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

Gamma glutamyl transferase as a biomarker to predict contrast-induced nephropathy among patients with acute coronary syndrome undergoing coronary interventions: a meta-analysis

The third most frequent reason for hospitalized acute kidney injury is contrast-induced nephropathy (CIN). Percutaneous coronary intervention (PCI) and coronary angiography (CAG) are two interventions that can result in CIN. In this study, we sought to determine how well gamma-glutamyl transferase (GGT) can predict CIN following CAG and PCI.

Method

Two researchers searched through PubMed, Scopus, and Web of Science in November 2022 to find articles that examined GGT levels in CIN patients following PCI or CAG. To rate the quality of the studies, the Joanna Briggs Institute Critical Appraisal Checklist was employed. The Cochran test and I2 statistics were utilized to assess study heterogeneity. To calculate the number of participants required to reject the null hypothesis, power analysis was used. We evaluated the epidemiologic strength of the results using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). The authors used Comprehensive Meta-analysis Version 3 to summarize the results.

Results

GGT was shown to be considerably greater in patients with CIN according to the meta-analysis's findings (odds ratio: 3.21, 95% CI: 1.26-8.15, P=0.014); nevertheless, the findings were accompanied by significant heterogeneity (I2=91.93%, P<0.001). Although the relationship between CIN and GGT was power full regarding power analysis (1- β =1, number of effect sizes=4, the average number per group=336), very low quality of evidence was observed regarding GRADE criteria.

Conclusions

These results suggest the GGT level may be a predictor of contrast-induced nephropathy in patients having cardiac catheterization; however, more research is required to prove the epidemiological validity.

Comparison urine neutrophil gelatinase - associated lipocalin with standard parameters in monitoring activity Lupus nephritis: Class IV

Background

Lupus nephritis (LN) is one of the most serious complications in the development of systemic lupus erythematosus, that can adversely affect the course and prognosis of this autoimmune disease. Therefore, monitoring the effect of applied therapy, achieving remission, or monitoring class IV LN activity is still a great challenge for nephrologists. This study aimed to compare the urinary neutrophile gelatinase associated lipocalin (u/NGAL) with traditionally accepted parameters for LNactivity to indicate the importance of its determination in these patients.

Methods

The study group consisted of 40 patients with class IV LN, who were prospectively followed for a period of 4 months within three control visits to 2 months. The first group (20/40) had active disease (Group A), and the second group had diseasein remission (Group B). The parameters we monitored and compared at each visit were standard biochemical parameters and kidney function parameters: C-reactive protein (CRP), blood count (CBC), creatinine, total proteins, albumin, cholesterol, triglycerides, glomerular filtration rate (eGFR). Regarding immune parameters, complement C3 and C4, antinuclear antibodies (ANA), anti-double stranded DNA antibody(anti ds DNA Ab) were monitored. Urine sediment, proteinuria 24h, urine culture, urinary protein/creatinine ratio - Up/Cre, and urinary NGAL (u/NGAL) were monitored in.

Results

Comparing standard parameters of disease activity and u/NGAL between groups, a statistically significant difference was obtained (p < 0.001). Within Group A, comparing the parameters by visits (0 : 2) for anti-ds-DNA Ab a significance of p< 0.05 was obtained, for albumin/s and C3 a significance of p<0.01 was obtained, and proteinuria/24h, Up/Cre, u/NGAL had a significance of p < 0.001. The mean level of u/NGAL was elevated at the initially visit (173.25 ± 172.12 ng/mL), after two months 73.2 ± 48.7 ng/mL, and in the second visit a lower level was recorded (49.60 ± 72.57 ng/mL). The negative correlation of u/NGAL was statistically significant at initial visit with albumin/s (p< 0.01) as well as the positive correlation with proteinuria 24h and Up/Cre (p< 0.001). In visit 2 significant negative correlation of u/NGAL with albumin/s and C3 p< 0.05, and positive correlation with anti-ds-DNA Ab, proteinuria 24h and Up/Cre p < 0.001.

Conclusions

The results of our study indicate that the level of u/N GLA is elevated in patients with active Lupus nephritis class IV, as well as that it correlates with other parameters of disease activity. Serial determination of u/NGAL could be significant in monitoring disease course and treatment.

