Serum cystatin C as a marker of renal function in detection of early acute kidney injury

High glucose induces DNA methyltransferase 1 dependent epigenetic reprogramming of the endothelial exosome proteome in type 2 diabetes

In response to hyperglycemia, endothelial cells (ECs) release exosomes with altered protein content and contribute to paracrine signalling, subsequently leading to vascular dysfunction in type 2 diabetes (T2D). High glucose reprograms DNA methylation patterns in various cell/tissue types, including ECs, resulting in pathologically relevant changes in cellular and extracellular proteome. However, DNA methylation-based proteome reprogramming in endothelial exosomes and associated pathological implications in T2D are not known. Hence, in the present study, we used Human umbilical vein endothelial cells (HUVECs), High Fat Diet (HFD) induced diabetic mice (C57BL/6) and clinical models to understand epigenetic basis of exosome proteome regulation in T2D pathogenesis . Exosomes were isolated by size exclusion chromatography and subjected to tandem mass tag (TMT) labelled quantitative proteomics and bioinformatics analysis. Immunoblotting was performed to validate exosome protein signature in clinically characterized individuals with T2D. We observed ECs cultured in high glucose and aortic ECs from HFD mouse expressed elevated DNA methyltransferase1 (DNMT1) levels. Quantitative proteomics of exosomes isolated from ECs treated with high glucose and overexpressing DNMT1 showed significant alterations in both protein levels and post translational modifications which were aligned to T2D associated vascular functions. Based on ontology and gene-function-disease interaction analysis, differentially expressed exosome proteins such as Thrombospondin1, Pentraxin3 and Cystatin C related to vascular complications were significantly increased in HUVECs treated with high glucose and HFD animals and T2D individuals with higher levels of glycated hemoglobin. These proteins were reduced upon treatment with 5-Aza-2'-deoxycytidine. Our study shows epigenetic regulation of exosome proteome in T2D associated vascular complications.

Renal impairment is prevalent in pediatric NAFLD/MASLD and associated with disease severity

OBJECTIVES

Renal impairment is prevalent in adults with nonalcoholic fatty liver disease (NAFLD/metabolic dysfunction associated steatotic liver disease [MASLD]) and is associated with increased mortality. Pediatric data are limited. Our objective was to determine the prevalence of hyperfiltration or chronic kidney disease (CKD) in children with NAFLD/MASLD and determine links with liver disease severity.

METHODS

Data from children who had previously participated in prospective, multicenter, pediatric studies by the Nonalcoholic Steatohepatitis Clinical Research Network (NASH-CRN) were collected. Renal function was determined using the calculated glomerular filtration rate (cGFR). Hyperfiltration was defined as cGFR > 135 mL/min/1.73m2, while CKD stage 2 or higher as cGFR < 90 mL/min/1.73 m2. Renal dysfunction progression was defined as transition from normal to hyperfiltration or to CKD stage ≥ 2, or change in CKD by ≥1 stage. Multinomial logistic regression models were used to determine the prevalence of CKD and independent associations between CKD and liver disease severity.

RESULTS

The study included 1164 children (age 13 ± 3 years, 72% male, 71% Hispanic). The median cGFR was 121 mL/min/1.73 m2; 12% had CKD stage 2-5, while 27% had hyperfiltration. Hyperfiltration was independently associated with significant liver fibrosis (odds ratio: 1.45). Baseline renal function was not associated with progression in liver disease over a 2-year period (n = 145). Renal dysfunction worsened in 19% independently of other clinical risk factors. Progression of renal impairment was not associated with change in liver disease severity.

CONCLUSIONS

Renal impairment is prevalent in children with NAFLD/MASLD and hyperfiltration is independently associated with significant liver fibrosis. Almost 1/5 children have evidence of progression in renal dysfunction over 2 years, not associated with change in liver disease severity. Future assessments including additional renal impairment biomarkers are needed.

Assessment of Plasma Cystatin C as a Marker of Acute Renal Injury in Patients Undergoing Extracorporeal Shock Wave Lithotripsy for Renal Stone Disease

Introduction This study aimed to assess plasma cystatin C (CysC) as a marker of acute kidney injury (AKI) in patients undergoing extracorporeal shock wave lithotripsy (ESWL). We compared serum levels of CysC, C-reactive protein (CRP), and creatinine before and after ESWL. The study results may have implications for early detection of AKI and prevention of progression to chronic kidney disease. Methodology This prospective observational study included 105 adult participants and was conducted from August 2022 to July 2024. ESWL was the only modality of treatment. Results Forty-eight (46%) patients developed AKI after ESWL. Patients with AKI had significantly higher post-ESWL mean plasma CysC levels than patients without AKI (121 ± 0.25 vs. 0.94 ± 0.22 mg/dL, respectively; P = 0.001). The mean serum CRP levels after ESWL were significantly higher in patients who developed AKI compared with those who did not (4.36 ± 1.63 vs. 2.64 ± 0.95 mg/dL, respectively; P = 0.001). Conclusions In patients with renal stone disease, serum creatinine, serum CRP, and plasma CysC can be used as markers of acute renal injury after ESWL.

Specific circulating miRNAs are associated with plasma lipids in a healthy American cohort

Low-density lipoprotein cholesterol (LDL-c) is both a therapeutic target and a risk factor for cardiovascular disease (CVD). MicroRNA (miRNA) has been shown to regulate cholesterol homeostasis, and miRNA in blood circulation has been linked to hypercholesterolemia. However, few studies to date have associated miRNA with phenotypes like LDL-c in a healthy population. To this end, we analyzed circulating miRNA in relation to LDL-c in a healthy cohort of 353 participants using two separate bioinformatic approaches. The first approach found that miR-15b-5p and miR-16-5p were upregulated in individuals with at-risk levels of LDL-c. The second approach identified two miRNA clusters, one that positively and a second that negatively correlated with LDL-c. Included in the cluster that positively correlated with LDL-c were miR-15b-5p and miR-16-5p, as well as other miRNA from the miR-15/107, miR-30, and let-7 families. Cross-species analyses suggested that several miRNAs that associated with LDL-c are conserved between mice and humans. Finally, we examined the influence of diet on circulating miRNA. Our results robustly linked circulating miRNA with LDL-c, suggesting that miRNA could be used as biomarkers for hypercholesterolemia or targets for developing cholesterol-lowering drugs.NEW & NOTEWORTHY This study explored the association between circulating microRNA (miRNA) and low-density lipoprotein cholesterol (LDL-c) in a healthy population of 353 participants. Two miRNAs, miR-15b-5p and miR-16-5p, were upregulated in individuals with at-risk LDL-c levels. Several miRNA clusters were positively and negatively correlated with LDL-c and are known to target mRNA involved in lipid metabolism. The study also investigated the influence of diet on circulating miRNA, suggesting potential biomarkers for hypercholesterolemia.

