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.

Urinary neutrophil gelatinase-associated lipocalin rapidly decreases in the first week after kidney transplantation

BACKGROUND

Recipient delayed graft function, which is defined as dialysis in the first week after transplantation, is one of the most common early complications after kidney transplantation. This study aimed to evaluate the daily changes in renal function-related biomarkers in the first week post-transplant.

METHODS

A total of 72 kidney transplant recipients were retrospectively included in this study. Clinical and laboratory data were collected daily during the first week post-transplant, including urinary concentrations of neutrophil gelatinase-associated lipocalin (NGAL), serum concentrations of NGAL, creatinine, urea nitrogen, uric acid (UA), β2-microglobulin, cystatin C, and estimated glomerular filtration rate (eGFR).

RESULTS

There were no significant differences in urea nitrogen (P = .375), UA (P = .090), and cystatin C (P = .691), while urinary NGAL (P < .0001), serum NGAL (P < .0001), creatinine (P < .0001), β2-microglobulin (P < .0001), and eGFR (P < .0001) were statistically significant in the first week post-transplant. In comparison with serum NGAL (P < .0001), creatinine (P < .0001), β2-microglobulin (P = .001), and eGFR (P = .001), the change ratios of urinary NGAL changed the most between day 1 and day 2 after renal transplantation, while the changing degree of urinary NGAL showed no significant difference compared with these indicators between day 1 and day 7 after kidney transplantation.

CONCLUSION

Urinary NGAL is a sensitive marker for indicating renal function. Urinary NGAL combined with other markers can be more helpful for evaluating renal function in the first week following kidney transplantation.

Urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL) Predicts Renal Function Decline in Patients With Glomerular Diseases

Objective

Available biomarkers for monitoring primary glomerulonephritides (GNs), often lack the ability to assess longitudinal changes and have great variability with poor sensitivity. Accruing evidence has demonstrated that Neutrophil Gelatinase-Associated Lipocalin (NGAL), holds promising capacities in predicting renal function worsening in various renal diseases. We aimed at analyzing urinary NGAL (uNGAL) levels in a cohort of individuals with biopsy-proven GNs in order to evaluate its ability to reflect the entity of renal damage and to predict disease evolution overtime.

Methods

We enrolled 61 consecutive GNs patients still naïve to pathogenic therapy. uNGAL levels were measured at baseline and patients prospectively followed until the manifestation of a combined outcome of doubling of baseline serum creatinine and/or end-stage kidney disease requiring permanent dialysis support.

Results

Median uNGAL levels were 107[35–312] ng/mL. At univariate and multivariate analyses an inverse correlation was found between eGFR and uNGAL levels (p = 0.001). Progressor subjects showed exceedingly increased baseline uNGAL values as compared with non-progressors (p < 0.001). Twenty-one patients (34%) reached the composite renal endpoint. Subjects with uNGAL values above the optimal, ROC-derived, cut-off of 107 ng/mL experienced a more rapid progression to the renal endpoint (p < 0.001; HR: 5.47; 95% CI 2.31–12.95) with a mean follow-up time to progression of 73.4 vs 83.5 months.

Conclusion

In patients affected by primary glomerulonephritides, uNGAL may represent a real-time indicator of renal damage and an independent predictor of renal disease progression. Further studies on larger populations are warranted to confirm these findings.

SHORT TERM EFFECT OF LAPAROSCOPIC SLEEVE GASTRECTOMY ON CLINICAL, RENAL PARAMETERS AND URINARY NGAL LEVELS IN DIABETIC AND NON DIABETIC OBESITY

Background

Although diseases such as diabetes, hypertension, obstructive sleep apnea and hyperlipidemia are clearly documented as obesity associated diseases, it is not well-known whether obesity causes renal pathologies. The aim of the present study was to evaluate the effect of weight loss following laparoscopic sleeve gastrectomy on clinical, renal parameters and urinary Neutrophil gelatinase-associated lipocalin (NGAL) levels in diabetic and non-diabetic obese patients.

Methods

Nineteen morbidly obese patients (10 diabetic and 9 non diabetic) who underwent laparoscopic sleeve gastrectomy were evaluated clinically (anthropometric measurements) and biochemically before surgery and at 6 months from surgery.

Results

Significant decreases in weight, BMI, FPG, PPG and HbA1c levels were observed in the diabetic group when the baseline and 6th month parameters of the patients were compared. There was also a significant decrease in SBP and DBP. At 6^th month following laparoscopic sleeve gastrectomy, renal parameters such as creatinine, mAlb/creatinine, NGAL/creatinine did not differ in the diabetic group. In the nondiabetic group, serum creatinine levels were significantly decreased, but other renal parameters such as mAlb/creatinine and NGAL/creatinine were not significantly different.

Conclusions

Our findings revealed significant decreases in weight, body mass index and glycemic parameters after sleeve gastrectomy in diabetic and non-diabetic patients, while no significant alteration was noted in renal functions, urinary NGAL and microalbumin levels.

