1–148.7) ng/mL versus 97.6 (IQR 69.4–127.0) ng/mL, p = 0.006) and at the 24th hour (Me 131.0 (IQR 81.1–240.8) ng/mL, p = 0.008). In patients with subclinical CI-AKI, NGAL also increased significantly at the 4th hour (Me 94.0 (IQR 75.5–148.2) ng/mL, p = 0.002) and reached levels close to those in patients with CI-AKI. Unlike the new biomarker, however, serum creatinine did not change significantly in this group. The diagnostic power of NGAL is extremely good—AUC 0.847 (95% CI: 0.677–1.000; p = 0.001) in CI-AKI and AUC 0.731 (95% CI: 0.539–0.924; p = 0.024) in subclinical CI-AKI. NGAL may be a reliable biomarker for the early diagnosis of clinical and subclinical forms of renal injury after contrast angiographic studies.

THE RISK OF ACUTE KIDNEY INJURY AFTER ELECTIVE VERSUS EMERGENCY CORONARY INTERVENTION

OBJECTIVE

The aim: A serious and common complication after percutaneous coronary intervention is acute kidney injury, which is associated with an increased risk of renal, cardiovascular and even mortality; therefore, early prognosis and identification of patients at higher risk are essential for early initiation of preventive measures. The aim of this study is to predict and compare the risk for the development of CI-AKI in patient with ACS who undergo emergency PCI or elective (i.e. after medical stabilization) PCI by utilizing the sensitivity of serum NGAL as an early and reliable predictor for CI-AK.

PATIENTS AND METHODS

Materials and methods: The study include 37 patients with acute coronary syndrome, baseline serum creatinine, complete blood count and pre and two hours post operative serum neutrophil gelatinase-associated lipocalin were measured and all patients underwent percutaneous coronary intervention according to the standard protocol used in Al Najaf Cardiac Center.

RESULTS

Results: This is a Two-Arm study that included a total of 37 patients with acute coronary syndrome aged 38-83 years. Eighteen of them had emergency percutaneous coronary intervention while the remaining 19 had elective percutaneous coronary intervention (after medical stabilization). Elevation of serum neutrophil gelatinase-associated lipocalin level two hours after percutaneous coronary intervention was found to be significantly higher among emergency percutaneous coronary intervention group compared to elective group.

CONCLUSION

Conclusions: Acute coronary syndrome patients are undergoing emergency percutaneous coronary intervention are at an increasing risk for the development of contrast induced acute kidney injury than those undergoing elective percutaneous coronary intervention.

Predictive and Prognostic Value of Serum Neutrophil Gelatinase-Associated Lipocalin for Contrast-Induced Acute Kidney Injury and Long-Term Clinical Outcomes after Percutaneous Coronary Intervention

Neutrophil gelatinase-associated lipocalin (NGAL) has been proposed as an early marker for estimating the risk of contrast-induced acute kidney injury (CI-AKI). However, the predictive value of baseline serum NGAL levels for CI-AKI remains unclear. Serum NGAL was measured before percutaneous coronary intervention in 633 patients with coronary artery disease. The primary clinical endpoints were a composite of major adverse cardiac and cerebrovascular events (MACCEs; cardiac death, myocardial infarction, stroke, and any revascularization). The mean follow-up duration was 29.4 months. Ninety-eight (15.5%) patients developed CI-AKI. Compared with patients without CI-AKI, baseline serum NGAL was higher in patients with CI-AKI (149.6 ± 88.8 ng/mL vs. 138.0 ± 98.6 ng/mL, p = 0.0279), although serum creatinine and estimated glomerular filtration rate were not different between groups. Patients in the highest tertile of baseline serum NGAL showed a significantly higher rate of MACCEs (10.5% vs. 3.8%, p = 0.02). Using the first tertile as a reference, the adjusted hazard ratios for MACCEs in patients in the second and third tertiles of NGAL were 2.151 (confidence interval (CI) 0.82 to 5.59, p = 0.116) and 2.725 (CI 1.05 to 7.05, p = 0.039), respectively. Baseline serum NGAL is a reliable marker for predicting CI-AKI, and high serum NGAL levels are associated with a higher incidence rate of long term MACCEs.

