Urinary mRNA-based biomarkers for non-muscle-invasive bladder cancer: a mini-review.

Bladder cancer (BC) is the second most common type of cancer of the urinary system. Approximately 75% of the cases are non-muscle invasive bladder cancer (NMIBC), which has a high recurrence and progression rate. Current diagnosis and surveillance methods present challenges, including risks to the patients. For this reason, urinary biomarkers have been proposed as alternatives to the methods. The goal of this mini-review is to describe urinary mRNA-based biomarkers available in current literature for NMIBC tumors, using the PubMed database. The search included the following keywords: "biomarkers" AND "bladder cancer" AND "urine" and "RNA" and "non-muscle". The search yielded 11 original researchers utilizing mRNA-based urinary biomarkers. Although there is a wide variety of biomarkers described, the cohorts of the studies were not exclusively NMIBC, which is the subtype of BC that would mostly benefit from the introduction of a good follow-up biomarker, highlighting the need for randomized interventional trials for NMIBC.

Kidney Disease and Proteomics: A Recent Overview of a Useful Tool for Improving Early Diagnosis.

Kidney disease is a critical and potentially life-threatening degenerative condition that poses a significant global public health challenge due to its elevated rates of morbidity and mortality. It manifests primarily in two distinct clinical forms: acute kidney injury (AKI) and chronic kidney disease (CKD). The development of these conditions hinges on a multitude of factors, including the etiological agents and the presence of coexisting medical conditions. Despite disparities in their underlying pathogenic mechanisms, both AKI and CKD can progress to end-stage kidney disease (ESKD). This advanced stage is characterized by organ failure and its associated complications, greatly increasing the risk of mortality. There is an urgent need to delve into the pathogenic mechanisms underlying these diseases and to identify novel biomarkers that can facilitate earlier diagnosis. Such early detection is crucial for enhancing the efficacy of therapy and impeding disease progression. In this context, proteomic approaches have emerged as invaluable tools for uncovering potential new markers of different pathological conditions, including kidney diseases. In this chapter, we overview the recent discoveries achieved through diverse proteomic techniques aimed at identifying novel molecules that may play a pivotal role in kidney diseases such as diabetic kidney disease (DKD), IgA nephropathy (IgAN), CKD of unknown origin (CKDu), autosomal dominant polycystic kidney disease (ADPKD), lupus nephritis (LN), hypertensive nephropathy (HN), and COVID-19-associated acute kidney injury (COVID-AKI).

Potential urinary biomarkers in preeclampsia: a narrative review.

INTRODUCTION: Preeclampsia (PE) is a highly relevant pregnancy-related disorder. An early and accurate diagnosis is crucial to prevent major maternal and neonatal complications and mortality. Due to the association of kidney dysfunction with the pathophysiology of the disease, urine samples have the potential to provide biomarkers for PE prediction, being minimally invasive and easy to perform. Therefore, searching for novel biomarkers may improve outcomes. This narrative review aimed to summarize the scientific literature about the traditional and potential urinary biomarkers in PE and to investigate their applicability to screen and diagnose the disorder. METHODS: A non-systematic search was performed in PubMed/MEDLINE, Scopus, and SciELO databases. RESULTS: There is significant divergence in the literature regarding traditionally used serum markers creatinine, cystatin C, and albuminuria, accuracy in PE prediction. As for the potential renal biomarkers investigated, including vascular epithelial growth factor (VEGF), placental growth factor (PlGF), and soluble fms-like tyrosine kinase (sFlt-1), urinary levels of PlGF and sFtl-1/PlGF ratio in urine seem to be the most promising as screening tests. The assessment of the global load of misfolded proteins through urinary congophilia, podocyturia, and nephrinuria has also shown potential for screening and diagnosis. Studies regarding the use of proteomics and metabolomics have shown good accuracy, sensitivity, and specificity for predicting the development and severity of PE. CONCLUSION: However, there are still many divergences in the literature, which requires future and more conclusive research to confirm the predictive role of urinary biomarkers in pregnant women with PE.

