A panel of urinary proteins predicts active lupus nephritis and response to rituximab treatment.

OBJECTIVES: ∼30% of patients with SLE develop LN. Presence and/or severity of LN are currently assessed by renal biopsy, but biomarkers in serum or urine samples may provide an avenue for non-invasive routine testing. We aimed to validate a urinary protein panel for its ability to predict active renal involvement in SLE. METHODS: A total of 197 SLE patients and 48 healthy controls were recruited, and urine samples collected. Seventy-five of the SLE patients had active LN and 104 had no or inactive renal disease. Concentrations of lipocalin-like prostaglandin D synthase (LPGDS), transferrin, alpha-1-acid glycoprotein (AGP-1), ceruloplasmin, monocyte chemoattractant protein 1 (MCP-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were quantified by MILLIPLEX® Assays using the MAGPIX Luminex platform. Binary logistic regression was conducted to examine whether proteins levels associate with active renal involvement and/or response to rituximab treatment. RESULTS: Urine levels of transferrin (P <0.005), AGP-1 (P <0.0001), MCP-1 (P <0.001) and sVCAM-1 (P <0.005) were significantly higher in SLE patients when compared with healthy controls. Furthermore, levels of transferrin, AGP-1, ceruloplasmin, MCP-1 and sVCAM-1 (all P <0.0001) were higher in SLE patients with active LN when compared with patients without active LN. A combination of five urine proteins, namely LPGDS, transferrin, ceruloplasmin, MCP-1 and sVCAM-1 was a good predictor of active LN (AUC 0.898). A combined model of LPGDS, transferrin, AGP-1, ceruloplasmin, MCP-1 and sVCAM-1 predicted response to rituximab treatment at 12 months (AUC 0.818). CONCLUSIONS: Findings support the use of a urinary protein panel to identify active LN and potentially predict response to treatment with rituximab in adult SLE patients. Prospective studies are required to confirm findings.

Prognostic and Diagnostic Values of Novel Serum and Urine Biomarkers in Lupus Nephritis: A Systematic Review.

INTRODUCTION: While renal biopsy remains the gold standard for diagnosing lupus nephritis (LN), the prognostic and diagnostic role of non-invasive biomarkers for LN is currently debated. METHODS: Available studies published in last 5 years (2015-2020) assessing the diagnostic and prognostic value of urinary and/or serological biomarkers in subjects with LN were analyzed in this systematic review. RESULTS: Eighty-five studies were included (comprehending 13,496 patients with systemic lupus erythematosus [SLE], 8,872 LN, 487 pediatric LN, 3,977 SLE but no LN, 160 pediatric SLE but no LN and 7,679 controls). Most of the studies were cross-sectional (62; 73%), while 14 (17%) were prospective. In sixty studies (71%), the diagnosis of LN was biopsy-confirmed. Forty-four out of 85 (52%) investigated only serological biomarkers, 29 studies (34%) tested their population only with urinary biomarkers, and 12 (14%) investigated the presence of both. Outcome measures to assess the clinical utility of the analyzed biomarkers were heterogeneous, including up to 21 different activity scores, with the SLEDAI (in 60%) being the most used. Despite some heterogeneity, promising results have been shown for biomarkers such as urinary monocyte chemoattractant protein, urinary adiponectin, and urinary vascular cell adhesion protein 1. DISCUSSION/CONCLUSION: While serum and urine biomarkers have the potential to improve diagnostic and prognostic pathways in patients with LN, the vast heterogeneity across studies severely limits their applicability in current clinical practice. With the kidney biopsy still representing the gold standard, future efforts should focus on harmonizing study inclusion criteria and outcomes, particularly in clinical trials, in order to improve comparability and facilitate the implementations of available biomarkers into the daily practice.

Systematic Evaluation of Urinary VCAM1 as Novel Biomarker for Prognosis of Lupus Nephritis.