Contrast-induced acute kidney injury and its contemporary prevention

The complexity and application range of interventional and diagnostic procedures using contrast media (CM) have recently increased. This allows more patients to undergo procedures that involve CM administration. However, the intrinsic CM toxicity leads to the risk of contrast-induced acute kidney injury (CI-AKI). At present, effective therapy of CI-AKI is rather limited. Effective prevention of CI-AKI therefore becomes crucially important. This review presents an in-depth discussion of CI-AKI incidence, pathogenesis, risk prediction, current preventive strategies, and novel treatment possibilities. The review also discusses the difference between CI-AKI incidence following intraarterial and intravenous CM administration. Factors contributing to the development of CI-AKI are considered in conjunction with the mechanism of acute kidney damage. The need for ultimate risk estimation and the prediction of CI-AKI is stressed. Possibilities of CI-AKI prevention is evaluated within the spectrum of existing preventive measures aimed at reducing kidney injury. In particular, the review discusses intravenous hydration regimes and pre-treatment with statins and N-acetylcysteine. The review further focuses on emerging alternative imaging technologies, alternative intravascular diagnostic and interventional procedures, and new methods for intravenous hydration guidance; it discusses the applicability of those techniques in complex procedures and their feasibility in current practise. We put emphasis on contemporary interventional cardiology imaging methods, with a brief discussion of CI-AKI in non-vascular and non-cardiologic imaging and interventional studies.

Renoprotective Effect of Vardenafil and Avanafil in Contrast-Induced Nephropathy: Emerging Evidence from an Animal Model

The potential renoprotective effects of vardenafil (VAR) have been evaluated in a very limited number of studies using acute kidney injury animal models other than contrast-induced nephropathy (CIN) with promising results, while avanafil (AVA) has not been evaluated in this respect before. The purpose of this study was to evaluate for the first time the potential renoprotective effect of VAR and AVA in a rat model of CIN. Twenty-five male Wistar rats were equally assigned into five groups: control, CIN, CIN+N-acetyl cysteine (NAC) (100 mg/kg/day) as a positive control, CIN+VAR (10 mg/kg/day) and CIN+AVA (50 mg/kg/day). CIN was induced by dehydration, inhibition of prostaglandin and nitric oxide synthesis as well as exposure to the contrast medium (CM). Serum Cr (sCr) levels were measured at 24 and 48 h after CIN induction. At 48 h of CM exposure, animals were sacrificed. Matrix metalloproteinase (MMP) 2 (MMP-2) and MMP-9, kidney injury molecule 1 (KIM-1) and cystatin-C (Cys-C) were measured on renal tissue. Histopathological findings were evaluated on kidney tissue. All treatment groups had close to normal kidney appearance. sCr levels subsided in all treatment groups compared to CIN group at 48 h following CIN induction. A significant decline in the levels of MMP-2, MMP-9, KIM-1 and Cys-C compared to CIN group was observed. These results provide emerging evidence that VAR and AVA may have the potential to prevent CIN.

Perioperative acute kidney injury: impact and recent update

PURPOSE OF REVIEW

Acute kidney injury (AKI) is common in hospitalized patients and is a major risk factor for increased length of stay, morbidity, and mortality in postoperative patients. There are multiple barriers to reducing perioperative AKI - the etiology is multi-factorial and the diagnosis is fraught with issues. We review the recent literature on perioperative AKI and some considerations for anesthesiologists that examine the far-reaching effects of AKI on multiple organ systems.

RECENT FINDINGS

This review will discuss recent literature that addresses the epidemiology, use of novel biomarkers in risk stratification, and therapeutic modalities for AKI in burn, pediatrics, sepsis, trauma, cardiac, and liver disease, contrast-induced AKI, as well as the evidence assessing goal-directed fluid therapy.

SUMMARY

Recent studies address the use of risk stratification models and biomarkers, more sensitive than creatinine, in the preoperative identification of patients at risk for AKI. Although exciting, these scores and models need validation. There is a need for research assessing whether early AKI detection improves outcomes. Enhanced recovery after surgery utilizing goal-directed fluid therapy has not been shown to make an appreciable difference in the incidence of AKI. Reducing perioperative AKI requires a multi-pronged and possibly disease-specific approach.

Early prediction of COVID-19-associated acute kidney injury: Are serum NGAL and serum Cystatin C levels better than serum creatinine?

BACKGROUND

Coronavirus disease-2019 (COVID-19) is associated with a high risk of acute kidney injury (AKI), often requiring renal replacement therapy (RRT). Serum Cystatin C (sCysC) and serum Neutrophil Gelatinase-Associated Lipocalin (sNGAL) are emerging biomarkers for kidney injury, and were suggested to be superior to serum creatinine (sCr) in several clinical settings. Moreover, elevated sCysC is associated with disease severity and mortality in COVID-19. We aimed to assess the utility of sCysC and sNGAL for predicting COVID-19-associated AKI, need for RRT, and need for intensive care unit (ICU) admission, when measured at presentation to the emergency department (ED).

METHODS

Patients presenting to the ED with laboratory-confirmed COVID-19 were included. The primary outcome was development of COVID-19-associated AKI, while the secondary outcomes were need for RRT and ICU admission.

