Plasma neutrophil gelatinase-associated lipocalin (NGAL) as an early predictive marker of contrast-induced nephropathy in hospitalized patients undergoing computed tomography

Risk of Acute Kidney Injury Following IV Iodinated Contrast Media Exposure: 2023 Update, From the AJR Special Series on Contrast Media

Iodinated contrast material (ICM) has revolutionized the field of diagnostic radiology through improvements in diagnostic performance and the expansion of clinical indications for radiographic and CT examinations. Historically, nephrotoxicity was a feared complication of ICM use, thought to be associated with a significant risk of morbidity and mortality. Such fears often precluded the use of ICM in imaging evaluations, commonly at the expense of diagnostic performance and timely diagnosis. Over the past 20 years, the nephrotoxic risk of ICM has become a topic of debate, as more recent evidence from higher-quality studies now suggests that many cases of what was considered contrast-induced acute kidney injury (CI-AKI) likely were cases of mistaken causal attribution; most of these cases represented either acute kidney injury (AKI) caused by any of myriad other known factors that can adversely affect renal function and were coincidentally present at the time of contrast media exposure (termed "contrast-associated AKI" [CA-AKI]) or a manifestation of the normal variation in renal function that increases with worsening renal function. This Special Series Review discusses the current state of knowledge regarding CI-AKI and CA-AKI, including the incidence, risk factors, outcomes, and prophylactic strategies in the identification and management of these clinical conditions.

C-Reactive Protein to Albumin Ratio as a Predictor of Contrast-Induced Nephropathy After Carotid Angiography

This study evaluated the role of the C-reactive protein (CRP)/albumin ratio (CAR) in estimating the probability of occurring contrast-induced nephropathy (CIN) after carotid artery angiography (CAAG). Patients (n = 410) who had CAAG for carotid artery stenosis (CAS) were included in this study. A spike in serum creatinine was used to define CIN within 72 h of the procedure (>.5 mg/dL or >25% above baseline). CAR was calculated by dividing the CRP by the albumin level. Patients with CIN had higher numbers of white blood cells (P = .002), numbers of neutrophils (P = .007), neutrophil-lymphocyte ratios (P = .026), high-sensitivity CRP levels (P < .001), and CAR levels (P < .001) than those without CIN. They were also older (P < .001) and more likely to have diabetes mellitus (P = .006) and hypertension (P = .016). According to receiver operator characteristic curve (ROC) analysis, the CAR value has a 75% sensitivity and a 68% specificity for identifying CIN at a cutoff of 1.8. Also, NLR and CRP predicted CIN with 71% sensitivity and 67% specificity, 71% sensitivity and 66% specificity at the best cutoff values of 1.96 and 7.91, respectively. According the present study, in patients with CAS, the development of CIN after CAAG is independently correlated with CAR at admission.

A prospective, multicenter, three-cohort study evaluating contrast-induced acute kidney injury (CI-AKI) in patients with cirrhosis

BACKGROUND & AIMS

Nephrotoxicity of intravenous iodinated contrast media (ICM) in cirrhosis is still a debated issue, due to scarce, low-quality and conflicting evidence. This study aims to evaluate the incidence and predisposing factors of acute kidney injury (AKI) in patients with cirrhosis undergoing contrast-enhanced computed tomography (CECT).

METHODS

We performed a prospective, multicenter, cohort study including 444 inpatients, 148 with cirrhosis (cohort 1) and 163 without cirrhosis (cohort 3) undergoing CECT and 133 with cirrhosis (cohort 2) unexposed to ICM. Kidney function parameters were assessed at T0, 48-72 h (T1), 5 and 7 days after CECT/enrollment. Urinary neutrophil gelatinase-associated lipocalin (U-NGAL) was measured in 50 consecutive patients from cohort 1 and 50 from cohort 2 as an early biomarker of tubular damage.

