Plasma and urine neutrophil gelatinase-associated lipocalin (NGAL) in dogs with acute kidney injury or chronic kidney disease

Urinary neutrophil gelatinase-associated lipocalin as early biomarker for renal disease in dogs with leishmaniosis

Canine leishmaniosis (CanL), caused by Leishmania sp., presents a wide array of symptoms; renal dysfunction is frequently observed in these dogs and is associated with a poor prognosis and increased mortality. The traditional biomarkers namely urea and creatinine can detect renal damage but only in advanced stages of the disease. However, it has been shown that the symmetric dimethylarginine assay (SDMA) or the protein/creatinine ratio (UPC) and are early biomarkers of renal dysfunction. Their elevation occurs earlier than that of creatinine, but other novel biomarkers such as neutrophil gelatinase-associated lipocalin (NGAL) are currently under investigation. Our objective was to determine whether the urine NGAL-creatinine ratio (uNGAL/c) can provide very early diagnosis of kidney disease in CanL. In total, 68 dogs were included in the study: 15 healthy dogs and 53 dogs with CanL who were classified according to International Renal Interest Society (IRIS) classification: IRIS 1 (N= 34), IRIS 2 (N= 9) and IRIS 3/4 (N= 10). IRIS 1 was subdivided according to proteinuria in IRIS 1NP (13 dogs with UPC < 0.2), IRIS 1BL (8 dogs with UPC = 0.2-0.5) and IRIS 1 P (13 dogs with UPC > 0.5). Blood samples were collected for complete hematological and biochemistry analysis including plasma NGAL. Urinalysis included specific gravity, UPC, CysC and NGAL expressed as a ratio with creatinine. The mean concentrations of pCysC and SDMA in CanL, show a statistically significant increase from IRIS 1NP, not being statistically significant for pCysC in the IRIS 1BL group. The UPC show a statistically significant increase from IRIS 1NP. In all groups with CanL for uCysC/c and uNGAL/c was observed a statistically significant increase. The uNGAL/c in the group proteinuric animals, presents a positive correlation with all renal biomarkers studied. In the group of non-proteinuric animals, the uNGAL/c presents a positive correlation with SDMA and UPC. The uNGAL/c can be considered a reliable indicator of renal disease in dogs diagnosed with CanL who are non-azotemic and non-proteinuric.

Assessment of cell cycle arrest biomarkers and neutrophil gelatinase-associated lipocalin to distinguish acute kidney injury from other diseases in dogs

BACKGROUND

Cell cycle arrest biomarkers (tissue inhibitor of metalloproteinase-2 [uTIMP-2] and insulin-like growth factor binding protein 7 [uIGFBP7]), and neutrophil gelatinase-associated lipocalin (NGAL) variables are valuable biomarkers for early diagnosis of acute kidney injury (AKI) in people.

OBJECTIVES

To evaluate uTIMP-2, uIGFBP7, fractional excretion of NGAL (FeNGAL), and urinary to serum NGAL ratio (u/sNGAL) in healthy dogs, dogs with AKI, dogs with chronic kidney disease (CKD), and critically ill (CI) dogs.

ANIMALS

Forty-two client-owned dogs (healthy, n = 10; AKI, n = 11; CKD, n = 11; CI, n = 10).

METHODS

Prospective, observational study. After assessment of routine renal biomarkers, stress (uTIMP-2, uIGFBP7) and damage (NGAL) biomarkers were measured, using ELISA kits, and normalized to urinary creatinine (uCr).

RESULTS

Normalized uTIMP-2 and [uTIMP-2] × [uIGFBP7]/uCr were significantly higher in the AKI group (median 151.9 [range, 2.2-534.2] and 62.9 [1.1-266.8] pg/mL respectively), compared to healthy dogs (0.3 [0.2-74.7]; P < .001 and 0.16 [0.1-58.1] pg/mL; P < .001), dogs with CKD (0.7 [0.3-742.5]; P = .04 and 0.37 [0.2-180.1] pg/mL; P = .03) and CI dogs (1.9 [0.2-37.0]; P = .03 and 0.8 [0.1-16.1] pg/mL; P = .02). Fractional excretion of NGAL was significantly higher in dogs with AKI (54.17 [7.93-155.32] %), than in healthy (0.03 [0.01-0.21] %; P < .001) and CI dogs (3.05 [0.05-28.86] %; P = .02).

CONCLUSIONS AND CLINICAL IMPORTANCE

Normalized uTIMP-2, [uTIMP-2] × [uIGFBP7]/uCr, and FeNGAL can be valuable renal biomarkers for early diagnosis of AKI in dogs.

Early Detection of Chronic Kidney Disease Using Plasma Neutrophil Gelatinase-Associated Lipocalin and Kidney Injury Molecule-1 in Small-Breed Dogs: A Retrospective Pilot Study

Multiple diagnostic modalities are urgently needed to identify early-stage kidney diseases. Various molecules have been investigated; however, most studies have focused on identifying specific biomarkers in urine. Considering that assessing the symmetrical dimethylarginine (SDMA) plasma concentration is more suitable as an early diagnostic test for chronic kidney disease (CKD) in routine veterinary practice, we aimed to investigate the clinical usefulness of plasma neutrophil gelatinase-associated lipocalin (pNGAL) and plasma kidney injury molecule-1 (pKIM-1) concentrations for CKD detection in small-breed dogs. Through a retrospective analysis, we found that numerous clinicopathological data showed a log-normal distribution, even when they satisfied normality tests. Moreover, the log-transformed pNGAL and pKIM-1 concentrations successfully identified CKD International Renal Interest Society (IRIS) stages 1-4 and the risk group with underlying CKD risk factors. Correlation analysis and group comparison of other factors confirmed the possibility of using these two biomarkers for detecting the CKD risk group and IRIS stage 1. Receiver operating characteristic curve analysis revealed that the diagnostic accuracy for discriminating the risk group was superior in the order of pKIM-1, pNGAL, SDMA, and serum creatinine levels. In conclusion, these results suggest that pKIM-1 and pNGAL are possible early or quantifiable markers of insignificant CKD or can be at least used as an adjunct with traditional indicators.

