Clinical significance of urinary plasminogen and fibrinogen gamma chain as novel potential diagnostic markers for non-small-cell lung cancer.

BACKGROUND: Urinary proteins could be useful as markers for the detection of non-small-cell lung cancer (NSCLC). We investigated the levels of two different proteins in urine samples from NSCLC patients and assessed their diagnostic value. METHODS: Urinary plasminogen (PLG) and fibrinogen gamma chain (FGG) levels in 112 NSCLC patients and 197 controls were detected using enzyme linked immunosorbent assay (ELISA). The expression of FGG and PLG in 20 NSCLC tissues and paired adjacent non-tumour tissues were detected through immunohistochemistry. The diagnostic value of FGG and PLG for NSCLC was evaluated through a receiver operating characteristic curve (ROC). RESULTS: PLG and FGG were significantly elevated in NSCLC tissues vs paired adjacent non-tumour tissues (p = 0.000) and in urinary samples from NSCLC patients vs healthy controls (p = 0.000). The expression level of PLG in urinary samples was related only to the histological type (p = 0.001). Further, ROC curve analysis revealed that PLG, FGG, and their combination could distinguish NSCLC and its subtypes from healthy controls with an AUC ranging from 0.827 to 0. 947. By comparing urine samples with matching plasma CEA from NSCLC stage I-IV patients (n = 81) and healthy controls (n = 31), the combination of CEA with PLG or FGG showed that the AUC was 0.889 and 0.806, respectively, which is superior to a single biomarker alone. CONCLUSIONS: These two urinary proteins could serve as potential markers for the diagnosis of NSCLC.

Urinary fibrinogen is elevated in hospitalized patients undergoing angiography.

OBJECTIVES: Previously, we found that urinary fibrinogen (Fg) levels were positively related to contrast-induced acute renal injury degree in mice. Reduction of fibrinogen in heterozygous mice can improve renal function. Here, we prospectively observed the variation in urinary Fg levels in patients undergoing angiography to determine the relationship between serum creatinine (Scr) and serum cystatin C (Cys C) levels. METHODS: Serum Cys C and urinary Fg levels were evaluated by ELISA before and 2, 12, and 24 h after angiography in 115 enrolled inpatients. Scr was assessed before and 24 and 48 h after angiography. Data were analyzed using ANOVA or Kruskal-Wallis ANOVA and Spearman correlation. RESULTS: Urinary Fg levels were elevated as early as 2 h after angiography and decreased thereafter before returning to baseline levels 24 h after angiography. Urinary Fg was correlated with the amount of contrast agent ( r = 0.24, p = 0.036) and the presence of diabetes and hypertension ( r = 0.31, r = 0.28, p < 0.05, respectively). Urinary Fg levels 2 h after angiography were positively related with Cys C at 12 and 24 h and Scr at 48 h after angiography ( r = 0.34, r = 0.51, r = 0.85, p < 0.05, respectively). CONCLUSIONS: Our results showed that variations in urinary Fg levels are consistent with serum Cys C and Scr in patients undergoing angiography and that urinary Fg levels were the earliest parameter to become elevated. Urinary Fg should be investigated as a useful predictor for abnormal renal function after angiography.

Urinary fibrin/fibrinogen degradation products measured using an anti-fibrinogen antibody predict orthostatic proteinuria.

