Serum Liver-type Fatty Acid-binding Protein Research Articles

Liver-type fatty acid-binding protein and neutrophil gelatinase-associated lipocalin in cats with chronic kidney disease and hyperthyroidism.

BackgroundLiver‐type fatty acid‐binding protein (L‐FABP) and neutrophil gelatinase‐associated lipocalin (NGAL) are candidate biomarkers for the detection of early chronic kidney disease (CKD) in cats.ObjectiveTo evaluate urinary and serum L‐FABP and NGAL concentrations in CKD cats and in hyperthyroid cats before and after radioiodine (131I) treatment.AnimalsNine CKD cats, 45 healthy cats and hyperthyroid cats at 3 time points including before (T0, n = 49), 1 month (T1, n = 49), and 11 to 29 months after (T2, n = 26) 131I treatment.MethodsCross‐sectional and longitudinal study. Serum L‐FABP (sL‐FABP), serum NGAL (sNGAL), urinary L‐FABP (uL‐FABP), and urinary NGAL (uNGAL) were compared between the 3 groups and between hyperthyroid cats before and after treatment. Data are reported as median (min‐max).ResultsCKD cats had significantly higher sL‐FABP (13.50 [3.40‐75.60] ng/ml) and uL‐FABP/Cr (4.90 [0.97‐2139.44] µg/g) than healthy cats (4.25 [1.34‐23.25] ng/ml; P = .01 and 0.46 [0.18‐9.13] µg/g; P < .001, respectively). Hyperthyroid cats at T0 had significantly higher uL‐FABP/Cr (0.94 [0.15‐896.00] µg/g) than healthy cats (P < .001), thereafter uL‐FABP/Cr significantly decreased at T2 (0.54 [0.10‐76.41] µg/g, P = .002). For the detection of CKD, uL‐FABP/Cr had 100% (95% confidence interval [CI], 66.4‐100.0) sensitivity and 93.2% (95% CI, 81.3‐98.6) specificity. There were no significant differences in sNGAL and uNGAL/Cr between the 3 groups.Conclusions and Clinical ImportanceL‐FABP, but not NGAL, is a potential biomarker for the detection of early CKD in cats. Utility of uL‐FABP to predict azotemia after treatment in hyperthyroid cats remains unknown.

Assessment of Body Fat Distribution and Serum Liver-Type Fatty Acid-Binding Protein (L-FABP) and Neutrophil Gelatinase-Associated Lipocalin (NGAL): Potential Noninvasive Markers for Non-Alcoholic Fatty Liver Disease

Previous studies reported significant positive correlations between liver-type fatty acid-binding protein (L-FABP) and neutrophil gelatinase-associated lipocalin (NGAL) marks with obesity. L-FABP is a cytosolic protein that modulates fatty acid metabolism, and NGALs a biomarker of inflammation and infection. Our objective was to investigate levels of NGAL and L-FABP in the serum of women with non-alcoholic fatty liver disease (NAFLD) and determine their diagnostic values. The subjects of this study comprised 150 women: 75 with NAFLD and 75 healthy control. Serum L-FABP and NGAL levels were determined by a sandwich enzyme-linked immunosorbent assay. Serum lipids were measured by enzymatic colorimetric methods. The abdominal fat was assessed by waist circumference (WC) and defined as WC ≥ 88 cm2. Visceral fat thicknesses (VFT) were investigated ultrasonographically. Anthropometry and systolic and diastolic blood pressure (BP) were taken. Body composition was measured by Tanita Body Composition Analyzer (SC-330). NAFLD patients were diagnosed with elevated transaminases and with steatosis by ultrasonography. Serum NGAL, L-FABP, WC, triglycerides, LDL-C, VFT, systolic and diastolic BP were significantly higher in NAFLD than controls. Significant positive correlations were observed between serum NGAL and L-FABP and adiposity parameters (WC and VFT), body fat% and blood pressure, AST and ALT levels. NGAL and L-FABP might be used as novel biomarkers for early detection of NAFLD and metabolic abnormalities. Elevated NGAL and L-FABP were associated with adiposity parameters, serum lipids, blood pressure, AST and ALT levels, which suggest the relationship of body fat distribution and lipid metabolism in NAFLD. Investigation of the two biomarkers and body fat content could serve as novel noninvasive diagnostic markers for NAFLD, propose a new perception for NAFLD's therapeutic interference, and might be useful biomarkers for detecting the preclinical stage of the metabolic abnormalities in the general population.