BACKGROUND: Lupus nephritis was established as the major cause of morbidity and mortality in systemic lupus erythematosus (SLE) patients. This severity could be monitored by laboratory prognosis with accuracy and specificity for the disease. Recently, various SLE laboratory investigations still have had improper prognosis and also possibly causing tissue injury in the patients. The present study thus aimed to systematically explore a novel urinary protein for further development into a prognosis biomarker in patients. METHODS: Several urinary proteins that previously were reported with abnormal expression in SLE patients between 2014 - 2019 were comprehensively collected. These proteins were also analyzed for functional category and sites of expression using STIRNG, FUNRICH, and Uniport database. Thereafter, the level of altered protein candidate was then validated by western blotting, correlation analysis, and diagnostic performance. RESULTS: Vascular cell adhesion molecule-1 (VCAM1) protein was found in higher levels and also specific in SLE patients with nephritis. Moreover, VCAM1 has a role in immune response, inflammation, is expressed on plasma membrane of renal cells, and has the ability to secret into urine. The level of VCAM1 in urine of SLE patients was significantly higher than in healthy controls. The area under ROC curve (AUC) was also 0.891. Furthermore, the level of VCAM1 was dramatically associated with the severity of renal insufficiency (r = 0.738). CONCLUSIONS: VCAM1 may be a novel urinary biomarker for reliable prognosis of nephritis severity in SLE patients.

ALCAM and VCAM-1 as urine biomarkers of activity and long-term renal outcome in systemic lupus erythematosus.

OBJECTIVES: We investigated the cell adhesion molecules (CAMs) Vascular CAM 1 (VCAM-1) and Activated Leucocyte CAM (ALCAM) as urinary biomarkers in SLE patients with and without renal involvement. METHODS: Female SLE patients (n = 111) and non-SLE population-based controls (n = 99) were enrolled. We measured renal activity using the renal domain of the BILAG index and urine (U) and plasma (P) concentrations of soluble (s)VCAM 1 and U-sALCAM using ELISA. U-sCAM levels were next corrected by U-creatinine. RESULTS: U-sVCAM-1/creatinine and U-sALCAM/creatinine ratios were higher in SLE patients vs non-SLE controls (P < 0.001 for both), as well as in patients with active/low-active (BILAG A-C; n = 11) vs quiescent (BILAG D; n = 19) LN (P = 0.023 and P = 0.001, respectively). U-sALCAM/creatinine but not U-sVCAM-1/creatinine ratios were higher in patients with nephritis history (BILAG A-D; n = 30) vs non-renal SLE (BILAG E; n = 79) (P = 0.014). Patients with baseline U-sVCAM-1/creatinine ratios ≥75th percentile showed a 23-fold increased risk of a deterioration in estimated glomerular filtration rate by ≥25% during a 10-year follow-up (odds ratio: 22.9; 95% CI: 2.8, 189.2; P = 0.004); this association remained significant after adjustments for age, disease duration and organ damage. Traditional markers including anti-dsDNA antibodies did not predict this outcome. CONCLUSION: While high U-sVCAM-1 levels appear to reflect SLE disease activity, sALCAM might have particular importance in renal SLE. Both U-sVCAM-1 and U-sALCAM showed ability to distinguish SLE patients with active renal involvement from patients with quiescent or no prior nephritis. High U-sVCAM-1 levels may indicate patients at increased risk for long-term renal function loss.

Investigating selected adhesion molecules as urinary biomarkers for diagnosing endometriosis.

RESEARCH QUESTION: Are selected cell adhesion molecules useful as urinary biomarkers for diagnosing endometriosis? DESIGN: Prospective, longitudinal study (the Endometriosis Marker Austria) in patients who underwent laparoscopic surgery for benign gynaecological pathologies. A total of 149 patients not receiving hormonal treatment for at least 3 months prior to recruitment were included and preoperative urine protein levels of soluble vascular adhesion molecule-1 (sVCAM-1), soluble intracellular adhesion molecule-1 (sICAM-1), E-selectin and P-selectin were measured using a magnetic bead-based multiplex assay, normalized to creatinine levels of each sample. Levels were correlated with endometriosis status, menstrual cycle phase, body mass index, cigarette smoking and severity and entity of the lesions. RESULTS: Urine levels of sVCAM-1, sICAM-1, E-selectin and P-selectin did not differ between women with (n = 84) and without (n = 65) endometriosis and among subgroups. Accordingly, receiver operating characteristic analysis to examine the value of using sVCAM-1, sICAM-1, E-selectin and P-selectin levels and sVCAM/sICAM ratio to diagnose endometriosis were not significant. Whether the serum sVCAM-1 levels correlated with the urine levels of the protein in the same women was also investigated, which revealed no significant correlations for sVCAM or sICAM. CONCLUSION: Although a previous study had suggested that serum sVCAM is a promising biomarker for diagnosing endometriosis, no significant differences were found in urine levels of sVCAM-1, sICAM-1, E-selectin and P-selectin between women with and without endometriosis. Other markers should be studied in an effort to establish a truly non-invasive urinary test for diagnosing endometriosis.