BACKGROUND: The aim of this study was to assess the diagnostic value of urinary fibrin/fibrinogen degradation products (uFDP) measured using an anti-fibrinogen antibody in patients with orthostatic proteinuria (OP), and their use in differentiating between OP and glomerulonephritis (GN). METHODS: uFDP were measured using first urine in the morning (supine) and non-first urine during a hospital visit (upright) and then normalized to urine creatinine (uFDP/Cr, ng/mgCr). We compared (i) OP patients (n = 16); (ii) those in remission from nephrotic syndrome (NS, n = 14) and from GN (IgA nephropathy [IgAN], n = 14; Henoch-Schönlein purpura nephritis [HSPN], n = 12); and (iii) those with active GN (IgAN, n = 12; HSPN, n = 19). RESULTS: The uFDP/Cr ratio increased from supine to upright urine in patients with OP (P < 0.001), but decreased in one case. uFDP were excreted in supine urine in 94% of OP patients, with no excretion in NS remission patients or in 92% of GN remission patients (P < 0.001 for both). uFDP/Cr in supine urine was similar between the OP and active GN patients (P = 0.40), whereas proteinuria in supine urine was in the normal range in all OP patients, but was significantly higher in upright urine in the OP patients (P < 0.001). In upright urine, urinary protein/creatinine ratio was significantly lower in patients with OP than in those with active GN (P = 0.005). A uFDP/Cr ratio cut-off of 1,108 ng/mgCr in upright urine correctly differentiated OP from active GN, with a sensitivity of 87.5% and a specificity of 100%. CONCLUSION: Comparison of uFDP levels in supine/upright urine can be reliable for diagnosing OP and for differentiating it from active GN.

Fibrinogen links podocyte injury with Toll-like receptor 4 and is associated with disease activity in FSGS patients.

AIM: Fibrinogen (Fg) is reported to participate in inflammation through Toll-like receptor 4 (TLR4). However, it remains unknown whether Fg might induce podocyte damage through TLR4 and be related to disease activity in patients with focal segmental glomerulosclerosis (FSGS). METHODS: We observed Fg-induced alterations in actin and apoptosis in cultured human podocytes transfected with or without TLR4 siRNA. Expression of TLR4, phospho-p38 MAPK and phospho-NF-κB p65 was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) or western blotting, and we analysed urinary Fg levels in adriamycin-treated mice and double immunofluorescence staining for TLR4, Fg and podocin. Urinary Fg changes were also analyzed in FSGS patients under prednisone treatment. RESULTS: First, Fg dose-dependently induced actin damage and apoptosis in cultured human podocytes, with an Fg-induced increase in TLR4 expression, and TLR4 siRNA transfection prevented these effects. TLR4 knockdown inhibited activation of p38 MAPK and NF-κB p65 in podocytes. Elevated urinary Fg levels were positively correlated with albuminuria in adriamycin-treated mice, in which Fg and TLR4 colocalized and exhibited increased expression in podocytes. Additionally, elevated urinary Fg levels were positively correlated with 24-h proteinuria and foot process width in FSGS patients. Urinary Fg levels were significantly decreased in patients with complete remission but not in those without remission. CONCLUSIONS: Fg induced podocytes injury via the TLR4-p38 MAPK-NF-κB p65 pathway. In FSGS patients, urinary Fg levels reflect therapeutic response to prednisone and disease activity.

Urinary Fibrinogen as a Predictor of Progression of CKD.

BACKGROUND AND OBJECTIVES: Fibrinogen has been reported to be involved in kidney tubulointerstitial fibrosis and podocyte injury in mouse models. However, the relationship between urinary fibrinogen and kidney outcomes has not been clarified in patients with CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We evaluated 402 patients with CKD and kidney biopsies, including 101 with diabetic nephropathy, 94 with idiopathic membranous nephropathy, 55 with idiopathic FSGS, and 152 with IgA nephropathy. We quantified urinary fibrinogen by ELISA and tested associations with kidney histology and progression to ESRD. RESULTS: Median (interquartile range) urinary fibrinogen-to-creatinine ratio was 536 (191-1461) ng/mg for patients with CKD, significantly higher than 2 (2-3) ng/mg for healthy controls (P<0.001). Urinary fibrinogen was positively correlated with urine protein (r=0.64; P<0.001) and interstitial fibrosis and tubular atrophy (r=0.10; P=0.04), and it was negatively correlated with eGFR (r=-0.20; P<0.001). Over a median follow-up period of 35 months (interquartile range, 24-78 months), 68 of 402 patients (17%) developed ESRD. Higher urinary fibrinogen level was associated with increased risk of ESRD (hazard ratio, 2.12; 95% confidence interval, 1.31 to 3.26) per log10 higher urinary fibrinogen-to-creatinine ratio (P=0.003) adjusting for age, sex, BP, urine protein, disease type, eGFR, and interstitial fibrosis and tubular atrophy. For prediction of ESRD, the addition of urinary fibrinogen to eGFR, urine protein, and BP increased the area under the receiver operating curve from 0.73 to 0.76, and the Akaike information criterion improved from 333.6 to 327.0. CONCLUSIONS: Urinary fibrinogen correlated with interstitial fibrosis and tubular atrophy and was an independent risk factor for progression of CKD to ESRD.