Congenital Solitary Functioning Kidney: A Review.

BACKGROUND: Solitary functioning kidney (SFK) is a subgroup of the Congenital Anomalies of the Kidneys and Urinary Tract (CAKUT). Although the prognosis of these patients was considered good in the past, numerous studies have shown different levels of kidney damage associated with this condition. Serum creatinine measurement is still the most used marker to assess renal function, even though the limitations are widely known. OBJECTIVE: The present review aims to summarize and update the scientific literature on congenital SFK, discussing its pathophysiology, diagnosis, complications, prognosis, role of novel urinary biomarkers, treatment, and follow-up. RESULTS: The natural history of congenital SFK is still an unresolved issue due to several factors. Although it has not yet been proven in humans, Brenner's hyperfiltration hypothesis is the most concrete theory to explain the poor renal outcomes of patients born with one functioning kidney. The search for novel urinary biomarkers capable of assessing renal function and predicting renal outcomes has already started, but there are still few studies on this specific population. Among the most studied markers, Cystatin C, EGF and NGAL have shown potential usefulness for the follow-up of these patients. The treatment still relies on the search for kidney injury and general renoprotective measures. CONCLUSION: Further research with a longer follow-up duration is needed to better understand the natural course of congenital SFK and the role of novel urinary biomarkers in this specific population. Thus, it will be possible to improve the prognosis of these patients.

Nephrogenesis, Renal Function, and Biomarkers in Preterm Newborns.

BACKGROUND: The survival of premature newborns increased in the last decades due to advances in neonatal care. The physiology of this group is still under investigation, once the incomplete organogenesis entails functional particularities that are not yet clarified by current clinical knowledge. The immature kidneys are especially susceptible to acute injury with potential long-term impacts. Current diagnostic parameters of acute kidney injury are limited among the preterm population. The commonly used serum creatinine protein constitutes a poor biomarker to predict early lesions as it is susceptible to several factors, including muscle mass and gestational age. OBJECTIVE: The present review explores the evidence on nephrogenesis, renal function, and acute kidney injury in neonatology, as well as studies on renal function biomarkers and their potential application for diagnosis, follow-up, and prognosis in preterm newborns. RESULTS: Premature newborns reach full-term gestational age with reduced number and quality of nephrons. Consequently, the glomerular filtration rate and tubular function become impaired and are proportional to the gestational age. Despite having a high incidence among the pediatric population, acute kidney injury is still underdiagnosed and poorly managed due to the absence of proper, sensible, and non-invasive biomarkers. Although cystatin C, NGAL, and KIM-1, are promising urinary markers, current literature remains inconsistent. CONCLUSION: Further research is needed to properly identify and standardize sensible and specific urinary biomarkers to better assess kidney function in preterm newborns.

Nanoproteomic Approach for Isolation and Identification of Potential Biomarkers in Human Urine from Adults with Normal Weight, Overweight and Obesity.

In this work, previously synthesized and characterized core-shell silica nanoparticles (FCSNP) functionalized with immobilized molecular bait, Cibacron blue, and a porous polymeric bis-acrylamide shell were incubated with pooled urine samples from adult women or men with normal weight, overweight or obesity for the isolation of potential biomarkers. A total of 30 individuals (15 woman and 15 men) were included. FCSNP allowed the capture of a variety of low molecular weight (LMW) proteins as evidenced by mass spectrometry (MS) and the exclusion of high molecular weight (HMW) proteins (>34 kDa) as demonstrated by SDS-PAGE and 2D SDS-PAGE. A total of 36 proteins were successfully identified by MS and homology database searching against the Homo sapiens subset of the Swiss-Prot database. Identified proteins were grouped into different clusters according to their abundance patterns. Four proteins were found only in women and five only in men, whereas 27 proteins were in urine from both genders with different abundance patterns. Based on these results, this new approach represents an alternative tool for isolation and identification of urinary biomarkers.