A Cross-Sectional Study of Glomerular Hyperfiltration in Polycystic Ovary Syndrome

Glomerular hyperfiltration (GH) has been reported to be higher in women with polycystic ovary syndrome (PCOS) and is an independent risk factor for renal function deterioration, metabolic, and cardiovascular disease. The aim of this study was to determine GH in type A PCOS subjects and to identify whether inflammatory markers, markers of CKD, renal tubule injury markers, and complement system proteins were associated. In addition, a secondary cohort study was performed to determine if the eGFR had altered over time. In this comparative cross-sectional analysis, demographic, metabolic, and proteomic data from Caucasian women aged 18-40 years from a PCOS Biobank (137 with PCOS, 97 controls) was analyzed. Slow Off-rate Modified Aptamer (SOMA)-scan plasma protein measurement was undertaken for inflammatory proteins, serum markers of chronic kidney disease (CKD), tubular renal injury markers, and complement system proteins. A total of 44.5% of the PCOS cohort had GH (eGFR ≥ 126 mL/min/1.73 m2 (n = 55)), and 12% (n = 17) eGFR ≥ 142 mL/min/1.73 m2 (super-GH(SGH)). PCOS-GH women were younger and had lower creatinine and urea versus PCOS-nonGH. C-reactive protein (CRP), white cell count (WCC), and systolic blood pressure (SBP) were higher in PCOS versus controls, but CRP correlated only with PCOS-SGH alone. Complement protein changes were seen between controls and PCOS-nonGH, and decay-accelerator factor (DAF) was decreased between PCOS-nonGH and PCOS-GSGH (p < 0.05). CRP correlated with eGFR in the PCOS-SGH group, but not with other inflammatory or complement parameters. Cystatin-c (a marker of CKD) was reduced between PCOS-nonGH and PCOS-GSGH (p < 0.05). No differences in tubular renal injury markers were found. A secondary cohort notes review of the biobank subjects 8.2-9.6 years later showed a reduction in eGFR: controls -6.4 ± 12.6 mL/min/1.73 m2 (-5.3 ± 11.5%; decrease 0.65%/year); PCOS-nonGH -11.3 ± 13.7 mL/min/1.73 m2 (-9.7 ± 12.2%; p < 0.05, decrease 1%/year); PCOS-GH (eGFR 126-140 mL/min/17.3 m2) -27.1 ± 12.8 mL/min/1.73 m2 (-19.1 ± 8.7%; p < 0.0001, decrease 2%/year); PCOS-SGH (eGFR ≥ 142 mL/min/17.3 m2) -33.7 ± 8.9 mL/min/17.3 m2 (-22.8 ± 6.0%; p < 0.0001, decrease 3.5%/year); PCOS-nonGH eGFR versus PCOS-GH and PCOS-SGH, p < 0.001; no difference PCOS-GH versus PCOS-SGH. GH was associated with PCOS and did not appear mediated through tubular renal injury; however, cystatin-c and DAF were decreased, and CRP correlated positively with PCOS-SGH, suggesting inflammation may be involved at higher GH. There were progressive eGFR decrements for PCOS-nonGH, PCOS-GH, and PCOS-SGH in the follow-up period which, in the presence of additional factors affecting renal function, may be clinically important in the development of CKD in PCOS.

A systematic review assessing the potential use of cystatin c as a biomarker for kidney disease in people living with HIV on antiretroviral therapy

The introduction of antiretroviral therapy (ART) has significantly prolonged the lifespan of people living with human immunodeficiency virus (PLWH). However, the sustained use of this drug regimen has also been associated with a cluster of metabolic anomalies, including renal toxicity, which can lead to the development of kidney diseases. In this study, we reviewed studies examining kidney disease in PLWH sourced from electronic databases such as PubMed/MEDLINE, Scopus, and Google Scholar, as well as gray literature. The narrative synthesis of data from these clinical studies demonstrated that the serum levels of cystatin C remained unchanged or were not affected in PLWH on ART, while the creatinine-based glomerular filtration rate (GFR) fluctuated. In fact, some of the included studies showed that the creatinine-based GFR was increased in PLWH taking tenofovir disoproxil fumarate-containing ART, perhaps indicating that the use of both cystatin C- and creatinine-based GFRs is vital to monitor the development of kidney disease in PLWH. Clinical data summarized within this study indicate the potential detrimental effects of tenofovir-based ART regimens in causing renal tubular injury, while highlighting the possible beneficial effects of dolutegravir-based ART on improving the kidney function in PLWH. However, the summarized literature remains limited, while further clinical studies are required to provide insights into the potential use of cystatin C as a biomarker for kidney disease in PLWH.

Safety of Administering Intravenous CT Contrast Agents Repeatedly or Using Both CT and MRI Contrast Agents on the Same Day: An Animal Study

OBJECTIVE

To investigate molecular and functional consequences of additional exposures to iodine- or gadolinium-based contrast agents within 24 hours from the initial intravenous administration of iodine-based contrast agents through an animal study.

MATERIALS AND METHODS

Fifty-six Sprague-Dawley male rats were equally divided into eight groups: negative control, positive control (PC) with single-dose administration of CT contrast agent, and additional administration of either CT or MR contrast agents 2, 4, or 24 hours from initial CT contrast agent injection. A 12 µL/g of iodinated contrast agent or a 0.47 µL/g of gadolinium-based contrast agent were injected into the tail vein. Serum levels of blood urea nitrogen, creatinine, cystatin C (Cys C), and malondialdehyde (MDA) were measured. mRNA and protein levels of kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) were evaluated.

RESULTS

Levels of serum creatinine (SCr) were significantly higher in repeated CT contrast agent injection groups than in PC (0.21 ± 0.02 mg/dL for PC; 0.40 ± 0.02, 0.34 ± 0.03, and 0.41 ± 0.10 mg/dL for 2-, 4-, and 24-hour interval groups, respectively; P < 0.001). There was no significant difference in the average Cys C and MDA levels between PC and repeated CT contrast agent injection groups (Cys C, P = 0.256-0.362; MDA, P > 0.99). Additional doses of MR contrast agent did not make significant changes compared to PC in SCr (P > 0.99), Cys C (P = 0.262), and MDA (P = 0.139-0.771) levels. mRNA and protein levels of KIM-1 and NGAL were not significantly different among additional CT or MR contrast agent groups (P > 0.05).

CONCLUSION

A sufficient time interval, probably more than 24 hours, between repeated contrast-enhanced CT examinations may be necessary to avoid deterioration in renal function. However, conducting contrast-enhanced MRI on the same day as contrast-enhanced CT may not induce clinically significant kidney injury.

Identification of phenomic data in the pathogenesis of cancers of the gastrointestinal (GI) tract in the UK biobank

Gastrointestinal (GI) cancers account for a significant incidence and mortality rates of cancers globally. Utilization of a phenomic data approach allows researchers to reveal the mechanisms and molecular pathogenesis of these conditions. We aimed to investigate the association between the phenomic features and GI cancers in a large cohort study. We included 502,369 subjects aged 37-73 years in the UK Biobank recruited since 2006, followed until the date of the first cancer diagnosis, date of death, or the end of follow-up on December 31st, 2016, whichever occurred first. Socio-demographic factors, blood chemistry, anthropometric measurements and lifestyle factors of participants collected at baseline assessment were analysed. Unvariable and multivariable logistic regression were conducted to determine the significant risk factors for the outcomes of interest, based on the odds ratio (OR) and 95% confidence intervals (CI). The analysis included a total of 441,141 participants, of which 7952 (1.8%) were incident GI cancer cases and 433,189 were healthy controls. A marker, cystatin C was associated with total and each gastrointestinal cancer (adjusted OR 2.43; 95% CI 2.23-2.64). In this cohort, compared to Asians, the Whites appeared to have a higher risk of developing gastrointestinal cancers. Several other factors were associated with distinct GI cancers. Cystatin C and race appear to be important features in GI cancers, suggesting some overlap in the molecular pathogenesis of GI cancers. Given the small proportion of Asians within the UK Biobank, the association between race and GI cancers requires further confirmation.

