Urinary Liver-type Fatty Acid-binding Protein Levels Research Articles

Urinary liver-type fatty acid-binding protein level as a prognostic indicator of acute kidney injury secondary to severe falciparum malaria.

Acute kidney injury (AKI) secondary to severe falciparum malaria possesses a high mortality rate; however, a prognostic marker of renal dysfunction has not yet been identified. Thus, we reported a case of a patient with AKI secondary to falciparum malaria who underwent hemodialysis and a renal biopsy due to prolonged renal dysfunction. The male patient, in his 50s, presented to our hospital with vomiting, diarrhea, fever, and decreased level of consciousness. The Giemsa-stained peripheral blood film revealed approximately 5% parasitemia, and a rapid diagnostic test was positive for Plasmodium falciparum. He was diagnosed with severe falciparum malaria and was started on quinine hydrochloride. Hemodialysis was initiated due to the decreased urine output and fluid retention. Subsequently, he was weaned off hemodialysis. The histopathological analysis of a renal biopsy revealed interstitial fibrosis, tubular atrophy, and chronic inflammatory cell infiltration; thus, malarial nephropathy was diagnosed. Thereafter, his renal function stabilized, and he was discharged from the hospital. The urinary liver-type fatty acid-binding protein (L-FABP) level decreased before renal function improved. Our report highlighted that long-term follow-up is essential for severe AKI secondary to malaria. The urinary L-FABP level may be a useful prognostic indicator of AKI secondary to severe falciparum malaria.

Urinary liver-type fatty acid-binding protein levels may be associated with the occurrence of acute kidney injury induced by trauma.

Acute kidney injury (AKI), with a fatality rate of 8.6%, is one of the most common types of multiorgan failure in the intensive care unit (ICU). Thus, AKI should be diagnosed early, and early interventions should be implemented. Urinary liver-type fatty acid-binding protein (L-FABP) could aid in the diagnosis of AKI. In this prospective, single-center, observational study, we included 100 patients with trauma. Urinary L-FABP levels were measured using a semi-quantitative rapid assay kit 6 and 12 h after injury. Negative, weakly positive, and strongly positive urinary L-FABP levels were examined using two protocols. Using protocol 1, measurements were performed at 6 h after injury negative levels were considered "negative," and weakly positive and strongly positive levels were considered "positive." Using protocol 2, strongly positive levels at 6 h after injury were considered "positive," and negative or weakly positive levels at 6 h after injury were considered "positive" if they were weakly positive or positive at 12 h after injury. Fifteen patients were diagnosed with AKI. Using protocol 1, the odds ratio (OR) was 20.55 (p = 0.001) after adjustment for the injury severity score (ISS), contrast media use, and shock index. When the L-FABP levels at 6 and 12 h were similarly adjusted for those three factors, the OR was 18.24 (p < 0.001). The difference in ORs for protocols 1 and 2 was 1.619 (p = 0.04). Associations between urinary L-FABP and AKI can be examined more precisely by performing measurements at 6 and 12 h after injury than only one time at 6 h.

Elevated urinary angiotensinogen excretion links central and renal hemodynamic alterations

Inappropriate activation of intrarenal renin–angiotensin system (RAS) may contribute to the pathogenesis of cardio-renal syndrome (CRS). We aimed to examine the cross-sectional associations of urinary angiotensinogen (AGT) excretion, a biomarker of intrarenal RAS activity, with central (aortic) and renal hemodynamic parameters in middle-aged and older adults, including patients with chronic kidney disease. Aortic and renal hemodynamic parameters were measured using applanation tonometry and duplex ultrasonography in 282 participants. Urinary AGT, liver-type fatty acid-binding protein (L-FABP), and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured for each participant. Multiple linear regression analyses demonstrated that urinary AGT levels were associated with aortic blood pressures, pulsatile measures of renal blood flow, plasma NT-proBNP and urinary L-FABP levels after adjusting for potential covariates, including age, sex, body mass index, estimated glomerular filtration rate (GFR), and medication use. Additionally, when classified based on GFR stages and urinary AGT levels, plasma NT-proBNP and urinary L-FABP levels increased in participants with lower GFR and higher AGT groups. Our findings suggest that urinary AGT excretion is a shared determinant of central (aortic) and renal hemodynamics in middle-aged and older adults, providing clinical evidence for the potential role of intrarenal RAS activity in the development of CRS.