Expression of BAFF, APRIL, and cognate receptor genes in lupus nephritis and potential use as urinary biomarkers.

BACKGROUND: B-cell activating factor (BAFF), a proliferation-inducing ligand (APRIL), and their receptors BAFF-R, BCMA, and TACI are crucial factors for the survival of B lymphocytes. Recent evidence has also demonstrated the importance of BAFF/APRIL signaling in lupus nephritis (LN). This study evaluated the relationships between LN clinical characteristics and the urinary expression levels of BAFF, APRIL, and cognate receptors to assess their potential value as disease biomarkers. METHODS: Expression levels of these genes were assessed in urine samples collected from systemic lupus erythematosus (SLE) patients before renal biopsy using reverse transcription real-time PCR. RESULTS: Thirty-five patients with LN were included. Most of the patients were female (82.86%) with median Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) of 15. BAFF mRNA was detectable in 28.57%, APRIL mRNA in 42.85%, BR3 mRNA in 48.57%, and TACI mRNA in 42.85% of urine samples. On the other hand, urinary (u)BCMA mRNA was not found in any sample. Urinary expression of most biomarkers was detected with greater frequency in class III and IV LN compared to class V LN. The expression level of uBR3 mRNA was correlated with SLEDAI-2K and histological activity index. CONCLUSION: Urinary expression of BAFF/APRIL signaling factors, especially TACI, APRIL, and BR3 mRNAs, may be useful biomarkers for LN.

Urinary biomarkers in lupus nephritis.

Systemic lupus erythematosus (SLE) is the prototypical autoimmune disease that can affect any organ of the body. Multiple mechanisms may contribute to the pathophysiology of systemic lupus, including failure to remove apoptotic bodies, hyperactivity of self-reactive B and T lymphocytes, abnormal exposure to autoantigens, and increased levels of B-cell stimulatory cytokines. The involvement of the kidney, called lupus nephritis (LN), during the course of the disease affects between 30% and 60% of adult SLE patients, and up to 70% of children. LN is an immune-mediated glomerulonephritis that is a common and serious finding in patients with SLE. Nowadays, renal biopsy is considered the gold standard for classifying LN, besides its degree of activity or chronicity. Nevertheless, renal biopsy lacks the ability to predict which patients will respond to immunosuppressive therapy and is a costly and risky procedure that is not practical in the monitoring of LN because serial repetitions would be necessary. Consequently, many serum and urinary biomarkers have been studied in SLE patients for the complementary study of LN, existing conventional biomarkers like proteinuria, protein/creatinine ratio in spot urine, 24 â€‹h urine proteinuria, creatinine clearance, among others and non-conventional biomarkers, like Monocyte chemoattractant protein-1 (MCP-1), have been correlated with the histological findings of the different types of LN. In this article, we review the advances in lupus nephritis urinary biomarkers. Such markers ideally should be capable of predicting early sub-clinical flares and could be used to follow response to therapy. In addition, some of these markers have been found to be involved in the pathogenesis of lupus nephritis.

Urinary biomarkers of inflammation and tissue remodeling may predict bladder dysfunction in patients with benign prostatic hyperplasia.