Association between echocardiographic indexes and urinary Neutrophil Gelatinase-Associated Lipocalin (uNGAL) in dogs with myxomatous mitral valve disease

Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of tubular damage, and its elevation has been described in human and canine cardiorenal syndrome. The aim was to evaluate the association between echocardiographic indexes and urine NGAL (uNGAL) and uNGAL normalized to urine creatinine (uNGALC) in dogs with MMVD. This is a multicentric prospective cross-sectional study. A total of 77 dogs with MMVD at different ACVIM stages were included. All dogs underwent echocardiography, serum chemistry, and urinalysis. Echocardiographic data analyzed were shortening fraction (SF), left ventricular diastolic (LVIDDn) and systolic (LVIDSn) diameters normalized for body weight, left atrium to aortic root ratio (LA/Ao), maximal (LAVMax) and minimal (LAVMin) left atrial volumes, LA stroke volume (LASV), early diastolic mitral peak velocity (EVmax), EVmax to tissue Doppler E' wave (E/E'), aortic (VTIAo) and mitralic (VTIMit) velocity time integrals and their ratio (VTIMit/VTIAo), and tricuspid regurgitation velocity (TRVmax). In the univariate analysis LASV, TRVmax, LAVMax, LVIDDn, and VTIMit/VTIAo were independent predictors of increased uNGAL and uNGALC; however, only LASV [(OR: 1.96, 95% CI: 1.16 to 3.31) P = 0.01 for NGAL, and (OR: 2.79, 95% CI: 1.50 to 5.17) P < 0.001 for NGALC] and TRVmax [(OR: 1.73, 95% CI: 1.20-2.51) P = 0.002 for NGAL, and (OR: 1.50, 95% CI: 10.07-2.10) P = 0.015 for NGALC] remained statistically significant in the multivariable analysis. Based on our results, LASV and TRVmax are associated with increased uNGAL and uNGALC. These parameters might detect dogs with MMVD at higher risk of developing kidney damage.

A Pilot Study of the Role of Selected Biomarkers of Kidney Injury in Dogs with Dilated Cardiomyopathy

Heart and kidney diseases are among the most frequent medical conditions diagnosed in small animals. Due to the functional interconnection between these organs, the concept of the cardio-renal axis has been developed. In this context, renal disease or dysfunction often occurs secondary to heart diseases, such as dilated cardiomyopathy (DCM). DCM is the most common cardiomyopathy and a leading cause of mortality in large-breed dogs. Traditional biomarkers like creatinine or symmetric dimethylarginine concentration are not always effective, especially in the early stages of the disease, underscoring the need for more sensitive markers of renal impairment during heart failure (HF). This study aimed to evaluate the efficacy of selected biomarkers as indicators for early kidney damage in dogs with stage B2 DCM. We measured serum concentrations of cystatin C, KIM-1 (kidney injury molecule-1), and NGAL (neutrophil gelatinase-associated lipocalin) and their ratios to creatinine, analyzing their diagnostic values. Cystatin C was quantified using a sandwich enzyme immunoassay, while KIM-1 and NGAL were measured with enzyme-linked immunosorbent assay kits designed for canine diagnostics. The concentrations were indexed against serum creatinine. The study included 26 dogs: 9 with HF and 17 healthy controls. The mean ± standard deviation for healthy dogs for cystatin C, cystatin C/creatinine ratio, KIM-1, KIM-1/creatinine ratio, NGAL, and NGAL/creatinine ratio were 0.24 ± 0.04, 0.26 ± 0.07, 0.61 ± 0.07, 0.67 ± 0.13, 2.76 ± 1.8, and 2.79 ± 1.81, respectively. For DCM dogs, these values were 0.27 ± 0.1, 0.32 ± 0.12, 0.61 ± 0.08, 0.69 ± 0.17, 6.46 ± 5.22 (p = 0.02), and 7.99 ± 6.53 (p = 0.04). This study's findings suggest that during the asymptomatic phase of DCM, only NGAL concentration and the NGAL/creatinine ratio may serve as diagnostic markers for early-stage kidney injury.

Endotoxic kidney injury in Beagle dogs assessed by serum creatinine and symmetric dimethylarginine, and urinary neutrophil gelatinase-associated lipocalin and clusterin

Sepsis of Gram negative bacterial origin results in lipopolysaccharide-induced endotoxemia. This often leads to acute kidney injury (AKI) and its recognition remains a challenge and delays treatment. As renal damage occurs before a rise in serum creatinine is detected, new early biomarkers of kidney injury need to be explored. The aim of this study was to determine changes in serum parameters of renal function and urine biomarkers of renal injury. This was a descriptive study. Endotoxemia was induced intravenously in six anaesthetized Beagles (T1). To achieve normotension, dogs received fluids (T2), followed by a continuous infusion of noradrenaline and dexmedetomidine or 0.9% NaCl (T3). Ten minutes later, the dogs received fluids (T4) and noradrenaline and dexmedetomidine or 0.9% NaCl in a crossover manner (T5). At each timepoint, blood and urine were collected for serum creatinine, urea, symmetric dimethylarginine, urine protein/creatinine (UPC) ratio, urine neutrophil-gelatinase-associated lipocalin (U-NGAL), U-NGAL/creatinine ratio, urine clusterin (U-clusterin) and U-clusterin/creatinine ratio. Data were analyzed using a mixed-effect model taking into account time and stage of veterinary AKI (VAKI). Three of six dogs had a VAKI stage ≥1; one with anuria and elevated creatinine. Serum creatinine (P < 0.001), U-NGAL/creatinine ratio (P = 0.01) and U-clusterin/creatinine ratio increased over time (P < 0.01). The UPC ratio (mean (range) 0.68 (0.35-2.3) versus 0.39 (0.15-0.71) P < 0.01) and U-NGAL (3164 pg/mL (100-147,555) versus 100 (100-14,524), P = 0.01) were higher in VAKI stage ≥1 versus stage 0, respectively. Endotoxemia induced VAKI stage ≥1 in half of the dogs. Repeated measurement of selected parameters could detect AKI early.

Concentrations and kinetics of renal biomarkers in dogs with gastric dilatation-volvulus with and without 24-h intravenous lidocaine

Background

Gastric dilatation volvulus (GDV) can lead to organ failure including acute kidney injury (AKI). Due to its cytoprotective, antioxidant and anti-inflammatory effects, lidocaine has a potential to prevent AKI in dogs with GDV.

Design and setting

Prospective, observational cohort study in client-owned dogs with GDV.

Objective

To determine concentrations of renal biomarkers for AKI in dogs with GDV with and without intravenous (IV) lidocaine therapy.

Methods

Thirty-two dogs were randomized to receive either IV lidocaine (2 mg/kg, followed by a lidocaine constant rate infusion at a dose of 50 μg/kg/min over 24 h; n = 17) or no lidocaine (n = 15). Blood and urine samples were taken at admission (T 0) (only blood), during or immediately after surgery (T 1), and 24 (T 24) and 48 (T 48) h after surgery. Plasma creatinine (pCr), plasma neutrophil gelatinase-associated lipocalin (pNGAL), urinary NGAL (uNGAL), uNGAL to creatinine ratio (UNCR), and urinary gamma-glutamyl transferase to creatinine ratio (uGGT/uCr) were evaluated. Biomarker concentrations were compared between dogs with and without IV lidocaine and the course of each marker was determined in comparison to its admission value.