Predictive value of novel biomarkers for chronic kidney disease among workers occupationally exposed to silica.

There is a pressing need to find reliable biomarkers for the early diagnosis of silica-induced nephropathy. Abundant genes are upregulated in damaged kidneys with subsequent protein products appearing in the urine. Liver-type fatty acid-binding protein (L-FABP) and kidney injury molecule-1 (KIM-1) are among the most promising. Our objective was to study the importance of L-FABP and KIM-1 genes and their urinary proteins in the early detection of silica-induced renal injury, as compared with other conventional biomarkers. A cross-sectional study was conducted among 90 pottery workers occupationally exposed to silica, as compared to 90 controls. A full history taking and complete clinical examination were performed. Levels of serum creatinine, liver enzymes, urinary silicon, KIM-1, and L-FABP gene expression and protein products were measured. Estimated glomerular filtration rate (eGFR) was calculated, and abdominal ultrasound was performed. The results showed that the silica-exposed group had a statistically significant increase in serum creatinine and urinary silica, as well as a significant decrease in eGFR. Additionally, a significant increase in KIM-1 and L-FABP gene expression, associated with a significant increase in their urinary protein, was found among the exposed group. A positive correlation between urinary silica level and L-FABP gene expression was also found. A receiver operating characteristic curve analysis for L-FABP and KIM-1 gene as predictors for silica-induced nephropathy showed that L-FABP gene and protein specificity were greater than the KIM-1 gene and protein. Taken together, these findings suggest that the L-FABP gene and its protein product may be used as early indicators for renal injury among silica exposed workers.

The Role of Elevated Liver-Type Fatty Acid-Binding Proteins in Liver Diseases.

Liver-type fatty acid-binding protein (L-FABP) is mainly expressed in the liver as well as the proximal tubular epithelial cells in the kidney. In general, the proteins and enzymes existing within the hepatocytes have the potential to become biomarkers, for instance alanine aminotransferase, which reflects hepatocellular damage. However, due to reduced hepatocellular function in late stage of chronic liver diseases (e.g. cirrhosis), proteins and enzymes relating to hepatocellular damage are not always accurate measures of disease progression. Recently, several publications have demonstrated elevated serum L-FABP levels during the progression of human liver diseases, including hepatocellular carcinoma (HCC), and were a prognostic factor for survival in acute and chronic liver disease patients. However, the study regarding serum L-FABP levels and hepatic L-FABP expression in liver diseases is not sufficient to understand the molecular mechanism of L-FABP during the progression of these disease states. In this review, we focus on the use of serum and/or hepatic L-FABP expression as a biomarker in human liver diseases, including mechanistic potential in HCC.

Liver-type fatty acid-binding protein as an early biomarker of nephropathy in type-2 diabetes

Objective The aim of this study was to evaluate serum liver-type fatty acid-binding protein (L-FABP) level as an early biomarker of diabetic nephropathy (DN) in type-2 diabetic patients. Background Tubular hypoxia upregulates the expression of the L-FABP gene in the kidney and increases the urinary excretion of L-FABP from the proximal tubules. Thus, in early stage DN, it is possible that chronic hypoxia could have induced an increase in urinary excretion of L-FABP. Patients and methods This was a case–control study that included ninety patients with type-2 diabetes mellitus selected from Military Hospital and Menoufia University Hospital who were divided into three groups: the first group comprised diabetic patients with microalbuminuria, second group comprised diabetic patients with macroalbuminuria, and the third group comprised nondiabetic patients with chronic kidney disease. A fourth group of healthy participants served as the control group. Results We found a significant increase of urinary L-FABP level in microalbuminuric diabetic patients and a significant positive correlation between urinary L-FABP level and the duration of diabetes. By using receiver operating characteristics curve analysis, calcium level at a cutoff point (≤8.3) discriminated patients with microalbuminuria from patients with macroalbuminuria, with excellent accuracy, sensitivity of 95% and specificity of 96%. Conclusion We conclude that the L-FABP level could be a suitable biomarker for early detection with good value to detect DN in patients with type-2 diabetes.