Urinary liver‐type fatty acid binding protein is increased in the early stages of the disease with a risk of acute kidney injury induced by histone

Urinary liver-type fatty acid binding protein (L-FABP) has potential utility as an early prognostic biomarker ahead of traditional severity scores in coronavirus disease 2019 and sepsis, however, the mechanism of elevated urinary L-FABP in the disease has not been clearly elucidated. We investigated the background mechanisms of urinary L-FABP excretion through non-clinical animal model focusing on histone, which is one of the aggravating factors in these infectious diseases. Male Sprague-Dawley rats were placed in central intravenous catheters, and these rats were given a continuous intravenous infusion of 0.25 or 0.5 mg/kg/min calf thymus histones for 240 min from caudal vena cava. After the administration of histone, urinary L-FABP and gene expression of an oxidative stress marker in the kidney increased in a histone dose-dependent manner before increased serum creatinine. Upon further investigation, fibrin deposition in the glomerulus was observed and it tended to be remarkable in the high dose administrated groups. The levels of coagulation factor were significantly changed after the administration of histone, and these were significantly correlated with the levels of urinary L-FABP. Firstly, it was suggested that histone is one of the causative agents for the urinary L-FABP increase at an early stage of the disease with a risk of acute kidney injury. Secondly, urinary L-FABP could be a marker reflecting the changes of coagulation system and microthrombus caused by histone in the early stage of acute kidney injury before becoming severely ill and maybe a guide to early treatment initiation.

Association of urinary liver-type fatty acid-binding protein with renal functions and antihyperglycemic drug use in type 2 diabetic nephropathy patients.

In diabetic nephropathy exacerbation, a reduction in the estimated glomerular filtration rate (eGFR) without raised albuminuria or proteinuria has been frequently observed. This study aimed to clarify the clinical usefulness of urinary liver-type fatty acid-binding protein (L-FABP) in the exacerbation of diabetic nephropathy in type 2 diabetes. A cross-sectional study and a retrospective observational study of 227 patients with type 2 diabetes were conducted to investigate the relationship between urinary L-FABP and renal dysfunction. Changes in urinary L-FABP with or without additional administration of antihyperglycemic drugs were examined in 63 patients. Baseline urinary L-FABP was significantly associated with baseline eGFR (ρ = -0.34, p < 0.001) and baseline albuminuria (ρ = 0.64, p < 0.001). In multivariate regression analysis, baseline urinary L-FABP was a significant independent factor for eGFR reduction [β = -0.348, 95% confidence interval (CI) = -0.482 to -0.214, p < 0.001]. Cox regression analysis showed that patients with a baseline urinary L-FABP above 6.5μg/g creatinine exhibited a higher hazard ratio (HR) for the renal dysfunction surrogate end point (HR = 15.00, 95% CI 3.640-61.40, p < 0.001). In logistic regression analysis, administration of sodium glucose cotransporter-2 inhibitors was associated with a statistically significant reduction in urinary L-FABP levels, independent of changes in systolic blood pressure, glycosylated hemoglobin, and eGFR (odds ratio = 0.75, 95% CI 0.56-0.99, p = 0.04). Urinary L-FABP may be associated with the future decrease in renal functions in type 2 diabetic nephropathy patients. Additionally, urinary L-FABP could be used as a marker of the effectiveness of diabetic nephropathy treatment.

Utility of urinary liver-type fatty acid-binding protein as a prognostic marker in adult congenital heart patients hospitalized for acute heart failure.

