Neutrophil gelatinase-associated lipocalin (NGAL): a new marker of kidney disease

The nephroprotective effect of metformin with cisplatin in bladder cancer: randomized clinical trial

PURPOSE

Cisplatin-based combination chemotherapy is the mainstay treatment strategy in various forms of carcinomas and sarcomas. However, its dosage and therapeutic efficacy are significantly limited by its nephrotoxicity. Based on metformin renal benefits in different studies, the study aims to determine safety and the potential nephroprotective effect of metformin when used with cisplatin in patients with bladder cancer.

METHODS

This was a prospective, randomized, parallel, controlled, open-label study in which 78 chemotherapy naïve bladder cancer patients aged 18-65 years and would receive gemcitabine/cisplatin regimen were selected and randomly assigned to treatment or control group in 1:1 allocation. Both groups were receiving cisplatin standard-of-care regimen, whereas metformin (500 mg, twice daily) was added to the treatment group's regimen only. Patients were prospectively followed up for four cycles of gemcitabine/cisplatin with assessment of renal function tests, serum neutrophil gelatinase-associated lipocalin (NGAL), cystatin-c, and metformin's adverse effects.

RESULTS

Serum creatinine, serum NGAL, and cystatin-C significantly increased in the control group only (P < 0.001). Estimated glomerular filtration rate (eGFR) significantly declines in the control group only (P < 0.001). On the contrary, serum NGAL significantly improved in the treatment group (P = 0.02) with stable and normal mean value of serum creatinine, eGFR, and cystatin-C without a concomitant significant increase in adverse events, such as hypoglycemia, gastrointestinal symptoms, or weight loss compared to the control group.

CONCLUSION

Metformin prevented renal damage and deterioration in kidney function in cisplatin-treated patients. Therefore, it is a promising agent in reducing cisplatin-induced nephrotoxicity. The study was registered in ClinicalTrials.gov on December, 16, 2023, Identifier Number NCT06215976.

Modulation of GLP-1 signalling as an innovative strategy counteracting the onset of heart failure: Potential for natural compound supplementation

The clinical continuum of heart failure (HF) is commonly divided into four stages (A, B, C and D), but despite the identification of its staging, to date, the management of the early phases remains an unmet need. In fact, the incomplete knowledge of the molecular mechanisms associated with the comorbidities leading to HF onset represents an obstacle to a targeted therapy. Recently, stages A and B have been further typified and, starting from this novel characterization, the aim of our review was to propose an alternative criterion to appropriately use GLP-1 RA in association with plant-derived polyphenolic extracts. This alternative approach is based on the selection of the main molecular mechanisms underlying the early and asymptomatic HF onset that might be further prevented or antagonized through the administration of natural extracts.

Evaluation of renal function with neutrophil gelatinase-associated lipocalin in patients with ıron deficiency anemia

The objective is to investigate the potential adverse effects of iron deficiency and iron deficiency anemia on renal functions by utilizing plasma Neutrophil Gelatinase-Associated Lipocalin (NGAL) levels. From September 2021 to February 2022, plasma NGAL levels, hemogram, biochemical parameters were assessed in all participants. They were divided into three groups: Group I (non-anemic iron deficiency), Group II (iron deficiency anemia), and Group III (healthy controls), with comparative analyses conducted. Group I had 38 individuals, Group II had 75 individuals, and Group III included 57 individuals. Plasma NGAL levels were higher in Groups I and II compared to Group III, with no significant difference between Groups I and II. ROC analysis revealed an AUC of 0.63 for NGAL in distinguishing Group II from Group III. No significant disparities were found in serum creatinine and glomerular filtration rate levels among the groups. A significant negative correlation was observed between plasma NGAL levels and ferritin, iron, hemoglobin, and mean corpuscular volume (MCV) levels. Plasma NGAL levels were significantly higher in adult patients with non-anemic iron deficiency and iron deficiency anemia compared to the healthy group. This suggests that elevated plasma NGAL levels in these patients might indicate renal injury due to various mechanisms.

Vitamin D and Acute Kidney Injury: A Reciprocal Relationship

Vitamin D is a sterol prohormone with no intrinsic biological activity. Calcitriol, the active form of vitamin D, is synthesized in the kidneys. It has well-known pleiotropic and cytoprotective properties. In addition to regulating parathyroid hormone secretion and enhancing gut calcium absorption, it exhibits antioxidant, anti-inflammatory, antiproliferative, and antineoplastic effects. However, the role of vitamin D in AKI is unclear, unlike in CKD. Thus, this review aimed to understand how dysregulated vitamin D homeostasis occurs in AKI, as well as to explore how vitamin D deficiency and excess influence AKI. A comprehensive literature search was conducted between January 2000 and June 2024 to uncover relevant works detailing vitamin D homeostasis in health as well as investigating the impact of vitamin D deficiency and excess in humans, animals, and in vitro cell models of AKI. According to the findings of this review, vitamin D appears to have a reciprocal relationship with AKI. Acute renal injury, among other factors, can cause hypo- or hypervitaminosis D. Conversely, AKI can also be caused by vitamin D deficiency and toxicity. Even though hypovitaminosis D is associated with AKI, it is uncertain how it impacts AKI outcomes in distinct clinical scenarios. Newer therapeutic options might emerge as a result of understanding these challenges. Vitamin D supplementation may ameliorate renal injury but needs further validation. Furthermore, hypervitaminosis D has also been implicated in AKI by causing hypercalcemia and hyperphosphatemia. It is crucial to avoid prolonged, uncontrolled, and unsupervised supraphysiological vitamin D administration, especially intramuscular injection.

Urinary Neutrophil Gelatinase-Associated Lipocalin Values in Preterm Neonates: A Systematic Review and Meta-analysis

Acute kidney injury (AKI) is common in hospitalized preterm neonates. Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is a promising noninvasive AKI biomarker. However, normal values of uNGAL in preterm neonates without AKI are poorly characterized. The objective of this study was to evaluate the current literature to determine normal uNGAL values for preterm neonates without AKI.Systematic review and meta-analysis of all articles published before November 2021 evaluating uNGAL values in preterm neonates without AKI.Of 1,607 studies evaluated for eligibility, 11 were included in the final meta-analysis (210 males, 202 females). uNGAL values were higher in the preterm neonates <29 weeks and ranged between 20.7 and 782.65 ng/mL. Meta mean estimates of gestational age (GA), birthweight, and neutrophil gelatinase-associated lipocalin were 29.4 weeks (95% confidence interval [CI]: 28.8-30.0), 1,241 g (95% CI: 1,111-1,372), and 148.9 ng/mL (95% CI: 48-231), respectively.In limited studies, a wide range of uNGAL values in preterm neonates without AKI are reported. Future studies should identify normal uNGAL values in preterm neonates using larger cohorts by GA and birthweight. · Urinary NGAL is a promising noninvasive biomarker of neonatal AKI.. · A wide range of uNGAL is reported in preterm neonates but the baseline values are not well defined.. · Urine NGAL values are higher in extremely preterm compared with preterm neonates..

Transcriptomic changes and mitochondrial toxicity in response to acute and repeat dose treatment with brequinar in human liver and kidney in vitro models

The potent dihydroorotate dehydrogenase (DHODH) inhibitor brequinar has been investigated as an anticancer, immunosuppressive, and antiviral pharmaceutical agent. However, its toxicity is still poorly understood. We investigated the cellular responses of primary human hepatocytes (PHH) and telomerase-immortalised human renal proximal tubular epithelial cells (RPTEC/TERT1) after a single 24-h exposure up to 100 μM brequinar. Additionally, RPTEC/TERT1 cells underwent repeated daily exposure for five consecutive days at 0.3, 3, and 20 μM. Transcriptomic analysis revealed that PHH were less sensitive to brequinar treatment than RPTEC/TERT1 cells. Upregulation of various phase I and II drug-metabolising enzymes, particularly Cytochrome P450 (CYP) 1 A and 3 A enzymes, in PHH suggests potential detoxification. Furthermore, brequinar exposure led to a significant upregulation of several stress response pathways in PHH and RPTEC/TERT1 cells, including the unfolded protein response, Nrf2, p53, and inflammatory responses. RPTEC/TERT1 cells exhibited greater sensitivity to brequinar at 0.3 μM with repeated exposure compared to a single exposure. Furthermore, brequinar could impair the mitochondrial respiration of RPTEC/TERT1 cells after 24 h. This study provides new insights into the differential responses of PHH and RPTEC/TERT1 cells in response to brequinar exposure and highlights the biological relevance of implementing repeated dosing regimens in in vitro studies.

Antitumoral effectiveness and safety of intravenous versus subcutaneous administration of immunomodulatory peptide GK-1 in a murine breast cancer model

INTRODUCTION

GK-1 is a safe and effective molecule with high antimetastatic activity against murine breast and skin cancer. GK-1 treatment enhances cytotoxic response of CD8+ lymphocytes against the tumor and modifies the oxidative stress in the tumor. This study was designed to compare the antitumor efficacy of GK-1 by subcutaneous (SC) versus intravenous (IV) route of administration in the 4T1 mouse mammary carcinoma model and to extend its innocuity in heart and kidney, key tissues for observing damage induced by anticancer drugs and immunotherapy.

MATERIAL AND METHODS

BALB/c female mice were injected orthotopically with 1000 4T1 cells. When palpable primary tumors of about 1 mm3 were detected, GK-1 (5 mg/kg) was administered IV or SC weekly for 21 days. Tumor growth and mouse weight were monitored weekly. The primary tumor weight and volume, the number of lung metastases, and programmed cell death protein 1 (PD-1) expression were recorded after 28 days of starting treatment. Kidney, heart, spleen, serum, and blood samples from naïve mice were obtained to evaluate the safety of GK-1 administration by measuring the degree of damage to these tissues with specific cytotoxic markers.