Successful Treatment of Generalized Essential Telangiectasia With 6-Mercaptopurine.

Generalized essential telangiectasia (GET) is a notoriously difficult to treat disorder with no current satisfactory treatments. This case and discussion report the use of 6-mercaptopurine (6-MP) as a successful treatment for GET. Moreover, we show that GET may represent a state of increased angiogenesis, a paradigm shift from the current understanding that these telangiectasias represent dilatations of only pre-existing vessels. This new view of GET may drive others to look at novel agents for treatment.

J Drugs Dermatol. 2017;16(3):280-282.

Novel urinary biomarkers and their association with urinary heavy metals in chronic kidney disease of unknown aetiology in Sri Lanka: a pilot study

Introduction: Chronic kidney disease of unknown etiology (CKDu) has emerged as a significant public health problem in Sri Lanka. The role of environmental exposure to cadmium and arsenic in the aetiology of CKDu is still unclear. Identification of a panel of novel urinary biomarkers would be invaluable in the study of toxin mediated damage postulated to be the aetiology of CKDu. Objectives: The aims of this study were to evaluate the profile of novel urinary biomarkers in CKDu patients and identify any association with environmental exposure to heavy metals. Methods: Thirty seven randomly selected CKDu patients attending a renal clinic in the North Central Province and two control groups namely a farmer group (n=39) and a non-farmer group (n=40) from a non-endemic area were included in this comparative cross sectional study. Urine samples were analyzed for heavy metals and five urinary biomarkers. Results: CKDu patients had significantly elevated urinary levels of fibrinogen (198.2 ng/mg creatinine p<0.001), clusterin (3479 ng/mg creatinine p<0.001), cystatin-C (5124.8 ng/mg creatinine p<0.001) and ß2-microglobulin (9913.4 ng/mg creatinine p<0.001) compared to the control groups. Fibrinogen and ß2-microglobulin were the best to discriminate CKDu patients from normal individuals with the receiver operator areas under the curve being 0.867 and 0.853, respectively. Urinary fibrinogen and KIM-1 levels correlated positively with urinary arsenic levels. KIM-1 levels correlated positively with urinary mercury and lead levels but no correlation was seen with urinary cadmium levels. Conclusions: Fibrinogen and ß2-microglobulin have the potential of being a screening tool for detection of CKDu and may aid the early diagnosis of toxin mediated tubular injury in CKDu. Their usefulness need to be further validated in a larger epidemiological study of patients with early stages of CKDu.

Urinary fibrinogen and renal tubulointerstitial fibrinogen deposition: Discriminating between primary FSGS and minimal change disease.

Primary focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) are common types of primary glomerular disease; they share numerous clinical and pathological similarities but have different treatment regimens and prognoses. It is therefore necessary to distinguish between them and to explore the mechanism underlying their differences. Fibrinogen is reportedly involved in podocyte damage and in renal fibrosis in vitro and in animal models of kidney disease. We thus tested urinary fibrinogen, serum fibrinogen, and renal fibrinogen deposition levels in a cohort comprising 50 patients with FSGS and 40 patients with MCD. Our results suggested that urinary fibrinogen and renal interstitial fibrinogen deposition levels were significantly higher in the FSGS patients than in the MCD patients, while serum fibrinogen levels did not differ between the groups. Receiver operating characteristic (ROC) curve analysis showed an excellent diagnostic ability for urinary fibrinogen and a fair diagnostic ability for tubulointerstitial fibrinogen deposition in differentiating FSGS from MCD. Additionally, we found that urinary fibrinogen levels were positively correlated with the 24-h urine protein levels in patients with FSGS but not in patients with MCD. In conclusion, urinary fibrinogen and renal interstitial fibrinogen deposition is elevated in primary FSGS compared to MCD, which may be relevant to both diagnosis and pathogenesis.