Restoring glucose balance: Conditional HMGB1 knockdown mitigates hyperglycemia in a Streptozotocin induced mouse model

Diabetes mellitus (DM) poses a significant global health burden, with hyperglycemia being a primary contributor to complications and high morbidity associated with this disorder. Existing glucose management strategies have shown suboptimal effectiveness, necessitating alternative approaches. In this study, we explored the role of high mobility group box 1 (HMGB1) in hyperglycemia, a protein implicated in initiating inflammation and strongly correlated with DM onset and progression. We hypothesized that HMGB1 knockdown will mitigate hyperglycemia severity and enhance glucose tolerance. To test this hypothesis, we utilized a novel inducible HMGB1 knockout (iHMGB1 KO) mouse model exhibiting systemic HMGB1 knockdown. Hyperglycemic phenotype was induced using low dose streptozotocin (STZ) injections, followed by longitudinal glucose measurements and oral glucose tolerance tests to evaluate the effect of HMGB1 knockdown on glucose metabolism. Our findings showed a substantial reduction in glucose levels and enhanced glucose tolerance in HMGB1 knockdown mice. Additionally, we performed RNA sequencing analyses, which identified potential alternations in genes and molecular pathways within the liver and skeletal muscle tissue that may account for the in vivo phenotypic changes observed in hyperglycemic mice following HMGB1 knockdown. In conclusion, our present study delivers the first direct evidence of a causal relationship between systemic HMGB1 knockdown and hyperglycemia in vivo, an association that had remained unexamined prior to this research. This discovery positions HMGB1 knockdown as a potentially efficacious therapeutic target for addressing hyperglycemia and, by extension, the DM epidemic. Furthermore, we have revealed potential underlying mechanisms, establishing the essential groundwork for subsequent in-depth mechanistic investigations focused on further elucidating and harnessing the promising therapeutic potential of HMGB1 in DM management.

Serum Proteomic Signatures of Common Health Outcomes among Older Adults

INTRODUCTION

In aging populations, the coexistence of multiple health comorbidities represents a significant challenge for clinicians and researchers. Leveraging advances in omics techniques to characterize these health conditions may provide insight into disease pathogenesis as well as reveal biomarkers for monitoring, prognostication, and diagnosis. Researchers have previously established the utility of big data approaches with respect to comprehensive health outcome measurements in younger populations, identifying protein markers that may provide significant health information with a single blood sample.

METHODS

Here, we employed a similar approach in two cohorts of older adults, the Baltimore Longitudinal Study of Aging (mean age = 76.12 years) and InCHIANTI Study (mean age = 66.05 years), examining the relationship between levels of serum proteins and 5 key health outcomes: kidney function, fasting glucose, physical activity, lean body mass, and percent body fat.

RESULTS

Correlations between proteins and health outcomes were primarily shared across both older adult cohorts. We further identified that most proteins associated with health outcomes in the older adult cohorts were not associated with the same outcomes in a prior study of a younger population. A subset of proteins, adiponectin, MIC-1, and NCAM-120, were associated with at least three health outcomes in both older adult cohorts but not in the previously published younger cohort, suggesting that they may represent plausible markers of general health in older adult populations.

CONCLUSION

Taken together, these findings suggest that comprehensive protein health markers have utility in aging populations and are distinct from those identified in younger adults, indicating unique mechanisms of disease with aging.

Cystatin C-based estimated glomerular filtration rate and risk of stroke in the general population: a prospective cohort study

Background

Previous results on the association between the estimated glomerular filtration rate (eGFR) and stroke are mixed. Most studies derived the eGFR from serum creatinine, which is affected by non-kidney determinants and thus has possibly biased the association with stroke risk.

Methods

In this cohort study, we included 429 566 UK Biobank participants (94.5% white, 54% women, age 56 ± 8 years) free of stroke at enrollment. The eGFRcys and eGFRcr were calculated with serum cystatin C and creatinine, respectively. Outcomes of interest were risk of total stroke and subtypes. We investigated the linear and nonlinear associations using Cox proportional hazards models and restricted cubic splines, corrected for regression dilution bias.

Results

During an average follow-up of 10.11 years, 4427 incident strokes occurred, among which 3447 were ischemic and 1163 were hemorrhagic. After adjustment for confounders, the regression dilution-corrected hazard ratios (95% confidence intervals) for every 10 mL/min/1.73 m2 decrement in eGFRcys were 1.10 (1.05-1.14) for total stroke and 1.11 (1.08-1.15) for ischemic stroke. A similar pattern was observed with eGFRcr, although the association was weaker. When either type of eGFR was below 75 mL/min/1.73 m2, the risks of total and ischemic stroke increased exponentially as eGFR decreased. A U-shaped relationship was witnessed if eGFRcr was used instead. There was a null association between eGFR and hemorrhagic stroke.

Conclusions

The risks of total stroke and ischemic stroke increased exponentially when the eGFRcys fell below 75 mL/min/1.73 m2.

Effect of duration of pneumoperitoneum on renal function in patients undergoing laparoscopic surgeries: a prospective observational study

This study aimed to assess the effect of pneumoperitoneum and, thereby, raised intra-abdominal pressure for different durations (≤ 1 h, 1-3 h and > 3 h) on renal function. One hundred and twenty adult patients were allocated to four groups-the Control Group A (N = 30; patients undergoing non-laparoscopic surgery) or Group B (N = 30; patients undergoing laparoscopic surgery with duration of pneumoperitoneum < 1 h) or Group C (N = 30; patients undergoing laparoscopic surgery with duration of pneumoperitoneum 1-3 h) or Group D (N = 30; patients undergoing laparoscopic surgery with duration of pneumoperitoneum > 3 h). The baseline, intraoperative (at the end of pneumoperitoneum/surgery), and postoperative (after 6 h) values of blood urea levels, creatinine clearance, and serum cystatin C were compared. The results showed that the raised IAP (10-12 mmHg) and varying durations of pneumoperitoneum (from less than 1 h to more than 3 h) did not significantly affect renal function measured in terms of change in serum cystatin levels from baseline to 6 h in postoperative period. The varying durations of pneumoperitoneum also did not significantly affect serum creatinine or blood urea levels in the postoperative period. CTRI registration: CTRI/2016/10/007334.

Genome-wide association analysis of cystatin-C kidney function in continental Africa

BACKGROUND

Chronic kidney disease is becoming more prevalent in Africa, and its genetic determinants are poorly understood. Creatinine-based estimated glomerular filtration rate (eGFR) is commonly used to estimate kidney function, modelling the excretion of the endogenous biomarker (creatinine). However, eGFR based on creatinine has been shown to inadequately detect individuals with low kidney function in Sub-Saharan Africa, with eGFR based on cystatin-C (eGFRcys) exhibiting significantly superior performance. Therefore, we opted to conduct a GWAS for eGFRcys.

METHODS

Using the Uganda Genomic Resource, we performed a genome-wide association study (GWAS) of eGFRcys in 5877 Ugandans and evaluated replication in independent studies. Subsequently, putative causal variants were screened through Bayesian fine-mapping. Functional annotation of the GWAS loci was performed using Functional Mapping and Annotation (FUMA).