RESULTS

Subcutaneous or intravenous administration of GK-1 significantly increased the lifespan of mice and significantly reduced the primary tumor weight and volume and the number of lungs macrometastases. GK-1 reduced the expression of PD-1 in tumor-infiltrating lymphocytes in mice regardless of the route of immunization used, which is especially encouraging. No evidence of damage to kidney or heart tissues was detected in the tumor-free mice.

CONCLUSIONS

This study supports that subcutaneous GK-1 administered, has an efficacy non-inferior to intravenous administration, well-tolerated with a similar safety profile and therefore offers a less invasive valid treatment alternative.

Association between objectively assessed physical activity and kidney function among female agricultural workers in hot environments in Spain

BACKGROUND

Physical activity in hot environments has been associated with impaired kidney function. We aimed to quantify the association between occupational physical activity and kidney function over one work shift in female agricultural workers exposed to environmental heat.

METHODS

We measured occupational physical activity in female berry pickers in Huelva, Spain, using movement intensity, based on vector magnitude units (VMU), and heart rate (HR). For both, we calculated the mean (VMU_mean; HR_mean), standard deviation (VMU_sd; HR_sd), and 3-min 95th percentile (VMU_p95; HR_p95). Environmental heat in greenhouses was estimated using wet bulb globe temperature (WBGT). Kidney function and injury were quantified using pre- and post-shift differences in serum creatinine (SCr_dif), Cystatin C (Cystatin C_dif) and neutrophil gelatinase associated lipocalin (NGAL_dif), respectively. Acute Kidney Injury (AKI) was defined as an increase in post-shift serum creatinine of ≥0.3 mg/dl, or ≥1.5 times pre-shift levels. Heat strain was estimated using the ISO 7933:2004 index. We used linear and logistic regressions.

RESULTS

Ninety women aged 37.4 ± 5.7 years were exposed to a mean WBGT of 25.2 (±3.6)°C and light intensity physical activity (HR_mean of 94 (±9)bpm). Of those, 26 % experienced heat strain, 68 % were dehydrated, and 7 % presented with AKI at the end of the shift. Higher VMU_sd was associated with higher Scr_dif (β: 0.029 (95 % CI: 0.00; 0.058) and meeting the threshold for AKI (OR: 1.6 (95 % CI: 0.8; 3.2)). We observed higher NGAL_dif with higher VMU_mean (β: 1.944 (95 % CI: 0.139; 3.748)) per 100 VMU_mean increase. The positive association between HR_mean and SCr_dif was stronger among women with heat strain (interaction p = 0.033).

CONCLUSIONS AND RELEVANCE

In female harvest workers, high means and variations in VMU over a single one shift worked under hot conditions were associated with kidney injury, as assessed by urinary biomarkers, though there is limited evidence for any change in kidney function. Precautiously, large changes in physical activity intensity over one work shift should be avoided to protect from renal injury.

Molecular docking, dynamics simulations, and in vivo studies of gallic acid in adenine-induced chronic kidney disease: targeting KIM-1 and NGAL

Gallic acid (GA), a naturally occurring compound with antioxidant, anti-inflammatory, anti-apoptotic, and regenerative properties, has gained attention for its potential protective role against kidney dysfunction and diseases, though its therapeutic efficacy in this context remains underexplored. The primary objective of this study was to explore the therapeutic effects of GA in treating adenine-induced chronic kidney disease (CKD) in male Wistar rats. The study evaluated GA's therapeutic potential against CKD, along with its pharmacokinetic and drug-likeness properties through a comprehensive analysis. It also assessed GA's inhibitory effects on key kidney proteins, KIM-1 and NGAL, using gene expression analysis, molecular docking, and molecular dynamics simulations. The results demonstrated a range of positive effects, including significant improvement in adenine-induced kidney damage, as shown by changes in urine and serum markers, as well as oxidative stress biomarkers, following GA treatment. The study revealed that GA effectively suppresses the adenine-induced gene expression of KIM-1 and NGAL. Furthermore, GA adhered to Lipinski's Rule of Five, and molecular docking analysis indicated strong interactions and low binding energies between GA and the target proteins KIM-1 and NGAL, further supporting its efficacy in targeting these markers. Additionally, 100 ns molecular dynamics simulations showed that gallic acid has a stronger binding affinity for NGAL than for KIM-1, with higher binding energy, stability, and stronger hydrogen bonds, suggesting that it primarily influences NGAL interactions. This study underscores gallic acid's potential in reducing adenine-induced kidney damage and improving kidney function, with computational evidence supporting its promise as a treatment for CKD.

Resazurin dye is an in vivo sensor of kidney tubular function

Glomerular filtration rate (GFR) is the main functional index of kidney health and disease. Currently, no methods are available to directly measure tubular mass and function. Here, we report a serendipitous finding that the in vitro cell viability dye resazurin can be used in mice as an exogenous sensor of tubular function. Intravenously injected resazurin exhibited significant plasma protein binding and was found to mainly undergo tubular secretion. Mechanistic studies showed that the blue-colored, weakly fluorescent resazurin is taken up by tubular cells through organic anion transporters, followed by conversion to a highly fluorescent, pink-colored resorufin by mitochondrial and cytosolic reductases, converted to an orange-colored β-d-glucuronide with subsequent efflux into the urine. Here we report a simple method in which the intravenous injection of resazurin is followed by the measurement of fluorescent metabolites in the urine, providing a sensitive readout of tubular function. Three mouse models of acute kidney injury (rhabdomyolysis, bilateral ischemia-reperfusion injury, and cisplatin nephrotoxicity) were tested and the resazurin-based method was able to sensitively detect the loss of tubular function much earlier than the increase in serum creatinine levels. Strikingly, in mice with unilateral ischemia-reperfusion injury and genetic mutation-linked kidney hypoplasia (oligosyndactylism, a genetic model for congenital kidney hypoplasia), the resazurin-based method was able to detect loss of tubular mass and function despite normal GFR levels. Collectively, our findings establish the preclinical utility of resazurin as a sensitive exogenous marker of tubular function and support future examination in larger animals for potential clinical translation.

Acute Kidney Injury Secondary to Abdominal Compartment Syndrome: Biomarkers, Pressure Variability, and Clinical Outcomes

Background and Objectives: Abdominal compartment syndrome (ACS) is a severe clinical condition caused by intra-abdominal hypertension (IAH), often observed in surgical and trauma patients. However, ACS can also develop in non-surgical patients with massive ascites, leading to acute kidney injury (AKI) due to renal hypoperfusion. This study investigates the association between intra-abdominal pressure (IAP) changes, renal biomarkers, and mortality in patients with ACS-related AKI. Materials and Methods: A prospective cohort study was conducted on 24 hospitalized patients with ascites due to malignancy, cirrhosis, or heart failure. IAP was measured via the trans-vesical method on the first and seventh days of hospitalization. Serum and urinary biomarkers, including kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and interleukin-6 (IL-6), were assessed for their correlation with IAP changes. The primary outcome was in-hospital mortality, and the secondary outcomes included AKI progression and the effect of paracentesis on IAP reduction. Results: The overall in-hospital mortality rate was 50%. Patients who survived had significantly lower IAP on the seventh day compared to those who died (14.9 ± 3.5 mmHg vs. 20.2 ± 5.6 mmHg, p = 0.01). A 25% reduction in IAP was associated with improved kidney function and increased survival (p < 0.001). Urinary KIM-1 and serum NGAL levels showed a moderate correlation with IAP (r = 0.55, p = 0.02 and r = 0.61, p = 0.018, respectively), while IL-6 levels were significantly higher in non-survivors (p = 0.03). Paracentesis was associated with improved survival outcomes (p = 0.04). Conclusions: ACS is a critical but often overlooked cause of AKI in non-surgical patients with massive ascites. Lowering IAP significantly improves renal function and reduces mortality. Urinary KIM-1 and serum NGAL may serve as useful biomarkers for monitoring IAP changes. The early identification and management of IAH through timely interventions such as paracentesis and volume control strategies could improve patient outcomes.

The efficacy of novel biomarkers for the early detection and management of acute kidney injury: A systematic review

Acute kidney injury (AKI) is a frequent clinical complication lacking early diagnostic tests and effective treatments. Novel biomarkers have shown promise for enabling earlier detection, risk stratification, and guiding management of AKI. We conducted a systematic review to synthesize evidence on the efficacy of novel biomarkers for AKI detection and management. Database searches yielded 17 relevant studies which were critically appraised. Key themes were biomarker efficacy in predicting AKI risk and severity before functional changes; potential to improve clinical management through earlier diagnosis, prognostic enrichment, and guiding interventions; emerging roles as therapeutic targets and prognostic tools; and ongoing challenges requiring further validation. Overall, novel biomarkers like neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and cell cycle arrest markers ([TIMP-2] •[IGFBP7]) demonstrate capability for very early AKI prediction and accurate risk stratification. Their incorporation has potential to facilitate timely targeted interventions and personalized management. However, factors influencing biomarker performance, optimal cutoffs, cost-effectiveness, and impact on patient outcomes require robust validation across diverse settings before widespread implementation. Addressing these limitations through ongoing research can help translate novel biomarkers into improved detection, prognosis, and management of AKI in clinical practice.