Urinary biomarkers for lupus nephritis: the role of the vascular cell adhesion molecule-1.

Renal involvement is one of the main complications of systemic lupus erythematosus, causing a significant impact on patients' morbidity and mortality. Renal biopsy is still the gold standard of diagnosis, but it has many limitations. In this sense, several recent studies aim to identify biomarkers that not only predict disease activity and renal histology, but also lead to earlier treatment. In previous studies, the soluble vascular cell adhesion molecule-1 measured in urine showed a strong association with the presence of lupus nephritis, with clinical and histological activity indexes of the disease and with more severe renal lesions. This paper reviews the main urinary biomarkers of lupus nephritis that have been studied, with special emphasis on vascular cell adhesion molecule-1 results.

An Improved Prediction Model for Ovarian Cancer Using Urinary Biomarkers and a Novel Validation Strategy.

This study was designed to analyze urinary proteins associated with ovarian cancer (OC) and investigate the potential urinary biomarker panel to predict malignancy in women with pelvic masses. We analyzed 23 biomarkers in urine samples obtained from 295 patients with pelvic masses scheduled for surgery. The concentration of urinary biomarkers was quantitatively assessed by the xMAP bead-based multiplexed immunoassay. To identify the performance of each biomarker in predicting cancer over benign tumors, we used a repeated leave-group-out cross-validation strategy. The prediction models using multimarkers were evaluated to develop a urinary ovarian cancer panel. After the exclusion of 12 borderline tumors, the urinary concentration of 17 biomarkers exhibited significant differences between 158 OCs and 125 benign tumors. Human epididymis protein 4 (HE4), vascular cell adhesion molecule (VCAM), and transthyretin (TTR) were the top three biomarkers representing a higher concentration in OC. HE4 demonstrated the highest performance in all samples withOC(mean area under the receiver operating characteristic curve (AUC) 0.822, 95% CI: 0.772-0.869), whereas TTR showed the highest efficacy in early-stage OC (AUC 0.789, 95% CI: 0.714-0.856). Overall, HE4 was the most informative biomarker, followed by creatinine, carcinoembryonic antigen (CEA), neural cell adhesion molecule (NCAM), and TTR using the least absolute shrinkage and selection operator (LASSO) regression models. A multimarker panel consisting of HE4, creatinine, CEA, and TTR presented the best performance with 93.7% sensitivity (SN) at 70.6% specificity (SP) to predict OC over the benign tumor. This panel performed well regardless of disease status and demonstrated an improved performance by including menopausal status. In conclusion, the urinary biomarker panel with HE4, creatinine, CEA, and TTR provided promising efficacy in predicting OC over benign tumors in women with pelvic masses. It was also a non-invasive and easily available diagnostic tool.

Growing international evidence for urinary biomarker panels identifying lupus nephritis in children - verification within the South African Paediatric Lupus Cohort.