Results

In the entire population, a significantly higher pCr at T 0 (median, 95 μmol/L, interquartile range, 82-105) compared with T 1 (69 μmol/L, 60-78), T 24 (63 μmol/L, 52-78), and T 48 (78 μmol/L, 65-87) (P < 0.001) was found. Plasma NGAL increased significantly between T 0 (5.66 ng/mL, 3.58-7.43) and T 24 (7.50 ng/mL, 4.01-11.89) (P = 0.006) and T 48 (9.86 ng/mL, 5.52-13.92) (P < 0.001), respectively. Urinary NGAL increased significantly between T 1 (0.61 ng/mL, 0.30-2.59) and T 24 (2.62 ng/mL, 1.86-10.92) (P = 0.001) and T 48 (4.79 ng/mL, 1.96-34.97 (P < 0.001), respectively. UNCR increased significantly between T 1 (0.15 μg/mmol, 0.09-0.54) and T 24 (1.14 μg/mmol, 0.41-3.58) (P = 0.0015) and T 48 (1.34 μg/mmol, 0.30-7.42) (P < 0.001), respectively. Concentrations of uGGT/uCr increased significantly from T 0 highest at T 24 (6.20 U/mmol, 3.90-9.90) and significantly decreased at T 48 (3.76 U/mmol, 2.84-6.22) (P < 0.001). No significant differences in any renal biomarker concentration were found between dogs with and without IV lidocaine therapy.

Conclusion and clinical relevance

Plasma NGAL, uNGAL and UNCR remained increased up to 48 h post-surgery. No evidence of lidocaine-associated renoprotection was found.

Short-term intra-individual variation of urinary biomarkers in dogs with stable chronic kidney disease

BACKGROUND

Active-ongoing kidney damage is present in animals with stable chronic kidney disease (CKD), as reflected by biomarkers in urine. Interpretation of serial messurements of biomarkers requires knowledge of its intra-individual variation.

AIMS

To evaluate the short-term intra-individual variation of urinary neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 (uNGAL, uKIM-1, respectively) in dogs with stable CKD, and to determine whether normalization to urinary creatinine (uCr) decreases variation.

ANIMALS

Twenty-five dogs with naturally-occurring stable CKD.

METHODS

Prospective, observational study. Dogs were diagnosed with CKD based on the International Renal Interest Society guidelines. Dogs were included only if the variation in serum creatinine concentration was <25% on at least 2 measurements during the 3 months preceding inclusion, and only if serum creatinine variation was <20% during the 14-day study period. Urine samples were collected on days 0, 4, 10 and 14. uNGAL and uKIM-1 were measured using ELISA.

RESULTS

The median coefficients of variation (CV) of uNGAL and uNGAL/uCr were 42% (range, 7%-127%), and 44% (range, 8%-100%), respectively, and the CV 90th percentiles were 97% and 83%, respectively. The median CV of uKIM-1 and uKIM-1/uCr were 29% (range, 16%-91%), and 23% (range, 6%-76%), respectively, and the CV 90th percentiles were 56% and 52%, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Changes of >100% and >60% for uNGAL and uKIM-1, respectively, in serial measurements are higher than the normal expected variation and therefore might indicate need for further investigation for underlying causes of kidney damage.

Evaluation of urinary neutrophil gelatinase-associated lipocalin to detect renal tubular damage in dogs with stable myxomatous mitral valve disease

BACKGROUND

Dogs with myxomatous mitral valve disease (MMVD) can experience progressive renal tubular damage and dysfunction. The prevalence of renal tubular damage is not known in dogs with stable MMVD.

OBJECTIVE

To evaluate renal tubular damage in dogs with stable MMVD by evaluation of urinary neutrophil gelatinase-associated lipocalin (NGAL).

ANIMALS

Ninety-eight MMVD dogs grouped according to the American College of Veterinary Internal Medicine (ACVIM) staging (group B1, n = 23; group B2, n = 27; group C + D, n = 48) and 46 healthy dogs.

METHODS

Multicenter prospective observational study. Serum and urine chemistry including NGAL reported as uNGAL concentration (uNGAL) and normalized with urinary creatinine (uNGALC) were compared between MMVD dogs and healthy controls, and among different MMVD ACVIM stages.

RESULTS

The MMVD dogs had significantly higher uNGAL and uNGALC (1204 pg/mL; range, 30-39 732 and 1816 pg/mg; range, 22-127 693, respectively) compared to healthy dogs (584 pg/mL; range, 56-4072 and 231 pg/mg; range, 15-2407, respectively; P = .002 and P < .0001, respectively). Both uNGAL and uNGALC increased with the increasing ACVIM stage (P = .001 and P < .001, respectively).

CONCLUSIONS AND CLINICAL IMPORTANCE

Renal tubular damage is present in dogs with stable MMVD, as measured by increased uNGAL. This tubular damage is subclinical, occurs in all stages of MMVD even in the absence of azotemia, and increases with the severity of MMVD. Reno-protective approaches to manage MMVD dogs should be explored to slow the progression of renal tubular damage in these patients.

Molecular Mechanisms of Diabetic Kidney Disease

The inflammatory component of diabetic kidney disease has become of great interest in recent years, with genetic and epigenetic variants playing a fundamental role in the initiation and progression of the disease. Cells of the innate immune system play a major role in the pathogenesis of diabetic kidney disease, with a lesser contribution from the adaptive immune cells. Other components such as the complement system also play a role, as well as specific cytokines and chemokines. The inflammatory component of diabetic kidney disease is of great interest and is an active research field, with the hope to find potential innovative therapeutic targets.

Concentrations of Neutrophil Gelatinase-Associated Lipocalin are increased in serum and peritoneal fluid from horses with inflammatory abdominal disease and non-strangulating intestinal infarctions

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is produced in response to inflammation in horses, but it has not yet been investigated as a biomarker in horses with abdominal disease.

OBJECTIVES

To investigate NGAL in serum and peritoneal fluid in horses with abdominal disease.

STUDY DESIGN

Retrospective clinical study.

METHODS

Data from medical records of 270 horses admitted with acute abdominal disease (simple obstructions [n=43], strangulating obstructions [n=104], inflammatory abdominal disease [n=99], non-strangulating intestinal infarction [NSII, n=24]) and 9 healthy control horses were reviewed, and serum and peritoneal fluid samples were retrieved from a biobank. NGAL was measured in serum and peritoneal fluid by ELISA. Differences in NGAL concentrations between groups were assessed.