Urine proteome analysis as a discovery tool in patients with deep vein thrombosis and pulmonary embolism.

PURPOSE: Early and accurate detection of deep vein thrombosis (DVT) is an important clinical need. Based on the hypothesis that urinary peptides may hold information on DVT in conjunction with pulmonary embolism (PE), the study was aimed at identifying such peptide biomarkers using capillary electrophoresis coupled mass spectrometry. EXPERIMENTAL DESIGN: Patients with symptoms of unprovoked/idiopathic DVT and/or PE were examined by doppler-sonography or angio-computed tomography. Urinary proteome analysis allowed for identification of respective peptide biomarkers. To confirm their biological relevance, we induced PE in mice and assessed human ex vivo thrombi. RESULTS: We identified 62 urinary peptides as DVT-specific biomarkers, i.e. fragments of collagen type I and a fragment of fibrinogen ß-chain. The presence of fibrinogen α/ß in the acute thrombus, and collagen type I and osteopontin in the older, organized thrombus was demonstrated. The classifier DVT62 established through support vector machine (SVM) modeling based on the 62 identified peptides was validated in an independent cohort of 47 subjects (six cases and 41 controls) with a sensitivity of 100% and specificity of 83%. CONCLUSIONS AND CLINICAL RELEVANCE: Urine proteome analysis enabled the detection of DVT-specific peptides, which were validated in human and mouse tissue. Furthermore, it allowed for the establishment of an urinary-proteome based classifier that is relatively specific for DVT. The data provide the basis for assessment of these biomarkers in a prospective clinical study.

Evaluation of urine fibrinogen level in a murine model of contrast-induced nephropathy.

OBJECTIVE: The mechanisms of contrast-induced nephropathy are not fully understood and sensitive biomarkers of contrast-induced nephropathy are yet to be found. We investigated whether urinary fibrinogen could be a potential biomarker for contrast-induced nephropathy. METHODS: To create a contrast-induced nephropathy model, mice received a prostaglandin synthesis inhibitor (indomethacin) and a nitric oxide synthase inhibitor (Nω-Nitro-L-arginine methyl ester) intraperitoneally followed by a different dose of iodixanol. In the control group, normal saline was administered. Urinary fibrinogen and serum creatinine were analyzed using enzyme-linked immunosorbent assay. Kidneys were used to quantify fibrinogen using qRT-PCR and Western blot and for histopathological examination. RESULTS: Histopathological examination demonstrated mild renal injury in the low-dose group, and moderate renal injury in the high-dose group. Urinary fibrinogen levels were significantly increased in an iodixanol dose-dependent manner (control vs. low-dose group, P < 0.05; control vs. high-dose group P < 0.01). Serum creatinine levels were only increased in the high-dose group (P < 0.01 compared to control), but not in the low-dose group. For fibrinogen-gene expression, in the low-dose group, Fgγ increased (qRT-PCR, Western blot, P < 0.05) in the high-dose group, Fgß and Fgγ decreased (qRT-PCR, P < 0.01; Western blot, P < 0.05), and Fgα increased (qRT-PCR, P < 0.05; Western blot, P < 0.05). CONCLUSIONS: We propose that urinary fibrinogen could be used as a potential biomarker for early contrast-induced nephropathy diagnosis.

Evidence of uncoupling between renal dysfunction and injury in cardiorenal syndrome: insights from the BIONICS study.