RESULTS

Among 52 COVID-19 patients, 22 (42.3%) developed AKI with 8/22 (36.4%) requiring RRT. Both sCr and sCysC demonstrated excellent performance for predicting AKI (AUC, 0.86 and 0.87, respectively) and need for RRT (AUC, 0.94 and 0.95, respectively). sNGAL displayed acceptable performance for predicting AKI (AUC, 0.81) and need for RRT (AUC, 0.87).

CONCLUSIONS

SCr and sCysC measured at ED presentation are both highly accurate predictors of AKI and need for RRT, whereas sNGAL demonstrated adequate diagnostic performance. While sCyC was previously shown to be superior to sCr as a diagnostic biomarker of kidney injury in certain etiologies, our findings demonstrate that sCr is comparable to sCyC in the context of predicting COVID-19-associated AKI. Given the high sensitivity of these biomarkers for predicting the need for RRT, and as sCysC is associated with mortality in COVID-19 patients, we recommend their measurement for enabling risk stratification and early intervention.

Acetylcysteine has No Mechanistic Effect in Patients at Risk of Contrast-Induced Nephropathy - A Failure of Academic Clinical Science

Contrast‐induced nephropathy (CIN) is a major complication of imaging in patients with chronic kidney disease (CKD). The publication of an academic randomized controlled trial (RCT; n = 83) reporting oral (N)‐acetylcysteine (NAC) to reduce CIN led to > 70 clinical trials, 23 systematic reviews, and 2 large RCTs showing no benefit. However, no mechanistic studies were conducted to determine how NAC might work; proposed mechanisms included renal artery vasodilatation and antioxidant boosting. We evaluated the proposed mechanisms of NAC action in participants with healthy and diseased kidneys. Four substudies were performed. Two randomized, double‐blind, placebo‐controlled, three‐period crossover studies (n = 8) assessed the effect of oral and intravenous (i.v.) NAC in healthy kidneys in the presence/absence of iso‐osmolar contrast (iodixanol). A third crossover study in patients with CKD stage III (CKD3) (n = 8) assessed the effect of oral and i.v. NAC without contrast. A three‐arm randomized, double‐blind, placebo‐controlled parallel‐group study, recruiting patients with CKD3 (n = 66) undergoing coronary angiography, assessed the effect of oral and i.v. NAC in the presence of contrast. We recorded systemic (blood pressure and heart rate) and renal (renal blood flow (RBF) and glomerular filtration rate (GFR)) hemodynamics, and antioxidant status, plus biomarkers of renal injury in patients with CKD3 undergoing angiography. Primary outcome for all studies was RBF over 8 hours after the start of i.v. NAC/placebo. NAC at doses used in previous trials of renal prophylaxis was essentially undetectable in plasma after oral administration. In healthy volunteers, i.v. NAC, but not oral NAC, increased blood pressure (mean area under the curve (AUC) mean arterial pressure (MAP): mean difference 29 h⋅mmHg, P = 0.019 vs. placebo), heart rate (28 h⋅bpm, P < 0.001), and RBF (714 h⋅mL/min, 8.0% increase, P = 0.006). Renal vasodilatation also occurred in the presence of contrast (RBF 917 h⋅mL/min, 12% increase, P = 0.005). In patients with CKD3 without contrast, only a rise in heart rate (34 h⋅bpm, P = 0.010) and RBF (288 h⋅mL/min, 6.0% increase, P = 0.001) occurred with i.v. NAC, with no significant effect on blood pressure (MAP rise 26 h⋅mmHg, P = 0.156). Oral NAC showed no effect. In patients with CKD3 receiving contrast, i.v. NAC increased blood pressure (MAP rise 52 h⋅mmHg, P = 0.008) but had no effect on RBF (151 h⋅mL/min, 3.0% increase, P = 0.470), GFR (29 h⋅mL/min/1.73m², P = 0.122), or markers of renal injury. Neither i.v. nor oral NAC affected plasma antioxidant status. We found oral NAC to be poorly absorbed and have no reno‐protective effects. Intravenous, not oral, NAC caused renal artery vasodilatation in healthy volunteers but offered no protection to patients with CKD3 at risk of CIN. These findings emphasize the importance of mechanistic clinical studies before progressing to RCTs for novel interventions. Thousands were recruited to academic clinical trials without the necessary mechanistic studies being performed to confirm the approach had any chance of working.

Clinical Utility of a Biomarker to Detect Contrast-Induced Acute Kidney Injury during Percutaneous Cardiovascular Procedures

INTRODUCTION

Contrast-induced acute kidney injury (CI-AKI) is a major clinical complication of percutaneous cardiovascular procedures requiring iodinated contrast. Despite its relative frequency, practicing physicians are unlikely to identify or treat this condition.

METHODS

In a 2-round clinical trial of simulated patients, we examined the clinical utility of a urine-based assay that measures liver-type fatty acid-binding protein (L-FABP), a novel marker of CI-AKI. We sought to determine if interventional cardiologists' ability to diagnose and treat potential CI-AKI improved using the biomarker assay for 3 different patient types: pre-procedure, peri-procedure, and post-procedure patients.