PURPOSE: To evaluate the expression of urinary biomarkers of inflammation and tissue remodeling in patients with BPH undergoing surgery and evaluate the association of biomarkers with postoperative urodynamic outcomes MATERIALS AND METHODS: We analyzed urine samples from 71 patients treated with TURP from 2011 to 2017. Urinary levels of epidermal growth factor (EGF), matrix-metalloproteinase-1 (MMP-1), interleukin-6 (IL-6), nerve growth factor (NGF) and monocyte-chemoattractant protein-1 (MCP-1) (by commercial ELISA kit) were measured, adjusted by urinary creatinine (Cr) and analyzed according to patients clinical and urodynamic characteristics (baseline and 12-month postoperative urodynamic) RESULTS: MMP-1/Cr levels were significantly higher among subjects with higher detrusor pressure on preoprative urodynamic. MCP-1/Cr levels were significantly higher amongs subjects with preoperative DO. Preoperative levels of NGF/Cr (0.13 vs 0.08, p = 0.005) and MMP-1/Cr (0.11 vs 0.04, p = 0.021) were predictors of persistent DO 12 months after surgery. The following factors were shown to be useful for predicting the persistence of DO in the postoperative period: NGF/Cr, with an AUC of 0.77 (95% CI 0.62-0.92) (p = 0.006), and MMP-1/Cr, with an AUC of 0.72 (95% CI 0.56-0.88) (p = 0.022). CONCLUSIONS: MMP-1/Cr was associated with higher detrusor pressure and MCP-1/CR with DO. NGF/Cr and MMP-1/Cr were shown to be predictors of persistent postoperative DO.

Reductions in urinary metabolites of exposure to household air pollution in pregnant, rural Guatemalan women provided liquefied petroleum gas stoves.

BACKGROUND: Household air pollution from solid fuels is a leading risk factor for morbidity and mortality worldwide. Pregnant women's exposure to polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs), two components of solid-fuel smoke, is associated with adverse birth outcomes. Even with improved solid-fuel stoves, exposure to PAHs and VOCs remains high. Therefore, cleaner cooking fuels need to be prioritized. OBJECTIVE: We aimed to quantify exposure reduction to PAHs and VOCs among pregnant women in rural Guatemala with a liquefied petroleum gas (LPG) stove intervention. MATERIALS AND METHODS: Urine from pregnant women (N = 50) was collected twice: at <20 weeks gestation, when women cooked exclusively with wood, and 6-8 weeks after receiving an LPG stove. Metabolites of four PAHs and eight VOCs were analyzed. Concurrent with urine collection, personal 48-h PM2.5 exposure was measured. RESULTS: Women cooking exclusively with wood were exposed to high levels of particulate matter (PM2.5), which was reduced by 57% with the LPG stove. Urinary concentrations of total PAH metabolites (-37%), PMA (benzene metabolite; -49%), and CNEMA (acrylonitrile metabolite; -51%) were reduced. However, recent use of a wood-fired sauna bath led to large increases in excretion of urinary toxicant metabolites (+66-135%). CONCLUSIONS: This is the first study to report PAH and VOC reductions from an LPG stove intervention introduced during pregnancy. However, other sources of air pollution minimized the gains seen from using an LPG stove. Thus, all sources of air pollution must be addressed in concert to reduce exposures to levels that protect health.

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.

Urinary Neutrophil Gelatinase-Associated Lipocalin in Cirrhotic Patients with Acute Kidney Injury.

INTRODUCTION AND AIM: It is well known that development of acute kidney injury (AKI) increases mortality in hospitalized cirrhotic patients; therefore many novel markers have been studied for early detection, differential diagnosis and prognosis in cirrhotic patients with AKI. The aim of the current work is to evaluate urinary Neutrophil Gelatinase-Associated Lipocalin (uNGAL) as a diagnostic biomarker for different causes of acute kidney injury in liver cirrhosis and to assess it as a prognostic marker. MATERIAL AND METHODS: Out of 83 cirrhotic patients with AKI admitted between October 2015 and June 2016; 70 patients were included in this prospective study. Routine laboratory tests, uNGAL and fractional excretion of Na were obtained on admission. End points were death or improvement of kidney function and discharge. RESULTS: The patients included in our study were 41 males and 29 females with mean age 54.27 ± 6.08 years. HCV was the etiology of cirrhosis in 69 cases while one had combined HBV and HCV infection. More than 50% of patients were classified as Child C. Causes of kidney injury were prerenal, hepatorenal syndrome (HRS) and intrinsic tubular injury (iAKI) in 39 patients (55.7%), 17 patients (24.3%) and 14 patients (20%) respectively. mean value of uNGAL in prerenal, HRS and iAKI was 21.70 ± 7.31, 115.53 ± 68.19 and 240.83 ± 116.94 ng/mg creatinine respectively. MELD above 20 and uNGL above 32 were predictors of mortality. CONCLUSION: A single baseline measurement of uNGAL level has the ability to determine type of kidney dysfunction in cirrhotic patients, perhaps accelerating management decisions and improving outcomes.