OBJECTIVE: The objective of the study was to assess urinary biomarkers of renal injury for their individual or collective ability to predict Worsening renal function (WRF) in patients with acutely decompensated heart failure (ADHF). METHODS: In a prospective, blinded international study, 87 emergency department (ED) patients with ADHF were evaluated with biomarkers of cardiac stretch (B type natriuretic peptide [BNP] and its amino terminal equivalent [NT-proBNP], ST2), biomarkers of renal function (creatinine, estimated glomerular filtration rate [eGFR]) and biomarkers of renal injury (plasma neutrophil gelatinase associated lipocalin [pNGAL], urine kidney injury molecule-1 [KIM-1], urine N-acetyl-beta-D-glucosaminidase [NAG], urine Cystatin C, urine fibrinogen). The primary endpoint was WRF. RESULTS: 26% developed WRF; baseline characteristics of subjects who developed WRF were generally comparable to those who did not. Biomarkers of renal function and urine biomarkers of renal injury were not correlated, while urine biomarkers of renal injury correlated between each other. Biomarker concentrations were similar between patients with and without WRF except for baseline BNP. Although plasma NGAL was associated with the combined endpoint, none of the biomarker showed predictive accuracy for WRF. CONCLUSIONS: In ED patients with ADHF, urine biomarkers of renal injury did not predict WRF. Our data suggest that a weak association exists between renal dysfunction and renal injury in this setting (Clinicaltrials.gov NCT#0150153).

Identification of urinary peptide biomarkers associated with rheumatoid arthritis.

Early diagnosis and treatment of rheumatoid arthritis are associated with improved outcomes but current diagnostic tools such as rheumatoid factor or anti-citrullinated protein antibodies have shown limited sensitivity. In this pilot study we set out to establish a panel of urinary biomarkers associated with rheumatoid arthritis using capillary electrophoresis coupled to mass spectrometry. We compared the urinary proteome of 33 participants of the Scottish Early Rheumatoid Arthritis inception cohort study with 30 healthy controls and identified 292 potential rheumatoid arthritis-specific peptides. Amongst them, 39 were used to create a classifier model using support vector machine algorithms. Specific peptidic fragments were differentially excreted between groups; fragments of protein S100-A9 and gelsolin were less abundant in rheumatoid arthritis while fragments of uromodulin, complement C3 and fibrinogen were all increasingly excreted. The model generated was subsequently tested in an independent test-set of 31 samples. The classifier demonstrated a sensitivity of 88% and a specificity of 93% in diagnosing the condition, with an area under the receiver operating characteristic curve of 0.93 (p<0.0001). These preliminary results suggest that urinary biomarkers could be useful in the early diagnosis of rheumatoid arthritis. Further studies are currently being undertaken in larger cohorts of patients with rheumatoid arthritis and other athridities to assess the potential of the urinary peptide based classifier in the early detection of rheumatoid arthritis.

Fibrinogen alpha chain precursor and apolipoprotein A-I in urine as biomarkers for noninvasive diagnosis of calcium oxalate nephrolithiasis: a proteomics study.

UNLABELLED: Calcium oxalate nephrolithiasis is the most common urological disease, but noninvasive and convenient methods of diagnosis are rarely available. OBJECTIVE: The present study aimed to identify potential urine biomarkers for noninvasive diagnosis of CaOx nephrolithiasis. METHODOLOGY: Urine samples from 72 patients with CaOx nephrolithiasis and 30 healthy controls were collected and proteomics analysis was performed using matrix-assisted laser desorption/ionization-time of flight-mass spectrometer (MALDI-TOF-MS). RESULTS: Thirteen proteins/peptides displayed statistically significant differences. The peptides of m/z 1207.23 and 2773.86 were selected by the genetic algorithm (GA) to build a possible diagnostic model. The area under the curve of m/z 1207.23 and 2773.86 was 0.936 and 0.987, respectively. The diagnostic model in distinguishing patients and healthy subjects showed 100% sensitivity and specificity. The peak at m/z 2773.86 was identified as fibrinogen alpha chain (FGA) with the sequence G.EGDFLAEGGGVR.G, and the peak at m/z 2773.86 was identified as apolipoprotein A-I (apoA-I) with the sequence L.PVLESFKVSFLSALEEYTKKLNTQ. CONCLUSION: The study results strongly suggested that urinary FGA and apoA-I are highly sensitive and specific biomarkers for noninvasive diagnosis of CaOx nephrolithiasis.

Carbon nanohorns as a scaffold for the construction of disposable electrochemical immunosensing platforms. Application to the determination of fibrinogen in human plasma and urine.