Evaluation of Crocin Effect on Contrast-Induced Nephropathy Following Coronary Angiography or Angioplasty: A Randomized Controlled Trial

Contrast-induced nephropathy (CIN) is the third cause of hospital-acquired acute kidney injury. The CIN prophylactic strategies adopted to date, although not highly efficient, are mostly based on antioxidant activity and hydration therapy. This study was designed and conducted to evaluate crocin’s efficacy in the prevention of CIN in chronic kidney disease (CKD) patients undergoing coronary angiography/angioplasty. In this randomized clinical trial, a total of 110 eligible CKD stage 3 patients requiring contrast agent administration for coronary angiography/angioplasty were enrolled and randomly assigned to either crocin (n = 57) or control (n = 53) group. The patients in both groups received standard hydration therapy; nevertheless, in the crocin group, the patients were also orally administered three consecutive oral doses of 30 mg crocin tablets 1 day before up to 1 day after contrast media (CM) exposure. The primary endpoint was CIN incidence defined as an increase in serum creatinine (SrCr) level by ≥ 0.3 mg/dL or any change in urinary neutrophil gelatinase-associated lipocalin (NGAL) from the baseline within 48 hours of CM exposure. During 4 months, 130 patients were recruited. The mean age of the patients was 65.62 ± 9.05 years, and the majority of them were male (64.54%). The SrCr in the crocin group did not significantly increase within 48 hours of angiography/angioplasty. The changes in the urinary NGAL level were not significant in both groups. The CIN incidence was significantly lower in the crocin group than in the control group (1.75% and 13.2%; P = 0.028). Crocin administration plays an important nephron-protective role in the prevention of CIN.

Comparison of Neutrophil Gelatinase-associated Lipocalin and Renal Resistive Index as Acute Kidney Injury Predictor in Critically Ill Patients at ICU H. Adam Malik Hospital Medan

BACKGROUND: Acute kidney injury (AKI) is a complication found in critically ill patients. Current consensus explains that diagnosis of AKI based on increased serum creatinine and decreased urine output. Neutrophil gelatinase-associated lipocalin (NGAL) level is increased a few hours after tubular damage occurred and can predict AKI more significantly than serum creatinine. Renal resistive index (RRI) is also a good marker in predicting the early stage of AKI. AIM: This study aimed to compare RRI and NGAL level as marker to predict incidence of AKI in critically ill patients treated in the Intensive Care Unit (ICU) at H. Adam Malik Hospital Medan. METHODS: This was an observational prospective cohort study and conducted in ICU at H. Adam Malik Hospital Medan in April-May 2021. This study had been approved by the Ethics Committee of Faculty of Medicine, Sumatera Utara University and H. Adam Malik Hospital Medan. Inclusion criteria are critical patients aged 18–65 years with 1st and 2nd priority level. Consecutive sampling was used. Resistive Index (RI) measured using USG Doppler by researcher and the results confirmed by ICU supervisors, while urine NGAL level measured within 3 h after ICU admission. Plasma urea and creatinine level measured after 24h after ICU admission. RESULTS: A total of 40 samples were collected; percentage of men and women are 66–35%, respectively (p = 0.001). There was a significant difference RI between AKI-group and non-AKI group (0.719 ± 0.060 and 0.060 ± 0.077, respectively) (p = 0.001). RI has a sensitivity of 71%, specificity of 84%, and accuracy of 87% in predicting occurrence of AKI with AUROC = 0.873. Meanwhile, NGAL has a sensitivity, specificity, and accuracy (66%, 89%, 78%, respectively) in early prediction of AKI incidence in critically ill patients. CONCLUSION: RI value was higher in AKI group than non-AKI group. RRI has better sensitivity than NGAL in predicting incidence of AKI.

Relation of Baseline Neutrophil Gelatinase-Associated Lipocalin (NGAL) Levels and Contrast-Induced Nephropathy following Percutaneous Coronary Intervention among Chronic Kidney Disease Patients

BACKGROUND

The risk of contrast-induced acute kidney injury (CI-AKI) following coronary intervention is particularly high among patients with chronic kidney disease (CKD). Among these patients, baseline neutrophil gelatinase-associated lipocalin (NGAL), a marker of tubular damage, reflects the severity of renal impairment. We evaluated whether the baseline serum NGAL level may be a marker for the development of CI-AKI following percutaneous coronary intervention (PCI).