Assessment of the Diagnostic Validities of Serum NGAL, KIM-1, and L-FABP in Patients With Chronic Kidney Disease

Introduction: Chronic kidney disease (CKD) is one of the most threatening and important disorders worldwide in both industrial and developing nations. In addition, neutrophil gelatinase-associated lipocalin (NGAL), liver-type fatty acid-binding protein (L-FABP), and kidney injury molecule-1 (KIM-1) are three factors suggested as diagnostic and prognostic biomarkers in CKDs. Considering the lack of enough efficiency of the creatinine in the prognosis of the CKD, the present study aimed to assess the relationship between these three factors and CKD occurrence and determine if they could be considered valid biomarkers in this regard. Materials and Methods: The present case-control study was designed enrolling 42 patients with confirmed CKD referring to the Imam Khomeini hospital of Kangan. The participants were 42 years old and gender-matched healthy counterparts. Blood samples were obtained, and then NGAL, KIM-1, and L-FABP were determined by the enzyme-linked immunosorbent assay using commercial kits (Bioassay Technology Laboratory). Finally, the serum creatinine was detected by applying Jaffe’s method. Results: Based on the results, significant differences were found in the serum levels of all four factors between CKD patients and the control group. More precisely, the serum levels of NGAL (P &lt; 0.0001, specificity: 87.6%, sensitivity: 79.3%, and the area under the curve, AUC: 0.89), L-FABP (P &lt; 0.0001, specificity: 83.3%, sensitivity: 78.3%, and AUC: 0.86), KIM-1 (P &lt; 0.0001, specificity: 85.7%, sensitivity: 78.6%, and AUC: 0.88), and creatinine (P &lt; 0.0001) were significantly higher in individuals with CKDs in comparison with controls. Eventually, the serum levels of NGAL, L-FABP, and KIM-1 were significantly correlated with each other in both patient and control groups (P &lt; 0.0001). Conclusion: In general, NGAL, L-FABP, KIM-1, and creatinine could be used as independent biomarkers for the diagnosis of CKD. Moreover, the measurement of NGAL, L-FABP, and KIM-1 altogether could be a valid assessment for the diagnosis of CKD.

Renal expression and urinary excretion of liver-type fatty acid-binding protein in cats with renal disease.

BackgroundLiver‐type fatty acid‐binding protein (L‐FABP) is a biomarker for early detection of renal disease in humans. Liver‐type fatty acid‐binding protein is cytotoxic oxidation products secreted from proximal tubules under ischemia and oxidative stress.ObjectiveTo examine renal expression and quantify urinary excretion of L‐FABP in catswith renal disease.AnimalsOne hundred and thirty‐four client‐owned cats including 34 cats with serum creatinine (sCre) values >1.6 mg/dL and 10 other cats that died in clinics.MethodsTissue expressions of L‐FABP were examined by reverse transcription polymerase chain reaction and Western blotting. Urinary L‐FABP (uL‐FABP) and serum L‐FABP (sL‐FABP) levels were determined by enzyme‐linked immunosorbent assay. Anti‐liver‐type fatty acid‐binding protein antibody immunostained renal sections.ResultsFeline kidneys express L‐FABP. Strong L‐FABP signals were observed in the lumens of proximal tubular cells in 5 cats with high uL‐FABP excretion, but not in 5 cats with low uL‐FABP excretion. In 9 normal cats, uL‐FABP index was <1.2 μg/g urinary creatinine (uCre). High uL‐FABP indexes (>10.0 μg/g uCre) were detected in 7 of 100 cats with low sCre (<1.6 mg/dL) and 18 of 44 cats with high sCre (>1.6 mg/dL). There was a weak correlation between L‐FABP index and sCre, serum symmetric dimethylarginine (SDMA), or blood urea nitrogen (BUN), and these correlation coefficients were increased by analyzing only data of cats with sCre >1.6 mg/dL. There was a weak correlation between u L‐FABP index and sL‐FABP in all tested cats, but not in cats with high sCre.Conclusions and Clinical ImportanceThis study demonstrates correlations between L‐FABP and current renal biomarkers for chronic kidney disease in cats, such as sCre and SDMA. Liver‐type fatty acid‐binding protein may be a potential biomarker to predict early pathophysiological events in feline kidneys.