Urinary Tubular Injury Biomarkers Are Associated With ESRD and Death in the REGARDS Study

Introduction

Urinary neutrophil gelatinase-associated lipocalin (uNGAL) and urinary kidney injury molecule-1 (uKIM-1) are established markers of subclinical acute kidney injury. In persons with reduced estimated glomerular filtration rate (eGFR) and albuminuria who are at high risk for end-stage renal disease (ESRD) and death, the associations of these urinary markers with incident ESRD or death is an area of active investigation.

Methods

Among 1472 black and white participants from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study with eGFR ≤60 ml/min per 1.73 m² (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] cystatin, 2012) and albumin-to-creatinine ratio (ACR) ≥30 mg/g, we evaluated the associations of baseline uNGAL and uKIM-1 with progression to ESRD and all-cause death. Cox models were sequentially adjusted for urinary creatinine, traditional risk factors, C-reactive protein, ACR, and eGFR.

Results

There were 257 ESRD events and 819 deaths over a median follow-up of 5.7 and 6.5 years, respectively. In demographic adjusted models, higher levels of uNGAL were associated with increased risk of ESRD and death, but these associations were attenuated in fully adjusted models including baseline eGFR for both ESRD (hazard ratio [HR] = 1.06 per doubling, 95% confidence interval [CI] 0.98-1.14) and death (HR = 1.04, 95% CI = 1.00-1.08). Higher levels of uKIM-1 were associated with increased risk of ESRD and death in demographic-adjusted models, and although attenuated in fully adjusted models, remained statistically significant for both ESRD (HR = 1.24 per doubling, 95% CI = 1.08-1.42) and death (HR = 1.10, 95% CI =1.03-1.19).

Conclusion

In this cohort of high-risk patients with baseline eGFR ≤60 ml/min per 1.73 m² and albuminuria, renal tubular injury is associated with higher mortality and progression to ESRD. Further studies are necessary to investigate the mechanism underlying this increased risk.

Urinary neutrophil gelatinase-associated lipocalin is an early predictor of acute kidney injury in premature infants

Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is produced in response to tubular epithelial injury and is a biomarker of tubulointerstitial injury. The aim of the present study was to examine whether acute kidney injury (AKI) could be predicted by measuring uNGAL in very low-birth weight (VLBW) infants. Forty VLBW infants with birthweight below 1,500 g were enrolled in the present study. uNGAL and serum creatinine (sCre) were measured daily from postnatal days 0 to 8. Infants with sCre ≥1.2 mg/dl were diagnosed with AKI. The relationship of uNGAL with sCre was measured on the day after uNGAL measurement (next-day sCre) was examined. The results showed that 16 infants had sCre ≥1.2 mg/dl in this period. Logistic regression analysis revealed that uNGAL on postnatal days 2, 3, 4, 5 and 6 was correlated with next-day sCre (P<0.05). uNGAL corrected by urinary Cre (uCre) (uNGAL/uCre) was only correlated with an increase in next-day sCre on postnatal days 5 and 6 (P<0.05). For the logistic analysis, subjects with high and low uNGAL levels based on the median value for each day, uNGAL on postnatal days 2, 3 and 6 in the high uNGAL group was correlated with an increase in next-day sCre. Thus, AKI may be predicted by measuring uNGAL in VLBW infants. This measurement was non-invasive, and is potentially useful for the evaluation of renal function in VLBW infants.

Diagnostic accuracy of urinary neutrophil gelatinase-associated lipocalin in patients with septic acute kidney injury

Background

Sepsis is the most common cause of acute kidney injury (AKI). Very few studies have investigated the predictive properties of urinary neutrophil gelatinase-associated lipocalin (uNGAL) as a marker of AKI in septic patients. The aim of this study is to examine uNGAL in septic patients with and without AKI and to evaluate its predictive value.

Methods

We prospectively studied 155 patients with sepsis over a period of 1 year. Urine was analyzed for neutrophil gelatinase-associated lipocalin at 12, 24, and 48 hours after admission. Patients with <24-hour stay and those with chronic kidney disease were excluded. AKI was classified according to the Acute Kidney Injury Network guidelines.

Results

The differences in mean change of uNGAL at 12, 24, and 48 hours were 80.00±7.00 ng/mL and 128.13±22.46 ng/mL, respectively in septic AKI, and 02.07±0.80 ng/mL and 26.13±15.12 ng/mL, respectively in septic non-AKI. At baseline or 12 hours, the cutoff value of 34.32 ng/mL had a sensitivity and specificity of 86.36 and 80.60, respectively and an area under curve of 0.81 (95% CI: 0.73–0.89) for predicting AKI. At the cutoff value 199.99 ng/mL sensitivity and specificity of 90.0 and 64.66, respectively and an area under curve of 0.82 (95% CI, 0.75–0.88) for predicting AKI.