METHODS

Eighty-eight CKD patients treated with PCI were included. Serum NGAL levels were drawn upon hospital admission. Receiver operator characteristic (ROC) methods were used to identify the optimal sensitivity and specificity for the observed NGAL level compared with the estimated glomerular filtration rate (eGFR) calculated for patients with CI-AKI.

RESULTS

Overall CI-AKI incidence was 43%. Baseline serum NGAL levels were significantly higher in patients with CI-AKI than in patients without CI-AKI (150 vs. 103 ng/mL, p < 0.001). According to the ROC curve, baseline NGAL levels performed better than eGFR to predict CI-AKI (AUC 0.753 vs. 0.604), with the optimal cutoff value for baseline NGAL to predict CI-AKI being 127 ng/mL (sensitivity of 68% and specificity of 68%, p < 0.001). In a multivariate logistic regression model, the NGAL level >127 ng/mL ng/mL was independently associated with CI-AKI (HR 9.84, 95% CI: 1.96-40.3; p = 0.01).

CONCLUSION

Baseline serum NGAL levels in CKD patients may identify a high-risk population for CI-AKI following PCI. Further studies on larger populations are required to validate the potential utility of NGAL measurements in monitoring specific CKD-associated conditions.

Biomarkers for the early prediction of contrast-induced nephropathy after percutaneous coronary intervention in adults: A systematic review and meta-analysis

Contrast-induced nephropathy (CIN) is a complication of patients undergoing percutaneous coronary intervention (PCI). Promising biomarkers for the early prediction of CIN can significantly improve outcomes of these patients. We searched PubMed, EMBASE, Web of Science, and Cochrane Library for studies. Trials reporting an area under the curve (AUC) for the utility of novel biomarkers in the early prediction of CIN in adults after PCI were included. In total, 42 studies comprising 11,984 adult patients undergoing PCI met the criteria. Four urinary biomarkers and four blood biomarkers were included. For urine biomarkers, the pooled AUCs for neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), liver-type fatty acid-binding protein (L-FABP), and kidney injury molecule-1 (KIM-1) were 0.91 (95% CI 0.89-0.94), 0.79 (0.75-0.82), 0.78 (0.74-0.82), and 0.79 (0.76-0.83), respectively. The blood biomarkers NGAL, cystatin C, brain natriuretic peptide (BNP), and C-reactive protein (CRP) had pooled AUCs of 0.93 (0.91-0.95), 0.92 (0.89-0.94), 0.78 (0.74-0.81), and 0.75 (0.71-0.79), respectively. Subgroup analysis showed that blood NGAL in early CIN predictive time (<6 h) was more effective in predicting CIN. The efficiency of cystatin C in predicting CIN was reduced, whereas that of L-FABP was increased among chronic kidney disease (CKD) patients.

Significance of serum FGF-23 for risk assessment of contrast-associated acute kidney injury and clinical outcomes in patients undergoing coronary angiography

Background

Fibroblast growth factor (FGF)-23 levels rise as kidney function declines. Whether elevated FGF-23 levels are associated with an increased risk for contrast-associated acute kidney injury (CA-AKI) and major adverse cardiovascular events (MACE) in patients undergoing coronary angiography remain uncertain.

Methods

In total, 492 patients receiving coronary angiography were enrolled. Their serum FGF-23 levels were measured before administration of contrast media. The occurrence of CA-AKI was defined as a rise in serum creatinine of 0.5 mg/dL or a 25% increase from the baseline value within 48 h after the procedure. All patients were followed up for at least 1 year or until the occurrence of MACE including death, nonfatal myocardial infarction (MI), and ischemic stroke.

Results

Overall, CA-AKI occurred in 41 (8.3%) patients. During a median follow-up of 2.6 years, there were 24 deaths, 3 nonfatal MIs, and 7 ischemic strokes. Compared with those in the lowest FGF-23 tertile, individuals in the highest FGF-23 tertile had a significantly higher incidence of CA-AKI (P < 0.001) and lower incidence of MACE-free survival (P = 0.001). In multivariate regression analysis, higher FGF-23 level was found to be independently associated with a graded risk for CA-AKI (OR per doubling, 1.90; 95% CI 1.48–2.44) and MACE (HR per doubling, 1.25; 95% CI 1.02–1.52).

Conclusions

Elevated FGF-23 levels were associated with an increased risk for CA-AKI and future MACE among patients undergoing coronary angiography. FGF-23 may play a role in early diagnosis of CA-AKI and predicting clinical outcomes after coronary angiography.