Development of gold nanoparticle-based lateral-flow strips for NGAL protein detection in urine samples

This study focuses on enhancing the sensitivity of lateral-flow strips (LFSs) based on gold nanoparticles (AuNPs) for the detection of Neutrophil Gelatinase-Associated Lipocalin (NGAL) protein in urine samples. Several sizes of AuNP-based LFS biosensors were tested to optimize colorimetric signals for NGAL detection based on improved conjugation conditions. AuNPs of 39.8 nm diameter at pH 8 were the most sensitive for the detection of NGAL. Through systematic enhancements to the AuNP-based LFS, the study significantly improves the sensitivity, enabling the reliable detection of NGAL protein in urine samples at a level as low as 12.5 ng mL-1. These advances contribute to the refinement of diagnostic tools for the early detection of kidney injury, specifically in cases associated with the presence of NGAL protein, offering a more precise and effective screening approach.

A low-dose pemetrexed-cisplatin combination regimen induces significant nephrotoxicity in mice

BACKGROUND

Pemetrexed is combined with cisplatin to treat cancer. Whether pemetrexed-cisplatin combination chemotherapy exacerbates cisplatin nephrotoxicity is unclear. Here, we investigated kidney injury in mice administered a non-lethal low-dose regimen of pemetrexed or cisplatin alone and compared it with a pemetrexed-cisplatin combination.

METHODS

Mice were randomly divided into four groups and administered intraperitoneally the experimental drugs solubilized in captisol (sulfobutylether β-cyclodextrin). Group 1 received captisol, Group 2 pemetrexed (10 mg/kg), Group 3 cisplatin (1 mg/kg), and Group 4 pemetrexed (10 mg/kg) plus cisplatin (1 mg/kg). The mice were treated every other day for two weeks, three times per week. Glomerular filtration rate (GFR) was determined on the third day after the last treatment, followed by a necropsy.

RESULTS

Whereas the relative kidney weight was comparable in the control vs. pemetrexed or cisplatin alone group, it was significantly increased in the combination group. Mice treated with cisplatin and pemetrexed-cisplatin combination exhibited reduced GFR. The pemetrexed-cisplatin combination caused significant increases in the plasma or urinary levels of kidney injury biomarkers, renal lipid peroxidation, and nitrosative stress compared with pemetrexed or cisplatin alone. Histopathology revealed that pemetrexed or cisplatin alone had minimal effects on the kidneys. By contrast, the pemetrexed-cisplatin combination caused tubular degeneration, dilatation, and granular casts. Live-cell imaging showed that the pemetrexed-cisplatin combination caused more severe apoptosis of primary renal epithelial cells than individual concentrations.

CONCLUSIONS

These findings suggest that combining pemetrexed and cisplatin causes oxidative kidney damage at individual doses that do not cause significant nephrotoxicity. Hence, the renal function of patients undergoing treatment with the pemetrexed-cisplatin combination needs extensive monitoring.

Pseudogene GSTM3P1 derived long non-coding RNA promotes ischemic acute kidney injury by target directed microRNA degradation of kidney-protective mir-668

Long non-coding RNAs (lncRNAs) are a group of epigenetic regulators that have been implicated in kidney diseases including acute kidney injury (AKI). However, very little is known about the specific lncRNAs involved in AKI and the mechanisms underlying their pathologic roles. Here, we report a new lncRNA derived from the pseudogene GSTM3P1, which mediates ischemic AKI by interacting with and promoting the degradation of mir-668, a kidney-protective microRNA. GSTM3P1 and its mouse orthologue Gstm2-ps1 were induced by hypoxia in cultured kidney proximal tubular cells. In mouse kidneys, Gstm2-ps1 was significantly upregulated in proximal tubules at an early stage of ischemic AKI. This transient induction of Gstm2-ps1 depends on G3BP1, a key component in stress granules. GSTM3P1 overexpression increased kidney proximal tubular apoptosis after ATP depletion, which was rescued by mir-668. Notably, kidney proximal tubule-specific knockout of Gstm2-ps1 protected mice from ischemic AKI, as evidenced by improved kidney function, diminished tubular damage and apoptosis, and reduced kidney injury biomarker (NGAL) induction. To test the therapeutic potential, Gstm2-ps1 siRNAs were introduced into cultured mouse proximal tubular cells or administered to mice. In cultured cells, Gstm2-ps1 knockdown suppressed ATP depletion-associated apoptosis. In mice, Gstm2-ps1 knockdown ameliorated ischemic AKI. Mechanistically, both GSTM3P1 and Gstm2-ps1 possessed mir-668 binding sites and downregulated the mature form of mir-668. Specifically, GSTM3P1 directly bound to mature mir-668 to induce its decay via target-directed microRNA degradation. Thus, our results identify GSTM3P1 as a novel lncRNA that promotes kidney tubular cell death in AKI by binding mir-668 to inducing its degradation.

Validation of plasma neutrophil gelatinase-associated lipocalin as a biomarker for diabetes-related acute kidney injury

OBJECTIVE

This retrospective study aimed to investigate the correlation between neutrophil gelatinase-associated lipocalin (NGAL) levels and the clinical progression and severity of diabetes-related acute kidney injury (AKI). The quantitative determination of NGAL in plasma on the Beckman Coulter AU480 analyzer was measured using the Bioporto NGAL TestTM, a particle-enhanced turbidimetric immunoassay with hospitalized patients at an East Central Georgia Medical Center.

METHODS

The clinical determination of plasma NGAL included a retrospective cohort study where 45 adult patients were selectively recruited. The selective criteria were patients with and without diabetes mellitus (DM) at risk for developing AKI admitted to the Medical Center between January and November 2023. All patients included in the study had pNGAL levels measured upon admission and up to 96 h post-admission. Receiver operating characteristics and likelihood ratio methods were used to determine optimal sensitivity, specificity, and cutoff value of pNGAL in AKI patients associated with and without DM.

RESULTS

The intra-assay and interassay imprecision percent relative standard deviation was between 2.7% and 4.2%. pNGAL levels were higher for patients with AKI compared to non-AKI patients, regardless of DM status. The optimal cutoff value for pNGAL to predict AKI for patients with DM was 293 ng/mL, with a sensitivity of 80% and specificity of 87%. In a multivariate logistic regression model, pNGAL levels at 48 h post-admission were determined to be associated with diabetes-related AKI patients.

CONCLUSION

Plasma NGAL levels at 48 h are associated with patients with diabetes-related AKI. The specific cutoff values for AKI for early diagnosis and risk stratification and its association with comorbidities must be determined to improve patient outcomes.

Urine-derived renal epithelial cells isolated after kidney transplant are sensitive to neutrophil gelatinase-associated lipocalin exposure during in vitro culture

Urine-derived renal epithelial cells (URECs) are highly voided after kidney transplant and express typical kidney markers, including markers of kidney epithelial progenitor cells. Recently URECs have shown promising immunomodulatory properties when cultured with Peripheral Blood Mononuclear Cells (PBMCs), promoting an increase in the T regulatory cells. In vivo, kidney cells are highly exposed to damage associated molecules during both acute and chronic kidney injury. Neutrophil gelatinase-associated lipocalin (NGAL) is one of the most -known early marker of acute and chronic kidney damage. However, its role on the evolution of renal damage has not yet been fully described, nor has its impact on the characteristics of renal-derived cells during in vitro culture. The aim of this study is to investigate the effect of NGAL on the characteristics of URECs isolated after kidney transplant, by exposing these cells to the treatment with NGAL during in vitro culture and evaluating its effect on UREC viability, proliferation, and immunomodulatory potential. The exposure of URECs to NGAL reduced their viability and proliferative capacity, promoting the onset of apoptosis. The immunomodulatory properties of URECs were partially inhibited by NGAL, without affecting the increase of Treg cells observed during UREC-PBMCs coculture. These results suggest that the exposure to NGAL may compromise some features of kidney stem and specialized cell types, reducing their viability, increasing apoptosis, and partially altering their immunomodulatory properties. Thus, NGAL could represent a target for approaches acting on its inhibition or reduction to improve functional recovery.

A Multimodal Fuzzy Approach in Evaluating Pediatric Chronic Kidney Disease Using Kidney Biomarkers

Chronic kidney disease (CKD) is one of the most important causes of chronic pediatric morbidity and mortality and places an important burden on the medical system. Current diagnosis and progression monitoring techniques have numerous sensitivity and specificity limitations. New biomarkers for monitoring CKD progression have been assessed. Neutrophil gelatinase-associated lipocalin (NGAL) has had some promising results in adults, but in pediatric patients, due to the small number of patients included in the studies, cutoff values are not agreed upon. The small sample size also makes the statistical approach limited. The aim of our study was to develop a fuzzy logic approach to assess the probability of pediatric CKD progression using both NGAL (urinary and plasmatic) and routine blood test parameters (creatinine and erythrocyte sedimentation rate) as input data. In our study, we describe in detail how to configure a fuzzy model that can simulate the correlations between the input variables ESR, NGAL-P, NGAL-U, creatinine, and the output variable Prob regarding the prognosis of the patient's evolution. The results of the simulations on the model, i.e., the correlations between the input and output variables (3D graphic presentations) are explained in detail. We propose this model as a tool for physicians which will allow them to improve diagnosis, follow-up, and interventional decisions relative to the CKD stage. We believe this innovative approach can be a great tool for the clinician and validates the feasibility of using a fuzzy logic approach in interpreting NGAL biomarker results for CKD progression.

Biomarkers of chronic kidney disease in older individuals: navigating complexity in diagnosis

Chronic kidney disease (CKD) in older individuals is a matter of growing concern in the field of public health across the globe. Indeed, prevalence of kidney function impairment increases with advancing age and is often exacerbated by age-induced modifications of kidney function, presence of chronic diseases such as diabetes, hypertension, and cardiovascular disorders, and increased burden related to frailty, cognitive impairment and sarcopenia. Accurate assessment of CKD in older individuals is crucial for timely intervention and management and relies heavily on biomarkers for disease diagnosis and monitoring. However, the interpretation of these biomarkers in older patients may be complex due to interplays between CKD, aging, chronic diseases and geriatric syndromes. Biomarkers such as serum creatinine, estimated glomerular filtration rate (eGFR), and albuminuria can be significantly altered by systemic inflammation, metabolic changes, and medication use commonly seen in this population. To overcome the limitations of traditional biomarkers, several innovative proteins have been investigated as potential, in this review we aimed at consolidating the existing data concerning the geriatric aspects of CKD, describing the challenges and considerations in using traditional and innovative biomarkers to assess CKD in older patients, highlighting the need for integration of the clinical context to improve biomarkers' accuracy.