We describe in this work a novel electrochemical immunosensor design making use of carbon nanohorns (CNHs) as a scaffold for the preparation of disposable immunosensing platforms for the determination of fibrinogen (Fib). The approach involved the immobilization of Fib onto activated CNHs deposited on screen-printed carbon electrodes (SPCEs) and the implementation of an indirect competitive assay using anti-Fib labeled with horseradish peroxidase (HRP) and hydroquinone (HQ) as the redox mediator. Both CNHs and the Fib-CNHs covalent assembly were characterized by microscopic and electrochemical techniques. The different variables affecting the analytical performance of the amperometric immunosensing strategy were optimized. The calibration plot for Fib allowed a range of linearity between 0.1 and 100 µg/mL (r(2) = 0.994) and a detection limit of 58 ng/mL to be achieved. The Fib-CNHs/SPCEs exhibited an excellent storage stability of at least 42 days. The developed immunosensor provides, in general, an analytical performance better than that reported for other Fib immunosensors and commercial ELISA kits. This simple and relatively low cost immunosensor configuration permitted the sensitive and selective determination of Fib in human plasma and urine.

Pharmacological and genetic depletion of fibrinogen protects from kidney fibrosis.

Fibrinogen (Fg) has been implicated in the pathogenesis of several fibrotic disorders by acting as a profibrotic ligand for a variety of cellular surface receptors and by modulating the provisional fibrin matrix formed after injury. We demonstrated increased renal Fg expression after unilateral ureteral obstruction and folic acid (FA) nephropathy in mice, respectively. Urinary Fg excretion was also increased in FA nephropathy. Using in vitro and in vivo approaches, our results suggested that IL-6 mediates STAT3 activation in kidney fibrosis and that phosphorylated (p)STAT3 binds to Fgα, Fgß, and Fgγ promoters in the kidney to regulate their transcription. Genetically modified Fg heterozygous mice (∼75% of normal plasma Fg levels) exhibited only 3% kidney interstitial fibrosis and tubular atrophy after FA nephropathy compared with 24% for wild-type mice. Fibrinogenolysis through Ancrod administration after FA reduced interstitial fibrosis more than threefold compared with vehicle-treated control mice. Mechanistically, we show that Fg acts synergistically with transforming growth factor (TGF)-ß1 to induce fibroblast proliferation and activates TGF-ß1/pSMAD2 signaling. This study offers increased understanding of Fg expression and molecular interactions with TGF-ß1 in the progression to kidney fibrosis and, importantly, indicates that fibrinogenolytics like Ancrod present a treatment opportunity for a yet intractable disease.

Urine protein biomarkers for the diagnosis and prognosis of necrotizing enterocolitis in infants.

OBJECTIVES: To test the hypothesis that an exploratory proteomics analysis of urine proteins with subsequent development of validated urine biomarker panels would produce molecular classifiers for both the diagnosis and prognosis of infants with necrotizing enterocolitis (NEC). STUDY DESIGN: Urine samples were collected from 119 premature infants (85 NEC, 17 sepsis, 17 control) at the time of initial clinical concern for disease. The urine from 59 infants was used for candidate biomarker discovery by liquid chromatography/mass spectrometry. The remaining 60 samples were subject to enzyme-linked immunosorbent assay for quantitative biomarker validation. RESULTS: A panel of 7 biomarkers (alpha-2-macroglobulin-like protein 1, cluster of differentiation protein 14, cystatin 3, fibrinogen alpha chain, pigment epithelium-derived factor, retinol binding protein 4, and vasolin) was identified by liquid chromatography/mass spectrometry and subsequently validated by enzyme-linked immunosorbent assay. These proteins were consistently found to be either up- or down-regulated depending on the presence, absence, or severity of disease. Biomarker panel validation resulted in a receiver-operator characteristic area under the curve of 98.2% for NEC vs sepsis and an area under the curve of 98.4% for medical NEC vs surgical NEC. CONCLUSIONS: We identified 7 urine proteins capable of providing highly accurate diagnostic and prognostic information for infants with suspected NEC. This work represents a novel approach to improving the efficiency with which we diagnose early NEC and identify those at risk for developing severe, or surgical, disease.