Progression to acute kidney injury (AKI) under treatment in adult congenital heart disease (ACHD) patients with heart failure is associated with poor prognosis, early detection and interventions are necessary. We aimed to explore the utility of urinary liver-type fatty acid binding protein (L-FABP) in ACHD patients hospitalized for acute decompensated heart failure (ADHF). We prospectively evaluated hemodynamic, biochemical data, and urinary biomarkers including urinary L-FABP in ACHD patients hospitalized in our institution from June 2019 to March 2022. The primary outcomes were the development of AKI and death. AKI was defined as serum creatinine level increased by 0.3mg/dl or more within 5days after hospitalization. A total of 104 ADHF patients aged 31 (36-51) years were enrolled. 26 cases (25% of ADHF patients) developed AKI during hospitalization and 4 died after hospital discharge. Serum creatinine (sCr), serum total bilirubin, brain natriuretic peptide (BNP), and urinary L-FABP in AKI patients were significantly higher than in non-AKI patients, whereas systemic oxygen saturation of the peripheral artery (SpO2) and estimated glomerular filtration ratio in AKI patients were lower than non-AKI patients. There was no difference in the intravenous diuretic dose on admission and during hospitalization between the two groups. In the receiver operating characteristic (ROC) analysis, the maximum area under the curve (AUC) of urinary biomarkers in AKI patients was urinary L-FABP (AUC = 0.769, p < 0.001) with a cutoff value of 4.86µg/gCr. Urinary L-FABP level on admission was associated with a predictor for AKI development during hospitalization after adjusting for sCr, BNP and SpO2. Urinary L-FABP was a useful predictor for the development of AKI in ACHD patients hospitalized for ADHF. Monitoring of urinary L-FABP allows us to detect a high-risk patient earlier than the conventional biomarkers.

Xanthine oxidoreductase activity in marathon runners: potential implications for marathon-induced acute kidney injury.

Excess activation of circulating xanthine oxidoreductase (XOR) may contribute to the pathogenesis of widespread remote organ injury, including kidney injury. The purpose of this study was to determine the acute impact of marathon running on plasma XOR activity and to examine whether plasma XOR activity is associated with marathon-induced elevations in biomarkers of acute kidney injury (AKI). Twenty-three young men (aged 20-25 yr) who participated in the 38th Tsukuba Marathon were included. Blood and urine samples were collected before, immediately, 2 h (only blood sample), and 24 h after a full marathon run. Plasma XOR activity was evaluated using a highly sensitive assay utilizing a combination of [13C2,15N2] xanthine and liquid chromatography-triple quadrupole mass spectrometry. The levels of several AKI biomarkers, such as serum creatinine and urinary liver-type fatty acid-binding protein (L-FABP) were measured in each participant. Marathon running caused a transient elevation in plasma XOR activity and levels of purine degradation products (hypoxanthine, xanthine, and uric acid) as well as serum creatinine, urinary albumin, and urinary L-FABP levels. Immediately after the marathon, individual relative changes in plasma XOR activity were independently correlated with corresponding changes in serum creatinine and urinary L-FABP levels. In addition, the magnitude of marathon-induced elevation in plasma XOR activity and levels of purine degradation products were higher in individuals who developed AKI. These findings collectively suggest that marathon running substantially influences the purine metabolism pathway including XOR activity. Moreover, activated circulating XOR can be partly associated with elevated biomarkers of AKI after marathon running.NEW & NOTEWORTHY This study is the first to show marathon running transiently increases plasma XOR activity and levels of purine degradation products (hypoxanthine, xanthine, and uric acid), and further to demonstrate that activated plasma XOR may contribute to marathon-induced elevations in biomarkers of AKI. These findings significantly extend our prior knowledge of the purine metabolic pathway and several AKI biomarkers under strenuous exercise conditions.

Urinary liver-type fatty acid-binding protein as a prognostic marker in patients with acute heart failure.

AimsUrinary liver‐type fatty acid‐binding protein (L‐FABP) is expressed in proximal tubular epithelial cells and excreted into the urine during tubular injury. We hypothesized that high urinary L‐FABP is associated with poor prognosis in patients with acute heart failure (AHF).Methods and resultsWe analysed 623 patients (74 ± 13 years old; 60.0% male patients) with AHF. Urinary L‐FABP levels were measured at the time of admission and adjusted for the urinary creatinine concentration. The primary endpoint was all‐cause mortality. The median value and interquartile range of urinary L‐FABP levels were 6.66 and 3.37–21.1 μg/gCr, respectively. Urinary L‐FABP levels were significantly correlated with both beta‐2 microglobulin and cystatin C levels; the correlation with the former was higher than that with the latter. During the follow‐up of 631 (interquartile range: 387–875) days, 142 deaths occurred. A high tertile of urinary L‐FABP level was associated with high mortality; this association was retained after adjusting for other covariates (second tertile hazard ratio 1.40, P = 0.152 vs. first tertile; third tertile hazard ratio 1.94, P = 0.005 vs. first tertile).ConclusionsUrinary L‐FABP is more closely associated with tubular dysfunction than with glomerular dysfunction. Tubular dysfunction, which was evaluated based on urinary L‐FABP levels, in patients with AHF is associated with all‐cause mortality and is independent of pre‐existing risk factors. L‐FABP should be considered for use in the prognosis of AHF.