Clinical outcomes prediction in kidney transplantation by use of biomarkers from hypothermic machine perfusion

PURPOSE

The clinical outcomes of kidney transplantation from deceased donors have seen significant improvements with the use of machine perfusion (MP), now a standard practice in transplant centers. However, the use of perfusate biomarkers for assessing organ quality remains a subject of debate. Despite this, some centers incorporate them into their decision-making process for donor kidney acceptance. Recent studies have indicated that lactate dehydrogenase (LDH), glutathione S-transferase, interleukin-18, and neutrophil gelatinase-associated lipocalin (NGAL) could predict post-transplant outcomes.

MATERIALS AND METHODS

Between August 2016 and June 2017, 31 deceased-donor after brain death were included and stroke was the main cause of death. Pediatric patients, hypersensitized recipients were excluded. 43 kidneys were subjected to machine perfusion. Perfusate samples were collected just before the transplantation and stored at -80ºC. Kidney transplant recipients have an average age of 52 years, 34,9% female, with a BMI 24,6±3,7. We employed receiver operating characteristic analysis to investigate associations between these perfusate biomarkers and two key clinical outcomes: delayed graft function and primary non-function.

RESULTS

The incidence of delayed graft function was 23.3% and primary non-function was 14%. A strong association was found between NGAL concentration and DGF (AUC=0.766, 95% CI, P=0.012), and between LDH concentration and PNF (AUC=0.84, 95% CI, P=0.027). Other perfusate biomarkers did not show significant correlations with these clinical outcomes.

CONCLUSION

The concentrations of NGAL and LDH during machine perfusion could assist transplant physicians in improving the allocation of donated organs and making challenging decisions regarding organ discarding. Further, larger-scale studies are required.

Current Prognostic Biomarkers for Abdominal Aortic Aneurysm: A Comprehensive Scoping Review of the Literature

Abdominal aortic aneurysm (AAA) is a progressive dilatation of the aorta that can lead to aortic rupture. The pathophysiology of the disease is not well characterized but is known to be caused by the general breakdown of the extracellular matrix within the aortic wall. In this comprehensive literature review, all current research on proteins that have been investigated for their potential prognostic capabilities in patients with AAA was included. A total of 45 proteins were found to be potential prognostic biomarkers for AAA, predicting incidence of AAA, AAA rupture, AAA growth, endoleak, and post-surgical mortality. The 45 proteins fell into the following seven general categories based on their primary function: (1) cardiovascular health, (2) hemostasis, (3) transport proteins, (4) inflammation and immunity, (5) kidney function, (6) cellular structure, (7) and hormones and growth factors. This is the most up-to-date literature review on current prognostic markers for AAA and their functions. This review outlines the wide pathophysiological processes that are implicated in AAA disease progression.

Nifuroxazide attenuates indomethacin-induced renal injury by upregulating Nrf2/HO-1 and cytoglobin and suppressing NADPH-oxidase, NF-κB, and JAK-1/STAT3 signals

Indomethacin (INDO) is an NSAID with remarkable efficacy and widespread utilization for alleviating pain. Nevertheless, renal function impairment is an adverse reaction linked to INDO usage. Nifuroxazide (NFX), an oral nitrofuran antibiotic, is frequently employed as an intestinal anti-infective agent. Our study aimed to investigate the renoprotective effects of NFX against INDO-induced nephrotoxicity and explore the protection mechanisms. Four groups of rats were allocated to (I) the normal control, (II) the NFX-treated (50 mg/kg), (III) INDO control (20 mg/kg), and (IV) NFX + INDO. NFX attenuates renal impairment in INDO-induced renal injury, proved by decreasing serum levels of urea, creatinine, uric acid, and NGAL while the albumin was elevated. NFX mitigates renal oxidative stress by decreasing MDA levels and restoring the antioxidants' GSH and SOD levels mediated by upregulating Nrf2, HO-1, and cytoglobin pathways. NFX mitigated renal inflammation and effectively decreased MPO, IL-1β, and TNF-α levels in the rat's kidney mediated by significant downregulation of NADPH-oxidase and NF-κB expression and suppression of JAK-1 and STAT3 phosphorylation. NFX mitigates renal apoptosis by decreasing the expression of cleaved caspase-3 expression. In conclusion, NFX treatment prevents INDO nephrotoxicity by regulating Nrf2/HO-1, cytoglobin, NADPH-oxidase, NF-κB, and JAK-1/STAT3 signals.

A rat model of multicompartmental traumatic injury and hemorrhagic shock induces bone marrow dysfunction and profound anemia

BACKGROUND

Severe trauma is associated with systemic inflammation and organ dysfunction. Preclinical rodent trauma models are the mainstay of postinjury research but have been criticized for not fully replicating severe human trauma. The aim of this study was to create a rat model of multicompartmental injury which recreates profound traumatic injury.

METHODS

Male Sprague-Dawley rats were subjected to unilateral lung contusion and hemorrhagic shock (LCHS), multicompartmental polytrauma (PT) (unilateral lung contusion, hemorrhagic shock, cecectomy, bifemoral pseudofracture), or naïve controls. Weight, plasma toll-like receptor 4 (TLR4), hemoglobin, spleen to body weight ratio, bone marrow (BM) erythroid progenitor (CFU-GEMM, BFU-E, and CFU-E) growth, plasma granulocyte colony-stimulating factor (G-CSF) and right lung histologic injury were assessed on day 7, with significance defined as p values <0.05 (*).

RESULTS

Polytrauma resulted in markedly more profound inhibition of weight gain compared to LCHS (p = 0.0002) along with elevated plasma TLR4 (p < 0.0001), lower hemoglobin (p < 0.0001), and enlarged spleen to body weight ratios (p = 0.004). Both LCHS and PT demonstrated suppression of CFU-E and BFU-E growth compared to naïve (p < 0.03, p < 0.01). Plasma G-CSF was elevated in PT compared to both naïve and LCHS (p < 0.0001, p = 0.02). LCHS and PT demonstrated significant histologic right lung injury with poor alveolar wall integrity and interstitial edema.

CONCLUSIONS

Multicompartmental injury as described here establishes a reproducible model of multicompartmental injury with worsened anemia, splenic tissue enlargement, weight loss, and increased inflammatory activity compared to a less severe model. This may serve as a more effective model to recreate profound traumatic injury to replicate the human inflammatory response postinjury.

Diabetes and Renal Complications: An Overview on Pathophysiology, Biomarkers and Therapeutic Interventions

Diabetic kidney disease (DKD) is a major microvascular complication of both type 1 and type 2 diabetes. DKD is characterised by injury to both glomerular and tubular compartments, leading to kidney dysfunction over time. It is one of the most common causes of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Persistent high blood glucose levels can damage the small blood vessels in the kidneys, impairing their ability to filter waste and fluids from the blood effectively. Other factors like high blood pressure (hypertension), genetics, and lifestyle habits can also contribute to the development and progression of DKD. The key features of renal complications of diabetes include morphological and functional alterations to renal glomeruli and tubules leading to mesangial expansion, glomerulosclerosis, homogenous thickening of the glomerular basement membrane (GBM), albuminuria, tubulointerstitial fibrosis and progressive decline in renal function. In advanced stages, DKD may require treatments such as dialysis or kidney transplant to sustain life. Therefore, early detection and proactive management of diabetes and its complications are crucial in preventing DKD and preserving kidney function.

Cholinergic Stimulation Exerts Cardioprotective Effects and Alleviates Renal Inflammatory Responses after Acute Myocardial Infarction in Spontaneous Hypertensive Rats (SHRs)

BACKGROUND

In this investigation, we explored the effects of pharmacological cholinergic stimulation on cardiac function and renal inflammation following acute myocardial infarction (AMI) in spontaneously hypertensive rats (SHRs).

METHODS

Adult male SHRs were randomized into three experimental groups: sham-operated; AMI + Veh (infarcted, treated with vehicle); and AMI + PY (infarcted, treated with the cholinesterase inhibitor, pyridostigmine bromide (PY)-40 mg/kg, once daily for seven days). Rats were euthanized 7 or 30 days post-surgery. The clinical parameters were assessed on the day before euthanasia. Subsequent to euthanasia, blood samples were collected and renal tissues were harvested for histological and gene expression analyses aimed to evaluate inflammation and injury.

RESULTS

Seven days post-surgery, the AMI + PY group demonstrated improvements in left ventricular diastolic function and autonomic regulation, and a reduction in renal macrophage infiltration compared to the AMI + Veh group. Furthermore, there was a notable downregulation in pro-inflammatory gene expression and an upregulation in anti-inflammatory gene expression. Analysis 30 days post-surgery showed that PY treatment had a sustained positive effect on renal gene expression, correlated with a decrease in biomarkers, indicative of subclinical kidney injury.

CONCLUSIONS

Short-term cholinergic stimulation with PY provides both cardiac and renal protection by mitigating the inflammatory response after AMI.