FINDINGS

Three independent lead single nucleotide polymorphisms (SNPs) (P-value <5 × 10-8 (based on likelihood ratio test (LRT))) were identified; rs59288815 (ANK3), rs4277141 (OR51B5) and rs911119 (CST3). From fine-mapping, rs59288815 and rs911119 each had a posterior probability of causality of >99%. The rs911119 SNP maps to the cystatin C gene and has been previously associated with eGFRcys among Europeans. With gene-set enrichment analyses of the olfactory receptor family 51 overlapping genes, we identified an association with the G-alpha-S signalling events.

INTERPRETATION

Our study found two previously unreported associated SNPs for eGFRcys in continental Africans (rs59288815 and rs4277141) and validated a previously well-established SNP (rs911119) for eGFRcys. The identified gene-set enrichment for the G-protein signalling pathways relates to the capacity of the kidney to readily adapt to an ever-changing environment. Additional GWASs are required to represent the diverse regions in Africa.

FUNDING

Wellcome (220740/Z/20/Z).

Ambient black carbon reaches the kidneys

BACKGROUND

Ultrafine particles, including black carbon (BC), can reach the systemic circulation and therefore may distribute to distant organs upon inhalation. The kidneys may be particularly vulnerable to the adverse effects of BC exposure due to their filtration function.

OBJECTIVES

We hypothesized that BC particles reach the kidneys via the systemic circulation, where the particles may reside in structural components of kidney tissue and impair kidney function.

METHODS

In kidney biopsies from 25 transplant patients, we visualized BC particles using white light generation under femtosecond-pulsed illumination. The presence of urinary kidney injury molecule-1 (KIM-1) and cystatin c (CysC) were evaluated with ELISA. We assessed the association between internal and external exposure matrices and urinary biomarkers using Pearson correlation and linear regression models.

RESULTS

BC particles could be identified in all biopsy samples with a geometric mean (5th, 95th percentile) of 1.80 × 103 (3.65 × 102, 7.50 × 103) particles/mm3 kidney tissue, predominantly observed in the interstitium (100 %) and tubules (80 %), followed by the blood vessels and capillaries (40 %), and the glomerulus (24 %). Independent from covariates and potential confounders, we found that each 10 % higher tissue BC load resulted in 8.24 % (p = 0.03) higher urinary KIM-1. In addition, residential proximity to a major road was inversely associated with urinary CysC (+10 % distance: -4.68 %; p = 0.01) and KIM-1 (+10 % distance: -3.99 %; p < 0.01). Other urinary biomarkers, e.g., the estimated glomerular filtration rate or creatinine clearance showed no significant associations.

DISCUSSION AND CONCLUSION

Our findings that BC particles accumulate near different structural components of the kidney represent a potential mechanism explaining the detrimental effects of particle air pollution exposure on kidney function. Furthermore, urinary KIM-1 and CysC show potential as air pollution-induced kidney injury biomarkers for taking a first step in addressing the adverse effects BC might exert on kidney function.

A comprehensive review of acute cardio-renal syndrome: need for novel biomarkers

Cardiorenal syndrome represents a wide-spectrum disorder involving the heart and kidneys as the primary affected organs. India has an increasingly high burden of acute CRS, coinciding with the rise in global statistics. Up to 2022, approximately 46.1% of all cardiorenal patients have been diagnosed with acute CRS in India. Acute CRS involves a sudden deterioration of kidney functionalities, referred to as acute kidney injury (AKI) in acute heart failure patients. The pathophysiology of CRS involves hyperactivation of the sympathetic nervous system (SNS) and the renin-angiotensin-aldosterone system (RAAS) following acute myocardial stress. The pathological phenotype of acute CRS is associated with perturbed inflammatory, cellular, and neurohormonal markers in circulation. These complications increase the risk of mortality in clinically diagnosed acute CRS patients, making it a worldwide healthcare burden. Hence, effective diagnosis and early prevention are crucial to prevent the progression of CRS in AHF patients. Present biomarkers, such as serum creatinine (sCr), cystatin C (CysC), glomerular filtration rate (GFR), blood urea nitrogen (BUN), serum and/or urine neutrophil gelatinase-associated lipocalin (NGAL), B-type natriuretic peptide (BNP), and NT-proBNP, are clinically used to diagnose AKI stages in CRS patients but are limitedly sensitive to the early detection of the pathology. Therefore, the need for protein biomarkers is emerging for early intervention in CRS progression. Here, we summarized the cardio-renal nexus in acute CRS, with an emphasis on the present clinicopathological biomarkers and their limitations. The objective of this review is to highlight the need for novel proteomic biomarkers that will curb the burgeoning concern and direct future research trials.

Dyslipidemia and serum cystatin C levels as biomarker of diabetic nephropathy in patients with type 2 diabetes mellitus

Background

Diabetic nephropathy is a leading cause of end-stage renal disease. The diagnostic markers of nephropathy, including the presence of albuminuria and/or a reduced estimated glomerular filtration rate, are not clinically ideal, and most of them are raised after a significant reduction in renal function. Therefore, it is crucial to seek more sensitive and non-invasive biomarkers for the diagnosis of diabetic nephropathy.

Objective of the study

This study aimed to investigate the serum cystatin C levels and dyslipidemia for the detection of diabetic nephropathy in patients with type 2 diabetes mellitus.

Methodology

A hospital-based comparative cross-sectional study was conducted from December 2021 to August 2022 in Tikur, Anbessa specialized teaching hospital with a sample size of 140 patients with type2 diabetes mellitus. Socio-demographic data was collected using a structured questionnaire, and 5 mL of blood was collected from each participant following overnight fasting for biochemical analyses.

Results

In type 2 diabetes patients with nephropathy, we found significant lipoprotein abnormalities and an increase in serum cystatin C (P &lt; 0.001) compared to those without nephropathy. Serum cystatin C, systolic blood pressure, fasting blood glucose, total cholesterol, triglyceride, low density lipoprotein, very low-density lipoprotein, high density lipoprotein, and duration of diabetes were identified as being significantly associated with diabetic nephropathy (P &lt; 0.05) in multivariable logistic regression analysis. The mean values of total cholesterol levels, triglyceride levels, and high-density lipoprotein cholesterol levels were also found to be significantly higher (P &lt; 0.05) in females as compared to male type-2 diabetic patients. The fasting blood glucose levels and lipid profiles of the participants were found to be significantly associated with serum cystatin C levels.

Conclusion

The present study found significant serum cystatin C and lipoprotein abnormalities in T2DM patients with diabetic nephropathy when compared with those without diabetic nephropathy, and these lipoprotein abnormalities were significantly associated with serum cystatin C levels.

Hemolysis scavenger proteins and renal function marker in children with sickle cell disease at steady state: A cross-sectional study

Background and Aims

Hemolysis is a fundamental feature of sickle cell disease (SCD) contributing to the vaso-occlusive crisis of patients. The objectives of the study were to assess the link between hemolysis proteins and hematological parameters, and to validate cystatin C (CYS C) as a potent renal marker in diagnoising SCD.

Method

Here, a cross-sectional study carried out at the pediatric SCD clinic of the Komfo Anokye Teaching Hospital comprised 90 SCD children (HbSC, HbSF, and HbSS). ANOVA, t-test, and Spearman's rank correlation analysis were done. Elevated proteins levels were compared to standard values; alpha-1 microglobulin (A1M) (1.8-65 µg/L), CYS C (0.1-4.5 µmol/L), and haemopexin (HPX) (500-1500 µg/mL).