Evaluation of liver-type fatty acid binding protein (L-FABP) and interleukin 6 in children with renal cysts.

Renal cysts, according to their etiology, can be divided into genetic and acquired cysts. This is of great importance in patients with cystic kidney disease with a possible poor prognosis to identify markers of early kidney damage. The objective of this study was to evaluate the concentration of serum and urine liver-type fatty acid binding protein (L-FABP) and interleukin 6 (IL-6) in children with kidney cysts. The study was conducted on a group of 39 children with kidney cysts including 20 subjects with autosomal dominant polycystic kidney disease (ADPKD). Serum and urine L-FABP concentration in children with renal cysts was significantly higher compared to the controls, regardless of the underlying type of cystic degeneration, number of cysts and gender. Also, serum and urinary IL-6 concentration was significantly higher than in the control group. There was a significant negative correlation between serum L-FABP concentration and standard deviation score (SDS) for diastolic blood pressure (DBP). A significant negative correlation was found between serum IL-6 concentration and systolic blood pressure (SBP), DBP and mean arterial pressure (MAP) values as well as SDS for SBP and DBP. In addition, a significant positive correlation was found between urinary IL-6 concentration and estimated glomerular filtration rate (eGFR). Higher concentration of L-FABP in serum and urine in children with kidney cysts indicates the early damage to the renal parenchyma, detectable before the onset of hypertension and other organ damage. Significantly higher serum and urinary IL-6 levels in children with cystic kidney disease compared to healthy children may suggest the role of this cytokine in chronic kidney disease development.

Serum Liver-Type Fatty Acid-Binding Protein Is a Possible Prognostic Factor in Human Chronic Liver Diseases From Chronic Hepatitis to Liver Cirrhosis and Hepatocellular Carcinoma.

Liver‐type fatty acid–binding protein (L‐FABP) is a key regulator of fatty acid metabolism, but serum L‐FABP levels are not well investigated in chronic liver diseases. We aimed to elucidate the prognostic ability of serum L‐FABP in human chronic liver diseases and compare it with the albumin‐bilirubin (ALBI) score. In 242 chronic liver disease patients, including chronic hepatitis (CH, n = 100), liver cirrhosis (LC, n = 142), and presence of hepatocellular carcinoma (HCC, n = 144), serum L‐FABP levels were correlated with liver function (P < 0.0001), increased in LC compared with CH (P < 0.01), and correlated to ALBI score (P < 0.0001). Serum L‐FABP levels were increased in the presence of HCC (P < 0.0001), correlating to des‐gamma‐carboxy prothrombin (P < 0.0001), alpha‐fetoprotein (P = 0.009), and Barcelona‐Clinic Liver Cancer stage. In the average follow‐up period of 1,054 days, serum L‐FABP levels were elevated (P < 0.0001) in patients who eventually died. The area under the curve (AUC) of serum L‐FABP (0.764) was higher than that of ALB (0.709), and the patients with serum L‐FABP ≤ 6.8 ng/mL had significantly longer rates of survival (P < 0.0001). Serum L‐FABP (hazard ratio [HR] 4.0; P < 0.001), HCC (HR 3.7; P = 0.001), ALBI score (HR 2.7; P < 0.001), and age (HR 1.0; P = 0.049) were independent predictors of survival. In the subgroup who maintained liver function, the AUC of serum L‐FABP (0.751) was higher than that of ALB (0.643). In this subgroup, serum L‐FABP (HR 4.4; P = 0.002) and HCC (HR 13.9; P < 0.001) were independent predictors of survival. Conclusion: Serum L‐FABP is a possible predictor of survival in chronic liver diseases from CH to LC and HCC, including any subgroup that maintains liver function.