Clonal hematopoiesis of indeterminate potential is associated with acute kidney injury

Age is a predominant risk factor for acute kidney injury (AKI), yet the biological mechanisms underlying this risk are largely unknown. Clonal hematopoiesis of indeterminate potential (CHIP) confers increased risk for several chronic diseases associated with aging. Here we sought to test whether CHIP increases the risk of AKI. In three population-based epidemiology cohorts, we found that CHIP was associated with a greater risk of incident AKI, which was more pronounced in patients with AKI requiring dialysis and in individuals with somatic mutations in genes other than DNMT3A, including mutations in TET2 and JAK2. Mendelian randomization analyses supported a causal role for CHIP in promoting AKI. Non-DNMT3A-CHIP was also associated with a nonresolving pattern of injury in patients with AKI. To gain mechanistic insight, we evaluated the role of Tet2-CHIP and Jak2V617F-CHIP in two mouse models of AKI. In both models, CHIP was associated with more severe AKI, greater renal proinflammatory macrophage infiltration and greater post-AKI kidney fibrosis. In summary, this work establishes CHIP as a genetic mechanism conferring impaired kidney function recovery after AKI via an aberrant inflammatory response mediated by renal macrophages.

Validation of CSF-1 receptor (CD115) staining for analysis of murine monocytes by flow cytometry

CD115, the receptor for colony stimulating factor 1, is essential for survival and differentiation of monocytes and macrophages and is therefore frequently used to define monocyte subsets and their progenitors in immunological assays. However, CD115 surface expression and detection by flow cytometry is greatly influenced by cell isolation and processing methods, organ source, and disease context. In a systematic analysis of murine monocytes, we define experimental conditions that preserve or limit CD115 surface expression and staining by flow cytometry. We also find that, independent of conditions, CD115 surface levels are consistently lower in Ly6Clo monocytes than in Ly6Chi monocytes, with the exception of Ly6Clo monocytes in the bone marrow. Furthermore, in contrast to IL-34, the presence of colony stimulating factor 1 impairs CD115 antibody staining in a dose-dependent manner, which, in a model of ischemic kidney injury with elevated levels of colony stimulating factor 1, influenced quantification of kidney monocytes. Thus, staining and experimental conditions affect quantitative and qualitative analysis of monocytes and may influence experimental conclusions.

Association of urine glyphosate levels with renal injury biomarkers in children living close to major vegetable-producing regions in China

Glyphosate (GLY)-based herbicides exposure contributes to renal dysfunction in experimental conditions, but the effects on humans are rarely reported. Biomonitoring is practically relevant for evaluating the association of urine GLY levels and renal damage in children living close to vegetable-cultivating regions. In this study, we collected the first-morning void urine samples of 239 healthy children (aged 3-12, 48.12 % boys) living near major vegetable-producing regions in March-May and August 2023 in Shandong Province, China. Urine levels of GLY and kidney injury-associated biomarkers were determined using ELISA kits to assess their correlation. GLY was detected in 92.05 % of urine samples (220 out of 239 participants) and the geometric concentration (GM) was 7.429 μg/L (range: 0.625 to 38.267 μg/L). Binary logistic regression and multivariate regression analysis revealed GLY detectability and levels positively correlated with home ventilation and self-producing vegetable intake of the subjects, as well as sampling periods. Moreover, a statistically significant concentration association with urine GLY was found for kidney injury-associated biomarkers (NGAL and KIM-1) (R2 = 0.923 and 0.855, respectively). Additionally, risk assessment revealed that the maximum value of probable daily intake was 0.150 mg/kg bw/day, accounting for 30.1 % of the established Acceptable Daily Intake of GLY. This study unveils a positive correlation between continuous GLY-based herbicide exposure and renal injury biomarkers of children. A large-scale epidemiological study is warranted for comprehensively assessing the effects of GLY-based herbicides on kidney function of the entire public.

Hyaluronidase inhibitor sHA2.75 alleviates ischemia-reperfusion-induced acute kidney injury

Hyaluronidases (HAases) are enzymes that degrade hyaluronic acid (HA) in the animal kingdom. The HAases-HA system is crucial for HA homeostasis and plays a significant role in biological processes and extracellular matrix (ECM)-related pathophysiological conditions. This study aims to explore the role of inhibiting the HAases-HA system in acute kidney injury (AKI). We selected the potent inhibitor "sHA2.75" to inhibit HAase activity through mixed inhibitory mechanisms. The ischemia-reperfusion mouse model was established using male BALB/c mice (7-9 weeks old), and animals were subjected to subcapsular injection with 50 mg/kg sHA2.75 twice a week to evaluate the effects of sHA2.75 on AKI on day 1, 5 and 14 after ischemia-reperfusion or sham procedure. Blood and tissue samples were collected for immunohistochemistry, biochemical, and quantitative analyses. sHA2.75 significantly reduced blood urea nitrogen (BUN) and serum creatinine levels in AKI mouse models. Expression of kidney injury-related genes such as Kidney injury molecule-1 (KIM-1), Neutrophil Gelatinase-Associated Lipocalin (NGAL), endothelial nitric oxide synthase (eNOS), type I collagen (Col1), type III collagen (Col3), alpha-smooth muscle actin (α-SMA) showed significant downregulation in mouse kidney tissues after sHA2.75 treatment. Moreover, sHA2.75 treatment led to decreased plasma levels of Interleukin-6 (IL-6) proteins and reduced mRNA levels in renal tissues of AKI mice. Inhibitor sHA2.75 administration in the AKI mouse model downregulated kidney injury-related biomarkers and immune-specific genes, thereby alleviating AKI in vivo. These findings suggest the potential use of HAase inhibitors for treating ischemic reperfusion-induced kidney injury.

Reduction in NGAL at 48 h predicts the progression to CKD in patients with septic associated AKI: a single-center clinical study

BACKGROUND

In this study, our objective was to investigate the predictive value of serum and urine fluctuations of neutrophil gelatinase-associated lipid transporters (NGAL) in relation to the progression of chronic kidney disease (CKD) among patients with septic associated AKI (SA-AKI).

METHODS

A total of 425 SA-AKI patients were enrolled in this study and divided into the recovery group (n = 320) and the AKI-to-CKD group (n = 105) based on 3-month follow-up data. The serum and urine NGAL levels on the day of AKI diagnosis (T0) and 48 h after anti-AKI treatment (T1) were recorded and calculated.

RESULTS

The levels of NGAL in serum and urine were found to be higher in the AKI-to-CKD group compared to the recovery group at T1 point (P < 0.05). The reductions of NGAL at 48 h in serum and urine were lower in the AKI-to-CKD group than those observed in the recovery group (P < 0.05). In comparison to T0, a significant decrease was noted for both serum and urine NGAL levels on T1 among patients who recovered from AKI (P < 0.05), whereas no such trend was observed among those with AKI-to-CKD transition (P > 0.05). After adjusting age, sex, and BMI through partial correlation analysis, the reduction of serum NGAL was found to be most strongly associated with the transition from AKI to CKD. ROC analysis showed an AUC of 0.832 for serum NGAL reduction, with a cut-off value of - 111.24 ng/ml and sensitivity and rates of 76.2% and 81.2%, respectively. Logistic regression analysis indicated that a reduction of serum NGAL ≥ - 111.24 ng/ml was the early warning indicator for the progression of CKD in SA-AKI patients.

CONCLUSION

The reduction of serum NGAL following 48 h of anti-AKI therapy represents a distinct hazard factor for the advancement of CKD in patients with SA-AKI, independent of other variables.

Oregano (Origanum vulgare) Essential Oil and Its Constituents Prevent Rat Kidney Tissue Injury and Inflammation Induced by a High Dose of L-Arginine

This study aimed to evaluate the protective action of oregano (Origanum vulgare) essential oil and its monoterpene constituents (thymol and carvacrol) in L-arginine-induced kidney damage by studying inflammatory and tissue damage parameters. The determination of biochemical markers that reflect kidney function, i.e., serum levels of urea and creatinine, tissue levels of neutrophil-gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1), as well as a panel of oxidative-stress-related and inflammatory biomarkers, was performed. Furthermore, histopathological and immunohistochemical analyses of kidneys obtained from different experimental groups were conducted. Pre-treatment with the investigated compounds prevented an L-arginine-induced increase in serum and tissue kidney damage markers and, additionally, decreased the levels of inflammation-related parameters (TNF-α and nitric oxide concentrations and myeloperoxidase activity). Micromorphological kidney tissue changes correlate with the alterations observed in the biochemical parameters, as well as the expression of CD95 in tubule cells and CD68 in inflammatory infiltrate cells. The present results revealed that oregano essential oil, thymol, and carvacrol exert nephroprotective activity, which could be, to a great extent, associated with their anti-inflammatory, antiradical scavenging, and antiapoptotic action and, above all, due to their ability to lessen the disturbances arising from acute pancreatic damage. Further in-depth studies are needed in order to provide more detailed explanations of the observed activities.

The Prevalence and Association of Different Uropathogens Detected by M-PCR with Infection-Associated Urine Biomarkers in Urinary Tract Infections

Background

Many emerging uropathogens are currently identified by multiplex polymerase chain reaction (M-PCR) in suspected UTI cases. Standard urine culture (SUC) has significantly lower detection rates, raising questions about whether these organisms are associated with UTIs and truly cause inflammation.

Objective

To determine if microbes detected by M-PCR were likely causative of UTI by measuring inflammatory biomarkers in the urine of symptomatic patients.

Design Setting and Participants

Midstream voided urine was collected from subjects ≥60 years presenting to urology clinics with symptoms of UTI (n = 1132) between 01/2023 and 05/2023. Microbe detection was by M-PCR and inflammation-associated biomarker (neutrophil gelatinase-associated lipocalin, interleukin 8, and interleukin 1β) was by enzyme-linked immunosorbent assay. Biomarker positivity was measured against individual and groups of organisms, E. coli and non-E. coli cases, emerging uropathogens, monomicrobial and polymicrobial cases.