Results

The mean (standard deviation) age of participants was 9.830 (±0.3217) years, and 46% of them were males. From simple descriptive analysis, we observed that all but one patient had their HPX level below the reference range (<500 µg/mL). Here, A1M levels were shown to be within the appropriate reference range for all the patients except few patients. CYS C levels were also all within the required reference values. A Spearman's rank correlation test between full blood count and HPX generally suggested a weak but positive correlation; RBC (coef. = 0.2448; p = 0.0248), HGB (coef. = 0.2310; p = 0.030), hematocrit (coef. = 0.2509; p = 0.020), and platelet (coef. = 0.1545; p = 0.160). Mean corpuscular volume (coef. = -0.5645; p = 0.610) had a stronger but negative correlation with HPX. This study depicts a positive and stronger association between CYS C and HPX levels (coef. = 0.9996; p < 0.0001), validating the use of CYS C as a useful marker of renal function in persons with SCDs.

Conclusion

In the present study, we show that A1M levels were normal for most of the patients, hence CYS C levels are not alarming in this study. Further, there exists a correlation between hemolysis scavenger proteins and hematological parameters.

Epidemiology and renal injury following 2-methyl-4-chlorophenoxyacetic acid (MCPA) poisoning

2-Methyl-4-chlorophenoxyacetic acid (MCPA) is a widely used chlorophenoxy herbicide. MCPA poisoning causes mitochondrial dysfunction, which can lead to kidney injury and death. The objective of this study is to describe the epidemiology, case fatality and extent of renal injury in a large cohort of MCPA self-poisonings. The study consists of two parts: (1) A report of epidemiological data and clinical outcomes in MCPA poisoned patients in Sri Lanka between 2002 and 2019; (2) Evaluation of acute kidney injury (AKI) using renal biomarkers in a subset from this cohort. Serum creatinine (sCr) and biomarkers were measured soon after hospitalization (2 [IQR 1-3] h) and at different time intervals. We measured serum biomarkers: sCr, cystatin C (sCysC), creatine kinase (CK), and urinary biomarkers: creatinine, kidney injury molecule-1 (KIM-1), clusterin, albumin, beta-2-microglobulin (β2M), cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), osteopontin (OPN), trefoil factor 3 (TFF3) and cytochrome C (CytoC). Kidney Disease Improving Global Outcomes (KDIGO) criteria was used to define acute kidney injury (AKI). There were 1653 patients; 65% were male. The median time from ingestion to examination was 3:54 (IQR 2:19-6:57) h. The overall case-fatality rate was 5.3%. Patients who died were older (42 [IQR 33.5-54] vs 27 [IQR 20-37] for survivors). The median estimated amount of MCPA ingested by patients who died was also greater (88 [IQR 34-200] vs. 30 [IQR 15-63] ml in survivors). Moderate to severe AKI (AKI2/3) was uncommon (6/59 patients in the biomarker study had KDIGO stage 2 or 3). Most patients in AKI2/3 group with increased sCr were older (median age 35 years [IQR 27-41]) compared to No AKI (23 years (19-29) years) or AKI1 (26 years (21-40) years) group who had no or mild increase in sCr. These patients had no pre-existing kidney diseases. In these patients, serum creatinine (maximum medium concentration; 1.12 [IQR 0.93-1.67] mg/dl) and CK (maximum medium concentration; 284 [IQR 94-428] U/l) were increased but sCysC (maximum medium concentration; 0.79 [IQR 0.68-0.81] mg/l) remained in the normal range within 72 h. All urinary biomarkers performed poorly in diagnosing AKI (area under the receiver operating characteristic curve < 0.68). The higher numbers of men with MCPA poisoning likely reflects greater occupational access to pesticides. Fatal outcome and higher ingested dose were more common in the elderly. Significant AKI with tubular injury biomarkers was uncommon. Most people with raised sCr were older and appeared to have no pre-existing kidney disease.

Serum and urinary biomarkers to predict acute kidney injury in premature infants: a systematic review and meta-analysis of diagnostic accuracy

BACKGROUND

Premature infants are at high risk for acute kidney injury (AKI) and current diagnostic criteria are flawed. The objective of this study was to determine the diagnostic accuracy of urine and serum biomarkers not currently used in routine clinical practice to predict AKI in premature infants.

METHOD

A systematic review was performed that followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy Studies (PRISMA-DTA). Data were extracted on the diagnostic accuracy of AKI biomarkers using serum creatinine or urine output as the reference standard. Quality and validity were assessed using modified Standards for Reporting Diagnostic Accuracy (STARD) criteria.

RESULTS

We identified 1024 articles, with 15 studies (791 infants) eligible for inclusion. Twenty-seven biomarkers were identified including serum cystatin C and urinary neutrophil gelatinase-associated lipocalin (uNGAL), osteopontin, kidney injury molecule-1, epidermal growth factor, and protein S100-P. However, many were only reported by one study each. A meta-analysis could only be conducted on uNGAL (288 infants from 6 studies) using a hierarchical, random-effects logistic-regression model. uNGAL had a summary sensitivity of 77% (95% CI 58-89%), specificity of 76% (95% CI 57-88%) and AUC-SROC of 0.83 (95% CI 0.80-0.86) for the diagnosis of AKI. By utilising uNGAL, the post-test probability of AKI increased to 52% (95% CI 37-66%) with a positive test and decreased to 9% (95% CI 5-16%) with a negative test if the pre-test probability was 25%.

CONCLUSION

uNGAL shows promise as a diagnostically accurate biomarker for AKI in premature infants.

Cardiorenal syndrome: Pathophysiology as a key to the therapeutic approach in an under-diagnosed disease

Cardiorenal syndrome is a clinical condition that impacts both the heart and the kidneys. One organ's chronic or acute impairment can lead to the other's chronic or acute dysregulation. The cardiorenal syndrome has been grouped into five subcategories that describe the etiology, pathophysiology, duration, and pattern of cardiac and renal dysfunction. This classification reflects the large spectrum of interrelated dysfunctions and underlines the bidirectional nature of heart-kidney interactions. However, more evidence is needed to apply these early findings in medical practice. Understanding the relationship between these two organs during each organ's impairment has significant clinical implications that are relevant for therapy in both chronic and acute conditions. The epidemiology, definition, classification, pathophysiology, therapy, and outcome of each form of cardiorenal syndrome are all examined in this review.

Impact of Elevated LDH on Cystatin C-Based Glomerular Filtration Rate Estimates in Patients with Cancer

Background: The determination of renal function is crucial for the clinical management of patients with cancer. The glomerular filtration rate (GFR) serves as a key parameter, estimated by creatinine clearance determination in 24-h collected urine (CrCl) as well as equation-based approaches (eGFR) relying on serum creatinine (eGFR CKD EPIcrea) or serum cystatin C (eGFR cystatin C). Serum creatinine and serum cystatin C levels differentially depend on muscle and tumor mass, respectively. Although muscle and tumor mass may thus represent confounding factors, comparative studies for eGFR estimate approaches in cancer patients are lacking. Methods: The present study retrospectively analyzed GFR estimates based on equations of creatinine (eGFRcr), cystatin C (eGFRcys) and combined creatinine-cystatin C levels (eGFRcr-cys) in a subset of patients. The associations of LDH with cystatin C or LDH with eGFRcr, eGFRcys and GFRcr-cys were explored. Results: The laboratory values of 123 consecutive patients were included. The median age was 59 (24−87) and 47.2% were female. There was a statistically significant difference in the mean of CKD EPIcrea (85.17 ± 21.63 mL/min/1.73 m2), CKD EPIcys (61.16 ± 26.03 mL/min/1.73 m2) and CKD EPIcrea-cys (70.42 ± 23.89 mL/min/1.73 m2) (p < 0.0001). Spearman’s correlation analysis revealed a significant correlation of elevated plasma LDH >1.5 UNV and cystatin C values (r = 0.270, p < 0.01, n = 123). LDH values >1.5 UNV were associated with significantly lower CKD EPIcys (r = 0.184, p < 0.01) or CKD EPIcrea-cys (r = 0.226, p < 0.05) estimates compared to CKD EPIcrea. Conclusions: The inclusion of cystatin C as a biomarker led to a lower eGFR estimates compared to creatinine alone or in a combination of both cystatin C and creatinine. The level of cystatin C correlated with the level of LDH, suggesting that the use of cystatin C-based calculations of GFR in cancer patients with elevated LDH should be used with caution.