Urinary Liver-Type Fatty Acid-Binding Protein Level as a Predictive Biomarker of Acute Kidney Injury in Patients with Acute Decompensated Heart Failure

Background: There are no biological markers to predict the onset of acute kidney injury (AKI) in patients with acute decompensated heart failure (ADHF). Liver-type fatty acid-binding protein (L-FABP) levels are markedly upregulated in the proximal tubules after renal ischemia. We investigated whether urinary L-FABP is a suitable marker to predict AKI in ADHF patients. Methods: We examined 281 consecutive patients with ADHF. Serum creatinine (Cr) and L-FABP levels were measured at admission and 24 and 48 h after admission. Results: AKI developed in 104 patients (37%). Urinary L-FABP levels at admission were significantly higher in patients with AKI than in those without (33.0 vs. 5.2 μg/g Cr; p < 0.001). Multivariate analysis showed that baseline urinary L-FABP level was an independent predictor of AKI in ADHF patients (odds ratio 1.08, 95% confidence interval 1.05-1.12; p < 0.001). Receiver operating characteristic analysis showed that baseline urinary L-FABP level exhibited 94.2% sensitivity and 87.0% specificity at a cutoff value of 12.5 μg/g Cr. Conclusions: Urinary L-FABP level is useful for predicting the onset of AKI in patients with ADHF. The results of our study could help clinicians diagnose AKI in ADHF patients earlier, leading to possible improvements in the treatment of this group of patients.

Cytokine-like Activity of Liver Type Fatty Acid Binding Protein (L-FABP) Inducing Inflammatory Cytokine Interleukin-6.

It has been reported that fatty acid binding proteins (FABPs) do not act only as intracellular mediators of lipid responses but also have extracellular functions. This study aimed to investigate whether extracellular liver type (L)-FABP has a biological activity and to determined serum L-FABP levels in patients with end-stage renal disease (ESRD). We isolated L-FABP complementary deoxyribonucleic acid (cDNA) from the Huh7 human hepatocarcinoma cell line and expressed the recombinant L-FABP protein in Escherichia coli. A549 lung carcinoma and THP-1 monocytic cells were stimulated with the human recombinant L-FABP. Human whole blood cells were also treated with the human recombinant L-FABP or interleukin (IL)-1α. IL-6 levels were measured in cell culture supernatants using IL-6 enzyme-linked immunosorbent assay (ELISA). Human recombinant L-FABP induced IL-6 in a dose-dependent manner in A549, THP-1 cells, and whole blood cells. The blood samples of healthy volunteers and patients with ESRD were taken after an overnight fast. The serum levels of L-FABP in healthy volunteers and ESRD patients were quantified with L-FABP ELISA. The values of L-FABP in patients with ESRD were significantly lower than those in the control group. Our results demonstrated the biological activity of L-FABP in human cells suggesting L-FABP can be a mediator of inflammation.

Serum liver fatty acid binding protein shows good correlation with liver histology in NASH.

Simple, reproducible and non-invasive tests that can be used to determine the severity of non-alcoholic steatohepatitis (NASH) are needed. Liver-type fatty acid binding protein (L-FABP) plays a key role in the fatty acid metabolism of the liver. We aimed to determine whether serum L-FABP levels in patients with NASH were different from those in healthy controls, and if so, whether this was associated with the degree of fibrosis, steatosis and inflammatory activity. Forty-seven patients with histologically confirmed NASH and 41 healthy controls were included in the study. Serum L-FABP levels were measured in all participants. Mean L-FABP levels were significantly higher in patients with NASH compared to the control group (2703.19±1603.47 vs. 1684.58±860.19, p<0.001). Serum L-FABP levels showed a significant positive correlation with NAS score (p=0.03, r=0.312), the degree of fibrosis (p=0.02, r=0.324) and inflammation (p=0.03, r=0.312), BMI (p=0.05, r=0.303), serum ALT (p=0.01, r=0.28), AST (p=0.04, r=0.315), and triglyceride levels (p=0.03, r=0.328). Serum L-FABP levels are elevated in NASH and this elevation is positively correlated with the degree of fibrosis and inflammation. L-FABP levels may aid as a non-invasive marker in determining the severity of fibrosis and inflammation in patients with NASH.