Outcome Measurements and Statistical Analysis

Distributions were compared using 2-sample Wilcoxon Rank Sum test with 2-tailed p-values < 0.05 considered statistically significant.

Results and Limitations

M-PCR was positive in 823 (72.7%) specimens with 28 of 30 (93%) microorganisms/groups detected. Twenty-six of twenty-eight detected microorganisms/groups (93%) had ≥2 biomarkers positive in >66% of cases. Both non-E. coli cases and E. coli cases had significant biomarker positivity (p < 0.05). Limitations were that a few organisms had low prevalence making inferences about their individual significance difficult.

Conclusion

The majority of microorganisms identified by M-PCR were associated with active inflammation measured by biomarker positivity, indicating they are likely causative of UTIs in symptomatic patients. This includes emerging uropathogens frequently not detected by standard urine culture.

Renoprotective Potency of Sitagliptin versus Pioglitazone in Type 2 Diabetic Patients: Impact on LncMIAT

Background: Diabetes mellitus (DM) represents one of the most important reasons for chronic kidney diseases due to the high level of blood glucose that destructs blood vessels. Objective: The present study focused on investigating the protective impact of sitagliptin on kidney complication in type 2 diabetes mellitus (T2DM) patients in comparison to pioglitazone to examine which has the superior effect against the nephritic complication of DM. Methods: Eighty adult subjects were classified into four groups: control group, pioglitazone-treated T2DM patients (P group), sitagliptin-treated T2DM patients for less than one year (SL group), and sitagliptin-treated T2DM patients for more than one year (SM group). Blood samples were withdrawn from all subjects for analysis of neutrophil gelatinase-associated lipocalin (NGAL), vanin-1, kidney injury molecule-1 (KIM-1), glyoxalase-1 (Glo-1), methylglyoxal (MG), cystatin-C, and interleukin-18 (IL-18) using competitive ELISA kits. Also, long noncoding myocardial infarction associated transcript (lncMIAT) was measured in whole blood using qRT-PCR. Results: The present study revealed that the lncMIAT expression level was significantly higher in the P group as compared to the SL group, SM group, or healthy control group. Additionally, serum NGAL, vanin-1, KIM-1, Glo-1, MG, and cystatin-C were significantly higher in the P group and SL group as compared to the SM group and healthy control group. Conclusion: Sitagliptin protected the kidney through downregulation of lncMIAT besides amelioration of kidney injury marker levels, which was more preferable than in pioglitazone therapy.

Cardiovascular risk factors and kidney function among automobile mechanic and their association with serum heavy metals in Southwest Nigeria: A cross-sectional study

INTRODUCTION

The burden of cardiovascular disease (CVD) is huge due to its associated morbidity, mortality and adverse socio-economic impact. Environmental pollution as a risk factor contributes significantly to the burden of CVD, especially in the low and middle income countries. One of the effective strategies to reduce CVD burden is to prevent or detect cardiovascular risk factors early in at-risk population. This study determined some cardiovascular risk factors, kidney function, and their association with heavy metals among automobile mechanics.

METHOD

This was a cross-sectional study involving 162 automobile mechanics and 81 age and sex matched controls. Serum levels of lead, cadmium and some cardiovascular risks were assessed and compared in the two groups. Associations between serum lead, cadmium and some cardiovascular risks were determined using correlation analysis. P value of <0.05 was taken as significant.

RESULTS

The mean ages of the automobile mechanics and controls were 47.27±9.99 years and 48.94±10.34 years, respectively. The prevalence of elevated serum cadmium was significantly higher in the automobile mechanics (25.9% vs 7.9%; p = <0.001). The significant cardiovascular risk factors in the automobile mechanics vs controls were elevated total cholesterol (32.1% vs 18.5%; p = 0.017), hyperuricemia (20.4% vs 1.2%; p = <0.001), elevated blood glucose (16.0% vs 4.9% p = 0.013); and alcohol use (55.1% vs 30.0%; p = 0.001). Among the automobile mechanics, there were significant positive correlations between serum cadmium, atherogenic index of plasma (AIP) (p = 0.024; r = 0.382) and triglyceride (p = 0.020; r = 0.391). Significant positive correlation was found between serum lead and neutrophil gelatinase associated lipocalin (NGAL) (p = <0.001; r = 0.329). There were significant positive correlation between serum cadmium level, AIP (p = 0.016; r = 0.373) and TG (p = 0.004; r = 0.439); between serum lead and NGAL in all the study participants (p = 0.005; r = 0.206).

CONCLUSION

Automobile mechanics have notable exposure to heavy metals and a higher prevalence of some cardiovascular risk factors. Health education and sensitisation as well as policies that would regulate exposure of persons to heavy metals should be implemented in Nigeria.

Elevated UTI Biomarkers in Symptomatic Patients with Urine Microbial Densities of 10,000 CFU/mL Indicate a Lower Threshold for Diagnosing UTIs

The literature lacks consensus on the minimum microbial density required for diagnosing urinary tract infections (UTIs). This study categorized the microbial densities of urine specimens from symptomatic UTI patients aged ≥ 60 years and correlated them with detected levels of the immune response biomarkers neutrophil gelatinase-associated lipocalin (NGAL), interleukin-8 (IL-8), and interleukin-1-beta (IL-1β). The objective was to identify the microbial densities associated with significant elevation of these biomarkers in order to determine an optimal threshold for diagnosing symptomatic UTIs. Biobanked midstream voided urine samples were analyzed for microbial identification and quantification using standard urine culture (SUC) and multiplex-polymerase chain reaction (M-PCR) testing, while NGAL, IL-8, and IL-1β levels were measured via enzyme-linked immunosorbent assay (ELISA). NGAL, IL-8, and IL-1β levels were all significantly elevated at microbial densities ≥ 10,000 cells/mL when measured via M-PCR (p < 0.0069) or equivalent colony-forming units (CFUs)/mL via SUC (p < 0.0104) compared to samples with no detectable microbes. With both PCR and SUC, a consensus of two or more elevated biomarkers correlated well with microbial densities > 10,000 cells/mL or CFU/mL, respectively. The association between ≥10,000 cells and CFU per mL with elevated biomarkers in symptomatic patients suggests that this lower threshold may be more suitable than 100,000 CFU/mL for diagnosing UTIs.

Kidney Damage in Long COVID: Studies in Experimental Mice

Signs and symptoms involving multiple organ systems which persist for weeks or months to years after the initial SARS-CoV-2 infection (also known as PASC or long COVID) are common complications of individuals with COVID-19. We recently reported pathophysiological changes in various organs post-acute infection of mice with mouse hepatitis virus-1 (MHV-1, a coronavirus) (7 days) and after long-term post-infection (12 months). One of the organs severely affected in this animal model is the kidney, which correlated well with human studies showing kidney injury post-SARS-CoV-2 infection. Our long-term post-infection pathological observation in kidneys includes the development of edema and inflammation of the renal parenchyma, severe acute tubular necrosis, and infiltration of macrophages and lymphocytes, in addition to changes observed in both acute and long-term post-infection, which include tubular epithelial cell degenerative changes, peritubular vessel congestion, proximal and distal tubular necrosis, hemorrhage in the interstitial tissue, and vacuolation of renal tubules. These findings strongly suggest the possible development of renal fibrosis, in particular in the long-term post-infection. Accordingly, we investigated whether the signaling system that is known to initiate the above-mentioned changes in kidneys in other conditions is also activated in long-term post-MHV-1 infection. We found increased TGF-β1, FGF23, NGAL, IL-18, HIF1-α, TLR2, YKL-40, and B2M mRNA levels in long-term post-MHV-1 infection, but not EGFR, TNFR1, BCL3, and WFDC2. However, only neutrophil gelatinase-associated lipocalin (NGAL) increased in acute infection (7 days). Immunoblot studies showed an elevation in protein levels of HIF1-α, TLR-2, and EGFR in long-term post-MHV-1 infection, while KIM-1 and MMP-7 protein levels are increased in acute infection. Treatment with a synthetic peptide, SPIKENET (SPK), which inhibits spike protein binding, reduced NGAL mRNA in acute infection, and decreased TGF-β1, BCL3 mRNA, EGFR, HIF1-α, and TLR-2 protein levels long-term post-MHV-1 infection. These findings suggest that fibrotic events may initiate early in SARS-CoV-2 infection, leading to pronounced kidney fibrosis in long COVID. Targeting these factors therapeutically may prevent acute or long-COVID-associated kidney complications.

Kidney disease in patients with chronic liver disease: Does sex matter?

Kidney disease in patients with liver disease is serious and increases mortality. Up to 50% of patients hospitalized experience an episode of acute kidney injury. In general, men with liver disease are thought to be at increased risk of kidney disease. However, this association should be considered with caution because most studies use creatinine-based inclusion criteria, which is negatively biased against women. In this review, we synthesize data on sex differences in kidney disease in patients with chronic liver disease in the clinical setting and discuss potential physiologic underpinnings.

A comparison between centrally and systemically administered erythropoietin on kidney protection in a model of fixed-volume hemorrhagic shock in male rats

BACKGROUND

In this study, a comparison between centrally and systemically administered erythropoietin (EPO) was performed on nephroprotection during hemorrhagic shock (HS) in male rats.

METHODS

Male rats were allocated into four experimental groups. (1) Sham; a guide cannula was inserted into the left lateral ventricle and other cannulas were placed into the left femoral artery and vein. (2) HS; stereotaxic surgery was done to insert a cannula in the left lateral ventricle and after a 7-day recovery; hemorrhagic shock and resuscitation were performed. (3) EPO-systemic; the procedure was the same as the HS group except that animals received 300 IU/kg erythropoietin into the femoral vein immediately before resuscitation. (4) EPO-central; animals was treated with erythropoietin (2 IU/rat) into the left lateral ventricle before resuscitation. Arterial oxygen saturation (SaO2) was measured during experiments. Urine and renal tissue samples were stored for ex-vivo indices assessments.