Predicting acute kidney injury and future cardiac events using urinary liver-type fatty acid-binding protein in patients with acute myocardial infarction

Abstract Background Urinary liver-type fatty acid-binding protein (L-FABP) has been known as a candidate biomarker for early detection of acute kidney injury (AKI). It has also been suggested to have an effective predictive value for cardiovascular mortality in patients. Therefore, this study aimed to examine the ability of urinary L-FABP in predicting AKI and future cardiovascular events in patients with acute myocardial infarction (AMI). Methods We evaluated consecutive 258 patients with AMI. Urinary L-FABP was measured at admission and a 2-year follow-up was performed. AKI was defined as an increase of &amp;gt;0.3 mg/dl in serum creatinine level within 2 days after emergency percutaneous coronary intervention. The composite endpoint was cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Results AKI was detected in 20 patients (7.8%). Patients with AKI had significantly higher urinary L-FABP levels (68.0 μg/gCr vs 3.1 μg/gCr, p&amp;lt;0.001) compared to those with non-AKI. Receiver operating characteristic analysis showed urinary L-FABP levels exhibited 85.7% sensitivity and 96.0% specificity, at a cutoff value of 29.7 μg/gCr. We used propensity score analyses to balance measurable confounders between patients with and without AKI, including age, left ventricular ejection fraction, an inflammation marker, renal function, and albuminuria. In logistic regression adjustment with the propensity score, urinary L-FABP level of &amp;gt;29.7 μg/gCr was an independent predictor of AKI (p=0.001). Furthermore, high urinary L-FABP (&amp;gt;29.7 μg/gCr) on admission correlated with an increased risk of the composite endpoints during 2-year follow-up in the Kaplan–Meier analysis (p&amp;lt;0.001). Conclusions Urinary L-FABP level may be a useful biomarker for predicting not only the onset of AKI but also adverse cardiovascular events in patients with AMI. Funding Acknowledgement Type of funding sources: None.

Clinical Utility of Urinary Biomarkers for Prediction of Acute Kidney Injury and Chronic Renal Dysfunction After Open Abdominal Aortic Aneurysm Repair.

PurposeWe examined the clinical utility of perioperative monitoring of urinary liver-type fatty acid binding protein (L-FABP), neutrophil gelatinase-associated lipocalin (NGAL), and albumin, for prediction of acute kidney injury (AKI) and prediction of chronic renal dysfunction in patients undergoing open surgical repair (OSR) of an abdominal aortic aneurysm.Patients and MethodsUrine and serum samples were obtained perioperatively from 64 such patients (n=64). Patients in whom OSR-related AKI (defined by the Kidney Disease Improving Global Outcomes criteria) occurred were identified. Renal function was evaluated 3 years after OSR in patients with OSR-related AKI.ResultsThe urinary biomarkers examined increased to maximum levels by 2 hours after aortic cross-clamping (AXC), regardless of whether AKI occurred. Notably, the serum creatinine (Cr) levels increased significantly immediately after OSR in patients with AKI (n=19) (vs that in patients without AKI). In patients with AKI, the increased serum Cr elevation rate, the urinary L-FABP levels 2 hours after AXC and immediately after OSR, and a reduction in eGFR documented 3 years after OSR were significantly greater in patients who underwent suprarenal AXC (n=11) than in those who underwent infrarenal AXC (n=8). Furthermore, urinary L-FABP levels 2 hours after AXC correlated significantly with the reductions in eGFR 3 years after OSR in patients with AKI.ConclusionUrinary L-FABP, NGAL and albumin concentrations 2 hours after AXC may be useful for early detection of OSR-related AKI. Furthermore, the increase in urinary L-FABP 2 hours after AXC may be predictive of chronic renal dysfunction in patients with OSR-related AKI.