RESULTS

AKI incidence was not significantly increased in patients with cirrhosis undergoing CECT (4.8%, 1.5%, 2.5% in cohorts 1, 2, 3 respectively, p = n.s.). Most AKI cases were mild and transient. The presence of concomitant infections was the only independent predictive factor of contrast-induced AKI (odds ratio 22.18; 95% CI 2.87-171.22; p = 0.003). No significant modifications of U-NGAL between T0 and T1 were detected, neither in cohort 1 nor in cohort 2 (median ΔU-NGAL: +0.2 [-7.6 to +5.5] ng/ml, +0.0 [-6.8 to +9.5] ng/ml, respectively [p = 0.682]).

CONCLUSIONS

AKI risk after CECT in cirrhosis is low and not significantly different from that of the general population or of the cirrhotic population unexposed to ICM. It mostly consists of mild and rapidly resolving episodes of renal dysfunction and it is not associated with tubular kidney injury. Patients with ongoing infections appear to be the only ones at higher risk of AKI.

IMPACT AND IMPLICATIONS

Nephrotoxicity due to intravenous iodinated contrast media (ICM) in patients with cirrhosis is still a debated issue, as the available evidence is limited and based on very heterogeneous studies, often conducted on small and retrospective cohorts. In this prospective three-cohort study we found that intravenous administration of ICM was associated with a low risk of AKI, similar to that of the general population and to that of patients with cirrhosis unexposed to ICM. Patients with ongoing infections were the only ones to have a significantly increased risk of contrast-induced AKI. Therefore, the actual recommendations of performing contrast imaging studies cautiously in cirrhosis do not seem to be reasonable anymore, with the exception of infected patients, who have a significantly higher risk of contrast-induced AKI.

Measurement of Neutrophil Gelatinase-Associated Lipocalin (Ngal) Following Neuroradiological Procedure/s in Patients with Aneurysmal Subarachnoid Hemorrhage: A Preliminary Study

Background

Radiocontrast administration during interventional neuroradiology (INR) procedures for aneurysmal subarachnoid haemorrhage (aSAH) can add to renal insult. Serum creatinine (sCr) is a conventional marker of acute kidney injury (AKI). Serum neutrophil gelatinase-associated lipocalin (sNGAL) is a novel marker which is increasingly used to predict renal injury in susceptible patients.

Objectives

The primary aim of this study was to evaluate correlation between serum neutrophil gelatinase-associated lipocalin (NGAL) and sCr in aSAH patients undergoing therapeutic or diagnostic INR procedures. The secondary aim was to find the incidence of contrast-induced AKI and hemodynamic complications during the study period.

Material and Methods

All consenting aSAH patients (18-60 years, Modified Hunt and Hess grade 1-4) posted for INR procedures during the study time were included. Patients with history of chronic renal disease, recent contrast exposure, or renal insufficiency were excluded. Blood samples for sCr and sNGAL were obtained preprocedure and then at 1, 6, 24, and 48 h after contrast administration. Hourly urine output was noted. AKI was defined by KDIGO guidelines.

Statistical Analysis Used

Repeated measurement analysis of variance, Posthoc Bonferroni test and Pearson correlation coefficient test.

Results

Fifty patients, mean age 47.34 ± 9.31 years, were enrolled for the study. Majority (48; 96%) were Hunt and Hess (H and H) grade I-III. The mean volume of contrast administered was 123.2 ± 53.08 mL. The mean sNGAL and sCr values at pre-op, 1, 6, 24, and 48 h were 124.99 ± 64.58, 148.40 ± 77.90, 147.33 ± 76.00, 125.49 ± 64.44, and 116.38 ± 61.79 ng/mL and 0.629 ± 0.23, 0.624 ± 0.22, 0.612 ± 0.21, 0.632 ± 0.19, and 0.577 ± 0.22 mg/dL, respectively. There was a correlation in sCr and sNGAL value (P < 0.001) at all study time points. However, no specific pattern was seen. No patient developed any AKI or hemodynamic complications in first 48 h.

Conclusions

There is a correlation between serum NGAL and sCr at individual time points. NGAL may represent a sensitive early biomarker of renal impairment after INR Procedures. There was no incidence of AKI after contrast administration in aSAH patients without predisposing renal risk factors.