RESULTS

Erythropoietin (systemically/centrally administered) significantly improved SaO2, renal functional and oxidative stress parameters and decreased renal inflammatory (TNF-α and IL-6) mRNA expression compared to the HS group. EPO-treated groups showed a decrease in active form of caspase-3 protein level and an increase in autophagy activity in comparison with the HS group.

CONCLUSION

Considering the fact that the effective dose of systemic EPO (300 IU/kg) was roughly 50 times higher than that of central administration (2 IU/rat), centrally administered EPO was accompanied by more advantageous consequences than systemic way. EPO is likely to act as a neuro-modulator or neuro-mediator in the central protection of organs including the kidneys.

Recent Advances in Urinary Peptide and Proteomic Biomarkers in Chronic Kidney Disease: A Systematic Review

Biomarker development, improvement, and clinical implementation in the context of kidney disease have been a central focus of biomedical research for decades. To this point, only serum creatinine and urinary albumin excretion are well-accepted biomarkers in kidney disease. With their known blind spot in the early stages of kidney impairment and their diagnostic limitations, there is a need for better and more specific biomarkers. With the rise in large-scale analyses of the thousands of peptides in serum or urine samples using mass spectrometry techniques, hopes for biomarker development are high. Advances in proteomic research have led to the discovery of an increasing amount of potential proteomic biomarkers and the identification of candidate biomarkers for clinical implementation in the context of kidney disease management. In this review that strictly follows the PRISMA guidelines, we focus on urinary peptide and especially peptidomic biomarkers emerging from recent research and underline the role of those with the highest potential for clinical implementation. The Web of Science database (all databases) was searched on 17 October 2022, using the search terms "marker *" OR biomarker * AND "renal disease" OR "kidney disease" AND "proteome *" OR "peptid *" AND "urin *". English, full-text, original articles on humans published within the last 5 years were included, which had been cited at least five times per year. Studies based on animal models, renal transplant studies, metabolite studies, studies on miRNA, and studies on exosomal vesicles were excluded, focusing on urinary peptide biomarkers. The described search led to the identification of 3668 articles and the application of inclusion and exclusion criteria, as well as abstract and consecutive full-text analyses of three independent authors to reach a final number of 62 studies for this manuscript. The 62 manuscripts encompassed eight established single peptide biomarkers and several proteomic classifiers, including CKD273 and IgAN237. This review provides a summary of the recent evidence on single peptide urinary biomarkers in CKD, while emphasizing the increasing role of proteomic biomarker research with new research on established and new proteomic biomarkers. Lessons learned from the last 5 years in this review might encourage future studies, hopefully resulting in the routine clinical applicability of new biomarkers.

Lipocalin-2 as a biomarker for diabetic nephropathy

Diabetes is a major global public health issue. The prevalence of type 1 diabetes is comparatively static, as hereditary and genetic causes are involved, while type 2 diabetes (T2D) prevalence is increasing day by day. T2D is associated with chronic complications, including diabetic neuropathy (DN), nephropathy, retinopathy, and other complications like diabetic foot. DN is the main complication of both types of diabetes. DN can be diagnosed by routine laboratory tests, microalbuminuria > 300 mg/24 h, and a gradual decrease in glomerular filtration rate. As the appearance of microalbuminuria is a late manifestation, an early marker for renal damage is needed. Lipocalin-2, also known as neutrophil gelatinase-associated lipocalin (NGAL), is a small protein purified from neutrophil granules and a good marker for kidney disease. NGAL is a transporter protein responsible for many physiological processes, such as inflammation, generation of the immune response, and metabolic homeostasis. NGAL has been reported to depict the early changes in renal damage when urine microalbumin is still undetecable. Therefore, elucidating the role of NGAL in detecting DN and understanding its mechanism can help establish it as a potential early marker for DN.

Vesicoureteral Reflux and Innate Immune System: Physiology, Physiopathology, and Clinical Aspects

Vesicoureteral reflux represents one of the most concerning topics in pediatric nephrology due to its frequency, clinical expression with the potential to evolve into chronic kidney disease, and last but not least, its socio-economic implications. The presence of vesicoureteral reflux, the occurrence of urinary tract infections, and the development of reflux nephropathy, hypertension, chronic kidney disease, and finally, end-stage renal disease represent a progressive spectrum of a single physiopathological condition. For the proper management of these patients with the best clinical outcomes, and in an attempt to prevent the spread of uropathogens' resistance to antibacterial therapy, we must better understand the physiopathology of urinary tract infections in patients with vesicoureteral reflux, and at the same time, we should acknowledge the implication and response of the innate immune system in this progressive pathological condition. The present paper focuses on theoretical aspects regarding the physiopathology of vesicoureteral reflux and the interconditionality between urinary tract infections and the innate immune system. In addition, we detailed aspects regarding cytokines, interleukins, antimicrobial peptides, and proteins involved in the innate immune response as well as their implications in the physiopathology of reflux nephropathy. New directions of study should focus on using these innate immune system effectors as diagnostic and therapeutic tools in renal pathology.

Urinary Biomarkers in a Living Donor Kidney Transplantation Cohort—Predictive Value on Graft Function

Early non-invasive detection and prediction of graft function after kidney transplantation is essential since interventions might prevent further deterioration. The aim of this study was to analyze the dynamics and predictive value of four urinary biomarkers: kidney injury molecule-1 (KIM-1), heart-type fatty acid binding protein (H-FABP), N-acetyl-β-D-glucosaminidase (NAG), and neutrophil gelatinase-associated lipocalin (NGAL) in a living donor kidney transplantation (LDKT) cohort. Biomarkers were measured up to 9 days after the transplantation of 57 recipients participating in the VAPOR-1 trial. Dynamics of KIM-1, NAG, NGAL, and H-FABP significantly changed over the course of 9 days after transplantation. KIM-1 at day 1 and NAG at day 2 after transplantation were significant predictors for the estimated glomerular filtration rate (eGFR) at various timepoints after transplantation with a positive estimate (p < 0.05), whereas NGAL and NAG at day 1 after transplantation were negative significant predictors (p < 0.05). Multivariable analysis models for eGFR outcome improved after the addition of these biomarker levels. Several donor, recipient and transplantation factors significantly affected the baseline of urinary biomarkers. In conclusion, urinary biomarkers are of added value for the prediction of graft outcome, but influencing factors such as the timing of measurement and transplantation factors need to be considered.

Myrrh Essential Oil Mitigates Renal Ischemia/Reperfusion-Induced Injury

BACKGROUND

Ischemia/reperfusion (I/R)-induced renal injury is a common reason for kidney injury in clinical settings; therefore, continuous investigation of novel nephroprotective agents is crucial. Myrrh, the oleoresin exudates generated by the genus Commiphora, display numerous pharmacological actions. This study tried to assess the preventive effects of myrrh essential oil against I/R-induced renal damage.

METHODS

Rats were randomized into five groups. In the sham group, the animals were subjected to bilateral renal artery separation with no occlusion. In the sham + myrrh group; the rats were administered myrrh essential oil and then treated similarly to the sham group. Renal I/R group: the animals were challenged with renal I/R. In the myrrh + renal I/R groups, rats were administered 50 or 100 mg/kg of myrrh essential oil orally for three weeks before being confronted with I/R.

RESULTS

Serum levels of renal function tests and renal injury biomarkers, including NGAL, KIM-1, and CysC, were amplified in the renal I/R group. Animals that experienced renal I/R exhibited elevated lipid peroxidation (MDA); declined SOD, CAT, and GPx activity; declined GSH content; augmented TLR4/NFκB gene expression; and subsequent enhancement of inflammatory mediators (TNF-α, IFN-γ, IL-1β, and IL-6). Myrrh reduced renal function tests and injury biomarkers and amended renal histological alterations. Pretreatment with myrrh reduced MDA, elevated the antioxidant enzymes' activities and GSH content, and reduced the TLR4 and NFκB gene expression, leading to subsequent inflammation and apoptosis alleviation.

CONCLUSIONS

The outcomes of the present investigation established the protective effect of myrrh essential oil against renal I/R via pointing out the antioxidant, anti-inflammatory, and anti-apoptotic effects of myrrh.

Neutrophil Gelatinase-Associated Lipocalin as a Predictor of Acute Kidney Injury in Children With Shock: A Prospective Study

BACKGROUND

The current definition of acute kidney injury (AKI) is based on serum creatinine (SrCr) and urine output, limited by delayed identification of such patients. Plasma neutrophil gelatinase-associated lipocalin (NGAL) is considered an early diagnostic and highly predictive biomarker of AKI.

OBJECTIVE

To determine the diagnostic accuracy of NGAL for AKI compared with creatinine clearance for early detection of AKI in children with shock receiving inotropic support.

METHODS

Critically ill children requiring inotropic support in the pediatric intensive care unit were enrolled prospectively. SrCr and NGAL values were obtained three times at six, 12, and 48 hours after vasopressor initiation. Patients with AKI were defined as having loss of >25% renal function based on creatinine clearance within 48 hours. NGAL level of more than 150 ng/dl was suggestive of the diagnosis of AKI. Receiver operator characteristic curves were generated for NGAL and SrCr to compare the predictive ability of both at 0, 12, and 48 hours of starting vasopressor support.  Results: A total of 94 patients were enrolled. The mean age was 43±50.95 months. Most common primary diagnoses were related to the cardiovascular system (46%). Twenty-nine patients (31%) died during the hospital stay. Thirty-four patients (36%) developed AKI within 48 hours following shock. The area under the curve (AUC) for NGAL at a cutoff of 150 ng/ml was 0.70, 0.74, and 0.73 at six-hour, 12-hour, and 48-hour follow-up, respectively. NGAL had a sensitivity of 85.3% and specificity of 50% at 0 hours of follow-up for diagnosis of AKI.