Conclusion

The baseline or 12-hour uNGAL is highly sensitive but a less specific predictor of AKI in septic patients.

Predictive Accuracy of Urinary neutrophil gelatinase associated lipocalin (NGAL) for renal parenchymal involvement in Children with Acute Pyelonephritis

Introduction

Urinary tract infections (UTIs) are among the most prevalent infections in children and infants. Early and accurate detection of renal parenchymal involvement in UTI is necessary for decision making and determining treatment strategies. The aim of this study was to determine the predictive accuracy of urinary neutrophil gelatinase-associated lipocalin (NGAL) for renal parenchymal involvement in children with acute pyelonephritis.

Methods

This descriptive, cross-sectional study was conducted in 2014 on children who had been diagnosed with UTI. Children who were admitted to Koodakan Hospital in Bandar Abbas, Hormozgan Province, Iran, and whose ages ranged from two months to 14 years were enrolled in the study. Urine samples were taken to conduct urinary NGAL tests, urine cultures, and urinalyses. In addition, some blood samples were collected for the purpose of determining leukocyte count and C-reactive protein (CRP) and to conduct erythrocyte sedimentation rate (ESR) tests. All patients underwent a dimercaptosuccinic acid (DMSA) scan. SPSS software was used to analyze the data.

Results

Among the participants in the study, 29 were male (32%), and 60 were female (68%). The mean age of the children who participated in the study was 2.99 ± 2.94 years. The results of the Kruskal-Wallis test showed a significant increase in the urinary NGAL level, an increase in the CRP level, and higher DMSA scan grades (p < 0.001). The cutoff point amounted to > 5 mg/l, having the negative predictive value (NPV) of 76.3%, the specificity of 97.83%, the positive predictive value (PPV) of 96.7%, and the sensitivity of 67.4%.

Conclusion

Urinary NGAL is not sensitive enough for the prediction of renal parenchymal involvement, but it is a specific marker.

Prognostic significance of urinary NGAL in chronic kidney disease

Background

Chronic kidney disease (CKD) is a worldwide public health problem. Recently urinary NGAL (uNGAL) has been proven to be a useful (potentially ideal) biomarker for early detection of CKD. The aim of the present study was to examine the correlation of uNGAL with severity of renal impairment in CKD and to evaluate its prognostic value in these subjects.

Methods

This was a prospective study carried out over a period of 24 months in subjects with CKD due to primary chronic glomerulonephritis. New cases of CKD stage II, III, IV aged between 18 and 65 years were enrolled as per KDIGO (Kidney Disease: Improving Global Outcomes) guidelines 2012. A total of 90 subjects completed the study up to the end-point. The primary follow-up end-point was 18 months, or decreased glomerular filtration rate of less than 15 mL/min. Secondary follow-up end-point was the number of subjects who expired during this period.

Results

Multiple regression model of estimated glomerular filtration rate showed significant associations with log uNGAL (β=0.38, P<0.001), Ca×PO4 (β=0.60, P<0.001), hemoglobin (β=0.37, P<0.001), urine protein (β=0.34, P<0.001), serum albumin (β=0.48, P<0.001), and systolic blood pressure (β=0.76, P<0.001). Receiver operator curve for uNGAL considering the progression of CKD showed area under the curve for uNGAL was 0.878 (95% confidence interval: 0.68–0.96). Cut-off value for uNGAL was log 3.5 unit with a sensitivity of 93.08% and specificity of 71.43% for predicting the progression of CKD. Kaplan–Meier survival curve showed that patients with log uNGAL levels <3.51 unit had a survival rate of 71.4% while patients with NGAL level >3.51 unit had a renal survival rate of 14.7%.

Conclusion

Our study result showed that uNGAL has a positive correlation with disease severity which signifies the prognostic importance of uNGAL in CKD.

Serum and Urinary Neutrophil Gelatinase-associated Lipocalin Monitoring in Normal Pregnancy Versus Pregnancies Complicated by Pre-eclampsia

AIM

Pre-eclampsia is a syndrome characterized by endothelium dysfunction, systemic inflammation, and kidney injury that could be associated with increased levels of neutrophil gelatinase-associated lipocalin (NGAL). We investigated whether serum and urinary NGAL may have a clinical value in defining the severity of pre-eclampsia.

PATIENTS AND METHODS

This cross-sectional case-control study enrolled 18 women with pre-eclampsia matched for gestational age with 22 uncomplicated pregnancies. We evaluated the correlation between NGAL levels and blood pressure and 24-hour proteinuria values by linear regression.

RESULTS

Linear regression disclosed a positive and significant correlation between urinary NGAL and 24-hour proteinuria. Serum NGAL appeared to be higher, but not significantly different, in severe pre-eclampsia.

CONCLUSION

These preliminary data indicate that NGAL may correlate with an inflammatory renal involvement in severe pre-eclampsia. Further studies would be useful to better estimate the clinical value of an NGAL increase for evaluating the possibility of delivery induction.