RESULTS

Healthy horses had low serum and peritoneal fluid concentrations of NGAL (median = 21.0 and 9.5 μg/L, respectively). Neither serum nor peritoneal fluid NGAL concentrations (median serum, peritoneal fluid) differed between healthy horses and horses with simple (28.1 μg/L, 13.0 μg/L) and strangulating intestinal obstructions (34.7 μg/L, 38.4 μg/L). Horses with NSII (308.0 μg/L, 2163.0 μg/L) and inflammatory abdominal disease (171.1 μg/L, 314.1 μg/L) had higher serum and peritoneal fluid concentrations of NGAL than the other groups (P<0.001). Peritoneal fluid NGAL concentrations in horses with NSII were higher than in horses with inflammatory abdominal disease (P=0.03).

MAIN LIMITATIONS

Retrospective study design; small group of control horses.

CONCLUSIONS

NGAL is a marker of inflammation in horses with abdominal disease. The high peritoneal fluid concentration of NGAL in horses with NSII compared to all other groups may render NGAL useful for identifying this condition, which is otherwise difficult to differentiate from other types of peritonitis. Thereby, NGAL may potentially facilitate timely surgical intervention in this group of patients. The results of this study must be evaluated in larger, and preferably prospective, studies to obtain a more comprehensive evaluation of the diagnostic utility of NGAL. This article is protected by copyright. All rights reserved.

Cystatin C and Iris: Advances in the Evaluation of Kidney Function in Critically Ill Dog

Critically ill hospitalized dogs are subject to certain complications, being acute kidney injury (AKI) a common one. Early diagnosis is crucial, and Cystatin C (CysC) is a reliable and early biomarker. The International Society of Renal Interest (IRIS) states that AKI severity can be assessed by mild changes in creatinine serum levels or reduction of urine output that cannot be considered biomarkers of renal injury but failure or insufficiency. Twenty-eight dogs admitted to the Intensive Care Unit under risk factors for the development of AKI were evaluated. Blood samples were collected for determination of sCr and CysC at admission and after 24, 48, and 72 h. Urine output was measured by daily monitoring, measured by collection in a closed system. The results showed the incidence of AKI was 67.9% based on the IRIS criteria and 78.6% based on cystatin C in critically ill patients' dogs. The measurement of serum cystatin C immediately on admission to the ICU was superior in the early identification of patients with AKI when compared to the IRIS classification and serum creatinine in critically ill dogs.

Cystatin C and Neutrophil Gelatinase-Associated Lipocalin as Early Biomarkers for Chronic Kidney Disease in Dogs

Early diagnosis of chronic kidney disease (CKD) could facilitate timely and appropriate monitoring and therapy. Traditional biomarkers have limitations. Thus, new biomarkers are needed. The objective of the present study was to compare renal biomarkers (including symmetric dimethylarginine [SDMA], cystatin C [CysC], and urine neutrophil gelatinase-associated lipocalin [NGAL]-creatinine ration [UNCR]) and creatinine (CREA) for early detection of CKD in dogs. Nine healthy dogs and 32 dogs with CKD were included in this study. All dogs underwent physical examination, blood analysis (included CREA and SDMA), urinalysis, and imaging examinations. CysC and NGAL levels were measured in serum and urine, respectively. SDMA, CysC, and UNCR were significantly elevated in dogs with CKD and IRIS stage Ι (P < .0001) than in controls. CysC demonstrated a strong correlation with CREA (r² = 0.6556, P < .0001). CysC (sensitivity 93.55%, specificity 100%) had the highest sensitivity for detecting CKD, followed by UNCR (sensitivity 90%, specificity 100%), SDMA (sensitivity 84.37%, specificity 100%), and CREA (sensitivity 43.75%, specificity 100%). Additionally, CysC and UNCR (sensitivity 88.89%, specificity 100%) exhibited higher sensitivity and specificity than CREA (sensitivity 88.89%, specificity 66.67%) and SDMA (sensitivity 88.89%, specificity 88.89%) in dogs with CKD International Renal Interest Society (IRIS) stage Ι. CysC as a marker of glomerular filtration rate (GFR) and urinary NGAL as a marker of tubular damage could be used to detect CKD early in dogs better than CREA and SDMA.

Prospective randomized controlled blinded clinical trial evaluating biomarkers of acute kidney injury following 6% hydroxyethyl starch 130/0.4 or Hartmann's solution in dogs

OBJECTIVE

To evaluate the effect of 6% hydroxyethyl starch (HES) 130/0.4, compared with a Hartmann's solution control (CRYST), on urine biomarkers of acute kidney injury (AKI) in dogs prescribed a fluid bolus.

DESIGN

Randomized, controlled, blinded clinical trial January 2018 to February 2019.

SETTING

University teaching hospital.

ANIMALS

Forty client-owned dogs.

INTERVENTIONS

Dogs prescribed a fluid bolus were randomized to receive at least 10 mL/kg of HES or CRYST with clinicians and investigators blinded to fluid type. Study fluid was used for further boluses as required in the following 24 hours, to a limit of 40 mL/kg total, after which fluid administration was open-label.

MEASUREMENTS AND MAIN RESULTS

Urine was collected prior to and 6, 12, and 24 hours after the first study fluid bolus. Urine concentrations of AKI biomarkers: neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, kidney injury molecule-1 (KIM), clusterin, and osteopontin were measured using a magnetic bead multiplexed assay. Osmolality-indexed biomarker concentrations were compared between groups over time with linear mixed-effects models, with P < 0.05 considered significant. The mean volume of study fluid administered was not significantly different between groups (HES: 23.1 mL/kg, CRYST: 25.9 mL/kg; P = 0.47, t-test). There were no significant differences between groups in change over time of osmolality-indexed urine concentrations of NGAL (P = 0.91), cystatin C (P = 0.95), KIM (P = 0.77), clusterin (P = 0.63), or osteopontin (P = 0.91). The maximum Veterinary Acute Kidney Injury (VAKI) score up to 7 days during hospitalization (P = 1.0) and in-hospital mortality (P = 0.49) were not significantly different between groups, as compared by Fisher's exact test.

CONCLUSIONS

There were no differences in change over time of urine AKI biomarkers in dogs treated with 10 - 40 mL/kg HES or CRYST over 24 hours. Larger clinical trials with patient-centered outcomes are required to investigate the safety of HES in dogs.