RESULTS

154 participating cardiologists were randomly divided into either control or intervention. At baseline, we found no difference in the demographics or how they identified and treated potential complications of AKI, with both groups providing less than half the necessary care to their patients (46.4% for control vs. 47.6% for intervention, p = 0.250). The introduction of L-FABP into patient care resulted in a statistically significant improvement of 4.6% (p = 0.001). Compared to controls, physicians receiving L-FABP results were 2.9 times more likely to correctly identify their patients' risk for AKI (95% CI 2.1-4.0) and were more than twice as likely to treat for AKI by providing volume expansion and withholding nephrotoxic medications. We found the greatest clinical utility in the pre-procedure and peri-procedure settings but limited value in the post-procedure setting.

CONCLUSION

This study suggests L-FABP as a clinical marker for assessing the risk of potential CI-AKI, has clinical utility, and can lead to more accurate diagnosis and treatment.

Using lipocalin as a prognostic biomarker in acute kidney injury

Introduction: Human lipocalin-2, known as neutrophil gelatinase-associated lipocalin (NGAL), is a widely studied biomarker of acute kidney injury (AKI).Areas covered: NGAL can serve as a predictor of AKI, disease progression, and mortality and can help in differentiating between AKI etiologies. We conducted a systematic review in the PubMed and Medline databases involving the clinical application of NGAL in patients with AKI.Expert opinion: In this review, we explored the usefulness of NGAL for AKI or clinical outcome prediction. The use of urine or blood NGAL levels alone or in combination with a clinical prediction model may facilitate AKI prediction, severity prediction, AKI etiological differentiation, and mortality prediction. For AKI prediction, urine and plasma NGAL levels have an area under the curve (AUC) ranging from 0.71 to 0.90 and from 0.71 to 0.89, respectively, in different populations. The diagnostic performance of NGAL alone for renal replacement therapy or successful discontinuation prediction is suboptimal (AUC range: 0.65-0.81). Sepsis limits the application of NGAL as a clinical predictor, and the prediction performance of NGAL is affected by baseline renal function, timing of sample collection, and underlying comorbidities. The lack of internationally approved reference material also limits the usefulness of NGAL.

Predictive value of plasma proenkephalin and neutrophil gelatinase-associated lipocalin in acute kidney injury and mortality in cardiogenic shock

BACKGROUND

Acute kidney injury (AKI) is a frequent form of organ injury in cardiogenic shock. However, data on AKI markers such as plasma proenkephalin (P-PENK) and neutrophil gelatinase-associated lipocalin (P-NGAL) in cardiogenic shock populations are lacking. The objective of this study was to assess the ability of P-PENK and P-NGAL to predict acute kidney injury and mortality in cardiogenic shock.

RESULTS

P-PENK and P-NGAL were measured at different time points between baseline and 48 h in 154 patients from the prospective CardShock study. The outcomes assessed were AKI defined by an increase in creatinine within 48 h and all-cause 90-day mortality. Mean age was 66 years and 26% were women. Baseline levels of P-PENK and P-NGAL (median [interquartile range]) were 99 (71-150) pmol/mL and 138 (84-214) ng/mL. P-PENK > 84.8 pmol/mL and P-NGAL > 104 ng/mL at baseline were identified as optimal cut-offs for AKI prediction and independently associated with AKI (adjusted HRs 2.2 [95% CI 1.1-4.4, p = 0.03] and 2.8 [95% CI 1.2-6.5, p = 0.01], respectively). P-PENK and P-NGAL levels at baseline were also associated with 90-day mortality. For patients with oliguria < 0.5 mL/kg/h for > 6 h before study enrollment, 90-day mortality differed significantly between patients with low and high P-PENK/P-NGAL at baseline (5% vs. 68%, p < 0.001). However, the biomarkers provided best discrimination for mortality when measured at 24 h. Identified cut-offs of P-PENK_24h > 105.7 pmol/L and P-NGAL_24h > 151 ng/mL had unadjusted hazard ratios of 5.6 (95% CI 3.1-10.7, p < 0.001) and 5.2 (95% CI 2.8-9.8, p < 0.001) for 90-day mortality. The association remained significant despite adjustments with AKI and two risk scores for mortality in cardiogenic shock.

CONCLUSIONS

High levels of P-PENK and P-NGAL at baseline were independently associated with AKI in cardiogenic shock patients. Furthermore, oliguria before study inclusion was associated with worse outcomes only if combined with high baseline levels of P-PENK or P-NGAL. High levels of both P-PENK and P-NGAL at 24 h were found to be strong and independent predictors of 90-day mortality.

TRIAL REGISTRATION

NCT01374867 at www.clinicaltrials.gov , registered 16 Jun 2011-retrospectively registered.