Reduced inflammation following human endometrial stromal/stem cell injection into male Wistar rats with cisplatin-induced acute kidney injury

Introduction: Inflammation is one of the most important mechanisms involved in cisplatin-induced acute kidney injury (AKI). Mesenchymal stromal/stem cells (MSCs) exhibit anti-inflammatory and immunomodulatory abilities. Human endometrial stromal/stem cells (hEnSCs) exhibit similar properties to MSCs. These cells secrete immunoregulators, so we investigated the inflammatory aspect of hEnSCs in the treatment of cisplatin-induced AKI in Wistar rats.

Methods: Each group consisted of 6 male Wistar rats. Groups were as follows: sham, model (5 mg/kg cisplatin, IP), and treatment (1 million hEnSCs, IV, 3 hours after cisplatin). Renal function, histopathology, proliferation rate, infiltration of CD3⁺ T cell, and expression of Il-10 and cystatin c (Cst3) were assessed on day 5. DiI-labeled cells were tracked in kidney and liver on days 4 and 14.

Results: HEnSC transplantation improved cisplatin-induced injuries such as renal dysfunction and tissue damage. The highest levels of pathologic scores and hyaline cast formation were observed in the model group while hEnSCs transplantation resulted in their reduction (154.00 ± 14.95, 8.00 ± 1.41 vs. 119.40 ± 5.43, 2.50 ± 1.05). The percentage of Ki-67 positive cells in the treatment group increased while cisplatin decreased proliferation (39.91 ± 5.33 vs. 23.91 ± 3.57 in glomeruli and 39.07 ± 2.95 vs. 16.61 ± 3.25 in tubules). The expression of Cst3 and Il-10 was higher in the model and treatment groups, respectively. DiI-labeled cells were observed in the renal tubules and liver lobes on days 4 and 14.

Conclusion: HEnSCs may ameliorate cisplatin-induced AKI through anti-inflammatory and immunomodulatory effects and/or through paracrine effects.

The Most Promising Biomarkers of Allogeneic Kidney Transplant Rejection

Clinical transplantology is a constantly evolving field of medicine. Kidney transplantation has become standard clinical practice, and it has a significant impact on reducing mortality and improving the quality of life of patients. Allogenic transplantation induces an immune response, which may lead to the rejection of the transplanted organ. The gold standard for evaluating rejection of the transplanted kidney by the recipient's organism is a biopsy of this organ. However, due to the high invasiveness of this procedure, alternative diagnostic methods are being sought. Therefore, the biomarkers may play an essential predictive role in transplant rejection. A review of the most promising biomarkers for early diagnosis and prognosis prediction of allogenic kidney transplant rejection summarizes novel data on neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), C-X-C motif chemokine 10 (CXCL-10), cystatin C (CysC), osteopontin (OPN), and clusterin (CLU) and analyses the dynamics of changes of the biomarkers mentioned above in kidney diseases and the mechanism of rejection of the transplanted kidney.

Investigating the effect of Fenofibrate on biomarkers of vascular inflammation in L-NAME induced hypertensive rats

This study aims to evaluate the impact of fenofibrate on the levels of (IL-6, hsCRP, Lp-PLA2, sCD40L, and cystatin C) in hypertensive rats. Twenty-four rats were divided into two groups each of twelve. The first group served as the normotensive group, while the second group was regarded as the hypertensive group. Each group was further divided into two subgroups (control and treated). The control subgroups only received a placebo and the treated subgroups were given fenofibrate 30 mg/kg daily orally by gastric gavage for 4 weeks. The level of hsCRP, IL6, and Lp-PLA2 significantly increased, but sCD40L and cystatin C levels were not changed in hypertensive rats. Fenofibrate has significantly reduced the levels of hsCRP and Lp-LPA2 in hypertensive rats while IL6 and sCD40s have not been changed in both groups. In conclusion, Fenofibrate has revealed a pleiotropic anti-inflammatory effect by reducing the level of hsCRP and Lp-LPA2 in hypertensive rats.

Therapeutic effect of quercetin polymeric nanoparticles on ischemia/reperfusion-induced acute kidney injury in mice

Acute kidney injury (AKI) is known as a sudden episode of kidney injury, which happens suddenly within a few hours or a few days. Quercetin (3,3',4',5,7-pentahydroxyflavone) is a flavonoid found in plants. Quercetin is known to have several biological activities, such as anti-oxidant, anti-inflammatory, and anti-carcinogenic effects. However, low water solubility and bioavailability are the limitations of quercetin for its clinical applications. Moreover, ischemia/reperfusion (I/R) injury is a common cause of AKI. There are no satisfactory strategies for I/R-induced AKI. Developing suitable preventive or therapeutic intervention for AKI is an important and urgent issue. We investigated the benefit effect of synthesized polyethylene glycol (PEG) conjugated polyethyleneimine (PEI) nanoparticles for targeted delivery of quercetin on AKI in a mouse model. An I/R-induced AKI mouse model was used to evaluate the therapeutic effect of quercetin polymeric nanoparticles by intravenous injection. Biochemical changes for renal function in blood samples were analyzed. Histological and immunohistochemical changes were also analyzed. The biochemical changes of blood urea nitrogen (BUN), creatinine, and cystatin C were significantly increased in I/R-induced AKI mice, which could be significantly reversed by quercetin polymeric nanoparticles. Quercetin polymeric nanoparticles could also significantly decrease the histological lesions, positive staining for 3-nitrotyrosine and cyclooxygenase-2, and lipid peroxidation in the kidneys of I/R-induced AKI mice. These results demonstrate for the first time that quercetin polymeric nanoparticles possess therapeutic potential for the treatment of I/R-induced AKI in vivo.

Changes in Mortality According to Creatinine/Cystatin C Ratio in Chronic Kidney Disease and Non-chronic Kidney Disease Patients

Background

Serum creatinine and cystatin C are not only good indicators of renal function but have also been confirmed to be related to disease prognosis and mortality in various diseases via creatinine/cystatin C ratio (CCR). However, although they are biomarkers of renal function, there is no study regarding renal impairment as a confounding variable in the relationship between CCR and all-cause mortality.

Methods

Patients who had simultaneous measurements of serum creatinine and cystatin C between 2003 and 2020 were enrolled. The patients with chronic kidney disease (CKD) were defined as having an estimated glomerular filtration rate (eGFR) CKD-EPI Cr-Cystatin C < 60 ml/min/1.73 m². CCR was calculated by dividing the serum creatinine level by the cystatin C level measured on the same day. The main outcome assessed was all-cause mortality according to CCR in CKD or non-CKD groups.