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.

Neutrophil gelatinase-associated lipocalin (NGAL) for the prediction of acute kidney injury in chronic kidney disease patients treated with primary percutaneous coronary intervention

INTRODUCTION

Elevated plasma levels of neutrophil gelatinase-associated lipocalin (NGAL) is a marker of tubular damage and aid in the early identification of acute kidney injury (AKI). We evaluated NGAL levels for identification of AKI superimposed on chronic kidney disease (CKD) vs. "de novo" AKI among ST elevation myocardial infarction (STEMI) patients undergoing primary coronary intervention (PCI).

METHODS

217 STEMI patients treated with PCI were prospectively included, 34 (16%) had baseline CKD. Plasma NGAL levels were drawn 24 h following PCI. Receiver-operator characteristic (ROC) methods were used to identify optimal sensitivity and specificity for the observed NGAL range in AKI patients with and without CKD.

RESULTS

Overall AKI incidence was 13%. NGAL levels were significantly higher for patients with AKI compared to no-AKI, irrespective of CKD. Different optimal cutoff value for NGAL to predict AKI were found for patients with CKD (133 ng/ml, sensitivity of 73% and specificity of 75%; AUC: 0.837, p < 0.001) and for non-CKD (104 ng/ml with sensitivity of 79% and specificity of 82%; AUC: 0.844, p < 0.001). In a multivariate logistic regression model, NGAL levels were independently associated with AKI in patients with and without CKD (HR 1.04, 95% CI: 1.01-1.08; p = 0.024; and HR 1.03, 95% CI: 1.01-1.04; p = 0.001), respectively.

CONCLUSIONS

Elevated plasma NGAL levels identify patients who are at high-risk to develop AKI following primary PCI. Determining different cutoff values of plasma NGAL for de novo AKI and AKI superimposed on CKD may be necessary for accurate AKI diagnosis and risk stratification.

Serum fibroblast growth factor 23 for early detection of acute kidney injury in critical illness

BACKGROUND

Serum fibroblast growth factor 23 (FGF23) is associated with acute kidney injury (AKI) and mortality in patients with critical illnesses. However, the accurate predictive performance of FGF23 on AKI remains inconclusive.

METHODS

Meta-analysis was performed using data sources including PubMed, Web of Science, EMBASE, and Cochrane (until June 1, 2021). Cohort or observational studies including patients with AKI and serum FGF23 level as the index test were included. The primary outcome was the AKI detective accuracy. This study has been registered in PROSPERO (CRD42021249930).

RESULTS

Eleven studies with 1946 patients in seven countries were included. Across all settings, the sensitivity and specificity for serum FGF23 levels to predict AKI were 82% (95% CI, 66-91%) and 77% (95% CI, 67-85%), respectively. The diagnostic odds ratio of FGF23 was 15.51 (95% CI, 4.89-49.19), with the pooled positive likelihood ratio of 3.62 (95% CI, 2.25-5.83) and a negative likelihood ratio of 0.23 (95% CI, 0.11-0.50). The area under the receiver operating characteristic curve to detect AKI was 0.86 (95% CI, 0.82-0.88). C-terminal FGF23 had a better performance than intact FGF23.

CONCLUSIONS

Plasma FGF23 is a valuable biomarker for incident AKI in critically ill patients. Comparisons of FGF23 with other biomarkers in AKI still need more studies to prove.

Predictive value of cystatin C and neutrophil gelatinase-associated lipocalin in contrast-induced nephropathy: A meta-analysis

Background

There are still limited studies comprehensively examining the diagnostic performance of neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C in contrast-induced nephropathy (CIN). The study aimed to investigate and compare the predictive value of NGAL and cystatin C in the early diagnosis of CIN.

Methods and materials

We searched the PubMed, EMBASE and Cochrane Library databases until November 10, 2019. The methodological quality of the included studies was assessed by the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Bivariate modeling and hierarchical summary receiver operating characteristic (HSROC) modeling were performed to summarize and compare the diagnostic performance of blood/urine NGAL and serum cystatin C in CIN. Subgroup and meta-regression analyses were performed according to the study and patient characteristics.