Assessment of Cardiopulmonary Bypass Duration Improves Novel Biomarker Detection for Predicting Postoperative Acute Kidney Injury after Cardiovascular Surgery.

Urinary liver-type fatty acid binding protein (L-FABP) is a novel biomarker with promising performance in detecting kidney injury. Previous studies reported that L-FABP showed moderate discrimination in patients that underwent cardiac surgery, and other studies revealed that longer duration of cardiopulmonary bypass (CPB) was associated with a higher risk of postoperative acute kidney injury (AKI). This study aims to examine assessing CPB duration first, then examining L-FABP can improve the discriminatory ability of L-FABP in postoperative AKI. A total of 144 patients who received cardiovascular surgery were enrolled. Urinary L-FABP levels were examined at 4 to 6 and 16 to 18 h postoperatively. In the whole study population, the AUROC of urinary L-FABP in predicting postoperative AKI within 7 days was 0.720 at 16 to 18 h postoperatively. By assessing patients according to CPB duration, the urinary L-FABP at 16 to 18 h showed more favorable discriminating ability with AUROC of 0.742. Urinary L-FABP exhibited good performance in discriminating the onset of AKI within 7 days after cardiovascular surgery. Assessing postoperative risk of AKI through CPB duration first and then using urinary L-FABP examination can provide more accurate and satisfactory performance in predicting postoperative AKI.

Urinary liver-type fatty acid-binding protein variation as a predictive value of short-term mortality in intensive care unit patients

Background Predicting the prognosis of intensive care unit (ICU) patients is crucial because it may lead to patient stratification that would in turn help in appropriately distributing limited medical resources. This study, therefore, aimed to investigate the use of the urinary liver-type fatty acid-binding protein (L-FABP) semi-quantitative kit in rapidly predicting the prognosis of patients admitted to the ICU. Methods We conducted a single-center, prospective, observational study wherein 100 consecutive patients admitted to the ICU with an indwelling bladder catheter were enrolled between April and October 2020. Urine specimens were collected at the time of admission (T1) and after 6 h (T2), and urinary L-FABP levels were semi-quantitatively measured. Based on the results, an L-FABP variation was defined as the change in L-FABP (negative, weakly positive, or strongly positive) from T1 to T2. Patients were divided into three groups (L-FABP decreased group, unchanged group, or increased group), following which we compared their 14-day mortality. Results Finally, a total of 79 patients were included in the analysis. In multivariate analysis, urinary L-FABP variation [Odds ratio (OR) = 14.327, 95% confidence interval (CI) = 1.819–112.868, p = 0.01] and lactate (OR = 1.234, 95%CI = 1.060–1.437, p = 0.01) were significantly associated with 14-day mortality. Conclusion Urinary L-FABP variation at 6 h after admission was significantly associated with 14-day mortality.

Urinary Liver-Type Fatty Acid-Binding Protein Predicts Residual Renal Function Decline in Patients on Peritoneal Dialysis

BackgroundLiver-type fatty acid-binding protein (L-FABP) is a predictive marker for the early detection of acute kidney injury; however, less is known about how useful it is for predicting residual renal function (RRF) decline in patients on peritoneal dialysis (PD).Material/MethodsThe study subjects were 35 patients on PD who underwent multiple peritoneal equilibration tests (PETs) between October 2011 and October 2019. Urinary L-FABP levels were analyzed with enzyme-linked immunosorbent assay. The relationship between baseline clinical data, including urinary L-FABP levels and the subsequent annual rate of renal Kt/V decline, was investigated.ResultsThe median follow-up duration was 11 months and the rate of renal Kt/V decline was 0.29/y. Compared with outcomes in the group with renal Kt/V preservation, renal Kt/V decline was associated with both high daily levels of urinary protein excretion (0.60 g/d [range, 0.50–0.87] vs. 0.36 g/d [range, 0.19–0.48]; P=0.01) and high daily levels of urinary L-FABP excretion (111.2 mg/d [range, 76.1–188.6] vs. 61.5 mg/d [range, 35.7–96.0]; P=0.002). Multiple logistic regression analysis showed that only high daily levels of urinary L-FABP excretion were independently associated with renal Kt/V decline (odds ratio 1.03, 95% confidence interval 1.00–1.05; P=0.001). Furthermore, higher daily levels of urinary L-FABP excretion were significantly correlated with the higher annual rate of renal Kt/V decline (r=0.71, P<0.001).ConclusionsWe demonstrated that daily levels of urinary L-FABP are associated with RRF decline in patients on PD. The results of the present study indicate that assessment of urinary L-FABP levels may help predict RRF decline in patients on PD.