Clinical value of NGAL, L-FABP and albuminuria in predicting GFR decline in type 2 diabetes mellitus patients.

ObjectivesNeutrophil gelatinase-associated lipocalin (NGAL) and liver-type fatty acid binding protein (L-FABP) are emerging as excellent biomarkers in the urine and plasma for the early prediction of acute and chronic kidney injury. The aims of this prospective study were to determine the role of albuminuria, and that of serum and urine levels of NGAL and L-FABP as predictors of a decline in the glomerular filtration rate (GFR) in patients with type 2 diabetes.MethodsA longitudinal cohort study with one hundred forty type 2 diabetic patients was conducted. Serum and urine levels of NGAL and L-FABP, and the urine albumin excretion rate were determined. The correlation between the kidney injury biomarkers and rate of GFR decline was analyzed.ResultsThe eGFR of study subjects decreased significantly as the study progressed (86.4±31.1 vs. 74.4±27.3 ml/min/1.73 m2, P<0.001), and the urine albumin excretion rate increased significantly (264.9±1060.3 vs. 557.7±2092.5 mg/day, P = 0.009). The baseline urine albumin excretion rate and serum L-FABP level were significantly correlated with baseline eGFR (P<0.05). The results of regression analysis for the correlations between the rate of eGFR change and the baseline levels of NGAL and L-FABP, and the urine albumin excretion rate showed that only the urine albumin excretion rate was significantly correlated with the rate of eGFR change (standardized coefficients: −0.378; t: −4.298; P<0.001).ConclusionsTubular markers, such as NGAL and L-FABP, may not be predictive factors associated with GFR decline in type 2 diabetic patients.

Urinary liver‐type fatty acid‐binding protein level as a predictive biomarker of contrast‐induced acute kidney injury

Contrast-induced acute kidney injury (CI-AKI) is a well-known complication of contrast medium exposure in patients with chronic kidney disease. However, there are no biological markers to accurately predict the onset of CI-AKI. Liver-type fatty acid-binding protein (L-FABP), an intracellular carrier protein for free fatty acids, is markedly upregulated and abundantly expressed in the proximal tubules after renal ischaemia. We prospectively investigated whether urinary L-FABP is a suitable marker for the prediction of CI-AKI. We performed a prospective study of 220 consecutive patients with chronic kidney disease who underwent elective catheterization [serum creatinine (Cr) ≥ 1.2 mg/dL (106 M)]. Serum Cr and L-FABP levels were measured immediately before and 1 and 2 days after the procedure. CI-AKI was defined as an increase in serum Cr level of ≥ 0.3 mg/dL within 48 h after the procedure. We observed the development of CI-AKI in 19 patients (8.6%). Urinary L-FABP levels were significantly higher in patients with CI-AKI than those without CI-AKI before contrast medium exposure. Receiver operating characteristic analysis showed that baseline urinary L-FABP level exhibited 82% sensitivity and 69% specificity, at a cut-off value of 24.5 μg/g Cr. Using multivariate analysis, we found that independent predictors of CI-AKI development were L-FABP level of ≥ 24.5 μg/g Cr [odds ratio (OR): 9.10; 95% confidence interval (CI), 3.20-28.9], and left ventricular ejection fraction ≤ 40% (OR, 3.42; 95% CI, 1.07-10.8). Urinary L-FABP level is useful for predicting the onset of CI-AKI before contrast medium exposure.