A novel urine peptide biomarker-based algorithm for the prognosis of necrotising enterocolitis in human infants.

OBJECTIVE: Necrotising enterocolitis (NEC) is a major source of neonatal morbidity and mortality. The management of infants with NEC is currently complicated by our inability to accurately identify those at risk for progression of disease prior to the development of irreversible intestinal necrosis. We hypothesised that integrated analysis of clinical parameters in combination with urine peptide biomarkers would lead to improved prognostic accuracy in the NEC population. DESIGN: Infants under suspicion of having NEC (n=550) were prospectively enrolled from a consortium consisting of eight university-based paediatric teaching hospitals. Twenty-seven clinical parameters were used to construct a multivariate predictor of NEC progression. Liquid chromatography/mass spectrometry was used to profile the urine peptidomes from a subset of this population (n=65) to discover novel biomarkers of NEC progression. An ensemble model for the prediction of disease progression was then created using clinical and biomarker data. RESULTS: The use of clinical parameters alone resulted in a receiver-operator characteristic curve with an area under the curve of 0.817 and left 40.1% of all patients in an 'indeterminate' risk group. Three validated urine peptide biomarkers (fibrinogen peptides: FGA1826, FGA1883 and FGA2659) produced a receiver-operator characteristic area under the curve of 0.856. The integration of clinical parameters with urine biomarkers in an ensemble model resulted in the correct prediction of NEC outcomes in all cases tested. CONCLUSIONS: Ensemble modelling combining clinical parameters with biomarker analysis dramatically improves our ability to identify the population at risk for developing progressive NEC.

Urinary proteome analysis in congenital bilateral hydronephrosis.

OBJECTIVE: A proteomics strategy was applied to map protein changes in urine after relief of congenital bilateral hydronephrosis to identify proteins correlated with the pathophysiological processes in congenital obstructive nephropathy as potential urinary biomarkers. MATERIAL AND METHODS: Urine samples from 10 infants with bilateral abnormal drainage from the kidneys were collected at the time of relief from obstruction, and after 2 and 4 weeks. Proteomics techniques were used on samples from three patients for identification of protein changes between the three time-points, and enzyme-linked immunosorbent assay (ELISA) was used on samples from all 10 patients for validation of five selected proteins. RESULTS: Mass spectrometry quantified 315 protein hits, out of which 33 proteins showed significantly changed urinary excretion between the time-points. Validation by ELISA showed high urinary excretion of fibrinogen, plasminogen, transthyretin and transferrin at the time of relief from obstruction, followed by a significant reduction. In contrast, Tamm-Horsfall protein exhibited the reverse pattern. CONCLUSION: Using a mass spectrometry-based proteomics approach, this study identified 33 proteins related to congenital bilateral hydronephrosis, and pinpointed a panel of five proteins consistently linked to this congenital kidney disorder as potential urinary biomarkers.

Fibrinogen excretion in the urine and immunoreactivity in the kidney serves as a translational biomarker for acute kidney injury.

Fibrinogen (Fg) is significantly up-regulated in the kidney after acute kidney injury (AKI). We evaluated the performance of Fg as a biomarker for early detection of AKI. In rats and mice with kidney tubular damage induced by ischemia/reperfusion (I/R) or cisplatin administration, respectively; kidney tissue and urinary Fg increased significantly and correlated with histopathological injury, urinary kidney injury molecule-1 (KIM-1) and N-acetyl glucosaminidase (NAG) corresponding to the progression and regression of injury temporally. In a longitudinal follow-up of 31 patients who underwent surgical repair of abdominal aortic aneurysm, urinary Fg increased earlier than SCr in patients who developed postoperative AKI (AUC-ROC = 0.72). Furthermore, in a cohort of patients with biopsy-proven AKI (n = 53), Fg immunoreactivity in the tubules and interstitium increased remarkably and was able to distinguish patients with AKI from those without AKI (n = 59). These results suggest that immunoreactivity of Fg in the kidney, as well as urinary excretion of Fg, serves as a sensitive and early diagnostic translational biomarker for detection of AKI.