BACKGROUND: A urinary biomarker panel including alpha-1-acid-glycoprotein (AGP), lipocalin-like-prostaglandin-D-synthase (LPGDS), transferrin and ceruloplasmin demonstrates an 'excellent' ability for identifying active lupus nephritis in UK/US children. This study aimed to assess whether this panel identifies active lupus nephritis within the South African Paediatric Lupus Cohort. METHODS: Juvenile-onset-systemic lupus erythematosus (JSLE) patients aged < 19 years at diagnosis and healthy controls were recruited. Patients were categorized as having active lupus nephritis (renal BILAG score; A/B and previous histological confirmation) or inactive lupus nephritis (renal BILAG score: D/E). Urinary biomarkers were quantified by ELISA. Mann-Whitney U-test compared biomarker levels between groups. Binary logistic regression and receiver operating curve analysis assessed biomarker combinations. RESULTS: Twenty-three juvenile-onset-systemic lupus erythematosus patients were recruited with a median age of 13.5 years (interquartile range (IQR) 12.7-14.9) and disease duration of 2.6 years (IQR 1.8-4.0). Eighteen healthy controls had a median age of 11.0 years (IQR 10.0-12.0). AGP, LPGDS, transferrin, ceruloplasmin and VCAM-1 were significantly higher in active than in inactive lupus nephritis patients (corrected p-values, all pc < 0.05), with no difference between inactive lupus nephritis patients and healthy controls (all pc = 1.0). The optimal biomarker combination included AGP, ceruloplasmin, LPGDS and transferrin (area under the curve = 1.0). CONCLUSIONS: A urinary biomarker panel comprising AGP, ceruloplasmin, LPGDS and transferrin previously validated within UK/US cohorts also performed excellently within a racially distinct South African cohort which displayed more severe lupus nephritis.

Systemic lupus erythematosus biomarkers: the challenging quest.

SLE, a multisystem heterogeneous disease, is characterized by production of antibodies to cellular components, with activation of both the innate and the adaptive immune system. Decades of investigation of blood biomarkers has resulted in incremental improvements in the understanding of SLE. Owing to the heterogeneity of immune dysregulation, no single biomarker has emerged as a surrogate for disease activity or prediction of disease. Beyond identification of surrogate biomarkers, a multitude of clinical trials have sought to inhibit elevated SLE biomarkers for therapeutic benefit. Armed with new -omics technologies, the necessary yet daunting quest to identify better surrogate biomarkers and successful therapeutics for SLE continues with tenacity.

International validation of a urinary biomarker panel for identification of active lupus nephritis in children.

BACKGROUND: Conventional markers of juvenile-onset systemic lupus erythematosus (JSLE) disease activity fail to adequately identify lupus nephritis (LN). While individual novel urine biomarkers are good at detecting LN flares, biomarker panels may improve diagnostic accuracy. The aim of this study was to assess the performance of a biomarker panel to identify active LN in two international JSLE cohorts. METHODS: Novel urinary biomarkers, namely vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein 1 (MCP-1), lipocalin-like prostaglandin D synthase (LPGDS), transferrin (TF), ceruloplasmin, alpha-1-acid glycoprotein (AGP) and neutrophil gelatinase-associated lipocalin (NGAL), were quantified in a cross-sectional study that included participants of the UK JSLE Cohort Study (Cohort 1) and validated within the Einstein Lupus Cohort (Cohort 2). Binary logistic regression modelling and receiver operating characteristic curve analysis [area under the curve (AUC)] were used to identify and assess combinations of biomarkers for diagnostic accuracy. RESULTS: A total of 91 JSLE patients were recruited across both cohorts, of whom 31 (34 %) had active LN and 60 (66 %) had no LN. Urinary AGP, ceruloplasmin, VCAM-1, MCP-1 and LPGDS levels were significantly higher in those patients with active LN than in non-LN patients [all corrected p values (p c) < 0.05] across both cohorts. Urinary TF also differed between patient groups in Cohort 2 (p c = 0.001). Within Cohort 1, the optimal biomarker panel included AGP, ceruloplasmin, LPGDS and TF (AUC 0.920 for active LN identification). These results were validated in Cohort 2, with the same markers resulting in the optimal urine biomarker panel (AUC 0.991). CONCLUSION: In two international JSLE cohorts, urinary AGP, ceruloplasmin, LPGDS and TF demonstrate an 'excellent' ability for accurately identifying active LN in children.

Detection of renal and urinary tract proteins before and after spaceflight.