Novel Urinary Biomarkers and Chronic Kidney Disease After Coronary Angiography: A Prospective Case-Controlled Study

BACKGROUND: Novel urinary biomarkers may have potential for early detection of acute kidney injury.&#x0D; AIM: The aim of the study was to test two urinary biomarkers: Kidney injury molecule-1(KIM-1) and liver-type fatty acid binding protein (L-FABP) as markers of kidney injury following coronary angiography.&#x0D; METHODS: This is a prospective non-randomized controlled trial, performed in two large teaching hospitals. Patients were recruited from the catheter lab or form nephrology outpatient clinics. In group (A), 100 patients with AKI on top of CKD after coronary angiography and Group B: Thirty-one patients with stable CKD as a control. KIM-1 and L-FABP were measured at base line and after 3 months. &#x0D; RESULTS: In group (A), 100 patients who had acute on top of CKD after coronary angiography, stage progression occurred in 15 patients in group (A) compared to two patients in group (B) (p = 0.28). The median change in eGFR after 3 months was not statistically significant between both groups (p = 0.8). Median baseline urinary liver-type fatty acid binding protein was higher in Group A compared to Group B (3.7 μg/g vs. 1.82μg/g). The change in L-FABP from baseline to 3 months was significant between both groups (p &lt; 0.001). The median urinary concentrations of KIM-1 and L-FABP were higher at the end of the follow-up compared to base line values in both groups, (p &lt; 0.000).&#x0D; CONCLUSION: Urinary L-FABP correlates with kidney function decline in patients with acute on top of CKD after coronary angiography. Urinary levels of KIM-1 and L-FABP at 3 months increase significantly compared to baseline in patients with progressive CKD.

Urinary biomarkers of kidney tubule injury, risk of acute kidney injury, and mortality in patients with acute ischaemic stroke treated at a stroke care unit.

Urinary liver-type fatty-acid binding protein (L-FABP), which is a biomarker of kidney tubule injury, has been studied extensively and established as a risk marker of acute kidney injury (AKI). The aim of this study was to investigate whether kidney tubule injury is associated with the development of AKI and mortality in patients with acute ischaemic stroke. Acute ischaemic stroke patients hospitalized in the stroke care unit (SCU) within 24h after symptom onset were prospectively investigated. AKI was defined on the basis of Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Baseline urinary L-FABP was measured on admission. We evaluated the associations among urinary L-FABP, incidence of AKI, and 90-day mortality adjusted for renal function, albuminuria and other potentially predictive variables, using multivariable analysis. In total, 527 acute ischaemic stroke patients (342 men, median age 74years) were enrolled in the study. Twenty-seven patients (5.1%) experienced AKI within 7days of admission. In the univariate analysis, high urinary L-FABP level had positive associations with AKI [53.8μg/g creatinine (Cr) vs. 3.9μg/g Cr; P<0.001] and 90-day mortality (15.5μg/g Cr vs. 4.0μg/g Cr; P<0.001). In the multivariate analysis, elevated urinary L-FABP level (per 10-μg/g Cr increase) was independently associated with AKI (odds ratio 1.225, 95% confidence interval (CI) 1.083-1.454; P=0.003) and 90-day mortality (hazard ratio 1.091, 95% CI 1.045-1.138; P<0.001). Urinary biomarkers of kidney tubule injury are independently associated with the development of AKI and 90-day mortality in patients with acute ischaemic stroke treated at the SCU.

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.

Increased Urinary Liver-Type Fatty Acid-Binding Protein Level Predicts Major Adverse Cardiovascular Events in Patients With Hypertension.