Results

Among the 8,680 patients in whom creatinine and cystatin C levels were measured simultaneously, 4,301 were included in the CKD group, and 4,379 were included in the non-CKD group, respectively. CCR was 1.4 ± 0.6 in total participants. The non-CKD group showed higher mean CCR, (1.5 ± 0.7 vs. 1.3 ± 0.5) as well as a wider distribution of CCR (p < 0.001) when compared to the CKD group. In non-CKD group, 1^st, 4^th and 5^th quintiles of CCR significantly increased the all-cause mortality risk compared to 2^nd quintile of CCR, suggesting U-shaped mortality risk according to CCR in non-CKD. On the other hand, in CKD group, the risk of all-cause mortality linearly increased and 5^th quintile of CCR showed 1.82 times risk of mortality compared to 2^nd quintile of CCR. In the subgroup analysis of mortality by age and sex, the mortality difference according to CCR were diminished in old age and female sex subgroups.

Conclusion

We discovered a U-shaped relationship between mortality and CCR levels in normal renal function, and an increased risk of mortality in CKD with elevated CCR.

Association of Serum Levels of Cystatin C and Cognition in a Cohort of Egyptian Elderly Patients with Chronic Kidney Disease

Chronic kidney disease (CKD) and dementia are common morbidities of elders. Serum cystatin C has been suggested to be an ideal marker for kidney function. The current study aimed to detect the serum levels of cystatin C in CKD patients and to correlate these levels to cognitive performance. The study involved 90 subjects aged 65 years and more, divided into two groups: Group 1: 60 patients with CKD, and Group 2: 30 control participants. Exclusion criteria included cardiac failure, hepatic failure, thyroid diseases, dialysis for more than one month, polycystic kidney disease, organ transplantation, and immunosuppressive therapy within the past six months. All participants had routine laboratory workup, serum cystatin C using enzyme-linked immunosorbent assay kits, and cognitive assessment using mini-mental state examination (MMSE). Serum cystatin level was significantly high in CKD patients while MMSE scores were significantly lower in CKD patients. A high significant negative correlation was found between serum cystatin C levels and both degree of cognitive impairment and glomerular filtration rate (GFR). Also, a significant positive correlation was found between the degree of cognitive impairment and GFR levels. Serum cystatin levels are significantly associated with cognitive impairment in CKD patients, and this correlation becomes more evident with the worsening of CKD stages. That may help in better understanding of the pathogenesis of dementia in CKD patients with the emergence of therapeutic options depending on these data.

Glyphosate and AMPA exposure in relation to markers of biological aging in an adult population-based study

BACKGROUND/AIM

Glyphosate, a broad-spectrum herbicide, and its main metabolite aminomethylphosphonic acid (AMPA) are persistent in the environment. Studies showed associations between glyphosate or AMPA exposure and several adverse cellular processes, including metabolic alterations and oxidative stress.

OBJECTIVE

To determine the association between glyphosate and AMPA exposure and biomarkers of biological aging.

METHODS

We examined glyphosate and AMPA exposure, mtDNA content and leukocyte telomere length in 181 adults, included in the third cycle of the Flemish Environment and Health Study (FLEHSIII). DNA was isolated from leukocytes and the relative mtDNA content and telomere length were determined using qPCR. Urinary glyphosate and AMPA concentrations were measured by Gas Chromatography-Tandem Mass Spectrometry (GC-MS-MS). We used multiple linear regression models to associate mtDNA content and leukocyte telomere length with glyphosate or AMPA exposure while adjusting for confounding variables.

RESULTS

A doubling in urinary AMPA concentration was associated with 5.19% (95% CI: 0.49 to 10.11; p = 0.03) longer leukocyte telomere length, while no association was observed with urinary glyphosate concentration. No association between mtDNA content and urinary glyphosate nor AMPA levels was observed.

CONCLUSIONS

This study showed that AMPA exposure may be associated with telomere biology in adults.

Treatment of Chronic Kidney Disease with Extracellular Vesicles from Mesenchymal Stem Cells and CD133+ Expanded Cells: A Comparative Preclinical Analysis

Chronic kidney disease (CKD) is characterized by structural abnormalities and the progressive loss of kidney function. Extracellular vesicles (EVs) from human umbilical cord tissue (hUCT)-derived mesenchymal stem cells (MSCs) and expanded human umbilical cord blood (hUCB)-derived CD133⁺ cells (eCD133⁺) maintain the characteristics of the parent cells, providing a new form of cell-free treatment. We evaluated the effects of EVs from hUCT-derived MSCs and hUCB-derived CD133⁺ cells on rats with CDK induced by an adenine-enriched diet. EVs were isolated by ultracentrifugation and characterized by nanoparticle tracking analysis (NTA) and electron microscopy. The animals were randomized and divided into the MSC-EV group, eEPC-EV group and control group. Infusions occurred on the seventh and 14th days after CKD induction. Evaluations of kidney function were carried out by biochemical and histological analyses. Intense labeling of the α-SMA protein was observed when comparing the control with MSC-EVs. In both groups treated with EVs, a significant increase in serum albumin was observed, and the increase in cystatin C was inhibited. The results indicated improvements in renal function in CKD, demonstrating the therapeutic potential of EVs derived from MSCs and eCD133⁺ cells and suggesting the possibility that in the future, more than one type of EV will be used concurrently.

Method of Calculating Renal Function Estimates Could Inappropriately Exclude Transgender Patients Receiving Gender-Affirming Hormone Therapy from Pre-Exposure Prophylaxis Eligibility

Purpose: Despite the importance of reliable renal function estimation among the growing transgender population, research describing the variability of existing equations is scarce. Study objectives were to (1) quantify the range of renal function estimates that would be observed if different gender coefficients are used in the estimating equations, (2) compare estimates of renal function (creatinine clearance [CL_CR] or estimated glomerular filtration rate [GFR]) between users and nonusers of gender-affirming therapies, and (3) quantify the proportion of subjects who would be deemed ineligible for tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) for pre-exposure prophylaxis (PrEP) based on the gender coefficient used. Methods: A retrospective analysis was performed among transgender PrEP users enrolled in a multicenter observational study between June 2017 and October 2021. The primary outcome was estimated kidney function, defined using calculated CL_CR or GFR before initiating TDF/FTC for PrEP based on the three most commonly used estimating equations. Results: A total of 258 participants were evaluated. Median differences in renal function ranged from 13 to 25 mL/min based on which gender coefficient and equation was used. Regardless of the method used to compute renal function, there were significant differences between users and nonusers of gender-affirming therapy. There were 17 (6.6%) participants where at least one of the methods would potentially render them ineligible to receive TDF/FTC for PrEP. Conclusions: Renal function estimates vary considerably with different estimating equations in the transgender population and are modified by use of gender-affirming therapy. These variations could result in exclusion from drug therapies such as TDF/FTC for PrEP.