BACKGROUND: The recent evolution of genomics and subsequently proteomics offers a major advance in the ability to understand individual human variation in disease and the molecular level changes induced by certain environmental exposures. This original study examines urinary proteome composition to enable the understanding of molecular homeostatic mechanisms in spaceflight and presents the potential for early detection of subclinical disease, microgravity risk mitigation strategies, and countermeasure development for exploration-class missions. METHODS: The urinary proteome composition of six Russian cosmonauts (men, ages 35-51) who flew long-duration missions of 169-199 d was determined 30 d before flight and compared to repeat studies 1 and 7 d postflight. RESULTS: There were 430 proteins identified. Of those, 15 proteins originated in the renal tissues. Of the 15 urinary proteins, 10 were consistently present in the urine. However, the presence of five of the urinary proteins--neutral endopeptidase (NEP), afamin (AFAM), aquaporin-2 (AQP2), aminopeptidase A (AMPE), and dipeptidyl peptidase 4 (DPP4)--was dependent on spaceflight exposure. DISCUSSION: Proteomic investigation of pre- and postflight urine and bioinformation approaches to proteome analysis provide important data relative the mechanism of kidney function in spaceflight. In this initial study, we determined that the evaluation of urinary proteins may help investigators understand changes that are occurring in microgravity. Once additional ground-based and in-flight data are collected, it is feasible to develop targeted studies for tracking specific spaceflight related changes, determine countermeasure and risk-mitigation effectiveness, and possibly detect subclinical disease in flight crewmembers.

Elevated urinary sVCAM-1, IL6, sIL6R and TNFR1 concentrations indicate acute kidney transplant rejection in the first 2 weeks after transplantation.

We tested the hypothesis that increased urinary cytokine concentrations may indicate an acute kidney transplant rejection. Eight patients with an early rejection in their protocol biopsy about 14days after transplantation (group A), 9 patients with a biopsy proven rejection 2-3months after transplantation (group B) and 18 patients without acute rejection in their protocol biopsies both at 14days and 3months (group C, represents the control group) were chosen for this study. At the time of biopsy, the mean urinary concentration of interleukin 6 (IL6), soluble IL6 receptor (sIL6R), tumor necrosis factor receptor 1 (TNFR1), and soluble vascular cell adhesion molecule -1 (sVCAM-1) were significantly higher in patients with an early acute transplant rejection, i.e. in group A compared to patients in the control group (p<0.01). Additionally we found already 14days after transplantation significantly higher concentrations of urinary sIL6R and sVCAM-1 in group B patients who suffered of late acute rejection compared to patients with no acute rejection (group C, p<0.05). No significant correlation could be shown for interleukin 1 receptor antagonist (IL1ra), TNF, and TNFR2. In conclusion, elevated urinary concentrations of IL6, sIL6R, TNFR1 and sVCAM-1 clearly indicate an early acute transplant rejection. Especially sVCAM-1 may also serve as an early marker of an upcoming late rejection. However, further studies are warranted to verify the value of individual cytokine profiles to predict acute rejection episodes.

Validity of biomarkers predicting onset or progression of nephropathy in patients with Type 2 diabetes: a systematic review.

Novel biomarkers predicting onset or progression of nephropathy in patients with Type 2 diabetes have been recently identified. We performed a systematic review to assess the validity of biomarkers predicting onset or progression of nephropathy in patients with Type 2 diabetes in longitudinal studies. The methodological quality of the studies was scored using Standards for Reporting of Diagnostic Accuracy (STARD) criteria and the independent predictive value of the biomarkers beyond conventional risk factors was scored according to the adjustment for these risk factors. Validity of the biomarkers was determined by summarizing the methodological quality and the adjustment score. We identified 15 studies describing 27 biomarkers. Six studies had sufficient methodological quality. These studies identified 13 valid and significant markers for nephropathy in diabetes: serum interleukin 18, plasma asymmetric dimethylarginine; and urinary ceruloplasmin, immunoglobulin G and transferrin were considered valid markers predicting onset of nephropathy. Plasma asymmetric dimethylarginine, vascular cell adhesion molecule 1, interleukin 6, von Willebrand factor and intercellular cell adhesion molecule 1 were considered valid biomarkers predicting progression of nephropathy. Plasma high-sensitivity C-reactive protein, E-selectin, tissue-type plasminogen activator, von Willebrand factor and triglycerides were considered valid markers predicting onset and progression of nephropathy. Several novel biomarkers for prediction of nephropathy in diabetes have been published, which can potentially be applied in clinical practice and research in future. Because of the heterogeneous quality of biomarker studies in this field, a more rigorous evaluation of these biomarkers and validation in larger trials are advocated.