Assessment of urinary TWEAK levels in Mexican patients with untreated lupus nephritis: An exploratory study.

OBJECTIVES: Urinary levels of TWEAK (uTWEAK) may be correlated with the degree of lupus nephritis (LN) activity. Our objective was to determine the sensitivity and specificity of uTWEAK in Mexican patients with untreated active lupus nephritis. METHODS: An exploratory study was performed; four groups of patients were analyzed as follows: 1) patients with systemic lupus erythematosus (SLE) without renal activity (SLE-LN), 2) patients with SLE with renal activity (SLE+LN), 3) patients with other types of glomerulopathy (glomerulonephritis, GMN), 4) and healthy patients (controls). RESULTS: In all, 44 patients, with an average age of 35.9±11.5 years, were evaluated. uTWEAK levels were higher in patients with SLE+LN compared with patients in the other groups: SLE+LN 12.88±8.33, SLE-LN 3.12±2.31, GMN 4.36±2.31 and controls 2.41±1.94pg/mg Cr (p=0.007). A total of 72.7% of the cases had renal activity index scores above 12, and 90.9% of the cases had scores of chronicity below 6 points. Receiver Operating Characteristic (ROC) curve analysis revealed that uTWEAK levels above 4.91pg/mg Cr had a sensitivity of 81% and a specificity of 75% for the diagnosis of renal activity due to lupus, with an area under the curve of 0.876 (95% CI: 0.75-0.99). However, no significant correlation was observed between the levels of uTWEAK and the histological findings specific to the activity and chronicity associated with SLE. CONCLUSIONS: Our study revealed that uTWEAK can adequately distinguish renal activity due to lupus, but cannot predict the degree of histological activity in Mexican patients with active lupus nephropathy.

Exposure to polycyclic aromatic hydrocarbons and volatile organic compounds among recently pregnant rural Guatemalan women cooking and heating with solid fuels.

BACKGROUND: Household air pollution is a major contributor to death and disability worldwide. Over 95% of rural Guatemalan households use woodstoves for cooking or heating. Woodsmoke contains carcinogenic or fetotoxic polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Increased PAHs and VOCs have been shown to increase levels of oxidative stress. OBJECTIVE: We examined PAH and VOC exposures among recently pregnant rural Guatemalan women exposed to woodsmoke and compared exposures to levels seen occupationally or among smokers. METHODS: Urine was collected from 23 women who were 3 months post-partum three times over 72h: morning (fasting), after lunch, and following dinner or use of wood-fired traditional sauna baths (samples=68). Creatinine-adjusted urinary concentrations of metabolites of four PAHs and eight VOCs were analyzed by liquid chromatography-mass spectrometry. Creatinine-adjusted urinary biomarkers of oxidative stress, 8-isoprostane and 8-OHdG, were analyzed using enzyme-linked immunosorbent assays (ELISA). Long-term (pregnancy through 3 months prenatal) exposure to particulate matter and airborne PAHs were measured. RESULTS: Women using wood-fueled chimney stoves are exposed to high levels of particulate matter (median 48h PM2.5 105.7µg/m3; inter-quartile range (IQR): 77.6-130.4). Urinary PAH and VOC metabolites were significantly associated with woodsmoke exposures: 2-naphthol (median (IQR) in ng/mg creatinine: 295.9 (74.4-430.9) after sauna versus 23.9 (17.1-49.5) fasting; and acrolein: 571.7 (429.3-1040.7) after sauna versus 268.0 (178.3-398.6) fasting. Urinary PAH (total PAH: ρ=0.89, p<0.001) and VOC metabolites of benzene (ρ=0.80, p<0.001) and acrylonitrile (ρ=0.59, p<0.05) were strongly correlated with long-term exposure to particulate matter. However urinary biomarkers of oxidative stress were not correlated with particulate matter (ρ=0.01 to 0.05, p>0.85) or PAH and VOC biomarkers (ρ=-0.20 to 0.38, p>0.07). Urinary metabolite concentrations were significantly greater than those of heavy smokers (mean cigarettes/day=18) across all PAHs. In 15 (65%) women, maximum 1-hydroxypyrene concentrations exceeded the occupational exposure limit of coke-oven workers. CONCLUSIONS: The high concentrations of urinary PAH and VOC metabolites among recently pregnant women is alarming given the detrimental fetal and neonatal effects of prenatal PAH exposure. As most women used chimney woodstoves, cleaner fuels are critically needed to reduce smoke exposure.