Results

Thirty-seven studies from thirty-one original studies were included (blood NGAL, 1840 patients in 9 studies; urine NGAL, 1701 patients in 10 studies; serum cystatin C, 5509 patients in 18 studies). Overall, serum cystatin C performed better than serum/urine NGAL (pooled DOR: 43 (95%CI: 12–152); AUROC: 0.93; λ: 3.79); serum and urine NGAL had a similar diagnostic performance (pooled DOR: 25 (95%CI: 6–108)/22(95%CI: 8–64); AUROC: 0.90/0.89; λ: 3.20/3.08). Meta-regression analysis indicated that the sources of heterogeneity might be CIN definition, assays, and nationalities.

Conclusion

Both NGAL and cystatin C can serve as early diagnostic indicators of CIN, while cystatin C may perform better than NGAL.

Neutrophil Gelatinase-Associated Lipocalin for the Early Prediction of Acute Kidney Injury in ST-Segment Elevation Myocardial Infarction Patients Treated with Primary Percutaneous Coronary Intervention

INTRODUCTION AND OBJECTIVE

Neutrophil gelatinase-associated lipocalin (NGAL), a glycoprotein released by renal tubular cells, can be used as a marker of early tubular damage. We evaluated plasma NGAL level utilization for the identification of acute kidney injury (AKI) among ST-elevation myocardial infarction (STEMI) patients undergoing primary coronary intervention (PCI).

METHODS

131 STEMI patients treated with PCI were prospectively included. Plasma NGAL levels were drawn prior to PCI (0 h) and 24 h afterwards. AKI was defined per KDIGO criteria of serum creatinine increase. Receiver-operating characteristic (ROC) methods were used to identify optimal sensitivity and specificity for the observed NGAL range.

RESULTS

Overall AKI incidence was 14%. NGAL levels were significantly higher for patients with AKI at both 0 h (164 ± 42 vs. 95 ± 30; p < 0.001) and 24 h (142 ± 41 vs. 93 ± 36; p < 0.001). Per ROC curve analysis, an optimal cutoff value of NGAL (>120 ng/mL) predicted AKI with 80% sensitivity and specificity (AUC 0.881, 95%, CI 0.801-0.961, p < 0.001). In a multivariate logistic regression model, NGAL levels were independently associated with AKI at 0 h (OR 1.044, 95% CI 1.013-1.076; p = 0.005) and 24 h (OR 1.018, 95% CI 1.001-1.036; p = 0.04).

CONCLUSIONS

Elevated NGAL levels, suggesting renal tubular damage, are independently associated with AKI in STEMI patients undergoing primary PCI.

The Prognostic Role of Klotho in Patients with Chronic Kidney Disease: A Systematic Review and Meta-analysis

Objective

The prognostic role of Klotho in patients with chronic kidney disease is still controversial. Therefore, we performed this meta-analysis to assess the relationship between the low sKlotho level and the risk of adverse kidney outcomes.

Materials and Methods

We systematically searched medical databases, such as PubMed, Embase, and the Cochrane Library, for eligible publications regarding the relationship between the low sKlotho level and risk of adverse kidney outcomes. The quality of included studies was assessed by using the Newcastle–Ottawa Scale. Combined hazard ratios (HRs) and its 95% confidence intervals (CIs) were calculated using a random- or fixed-effect model. Subgroup analysis was conducted with stratification by age, estimated glomerular filtration rate (eGFR), follow-up interval, region, and study quality. All data was analyzed by RevMan 5.3 analysis software.

Results

Eight cohort studies with 3586 participants from 3818 studies were included in our final analysis. Levels of sKlotho were significantly correlated with the eGFR, with a summary correlation coefficient r and 95% CI of 0.469 (0.226, 0.658). Additionally, low sKlotho levels were strongly associated with increased adverse kidney outcomes, and the pooled HR and its 95% CI were 1.64 (1.19, 2.26; P = 0.002), despite publication bias and statistical heterogeneity (I² = 52%, P = 0.07). Furthermore, this positive correlation was still observed in all of the subgroup analyses. However, heterogeneity was present in subgroup analyses stratified by the eGFR and follow-up interval.

Conclusion

Levels of sKlotho are positively correlated with the eGFR, and low sKlotho levels are significantly associated with an increased risk of poor kidney outcomes. Therefore, sKlotho could be used as a novel biomarker for early diagnosis and prognostic assessment for patients with chronic kidney disease. Studies with a larger sample size and longer follow-up period are warranted to validate our results.

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.