Urinary HER2, TWEAK and VCAM-1 levels are associated with new-onset proteinuria in paediatric lupus nephritis.

OBJECTIVE: Lupus nephritis is a key driver of morbidity and mortality in SLE. Detecting active nephritis on a background of pre-existing renal damage is difficult, leading to potential undertreatment and accumulating injury. An unmet need is a biomarker that distinguishes active lupus nephritis, particularly important in paediatrics where minimising invasive procedures is desirable. METHODS: This was a multicentre, prospective study of 113 paediatric patients with biopsy-proven lupus nephritis. Clinical data and urine were obtained every 3-4 months and patients averaged 2 years on study with seven time points. Urine was analysed for human epidermal growth factor receptor 2 (HER2), tumour necrosis factor-like weak inducer of apoptosis and vascular cell adhesion molecule-1 (VCAM-1) by ELISA. We defined active disease as either a rise in serum creatinine ≥0.3 mg/dL from baseline or a rise in renal Systemic Lupus Erythematosus Disease Activity Index score from the previous visit. These markers were also studied in patients with acute kidney injury, juvenile idiopathic arthritis (JIA), amplified pain syndrome and healthy controls. RESULTS: The rate of active disease was 56% over an average of 2 years of follow-up. HER2 and VCAM-1 were significantly elevated at time points with active disease defined by increased serum creatinine compared with time points with inactive disease or patients who never flared. All three biomarkers were associated with new-onset proteinuria and VCAM-1 was elevated at time points preceding new-onset proteinuria. These biomarkers were not increased in acute kidney injury or JIA. CONCLUSION: All three biomarkers were associated with new onset proteinuria and increased VCAM-1 may predict impending proteinuria. These biomarkers provide potential non-invasive measures for monitoring that may be more sensitive to impending flare than conventional measures.

Increased urinary levels of the leukocyte adhesion molecules ICAM-1 and VCAM-1 in human lupus nephritis with advanced renal histological changes: preliminary findings.

BACKGROUND: Leukocyte adhesion molecules are important for migration of the inflammatory cells into sites of inflammation. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) are members of the immunoglobulin superfamily that are expressed in normal kidney. Their expression is up-regulated in the renal tissue of patients with lupus nephritis (LN). OBJECTIVES: We evaluated whether changes in urinary levels of ICAM-1 and VCAM-1 reflect renal tissue damage in LN. We related the levels of these molecules to other laboratory findings, especially complement C3/C4 levels. We also tested the hypothesis that changes in urinary levels of ICAM-1 and VCAM-1 reflect the severity of renal tissue damage in LN. PATIENTS AND METHODS: This study included 30 systemic lupus erythematosus (SLE) patients with LN (16 with mild histological changes, i.e., with World Health Organization (WHO) class I and II LN, and 14 with advanced histological changes, i.e., class III, IV, and V LN) and 20 with SLE without nephritis. In addition, 20 healthy individuals of comparable age were included as a control group. The levels of urinary ICAM-1 and VCAM-1 were measured by enzyme-linked immunosorbent assay (ELISA) and related to the clinical, laboratory [rheumatoid factor(RF), antinuclear antibodies (ANA), anti-double-stranded DNA (anti-dsDNA), complements C3 and C4] and histological findings. RESULTS: Levels of urinary ICAM-1 and VCAM-l in LN patients with advanced histological changes (renal damage) were statistically significantly higher than those in other groups (LN patients with mild histological changes or SLE patients without nephritis and control group; p < 0.01). In contrast, serum levels of C3 and C4 in LN patients with advanced histological changes were significantly lower than those in other groups (p < 0.01). There was a significant negative correlation between the levels of urinary adhesion molecules and serum complement levels (p < 0.01). CONCLUSIONS: The significantly high urinary levels of the adhesion molecules in the LN group with advanced histological changes may reflect their renal tissue expression and therefore the severity of the nephritis. Renal tissue damage in these cases may be the result of transmigration of activated inflammatory cells, inducing serious tissue damage. The hypocomplementemia combined with increased urinary levels of adhesion molecules seems to be a useful biomarker of disease severity in LN.