Urinary liver-type fatty acid-binding protein (L-FABP) has been known as a potential biomarker for acute kidney injury. It has also been suggested to have an effective predictive value for cardiovascular mortality in patients with diabetes or critically ill condition. Therefore, this study aimed to examine the ability of urinary L-FABP in predicting mid-term cardiovascular morbidity and mortality in patients with hypertension. Urinary L-FABP levels in stable outpatients without diabetes who were treated with antihypertensive drugs were measured, and a 5-year follow-up was planned. The primary end-point was a combination of acute heart failure requiring hospitalization, myocardial infarction, stroke, and cardiovascular death. The secondary end-point was kidney disease progression defined as a relative decline in the estimated glomerular filtration rate of ≥30% from the baseline. A total of 197 patients were recruited. Primary and secondary end-points occurred in 24 (12.2%) and 42 (21.3%) patients, respectively, during a median follow-up of 5.7 years. Patients with urinary L-FABP levels higher than the upper limit (8.4 µg/g creatinine) were more likely to reach the primary (30.43% vs. 9.77%; P = 0.003) and secondary end-points (56.52% vs. 16.67%; P < 0.001) than those with urinary L-FABP levels within the normal limits. Urinary L-FABP level was independently associated with both primary (hazard ratio (HR) 1.21; P = 0.03) and secondary end-points (HR 1.19; P = 0.02). This study demonstrated that increased urinary L-FABP levels may predict adverse cardiovascular events and renal dysfunction progression even among stable nondiabetic patients with hypertension.

Effects of exercise on residual renal function in patients undergoing peritoneal dialysis: A post-hoc analysis of a randomized controlled trial.

We aimed to investigate the effects of exercise on renal outcomes in patients undergoing peritoneal dialysis (PD). In a post-hoc analysis of a randomized controlled trial of a 12-week home-based exercise program involving 47 patients undergoing PD, we excluded 18 patients with anuria and analyzed 13 and 16 patients in the usual care and exercise groups, respectively. The primary outcomes were weekly renal creatinine clearance (CCr) and urinary biomarkers: liver-type fatty acid-binding protein (L-FABP) and the microalbumin-to-creatinine ratio (ACR). Although the maintenance of weekly renal CCr in the exercise group was not significantly different compared with that in the usual care group (P = .09), urinary L-FABP levels (P = .02) and ACR (P = .04) were significantly decreased in the exercise group. To the best of our knowledge, this is the first study to demonstrate the beneficial effects of exercise on renal outcomes in patients undergoing PD.

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.

Urinary Liver-Type Fatty-Acid-Binding Protein Predicts Long-Term Adverse Outcomes in Medical Cardiac Intensive Care Units.

We prospectively investigated the prognostic value of urinary liver-type fatty-acid-binding protein (L-FABP) levels on hospital admission, both independently and in combination with serum creatinine-defined acute kidney injury (AKI), to predict long-term adverse outcomes in 1119 heterogeneous patients (mean age; 68 years) treated at medical (non-surgical) cardiac intensive care units (CICUs). Patients with stage 5 chronic kidney disease were excluded from the study. Of these patients, 47% had acute coronary syndrome and 38% had acute decompensated heart failure. The creatinine-defined AKI was diagnosed according to the “Kidney Disease: Improving Global Outcomes” criteria. The primary endpoint was a composite of all-cause death or progression to end-stage kidney disease, indicating the initiation of maintenance dialysis therapy or kidney transplantation. Creatinine-defined AKI occurred in 207 patients, with 44 patients having stage 2 or 3 disease. During a mean follow-up period of 41 months after enrollment, the primary endpoint occurred in 242 patients. Multivariate Cox regression analyses revealed L-FABP levels as independent predictors of the primary endpoint (p < 0.001). Adding L-FABP to a baseline model with established risk factors further enhanced reclassification and discrimination beyond that of the baseline model alone, for primary-endpoint prediction (both; p < 0.01). On Kaplan–Meier analyses, increased L-FABP (≥4th quintile value of 9.0 ng/mL) on admission or presence of creatinine-defined AKI, correlated with an increased risk of the primary endpoint (p < 0.001). Thus, urinary L-FABP levels on admission are potent and independent predictors of long-term adverse outcomes, and they might improve the long-term risk stratification of patients admitted at medical CICUs, when used in combination with creatinine-defined AKI.