A Review of Specific Biomarkers of Chronic Renal Injury and Their Potential Application in Nonclinical Safety Assessment Studies

A host of novel renal biomarkers have been developed over the past few decades which have enhanced monitoring of renal disease and drug-induced kidney injury in both preclinical studies and in humans. Since chronic kidney disease (CKD) and acute kidney injury (AKI) share similar underlying mechanisms and the tubulointerstitial compartment has a functional role in the progression of CKD, urinary biomarkers of AKI may provide predictive information in chronic renal disease. Numerous studies have explored whether the recent AKI biomarkers could improve upon the standard clinical biomarkers, estimated glomerular filtration rate (eGFR), and urinary albumin to creatinine ratio, for predicting outcomes in CKD patients. This review is an introduction to alternative assays that can be utilized in chronic (>3 months duration) nonclinical safety studies to provide information on renal dysfunction and to demonstrate specific situations where these assays could be utilized in nonclinical drug development. Novel biomarkers such as symmetrical dimethyl arginine, dickkopf homolog 3, and cystatin C predict chronic renal injury in animals, act as surrogates for GFR, and may predict changes in GFR in patients over time, ultimately providing a bridge from preclinical to clinical renal monitoring.

Neutrophil Gelatinase-Associated Lipocalin (NGAL) Is Related with the Proteinuria Degree and the Microscopic Kidney Findings in Leishmania-Infected Dogs

Early diagnosis of renal damage in Leishmania infected dogs may allow appropriate treatments and prevent some deaths. This study investigates neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker of kidney disease in dogs experimentally infected with Leishmania infantum. Serum, urine, and kidney samples were collected from 30 infected beagle dogs and six uninfected control dogs. Based on proteinuria and azotemia values, dogs were initially classified. NGAL was measured in urine and serum samples. Then, the urinary NGAL to creatinine ratio (uNGAL/C) was calculated. Kidney samples were taken for histopathological studies, and the dogs were classified according to the severity of glomerular and tubulointerstitial lesions. In Leishmania-infected dogs, the uNGAL/C was significantly higher in proteinuric non-azotemic dogs compared with non-proteinuric non-azotemic dogs (p = 0.038). Serum NGAL (sNGAL) concentration did not differ between groups. Microscopic studies revealed several degrees of glomerulonephritis and slight focal lymphoplasmacytic interstitial nephritis in 89% and 55% of infected dogs, respectively. Urinary protein to creatinine ratio (UPC) and uNGAL/C were significantly higher in dogs with affected glomeruli compared to infected dogs without renal lesions (p = 0.045 and p = 0.043, respectively). The results show that uNGAL/C correlates with proteinuria and the presence of moderate glomerular lesions in non-azotemic dogs experimentally infected with L. infantum.

Validation of a commercial magnetic bead-based multiplex assay for 5 novel biomarkers of acute kidney injury in canine serum

Interest is growing in measurement of novel biomarkers for the diagnosis of acute kidney injury. Multiplex assays may provide a rapid and cost-effective way of measurement; however, sparse information is published regarding their use in dogs. We aimed to validate a commercial magnetic bead-based assay for 5 biomarkers: clusterin (Clus), cystatin C (CysC), kidney injury molecule 1 (KIM-1), monocyte chemoattractant protein 1 (MCP-1), and neutrophil gelatinase-associated lipocalin (NGAL). Intra- and inter-assay imprecision, linearity under dilution (LUD), spike recovery (S-R), and hemoglobin interference were evaluated using serum from healthy and diseased dogs. Additionally, the effect of sample type (serum vs. plasma) was investigated. All values for Clus and MCP-1 were outside the assay's measurable range. Intra- and inter-assay precision were acceptable for NGAL (CVs 8.8% and 13.2%, respectively). Regression analysis of LUD and S-R indicated good linearity for CysC and NGAL. Hemolysis did not affect measurement of any biomarker. Measured concentrations of CysC (p = 0.018) and NGAL (p = 0.015) were significantly lower in sodium citrate plasma compared to serum. We conclude that this magnetic bead-based assay is precise and accurate for NGAL measurement in canine serum. Inappropriate standards for MCP-1 and Clus, and poor accuracy for KIM-1 measurement, suggest that this assay cannot reliably quantify those biomarkers in canine blood. Measurements of CysC in canine blood using this assay must be interpreted with caution given inter-assay imprecision.

Animal Models and Renal Biomarkers of Diabetic Nephropathy

Diabetes mellitus (DM) is the first cause of end stage chronic kidney disease (CKD). Animal models of the disease can shed light on the pathogenesis of the diabetic nephropathy (DN) and novel and earlier biomarkers of the condition may help to improve diagnosis and prognosis. This review summarizes the most important features of animal models used in the study of DN and updates the most recent progress in biomarker research.

Urinary neutrophil gelatinase-associated lipocalin as an early biomarker for acute kidney injury in dogs

Neutrophil gelatinase-associated lipocalin (NGAL) is used as an early biomarker of renal injury in people. In dogs, increases in urinary NGAL (uNGAL) precede increases in serum creatinine (sCr) in experimental and clinical evaluations of acute kidney injury (AKI) and chronic kidney disease. This study compared uNGAL in two subsets of dogs with AKI and their respective controls. One set included dogs with snake-envenomation at risk for or presenting with International Renal Interest Society (IRIS) grade I AKI; the other group included dogs with AKI, where renal injury was the result of various causes, and IRIS grade was ≥II. Additionally, this study evaluated haemoglobin (Hb) interference during NGAL analysis in Hb spiked urine and plasma from healthy dogs. In both AKI groups, uNGAL was significantly higher than in matched healthy control dogs (P<0.01). Moreover, uNGAL was significantly higher in dogs with IRIS grade ≥II AKI than in dogs at risk of IRIS grade I AKI (P=0.04). In dogs at risk of IRIS grade I AKI, there were no significant differences in uNGAL and uNGAL/uCr between dogs bitten by cytotoxic or neurotoxic snakes (P=0.44). Additionally, Hb did not interfere with the canine NGAL immunoassay. In conclusion, this study confirms the value of uNGAL as a biomarker for early renal damage: uNGAL was significantly increased in dogs with snake-envenomation at risk for or presenting with IRIS grade I AKI, which could be left undiagnosed if evaluated with the traditional renal biomarker sCr. In addition, Hb did not interfere with NGAL measurement in dogs.