Comprehensive aptamer-based screening identifies a spectrum of urinary biomarkers of lupus nephritis across ethnicities.

Emerging urinary biomarkers continue to show promise in evaluating lupus nephritis (LN). Here, we screen urine from active LN patients for 1129 proteins using an aptamer-based platform, followed by ELISA validation in two independent cohorts comprised of 127 inactive lupus, 107 active LN, 67 active non-renal lupus patients and 74 healthy controls, of three different ethnicities. Urine proteins that best distinguish active LN from inactive disease are ALCAM, PF-4, properdin, and VCAM-1 among African-Americans, sE-selectin, VCAM-1, BFL-1 and Hemopexin among Caucasians, and ALCAM, VCAM-1, TFPI and PF-4 among Asians. Most of these correlate significantly with disease activity indices in the respective ethnic groups, and surpass conventional metrics in identifying active LN, with better sensitivity, and negative/positive predictive values. Several elevated urinary molecules are also expressed within the kidneys in LN, based on single-cell RNAseq analysis. Longitudinal studies are warranted to assess the utility of these biomarkers in tracking lupus nephritis.

Urinary fatty acid and retinol binding protein-4 predict CKD progression in severe NAFLD patients with hypertension: 4-year study with clinical and experimental approaches.

Detection of the chronic kidney disease (CKD) progression can begin early intervention to improve the prognosis of severe non-alcoholic fatty liver disease (NAFLD). This bi-directional cross-sectional study evaluates the roles of fatty acid-binding protein (FABP) and retinol binding protein (RBP4), which are produced from inflamed liver, adipose tissue and immune cells, for the prediction of CKD progression in severe NAFLD. Ninety severe NAFLD patients with hypertension and proteinuria (NAFLDHTN) were enrolled and divided into CKD (n = 39) and non-CKD groups (n = 51). Among 39 NAFLDHTN patients, 18 cases were categorized as CKD progression group. In comparison with CKD stable group (n = 21), the positive correlation between fold change values of hepatic fibrotic score (KPa), urinary FABP4 or urinary RBP4 versus severity of albuminuria were noted among CKD progression group. On multivariate analysis, high body mass index (BMI, >25 kg/m), high hepatic fibrosis score (>9.5 KPa), high urinary level of vascular cell adhesion molecule-1 (VCAM-1, >2239 µg/g cr), high urinary level of FABP4 (>115 ng/g cr) and high urinary level of RBP4 (>33.5 mg/g cr) are 5 independent predictors for progressive CKD during 24 months of follow-up. Synergetic effect was noted among these 5 risk factors for the prediction of CKD progression in NAFLDHTN patients. The in vitro experiments revealed that both FABP4 and RBP4 directly enhanced albumin-induced ER stress and apoptosis of human renal tubular epithelial cell line HK-2 cells and human podocytes cell lines. Through clinical and experimental approaches, this study revealed new 5 synergetic predictors including high BMI, hepatic fibrosis score, urinary level of VCAM-1, urinary level of FABP4 and RBP4, for the CKD progression in severe NAFLD patients with hypertension and proteinuria.

IL-18, VCAM-1 and P-selectin as early biomarkers in normoalbuminuric Type 2 diabetes patients.

Aim: To investigate the pathophysiological role of different biomarkers in diabetic kidney disease (DKD) among normoalbuminuric patients with a low-estimated glomerular filtration rate (eGFR). Methods: In this cross-sectional study of 200 normoalbuminuric Type 2 diabetes patients, 28 patients (14%) had a low eGFR. Results: The IL-18, VCAM-1 and P-selectin levels were significantly higher at a low eGFR. On analyzing the area under the receiver operating characteristic curve, these biomarkers had significant diagnostic value and have important pathophysiological role in the progression of DKD. Conclusion: Among normoalbuminuric Type 2 diabetes patients, IL-18, VCAM-1 and P-selectin may play a significant role in the prediction of early DKD. Further prospective studies need to be conducted to confirm this observation.