CONCLUSION

Serum NGAL has better sensitivity and AUC compared to SrCr for early diagnosis of AKI in children admitted with shock.

Smartphone surface plasmon resonance imaging for the simultaneous and sensitive detection of acute kidney injury biomarkers with noninvasive urinalysis

A surface plasmon resonance imaging (SPRi) platform integrated with a smartphone was constructed for the simultaneous and sensitive detection of acute kidney injury (AKI) biomarkers. The smartphone SPRi platform was developed without the requirement of additional light and power sources. The LED flash of the smartphone was used as the light source for the excitation of surface plasmon resonance of a gold sensor chip based on the Kretschmann configuration, while the reflected light was collected by the camera of the smartphone. This smartphone SPRi system was conveniently fabricated by 3D printing and showed a sensitivity of 1.78 × 10^-5 refractive index unit (RIU). In addition, based on a magnetic nanoparticle-enhanced sandwich immunoassay, the smartphone SPRi system with a gold array chip was employed for the detection of multiple AKI biomarkers, with a low limit of detection (LOD) of 0.19 ng ml^-1, 0.51 ng ml^-1 and 0.7 ng ml^-1 for the simultaneous detection of neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18) and retinol-binding protein (RBP) in urine, respectively. The biosensors demonstrated high specificity and sensitivity for the simultaneous detection of multiple AKI biomarkers in PBST and urine. The smartphone SPRi system provided a portable and cost-effective platform for point-of-care diagnosis, in-field healthcare and environmental monitoring.

Empagliflozin protects against renal ischemia/reperfusion injury in mice

Renal ischemia/reperfusion (I/R) can induce acute kidney injury. Empagliflozin is a newly developed inhibitor of sodium-glucose cotransporter-2 (SGLT2) approved as an antidiabetic medication for patients with type 2 diabetes mellitus. Despite the established cardioprotective functions of empagliflozin, its protective role in renal I/R is unclear. Here, the present study evaluated the renoprotective effects of empagliflozin in a mouse model of renal I/R injury. Male C57/BL6 mice were allocated to sham-operated, I/R, and empagliflozin groups. Kidney pedicles on both sides were clamped for 45 min and were reperfused for 24 h. Empagliflozin (1 mg/kg) was administered to the mice for 2 days preischemia. The GSK-3β inhibitor SB216763 was administered intravenously at the beginning of reperfusion (0.1 mg/kg). Renal function and histological scores were evaluated. The kidneys were taken for immunohistochemical analysis, western blotting and apoptosis measurements. We found that empagliflozin decreased serum levels of creatinine and urea, reduced the average kidney weight-to-tibia length ratio, attenuated tubular damage, reduced renal proinflammatory cytokine expression and inhibited apoptosis in injured kidneys. Furthermore, empagliflozin increased renal glycogen synthase kinase 3β (GSK-3β) phosphorylation post I/R. Pharmacological inhibition of GSK-3β activity mimicked the renal protective effects offered by empagliflozin. In summary, these results support a protective role of empagliflozin against renal I/R injury.

The sequestration mechanism as a generalizable approach to improve the sensitivity of biosensors and bioassays

Biosensors and bioassays, both of which employ proteins and nucleic acids to detect specific molecular targets, have seen significant applications in both biomedical research and clinical practice. This success is largely due to the extraordinary versatility, affinity, and specificity of biomolecular recognition. Nevertheless, these receptors suffer from an inherent limitation: single, saturable binding sites exhibit a hyperbolic relationship (the "Langmuir isotherm") between target concentration and receptor occupancy, which in turn limits the sensitivity of these technologies to small variations in target concentration. To overcome this and generate more responsive biosensors and bioassays, here we have used the sequestration mechanism to improve the steepness of the input/output curves of several bioanalytical methods. As our test bed for this we employed sensors and assays against neutrophil gelatinase-associated lipocalin (NGAL), a kidney biomarker for which enhanced sensitivity will improve the monitoring of kidney injury. Specifically, by introducing sequestration we have improved the responsiveness of an electrochemical aptamer based (EAB) biosensor, and two bioassays, a paper-based "dipstick" assay and an enzyme-linked immunosorbent assay (ELISA). Doing so we have narrowed the dynamic range of these sensors and assays several-fold, thus enhancing their ability to measure small changes in target concentration. Given that introducing sequestration requires only the addition of the appropriate concentration of a high-affinity "depletant," the mechanism appears simple and easily adaptable to tuning the binding properties of the receptors employed in a wide range of biosensors and bioassays.

Neutrophil Gelatinase-Associated Lipocalin (NGAL) in kidney injury- A systematic review

BACKGROUND

Neutrophil Gelatinase Associated Lipocalin (NGAL) is a secretory protein of neutrophils that can be found both in plasma and urine. Previous works have demonstrated a valuable marker for the early detection of acute kidney injury. In this systematic review, we aimed to assess whether NGAL could be helpful in the diagnosis and prognosis of systemic diseases with kidney involvement.

METHODS

MEDLINE, PubMed, and EMBASE databases were searched for NGAL, described as a human biomarker for diseases (total: 1690). Specifically, included studies describing the use of NGAL for determining kidney injury outcomes and other conditions associated with kidney dysfunction, including cardiovascular diseases, cardiac surgery, and critically ill systemic disorders.

RESULTS

A total of 24 validated studies were included in the systemic review after applying the exclusion criteria. In all these studies, NGAL appeared to have a predictive value irrespective of age, from newborn to 78 years. The results indicate that NGAL levels can accurately predict the outcome and severity of acute kidney injury occur in several disease processes, including contrast-induced AKI during cardiac surgery, kidney transplant rejection, chronic heart failure, and systemic inflammation in critically ill patients, even though the significance of NGAL is highly variable across studies. Very high plasma NGAL levels were observed in the patients before the acute rejection of the kidney, indicating the prognostic potential of the NGAL. Specifically, the assays conducted before 72 hrs provided a significant predictive value.

CONCLUSION

Urinary and serum NGAL appears to be an independent predictor of not only kidney complications but also cardiovascular and liver-related diseases. The kidney is also involved in pathogenesis.

Insights into the role of neutrophils in neuropsychiatric systemic lupus erythematosus: Current understanding and future directions

Central nervous system (CNS) involvement of systemic lupus erythematosus (SLE), termed neuropsychiatric SLE (NPSLE), is a major and debilitating manifestation of the disease. While patients with SLE mostly complain of common neuropsychological symptoms such headache and mild mood disorders that may not even be technically attributed to SLE, many SLE patients present with life-threatening NPSLE syndromes such as cerebrovascular disease, seizures and psychosis that are equally challenging in terms of early diagnosis and therapy. While we are just beginning to unravel some mysteries behind the immunologic basis of NPSLE, advancements in the mechanistic understanding of the complex pathogenic processes of NPSLE have been emerging through recent murine and human studies. The pathogenic pathways implicated in NPSLE are multifarious and various immune effectors such as cell-mediated inflammation, autoantibodies and cytokines including type I interferons have been found to act in concert with the disruption of the blood-brain barrier (BBB) and other neurovascular interfaces. Beyond antimicrobial functions, neutrophils are emerging as decision-shapers during innate and adaptive immune responses. Activated neutrophils have been recognized to be involved in ischemic and infective processes in the CNS by releasing neutrophil extracellular traps (NETs), matrix metalloproteinase-9 and proinflammatory cytokines. In the context of NPSLE, these mechanisms contribute to BBB disruption, neuroinflammation and externalization of modified proteins on NETs that serve as autoantigens. Neutrophils that sediment within the peripheral blood mononuclear cell fraction after density centrifugation of blood are generally defined as low-density neutrophils (LDNs) or low-density granulocytes. LDNs are a proinflammatory subset of neutrophils that are increased with SLE disease activity and are primed to undergo NETosis and release cytokines such as interferon-α and tumor necrosis factor. This review discusses the immunopathogenesis of NPSLE with a focus on neutrophils as a core mediator of the disease and potential target for translational research in NPSLE.

Diagnosis of Cardiac Surgery-Associated Acute Kidney Injury: State of the Art and Perspectives

Diagnosis of cardiac surgery-associated acute kidney injury (CSA-AKI), a syndrome of sudden renal dysfunction occurring in the immediate post-operative period, is still sub-optimal. Standard CSA-AKI diagnosis is performed according to the international criteria for AKI diagnosis, afflicted with insufficient sensitivity, specificity, and prognostic capacity. In this article, we describe the limitations of current diagnostic procedures and of the so-called injury biomarkers and analyze new strategies under development for a conceptually enhanced diagnosis of CSA-AKI. Specifically, early pathophysiological diagnosis and patient stratification based on the underlying mechanisms of disease are presented as ongoing developments. This new approach should be underpinned by process-specific biomarkers including, but not limited to, glomerular filtration rate (GFR) to other functions of renal excretion causing GFR-independent hydro-electrolytic and acid-based disorders. In addition, biomarker-based strategies for the assessment of AKI evolution and prognosis are also discussed. Finally, special focus is devoted to the novel concept of pre-emptive diagnosis of acquired risk of AKI, a premorbid condition of renal frailty providing interesting prophylactic opportunities to prevent disease through diagnosis-guided personalized patient handling. Indeed, a new strategy of risk assessment complementing the traditional scores based on the computing of risk factors is advanced. The new strategy pinpoints the assessment of the status of the primary mechanisms of renal function regulation on which the impact of risk factors converges, namely renal hemodynamics and tubular competence, to generate a composite and personalized estimation of individual risk.