Values of serum neutrophil gelatinase-associated lipocalin and cystatin C after percutaneous coronary intervention for early diagnosis of contrast-induced nephropathy

Objective

Serum creatinine (SCr) is not a sensitive and reliable index for the early diagnosis of acute kidney injury caused by contrast-induced nephropathy (CIN). The aim of this study was to explore the values of serum neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C (Cys-C) after percutaneous coronary intervention (PCI) for the early diagnosis of CIN.

Methods

Three hundred patients receiving PCI from January 2018 to December 2020 were assigned to a CIN group (n=25) and a non-CIN group (n=275), respectively. SCr, Cys-C and NGAL levels were measured, and their sensitivities for early CIN diagnosis were evaluated by the area under the receiver operating characteristic curve (AUC) values.

Results

The NGAL and Cys-C levels of the CIN group began to rise 6 and 12 h after operation, respectively (P<0.05). The CIN group had higher NGAL and Cys-C levels than those of the non-CIN group 12, 24 and 48 h after operation (P<0.05). The AUC values of NGAL, Cys-C and SCr 24 h after operation were 0.885, 0.874 and 0.856, respectively.

Conclusion

The serum NGAL and Cys-C levels of patients after PCI reflect the early changes of renal function, which are valuable for early CIN diagnosis.

A Novel Predictor of Contrast-Induced Nephropathy in Patients With Carotid Artery Disease; the Systemic Immune Inflammation Index

Contrast-induced nephropathy (CIN) is associated with increased mortality and morbidity. The present study investigated the role of systemic immune inflammation index (SII) in predicting the risk of developing CIN after carotid artery angiography (CAAG). This study included 262 patients who underwent CAAG for symptomatic carotid artery stenosis (CAS). Simultaneous carotid stenting was applied to 232 of these patients. CIN was defined as an increase in serum creatinine level ≥.5 mg/dL or ≥25% above baseline within 72 hours after the procedure. The SII score was calculated as platelet × neutrophil/lymphocyte counts. Patients who developed CIN, had higher glucose (P = .009), total cholesterol (P < .001), low density lipoprotein cholesterol (<.001), and high sensitivity C-reactive protein (P = .001) levels, as well as greater neutrophil counts (P < .001), platelet counts (P < .001), neutrophil-lymphocyte ratio (P < .001), and SII score (P < .001) than those who did not develop CIN. The Receiver Operating Characteristic analysis showed that at a cutoff of 519.9, the SII exhibited 80% sensitivity and 64% specificity for detecting CIN. SII levels on admission were independently associated with CIN development after CAAG in patients with CAS.

Effectiveness of Plasma and Urine Neutrophil Gelatinase-Associated Lipocalin for Predicting Acute Kidney Injury in High-Risk Patients

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is a useful biomarker for acute kidney injury (AKI) prediction. However, studies on whether using both plasma NGAL (PNGAL) and urine NGAL (UNGAL) can improve AKI prediction are limited. We investigated the best approach to predict AKI in high-risk patients when using PNGAL and UNGAL together.

METHODS

We enrolled 151 AKI suspected patients with one or more AKI risk factors. We assessed the diagnostic performance of PNGAL and UNGAL for predicting AKI according to chronic kidney disease (CKD) status by determining the areas under the receiver operating curve (AuROC). Independent predictors of AKI were assessed using univariate and multivariate logistic regression analyses.

RESULTS

In the multivariate logistic regression analysis for all patients (N=151), Model 2 and 3, including PNGAL (P=0.012) with initial serum creatinine (S-Cr), showed a better AKI prediction power (R2=0.435, both) than Model 0, including S-Cr only (R2=0.390). In the non-CKD group (N=135), the AuROC of PNGAL for AKI prediction was larger than that of UNGAL (0.79 vs 0.66, P=0.010), whereas in the CKD group (N=16), the opposite was true (0.94 vs 0.76, P=0.049).

CONCLUSIONS

PNGAL may serve as a useful biomarker for AKI prediction in high-risk patients. However, UNGAL predicted AKI better than PNGAL in CKD patients. Our findings provide guidance for selecting appropriate specimens for NGAL testing according to the presence of CKD in AKI high-risk patients.