Urinary angiostatin, CXCL4 and VCAM-1 as biomarkers of lupus nephritis.

BACKGROUND: The aim was to study urinary angiostatin, CXC chemokine ligand 4 (CXCL4) and vascular cell adhesion molecule-1 (VCAM-1) as biomarkers of renal disease in systemic lupus erythematosus (SLE). METHOD: Patients who fulfilled ≥ 4 American College of Rheumatology (ACR) criteria for SLE with active renal, active non-renal or inactive disease, and a group of healthy controls were studied. Urine samples were assayed for angiostatin, CXCL4 and VCAM-1 by ELISA, and normalized by creatinine. Receiver operating characteristic analysis was performed to obtain the best cutoff values to calculate the performance of these markers in differentiating the different groups of patients as compared to anti-double-stranded DNA (anti-dsDNA) and complement C3. Correlation between these urinary biomarkers and various renal parameters was also tested. RESULTS: Patients with SLE (n = 227; 80 with inactive SLE, 67 with active non-renal disease and 80 with active renal disease; 94% women; age 39.2 ± 13.8 years) and 53 controls (96% women) were studied. All were ethnic Chinese. Urinary angiostatin, CXCL4 and VCAM-1 (normalized for creatinine) were significantly higher in patients with active renal disease than in patients with active non-renal disease, patients with inactive SLE and controls. These markers correlated significantly with total SLE disease activity index (SLEDAI) and renal SLEDAI scores, and with the urinary protein-to-creatinine ratio. Urine angiostatin exhibited higher specificity and sensitivity in differentiating active renal from active non-renal SLE (area under the curve (AUC) 0.87) than serum anti-dsDNA/C3. Urine CXCL4 (AUC 0.64) and VCAM-1 (AUC 0.73), on the other hand, performed similarly to anti-dsDNA/C3. All three markers performed comparably to anti-dsDNA/C3 in distinguishing active from inactive SLE. In a subgroup of 68 patients with paired renal biopsy, the urinary levels of these proteins did not differ significantly between the proliferative and non-proliferative types of lupus nephritis. Urinary CXCL4 and VCAM-1 correlated significantly with the histologic activity score, and urinary angiostatin correlated significantly with proteinuria in this subgroup. CONCLUSIONS: Urinary angiostatin, CXCL4 and VCAM-1 are potential biomarkers for SLE, in particular lupus nephritis. Further longitudinal studies are necessary to delineate the performance of these markers in predicting renal flares and prognosis in SLE patients.

Urinary Proteome Analysis Identified Neprilysin and VCAM as Proteins Involved in Diabetic Nephropathy.

Urinary proteome was analyzed and quantified by tandem mass tag (TMT) labeling followed by bioinformatics analysis to study diabetic nephropathy (DN) pathophysiology and to identify biomarkers of a clinical outcome. We included type 2 diabetic normotensive non-obese males with (n = 9) and without (n = 11) incipient DN (microalbuminuria). Sample collection included blood and urine at baseline (control and DN basal) and, in DN patients, after 3 months of losartan treatment (DN treated). Urinary proteome analysis identified 166 differentially abundant proteins between controls and DN patients, 27 comparing DN-treated and DN-basal patients, and 182 between DN-treated patients and controls. The mathematical modeling analysis predicted 80 key proteins involved in DN pathophysiology and 15 in losartan effect, a total of 95 proteins. Out of these 95, 7 are involved in both processes. VCAM-1 and neprilysin stand out of these 7 for being differentially expressed in the urinary proteome. We observed an increase of VCAM-1 urine levels in DN-basal patients compared to diabetic controls and an increase of urinary neprilysin in DN-treated patients with persistent albuminuria; the latter was confirmed by ELISA. Our results point to neprilysin and VCAM-1 as potential candidates in DN pathology and treatment.