Increased levels of adenosine and ecto 5'-nucleotidase (CD73) activity precede renal alterations in experimental diabetic rats.

The pathogenesis of diabetic nephropathy (DN) has not been clearly established, making diagnosis and patient management difficult. Recent studies using experimental diabetic models have implicated adenosine signaling with renal cells dysfunction. Therefore, the study of the biochemical mechanisms that regulate extracellular adenosine availability during DN is of emerging interest. Using streptozotocin-induced diabetic rats we demonstrated that urinary levels of adenosine were early increased. Further analyses showed an increased expression of the ecto 5'-nucleotidase (CD73), which hydrolyzes AMP to adenosine, at the renal proximal tubules and a higher enzymatic activity in tubule extracts. These changes precede the signs of diabetic kidney injury recognized by significant proteinuria, morphological alterations and the presence of the renal fibrosis markers alpha smooth muscle actin and fibronectin, collagen deposits and thickening of the glomerular basement membrane. In the proximal tubule cell line HK2 we identified TGF-ß as a key modulator of CD73 activity. Importantly, the increased activity of CD73 could be screened in urinary sediments from diabetic rats. In conclusion, the increase of CD73 activity is a key component in the production of high levels of adenosine and emerges as a new tool for the early diagnosis of tubular injury in diabetic kidney disease.

Increased urinary cystatin C level is associated with interstitial fibrosis and tubular atrophy in kidney allograft recipients.

AIM: The objective of this study was to investigate the correlation between the urinary excretion of cystatin C (CysC) and the presence of interstitial fibrosis/tubular atrophy (IF/TA) in renal transplant (RT) recipients. METHODS: This prospective study included 21 adult patients who had undergone renal biopsy and RT ≥6 months prior. According to the renal biopsy reports, the patients were divided into groups with (n=12) or without (n=9) IF/TA. Analytical parameters included the following: serum and urinary levels of CysC, creatinine (Cr) and sodium (Na), total urinary protein, urinary CysC/creatinine ratio [u(CysC/Cr)], fractional excretion of sodium (FENa) and estimated glomerular filtration rate (eGFR) based on the Chronic Kidney Disease Epidemiology Collaboration equation. RESULTS: The values of uCysC, u(CysC/Cr), proteinuria, and FENa were significantly higher in patients with IF/TA than in patients without IF/TA. The values of eGFR were statistically lower in patients with IF/TA (p=0.001). Values of uCysC significantly correlated with those of serum Cr, FENa, and eGFR (p<0.001). Among the patients with IF/TA, 67% presented with glomerulosclerosis (segmental/global). CONCLUSION: Elevated levels of urinary CysC are associated with interstitial fibrosis and tubular atrophy in RT recipients and may become a useful tool for monitoring kidney allografts.