Evaluation of a Diagnostic Test of Serum Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Urine KIM-1 in Contrast-Induced Nephropathy (CIN)

Background

The aim of this study was to assess changes in serum neutrophil gelatinase-associated lipocalin (NGAL) and urine KIM-1 after percutaneous coronary intervention (PCI).

Material/Methods

A total of 240 patients receiving coronary stent implantation were selected. All patients were divided into 2 groups: a CIN group (n=25) and a non-CIN group (n=215). The serum creatinine (SCr), NGAL, and urine KIM-1 levels of the patients in both groups were measured before and after surgery, and the sensitivity of serum NGAL and urine KIM-1 in diagnosing CIN in the early stage was assessed by the area under receiver operating characteristic (ROC) curve (ROC-AUC).

Results

In the CIN group, the serum NGAL and urine KIM-1 levels started to rise at 6 h after surgery. The serum NGAL and urine KIM-1 levels in CIN group were significantly higher than those in the non-CIN group at 6, 12, 24, and 48 h after surgery. However, the SCr levels in the CIN group were not higher than those in the non-CIN group at 6 h after surgery. At 6, 12, and 24 h after PCI, the AUCs for serum NGAL and urine KIM-1 were increased compared with that for SCr, while the AUCs for serum NGAL and urine KIM-1 were decreased at 48 h after PCI compared with that for SCr.

Conclusions

Serum NGAL and urine KIM-1 levels in the patients after coronary stent implantation can reflect the changes in renal functions early, thus providing a certain basis for the early diagnosis of CIN.

Aging Male Spontaneously Hypertensive Rat as an Animal Model for the Evaluation of the Interplay between Contrast-Induced Acute Kidney Injury and Cardiorenal Syndrome in Humans

BACKGROUND

Although there are some animal models for biomarkers of contrast-induced acute kidney injury (CI-AKI), for cardiorenal syndrome (CRS) and for acute renal failure, the interplay between CI-AKI and CRS has yet to be evaluated. Insight into the pathogenesis of CRS is urgently needed from animal models in order to foster the discovery and implementation of novel biomarkers for this disease. Specially designed animal models for type 1 and 3 CRS, particularly CI-AKI, have not yet emerged.

SUMMARY

We hypothesize that the aging male spontaneously hypertensive rat (SHR) is likely to be a suitable model. The SHR model is able to mimic risk factors for preclinical CRS that appears in the clinical setting, specifically hypertension, age, preexisting damage and dysfunction of the heart and kidney, endothelial dysfunction, increased level of reactive oxygen species, decreased level and bioavailability of nitric oxide (NO), impairment of the L-arginine-NO pathway, and insulin resistance. In the SHR, CI-AKI results in a different profile of AKI biomarkers than is seen with preexisting chronic kidney injury.

KEY MESSAGES

The SHR model can be used to evaluate the interaction between CI-AKI and CRS type 1 and 3 and to verify neutrophil gelatinase-associated lipocalin (NGAL) as a reliable CI-AKI biomarker for clinical application. Further research is warranted with a large number of aging male SHRs to prove NGAL as a sensitive, specific, highly predictive, early biomarker for CI-AKI.

Contrast-associated AKI in the critically ill: relevant or irrelevant?

PURPOSE OF REVIEW

Iodinated contrast media are frequently administered in ICU patients. Recent studies challenge the relevance of contrast media toxicity in ICU patients and relate occurrence of acute kidney injury to baseline characteristics and severity of illness.

RECENT FINDINGS

Various findings in studies with kidney biomarkers indicate the causal relationship between contrast media exposure and kidney damage. Contrast media exposure not only causes direct tubular damage and renal hypoperfusion but also initiates the formation of reactive oxygen species in its turn causing tissue damage. The route of administration determines the incidence of contrast-induced acute kidney injury with a higher incidence when contrast media are administered by intra-arterial route versus intravenous route. The impact of contrast-associated acute kidney injury on hospital length of stay, the need for renal replacement therapy and survival remains a matter of debate because of discrepancies between observational versus case-matched studies and limitations of the individual studies.