Measurements of echocardiographic indices and biomarkers of kidney injury in dogs with chronic kidney disease

Pathophysiological cardiac and renal interactions are termed cardiovascular-renal disorder (CvRD). Cardiovascular disease/dysfunction secondary to kidney disease (CvRD_K), is a leading cause of death in human chronic kidney disease (CKD) patients. The presence and clinical impact of CvRD_K in dogs with CKD is unknown. We hypothesized that echocardiographic measurements, and cardiac and renal biomarkers, will be altered in dogs with CKD and associated with survival. Eleven dogs with CKD (n = 6 IRIS stage 2, n = 5 IRIS stage 3) and without primary cardiac disease, plus 12 healthy age-matched control dogs, were recruited to this prospective observational study. Dogs underwent standard echocardiography, glomerular filtration rate (GFR) estimation by iohexol clearance, and measurement of plasma cardiac troponin I and N-terminal pro-B-type natriuretic peptide (NT-proBNP), plasma and urinary cystatin B, and urinary clusterin and neutrophil gelatinase-associated lipocalin (NGAL). Values were compared between groups, and their association with all-cause mortality explored. Dogs with CKD had significantly lower GFR and higher NT-proBNP, urinary cystatin B, clusterin, and NGAL, compared to controls (P < 0.05). Echocardiographic measurements were similar between dogs with CKD and controls. Median follow-up time was 666 days, during which six dogs with CKD died. Risk of death was associated with increasing age, serum total protein, and normalized left ventricular posterior wall thickness (LVPWDN) and decreasing bodyweight and packed cell volume. Although baseline differences in echocardiographic measurements were not evident between dogs with moderate CKD and controls, the presence of CvRD_K was suggested by the association between LVPWDN and survival.

Investigation of interference from synthetic colloids on the performance of a canine neutrophil gelatinase-associated lipocalin immunoassay

BACKGROUND

Synthetic colloid solutions, administered by rapid infusion to volume-depleted dogs, might be present in high concentrations in subsequent urine samples. The potential for these solutions to affect the performance of ELISA measurements due to sample matrix effects when studying kidney injury biomarkers requires investigation.

OBJECTIVE

We aimed to investigate two different synthetic colloid solutions, 4% succinylated bovine gelatin (GEL) and 6% hydroxyethyl starch (HES), for potential interferences with a commercially available canine neutrophil gelatinase-associated lipocalin (NGAL) ELISA.

METHODS

Assay interference was assessed by measuring the linearity of NGAL concentrations measured using a canine NGAL ELISA after serial dilution of a canine pooled urine sample with an assay diluent, GEL, or HES.

RESULTS

NGAL recovery from urine specimens containing up to 75% HES and up to 62.5% GEL was within acceptable limits (80%-120%). NGAL recovery from the urine specimen containing 75% GEL was poor (76%). Linear regression analysis demonstrated excellent linearity under dilution when a canine urine sample was diluted with the assay diluent, GEL, or HES.

CONCLUSIONS

The presence of large amounts (>62.5%) of GEL in canine urine samples could cause negative interference in the performance of the NGAL ELISA investigated.

Translational Safety Biomarkers of Kidney Injury

Acute kidney injury continues to be a common problem and there continues to be a medical need for sensitive translational biomarkers for clinical monitoring. The past decade has yielded unprecedented progress in fundamental research into novel kidney biomarker evaluation and the mechanistic understanding of kidney injury; as such, these novel biomarkers increasingly are being used in preclinical drug development and in early clinical trials of drug candidates on a case-by-case basis, as well as in medical and veterinary practice. With the recent successful clinical qualification of a subset of novel accessible biomarker candidates for use in early phase clinical trials, continued clinical evaluation may enable expanded regulatory qualification for more generalized clinical use. This review provides a comprehensive overview about the discovery and development of kidney safety biomarkers with a focus on current progress in nonclinical research, progress toward translation to the clinic, and perspectives on future opportunities.

Urinary neutrophil gelatinase-associated lipocalin in dogs with stable or progressive kidney disease

BACKGROUND

Active kidney injury may play a role in chronic kidney disease (CKD) progression in dogs. Neutrophil gelatinase-associated lipocalin (NGAL), a novel tubular kidney injury biomarker, may help differentiate progressive CKD from stable CKD in dogs.

OBJECTIVES

To determine if urinary NGAL : creatinine ratio (UNCR) differentiates stable and progressive CKD in dogs. We hypothesized that UNCR would be higher in dogs with progressive CKD versus stable CKD.

ANIMALS

Twenty-one healthy control dogs, 22 with prerenal azotemia, 19 with stable CKD, 30 with progressive CKD, and 27 with acute kidney injury (AKI).

METHODS

Prospective study. Azotemic (serum creatinine concentration >1.6 mg/dL) dogs or nonazotemic AKI dogs were enrolled and classified into 4 groups: (1) prerenal azotemia, (2) stable CKD, (3) progressive CKD, and (4) AKI. Urinary NGAL was measured by ELISA and UNCR compared among groups. Urine protein : creatinine ratio (UPC) in dogs with stable and progressive CKD was compared to UNCR for differentiating CKD groups.

RESULTS

UNCR was significantly higher in dogs with progressive CKD than stable CKD. UNCR of the prerenal azotemia group was significantly lower than that of the progressive CKD and AKI groups. No significant difference was found in UNCR between stable CKD and prerenal azotemia groups. ROC curve analysis of UNCR for differentiating progressive CKD from stable CKD resulted in an AUC of 0.816 (95% confidence interval [CI], 0.673-0.959), greater than that of UPC (0.696; 95% CI, 0.529-0.863).

CONCLUSIONS AND CLINICAL IMPORTANCE

Urinary NGAL could be helpful to predict the risk of progression in dogs with CKD.

Assessment of acute kidney injury in canine parvovirus infection: Comparison of kidney injury biomarkers with routine renal functional parameters

Dogs with naturally occurring canine parvovirus (CPV) infection are at risk of developing acute kidney injury (AKI) due to several factors, including severe dehydration, hypotension and sepsis. Serum creatinine (sCr) and serum urea are insensitive markers for the assessment of early kidney injury. Therefore, the aim of this study was to investigate potential kidney injury in dogs with CPV infection using both routine renal functional parameters and several kidney injury biomarkers. Twenty-two dogs with CPV infection were prospectively enrolled and compared with eight clinically healthy control dogs. Urinary immunoglobulin G (uIgG) and C-reactive protein (uCRP) were measured to document glomerular injury, whereas urinary retinol-binding protein (uRBP) and neutrophil gelatinase-associated lipocalin (uNGAL) served as markers for tubular injury. These biomarkers were compared to routine renal functional parameters, including sCr, serum urea, urinary protein:creatinine ratio (UPC) and urine specific gravity (USG). Dogs with CPV infection had significantly higher concentrations of uIgG, uCRP, uRBP and uNGAL compared to healthy dogs. In contrast, sCr was significantly lower in dogs with CPV infection compared to controls, while serum urea was not significantly different. UPC and USG were both significantly higher in CPV-infected dogs. This study demonstrated that dogs with CPV infection had evidence of AKI, which remained undetected by the routine functional markers sCr and serum urea, but was revealed by UPC, uIgG, uCRP, uRBP and uNGAL. These results emphasize the added value of novel urinary kidney injury biomarkers to detect canine patients at risk of developing AKI.