URINARY LIVER-TYPE FATTY ACID-BINDING PROTEIN IN SEPTIC SHOCK

We aimed to determine retrospectively whether urinary liver-type fatty acid-binding protein (L-FABP) levels are altered in patients with septic shock or severe sepsis without shock and whether polymyxin B-immobilized fiber (PMX-F) hemoperfusion affects these levels. Forty patients with septic shock, 20 patients with severe sepsis without shock, 20 acute renal failure (ARF) patients without septic shock (mean serum creatinine, 2.8 mg/dL), and 30 healthy volunteers were included in this study. Polymyxin B-immobilized fiber hemoperfusion was performed twice in 40 patients. In addition, 10 patients with septic shock without PMX-F treatment (conventional treatment) were also enrolled in this study. Their families did not choose PMX-F treatment. Thus, their informed consents to perform PMX-F treatment were not obtained. Septic shock or severe sepsis was defined by the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference Committee. Patients with septic shock were eligible for inclusion in the study if they had a definable source of infection and/or positive blood cultures. Patients with cardiogenic or hemorrhagic shock were excluded from the study. The patients were not randomly allocated to receive PMX-F treatment. Urinary and serum L-FABP levels were measured by enzyme-linked immunosorbent assay method. Plasma endotoxin levels in patients with septic shock were significantly higher than those in patients with severe sepsis (P < 0.05), patients with ARF (P < 0.001), and healthy subjects (P < 0.001). Urinary L-FABP levels in patients with septic shock were significantly higher than those in patients with severe sepsis without shock (P < 0.001), patients with ARF (P < 0.001), and healthy subjects (P < 0.001), whereas serum L-FABP levels showed no significant differences between patients with septic shock, patients with severe sepsis, patients with ARF, and healthy subjects. Urinary L-FABP was not correlated with serum L-FABP. Twenty-eight patients with septic shock survived, and 12 patients died. Polymyxin B-immobilized fiber treatment reduced plasma endotoxin levels (P < 0.01) and urinary L-FABP levels (P < 0.01). In 10 patients with septic shock without PMX-F treatment, L-FABP levels remained high 7 days after initiation of conventional treatment (P = 0.12). These results suggest that urinary L-FABP levels are significantly increased in patients with septic shock and that PMX-F treatment is effective in reducing these levels.

NGAL (neutrophil gelatinase-associated lipocalin) and L-FABP after percutaneous coronary interventions due to unstable angina in patients with normal serum creatinine

The value of NGAL (neutrophil gelatinase-associated lipocalin) and L-FABP (liver-type fatty acid binding protein) has been highlighted as a novel biomarker of detection of acute renal failure in children after cardiac surgery. Interventional cardiologists are being asked more frequently to perform percutaneous coronary intervention (PCI) and contrast nephropathy is its potentially serious complication. We aimed to prospectively assess NGAL and L-FABP in patients with normal serum creatinine undergoing PCI due to unstable angina. We measured serum NGAL, urinary NGAL and L-FABP using commercially available kits before and after 2, 4, 12, 24 and 48 hours following PCI in 25 patients. We found a significant rise in serum NGAL after 2 and 4 hours. Urinary NGAL and urinary L-FABP followed the same pattern. Both markers increased significantly after 4 hours and remained elevated up to 48 hours after PCI. Serum creatinine did not change significantly during the study period. NGAL and L-FABP may represent a sensitive early biomarkers of renal impairment after PCI. Persistently increased urinary NGAL and L-FABP may suggest renotubular damage in this population.

Urinary liver-type fatty acid binding protein as a useful biomarker in chronic kidney disease

We reported that urinary L-FABP reflected the progression of chronic kidney disease (CKD). This study is aimed to evaluate the clinical significance of urinary liver type fatty acid binding protein (L-FABP) as a biomarker for monitoring CKD. Urinary L-FABP was measured using human L-FABP ELISA kit (CMIC.Co., Ltd., Tokyo, Japan). The relations between urinary L-FABP and clinical parameters were evaluated in non-diabetic CKD (n = 48) for a year. In order to evaluate the influence of serum L-FABP derived from liver upon urinary L-FABP, both serum and urinary L-FABP were simultaneously measured in patients with CKD (n = 73). For monitoring CKD, the cut-off value in urinary L-FABP was determined as 17.4 microg/g.cr. by using a receiver operating characteristics (ROC) curve. Renal function deteriorated significantly more in patients with 'high' urinary L-FABP (n = 36) than in those with 'low' L-FABP (n = 12). The decrease in creatinine clearance was accompanied by an increase in urinary L-FABP, but not in urinary protein. Serum L-FABP in patients with CKD was not correlated with urinary L-FABP. Urinary excretion of L-FABP increases with the deterioration of renal function. Serum L-FABP did not influence on urinary L-FABP. Urinary L-FABP may be a useful clinical biomarker for monitoring CKD.