SUMMARY

There are diverse pathophysiologic mechanisms explaining the causal relationship between the administration of contrast media and the development of acute kidney injury. Some studies challenge the relevance of contrast media toxicity in ICU patients. However, limitations of the available studies in ICU patients preclude firm conclusions. A precautionary approach in the administration of contrast media is justified.

No increase in Kidney Injury Molecule-1 and Neutrophil Gelatinase-Associated Lipocalin excretion following intravenous contrast enhanced-CT

Objectives

To analyze kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (N-GAL) excretion post-intravenous contrast enhanced-CT (CE-CT) in patients with chronic kidney disease (CKD).

Methods

Patients were enrolled in a trial on hydration regimes to prevent contrast-induced acute kidney injury (CI-AKI). Blood and urine samples were taken at baseline, 4 – 6, and 48 – 96 h post CE-CT. Urinary KIM-1 and N-GAL values were normalized for urinary creatinine levels, presented as medians with 2.5 – 97.5 percentiles.

Results

Of the enrolled 511 patients, 10 (2 %) were lost to follow-up. CI-AKI occurred in 3.9 % of patients (20/501). Median KIM-1 values were 1.2 (0.1 – 7.7) at baseline, 1.3 (0.1 – 8.6) at 4 – 6 h, and 1.3 ng/mg (0.1 – 8.1) at 48 – 96 h post CE-CT (P = 0.39). Median N-GAL values were 41.0 (4.4 – 3,174.4), 48.9 (5.7 – 3,406.1), and 37.8 μg/mg (3.5 – 3,200.4), respectively (P = 0.07). The amount of KIM-1 and N-GAL excretion in follow-up was similar for patients with and without CI-AKI (P-value KIM-1 0.08, P-value N-GAL 0.73). Neither patient characteristics at baseline including severe CKD, medication use, nor contrast dose were associated with increased excretion of KIM-1 or N-GAL during follow-up.

Conclusion

KIM-1 and N-GAL excretion were unaffected by CE-CT both in patients with and without CI-AKI, suggesting that CI-AKI was not accompanied by tubular injury.

Key Points

• KIM-1 and N-GAL excretion were unaffected by intravenous contrast-enhanced CT (CE-CT).

• Patient or procedure characteristics were not associated with increased KIM-1 or N-GAL excretion.

• Performance of CE-CT in CKD patients is likely to be safe.

Neutrophil gelatinase-associated lipocalin (NGAL): a promising biomarker of contrast-induced nephropathy after computed tomography

Contrast-induced nephropathy (CIN) is a common cause of hospital-acquired acute kidney injury (AKI) and a source of significantly increased short- and long-term mortality. Studies of large cohorts have revealed that more than half of these cases are in subjects undergoing cardiac catheterization and intra-arterial coronary angiography, and nearly a third follow computed tomography (CT) scans. Neutrophil gelatinase-associated lipocalin (NGAL) represents an early predictive troponin-like biomarker for AKI. Its role in the timely diagnosis of CIN has already been examined in adults and children undergoing coronary angiography and a meta-analysis revealed a very good performance of plasma or urine NGAL in the prediction of CIN. Much of these data have been extrapolated to patients receiving intravenous (IV) contrast agent for CT scans, although major differences in patient populations, contrast volume administered and intra-procedural complications between the two settings exist. In this context, a recent prospective study by our group evaluated plasma NGAL, measured using standardized Τriage® NGAL test (Biosite Incorporated, San Diego, CA) at baseline and 6-h post-procedure, for early detection of CIN among hospitalized patients undergoing elective contrast-enhanced CT. CIN, defined as an increase in serum creatinine (SCr) of >25% or >0.5 mg/dL from baseline within 48-h post-procedure, was found in 8.51% of subjects. In contrast, significant elevation of plasma NGAL was found at 6-h post-procedure with excellent performance characteristics. This review presents the current status of NGAL in the prediction of CIN after IV contrast administration among hospitalized patients undergoing elective contrast-enhanced CT.