Plasma Symmetric Dimethylarginine Concentration in Dogs with Acute Kidney Injury and Chronic Kidney Disease

Background

Symmetric dimethylarginine (SDMA) is considered a biomarker for early detection of renal dysfunction in human patients with acute kidney injury (AKI). At present, no studies exist analyzing the relevance of SDMA in dogs with AKI.

Hypothesis/objectives

SDMA would correctly identify dogs with renal disease but would not be able to differentiate between AKI and CKD.

Animals

Eighteen healthy control dogs, 48 dogs with AKI, and 29 dogs with CKD.

Methods

Prospective study. Dogs with kidney disease were categorized as having AKI or CKD according to the history, clinical signs, laboratory findings, and results of diagnostic imaging. Plasma SDMA concentration was measured by IDEXX Laboratories. SDMA/creatinine ratio was calculated in dogs with AKI or CKD.

Results

Median SDMA concentrations were 8.5 μg/dL (6–12 μg/dL), 39.5 μg/dL (8–>100 μg/dL), and 35 μg/dL (12–>100 μg/dL), in healthy, AKI, and CKD, respectively. SDMA concentrations were significantly higher in dogs with AKI (P < .0001) or CKD (P < .0001) in comparison with healthy dogs. Median SDMA/creatinine ratio in dogs with AKI and CKD was 6.5 (1.7–20.9) and 10 (2.4–33.9) (P = .0004), respectively. Although there was overlap of the SDMA/creatinine ratio in dogs with AKI or CKD, it was significantly higher in dogs with CKD compared to dogs with AKI (P = .0004).

Conclusions and Clinical Importance

In this population, SDMA was suitable for identifying dogs affected by AKI or CKD, but could not differentiate between them.

Neutrophil Gelatinase-Associated Lipocalin in Cats with Naturally Occurring Chronic Kidney Disease

Background

Neutrophil gelatinase‐associated lipocalin (NGAL) is a biomarker for the early prediction of renal damage and the progression of chronic kidney disease (CKD) in humans and dogs.

Hypothesis

Neutrophil gelatinase‐associated lipocalin also may play a role in the progression of CKD in cats.

Animals

Eighty CKD and 18 control cats.

Methods

Cats were categorized into different stages according to the International Renal Interest Society (IRIS) staging system. Urine and plasma samples were collected and tested for NGAL concentrations using an in‐house sandwich ELISA system and urinary NGAL (uNGAL)‐to‐creatinine ratio (UNCR) was determined. Cats in which serum creatinine concentration increased by >0.5 mg/dL from baseline within 30 days were defined as exhibiting progression.

Results

The urinary NGAL and UNCR of CKD cats were significantly higher than those of healthy cats (P < .05) and were highly correlated with serum creatinine concentration. The area under the receiver operating characteristic curve (AUROC) for uNGAL, when predicting the progression of CKD, was 0.71 and the best cutoff value was 2.06 ng/mL with a sensitivity of 76.9% and a specificity of 75%. The AUROC for UNCR when predicting the progression of CKD was 0.79 and the best cutoff value was 4.08 × 10⁻⁶ with a sensitivity of 76.9% and specificity of 79.2%. Cats with UNCR values higher than their cutoffs experienced significantly faster deterioration with a median of 19 days.

Conclusions

Both urinary NGAL and UNCR are useful markers for the prediction of CKD progression in cats.

A mixed grape and blueberry extract is safe for dogs to consume

Background

Grape and blueberry extracts are known to protect against age-related cognitive decline. However, beneficial effects achieved by mixing grape and blueberry extracts have yet to be evaluated in dogs, or their bioavailability assessed. Of concern to us were cases of acute renal failure in dogs, after their ingestion of grapes or raisins. The European Pet Food Industry Federation (2013) considers only the grape or raisin itself to be potentially dangerous; grape-seed extracts per-se, are not considered to be a threat. Our aim was therefore to evaluate the renal and hepatic safety, and measure plasma derivatives of a polyphenol-rich extract from grape and blueberry (PEGB; from the Neurophenols Consortium) in dogs. Polyphenol expression was analyzed by UHPLC-MS/MS over 8 hours, for dogs given PEGB at 4 mg/kg. Safety was evaluated using four groups of 6 dogs. These groups received capsules containing no PEGB (control), or PEGB at 4, 20, or 40 mg/kg BW/d, for 24 weeks. Blood and urine samples were taken the week prior to study commencement, then at the end of the 24-wk study period. Routine markers of renal and liver damage, including creatinine (Creat), blood urea nitrogen, albumin, minerals, alkaline phosphatase (ALP), and alanine transaminase (ALT) were measured. Biomarkers for early renal damage were also evaluated in plasma (cystatin C (CysC), and neutrophil gelatinase-associated lipocalin (NGAL)), and urine (CysC, clusterin (Clu), and NGAL). Ratios of urinary biomarkers to Creat were calculated, and compared with acceptable maximal values obtained for healthy dogs, as reported in the literature.

Results

While several PEGB-specific polyphenols and metabolites were detected in dog plasma, at the end of the PEGB consumption period, our biomarker analyses presented no evidence of either renal or liver damage (Creat, BUN, ionogram, albumin and ALT, ALP). Similarly, no indication of early renal damage could be detected. Plasma CysC, urinary CysC/Creat, Clu/Creat, and NGAL/Creat ratios were all beneath reported benchmarked maximums, with no evidence of PEGB toxicity.

Conclusions

Long-term consumption of a pet specific blend of a polyphenol-rich extract from grape and blueberry (PEGB; from the Neurophenols Consortium), was not associated with renal or hepatic injury, and can therefore be considered safe.

Advances in the evaluation of canine renal disease

Many recent advances in the evaluation of dogs with kidney disease have improved our diagnostic algorithms and have impacted our therapeutic strategies. Non-invasive techniques, such as urinary and serologic biomarker evaluation, can help a clinician diagnose and treat a patient that cannot undergo a renal biopsy for clinical or financial reasons. Some biomarkers might help localize the affected structure (glomerulus vs. tubule) and indicate the type or severity of injury present. Although more research is needed, studies indicate that some biomarkers (e.g. urine protein to creatinine ratio and urinary immunoglobulins) can be useful in predicting adverse outcomes. Importantly, the sensitivity and specificity of biomarkers for renal injury should be established and clinicians need to understand the limitations of these assays. If a renal biopsy is performed, then it should be evaluated by a specialty diagnostic service with expertise in nephropathology. A panel of special stains, immunofluorescence for the detection of immunoglobulins and complement factors, and transmission electron microscopy can be routinely employed in cases of glomerular disease. These advanced diagnostics can be used to detect immune deposits in order to definitively diagnose immune complex mediated glomerular disease. Integrating the results of biomarker assays and comprehensive renal biopsy evaluation, the clinician can make informed therapeutic decisions, such as whether or not to immunosuppress a patient.

Correlation of Urine and Serum Biomarkers with Renal Damage and Survival in Dogs with Naturally Occurring Proteinuric Chronic Kidney Disease

Background

Urine protein loss is common in dogs with chronic kidney disease (CKD).

Hypothesis/Objectives

To evaluate new biomarkers of glomerular and tubulointerstitial (TI) damage compared with histology and as survival indicators in dogs with naturally occurring, proteinuric CKD.

Animals

One hunderd and eighty dogs with naturally occurring kidney disease.

Methods

Retrospective study using urine, serum, and renal biopsies from dogs with kidney disease, 91% of which had proteinuric CKD. Biomarkers were evaluated and correlated with pathologic renal damage, and significant associations, sensitivities, and specificities of biomarkers for renal disease type were determined.

Results

Fractional excretions of immunogloblin M (IgM_FE) and immunoglobulin G (IgG_FE) correlated most strongly with glomerular damage based on light microscopy (r = 0.58 and 0.56, respectively; P < .01). Serum creatinine (SCr) correlated most strongly with TI damage (r = 0.70, P < .01). Urine IgM/creatinine and urine NAG/creatinine had the highest sensitivity (75%) and specificity (78%) for detection of immune complex‐mediated glomerulonephritis. Although individually most biomarkers were significantly associated with decreased survival time (P < .05), in a multivariate analysis, SCr, IgM_FE, and glomerular damage based on transmission electron microscopy (TEM) were the only biomarkers significantly associated with survival time (SCr: P = .001; IgM_FE: P = .008; TEM: P = .017).

Conclusions and Clinical Importance

Novel urine biomarkers and FEs are useful for detection of glomerular and TI damage in dogs with proteinuric CKD and might predict specific disease types and survival.

Neutrophil Gelatinase-Associated Lipocalin in Dogs With Sepsis Undergoing Emergency Laparotomy: A Prospective Case-Control Study

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is an early indicator of acute kidney injury (AKI) in dogs and its use has not been evaluated in dogs with sepsis.

ANIMALS

Fifteen dogs with sepsis requiring laparotomy (study dogs) and 10 dogs undergoing surgery for intervertebral disc disease (control dogs).

OBJECTIVE

To determine whether NGAL increases in dogs with sepsis undergoing emergency laparotomy and whether it is correlated with development of AKI and survival.

METHODS

Longitudinal study conducted at a referral teaching hospital. Serum neutrophil gelatinase-associated lipocalin (sNGAL), urinary NGAL normalized to urinary creatinine concentration (UNCR), and serum creatinine concentration were measured at 4 time points (admission, after anesthesia, and 24 and 48 hours postsurgery). Development of AKI (increase in serum creatinine concentration of 0.3 mg/dL) and in-hospital mortality were recorded. Linear mixed-model analysis was employed to assess differences between groups over time. Mann-Whitney U-test was performed for comparison of continuous variables between groups and Chi square or Fisher's exact tests were used to assess correlation between discrete data.

RESULTS

Serum NGAL and UNCR were significantly higher in study dogs across all time points (P = .007 and P < .001, respectively) compared with controls. Urinary NGAL normalized to creatinine in the study group was not significantly different between survivors (n = 12) and nonsurvivors (n = 3). Dogs that received hydroxyethyl starch had significantly higher UNCR across all time points (P = .04) than those that did not.

DISCUSSION-CONCLUSION

Serum neutrophil gelatinase-associated lipocalin and UNCR are increased in dogs with sepsis requiring emergency laparotomy. Additional studies are needed to evaluate its role as a marker of AKI in this population.

Investigations of renal function using the level of neutrophil gelatinase-associated lipocalin associated with single-dose of cisplatin during chemotherapy

Background

Neutrophil gelatinase-associated lipocalin (NGAL) is known as a primary indicator of acute and chronic renal and can be effective in chronic kidney injury (CKI) with kidney tumors cisplatin (CP) chemotherapy. The aim of this study was to evaluate serum and urinary biomarker including NGAL (sNGAL and uNGAL) in canine with solid renal tumors who suffered from cisplatin after short and long-term chemotherapy.

Methods

In this study, in treatment and control groups, canine (n = 10 and n = 5) were administered cisplatin at 1.2 mg/kg/day (i.v.) for five consecutive days with CKI and without CKI, respectively. Serum and urine NGAL levels (ng/mL) were evaluated at 0, 1, 5, 9, 13, 17, 21, 25 and 29 days after drug injection versus baseline in treated and control groups.

Results

Canine in treatment group had shown symptoms of toxicity of cisplatin. The results indicated the higher concentrations of serum, sNGAL and uNGAL (P = 0.024; P = 0.011) compared with control group (P = 0.701, P = 0.612), (Table 2, Figs. 1 and 2). Indeed, our results showed that canine with CKI were associated with higher levels of sNGAL and uNGAL compared with control group without CKI. Moreover, the highest level of uNGAL was seen in comparison with sNGAL, after a high dose (1.2 mg/kg) administration of CP.

Conclusion

Our data suggested that U-NGAL may be useful for monitoring of renal injury in CKI patients that exposed with cisplatin. Furthermore, a primary elevate in urinary NGAL expulsion may help in identifying cases at danger of cisplatin-induced CKI that might profit from innovative remedies to prevent cisplatin nephrotoxicity.

Short communication: Relationship between urinary neutrophil gelatinase-associated lipocalin and noninfectious pyuria in dogs

Neutrophil gelatinase-associated lipocalin (NGAL) is a neutrophil-derived protein whose concentration increases in plasma and urine with ongoing renal damage. Urinary leucocytes can be a potential source of urinary NGAL. The aim of this study is to investigate the effects of urinary neutrophil count and other urinary parameters on urinary NGAL values in urine with negative culture. Urinalysis, urine culture, and determination of urinary NGAL were performed on 33 clinically healthy nonproteinuric dogs with negative urinoculture. The median uNGAL concentration in dogs in this study population was 9.74 ng/mL (IQR 1.93–25.43 ng/mL). In samples with WBCs > 5 hpf (mean 15.9, 6–50 leucocytes/hpf), median uNGAL value was significantly higher than that in samples with WBCs < 5 hpf (mean 0.9, 0–3 leucocytes/hpf), (4.96 pg/mL (0.29–11.34) and 23.65 pg/mL (20.04–29.80), resp.; P = 0.0053). The severity of urinary pyuria and the UPC value were correlated with uNGAL concentration. The results of our study show that urinary NGAL concentration is correlated with WBCs number in urinary sediment of dogs with negative urinoculture. The present study suggests that noninfectious pyuria is significantly correlated with urinary NGAL values and might influence uNGAL values.