Serum Cystatin C as a Biomarker for Early Diabetic Kidney Disease and Dyslipidemia in Young Type 1 Diabetes Patients

Background and objectives: This study aimed to assess the clinical significance of serum cystatin C in the early diagnosis of renal injury and its association with dyslipidemia in young T1D patients. Materials and Methods: A total of 779 subjects were evaluated for kidney function by estimating glomerular filtration rate (eGFR) based on serum creatinine (eGFRcreat) and cystatin C (eGFRcys). Results: The median age of study subjects was 16.2 years (2.1;26.4), diabetes duration—5.3 years (0.51;24.0). The median of HbA1c was 8% (5.2;19.9) (64 mmol/mol (33.3;194)); 24.2% of participants had HbA1c < 7% (53 mmol/mol). Elevated albumin excretion rate was found in 13.5% of subjects. The median of cystatin C was 0.8 mg/L (0.33;1.71), the median of creatinine—63 µmol/L (6;126). The median of eGFRcys was lower than eGFRcreat (92 mL/min/1.73 m² vs. 101 mL/min/1.73 m², p < 0.001). A total of 30.2% of all patients were classified as having worse kidney function when using cystatin C vs. creatinine for eGFR calculation. Linear correlations were found between cystatin C and HbA1c, r = −0.088, p < 0.05, as well as cystatin C and HDL, r = −0.097, p < 0.01. Conclusions: This study showed that cystatin C might be used as an additional biomarker of early kidney injury in young patients with T1D.

Population Pharmacokinetics of Intravenous Amoxicillin Combined With Clavulanic Acid in Healthy and Critically Ill Dogs

Background: Data regarding antimicrobial pharmacokinetics (PK) in critically ill dogs are lacking and likely differ from those of healthy dogs. The aim of this work is to describe a population PK model for intravenous (IV) amoxicillin–clavulanic acid (AMC) in both healthy and sick dogs and to simulate a range of clinical dosing scenarios to compute PK/PD cutoffs for both populations.

Methods: This study used a prospective clinical trial in normal and critically ill dogs. Twelve client-owned dogs hospitalized in the intensive care unit (ICU) received IV AMC 20 mg/kg every 8 h (0.5-h infusion) during at least 48 h. Eight blood samples were collected at predetermined times, including four trough samples before the next administration. Clinical covariates and outcome were recorded, including survival to discharge and bacteriologic clinical failure. Satellite PK data were obtained de novo from a group of 12 healthy research dogs that were dosed with a single AMC 20 mg/kg IV. Non-linear mixed-effects model was used to estimate the PK parameters (and the effect of health upon them) together with variability within and between subjects. Monte Carlo simulations were performed with seven dosage regimens (standard and increased doses). The correlation between model-derived drug exposure and clinical covariates was tested with Spearman's non-parametric correlation analysis. Outcome was recorded including survival to discharge and bacteriologic clinical failure.

Results: A total of 218 amoxicillin concentrations in plasma were available for healthy and sick dogs. A tricompartmental model best described the data. Amoxicillin clearance was reduced by 56% in sick dogs (0.147 L/kg/h) compared with healthy dogs (0.336 L/kg/h); intercompartmental clearance was also decreased (p <0.01). None of the clinical data covariates were significantly correlated with individual exposure. Monte Carlo simulations showed that higher PK/PD cutoff values of 8 mg/L could be reached in sick dogs by extending the infusion to 3 h or doubling the dose.

Conclusions: The PK of AMC is profoundly different in critically ill dogs compared with normal dogs, with much higher interindividual variability and a lower systemic clearance. Our study allows to generate hypotheses with regard to higher AMC exposure in clinical dogs and provides supporting data to revise current AMC clinical breakpoint for IV administration.

Review of early circulating biomolecules associated with diabetes nephropathy - Ideal candidates for early biomarker array test for DN

BACKGROUND

Diabetic nephropathy (DN) is one of the catastrophic complications of type 2 diabetes mellitus (T2DM). 45% of DN patients progressed to End Stage Renal Disease (ESRD) which robs casualties of the quality of live. The challenge in early diagnosis of DN is it is asymptomatic in the early phase. Current gold standard test for screening and diagnosis of DN are nonspecific and are not sensitive in detecting DN early enough and subsequently monitor renal function during management and intervention plans. Recent studies reported various biomolecules which are associated with the onset of DN in T2DM using cutting-edge technologies. These biomolecules could be potential early biomarkers for DN. This review selectively identified potential early serum biomolecules which are potential candidates for developing an Early Biomarker Array Test for DN.

METHODS

An advanced literature search was conducted on 4 online databases. Search terms used were "Diabetes Mellitus, Type 2", "Diabetic nephropathy", "pathogenesis" and "early biomarker. Filters were applied to capture articles published from 2010 to 2020, written in English, human or animal models and focused on serum biomolecules associated with DN.

RESULTS

Five serum biomolecules have been evidently described as contributing pivotal roles in the pathophysiology of DN. MiR-377, miR-99b, CYP2E1, TGF-β1 and periostin are potential candidates for designing an early biomarker array for screening and diagnosis of early stages of DN. The five shortlisted biomolecules originates from endogenous biochemical processes which are specific to the progressive pathophysiology of DN.

CONCLUSION

miR-377, miR-99b, CYP2E1, TGF-β1 and periostin are potential candidate biomolecules for diagnosing DN at the early phases and can be developed into a panel of endogenous biomarkers for early detection of DN in patients with T2DM. The outcomes of this study will be a stepping stone towards planning and developing an early biomarker array test for diabetic nephropathy. The proposed panel of early biomarkers for DN has potential of stratifying the stages of DN because each biomolecule appears at distinct stages in the pathophysiology of DN.

Cystatin and Glomerular Filtration Rate in Obese Versus Non-obese Adolescents

Background: Obesity is well known as an independent risk factor for chronic kidney disease. Thus meticulous assessment of renal function is more essential in obese individuals. Glomerular filtration rate (GFR) is commonly estimated based on serum creatinine (Cr).  However, using Cr as marker of kidney function has some limitations and Cystatin C has been reported as an alternative marker. Aim of work: This study was designed to assess renal function using both GFR and cystatin in obese adolescents. Methods: This case-control study enrolled ninety Egyptian adolescents aged between 10 and 18 years old who were divided equally into two groups according to body mass index (obese and non-obese).  Each participant was subjected to full medical history taking, anthropometric measures, and Laboratory investigation including CBC, serum Cr, estimated GFR and cystatin C. Results:  Serum Cr level was significantly higher in obese adolescents compared to non-obese mean value (0.94) and (0.79) resepectively. Also, eGFR based on Cr was significantly lower in obese group compared to controls (73.1) and ( (85.30)respectively. Cystatin C showed non-significant higher levels in obese group versus controls with mean value (2.28) and (1.85)respectively. Cystatin C at Cut-off value of 1.525 and 95% CI showed sensitivity of 47.2% and specificity of 63.9% for evaluation of kidney affection in obese children and adolescences. Conclusion: GFR is affected in obese adolescence with elevation of serum creatinine and unexpected non significant elevation of cystatin C in obese adolescence when compared by control group. Keywords: Cystatin, Creatinine, Pediatric obesity, GFR, renal function.

Detection of Renal Insufficiency in a Cohort of Patients With Beta-thalassemia Major Using Cystatin-C

With increased life expectancy among patients with beta-thalassemia major (β-TM) renal insufficiency has been frequently noted because of the persistence of anemia, iron overload and some drug side effects. Serum creatinine becomes elevated in late stage of kidney affection. Cystatin-C is more sensitive biomarker for kidney dysfunction. Our aim was to measure Cystatin-C serum level among patients with β-TM as a marker of early nephropathy. Serum Cystatin-C was measured in 94 patients with β-TM using Enzyme-Linked Immunosorbent Assay (ELISA) and correlated to other clinical, laboratory and radiologic data. Glomerular hyperfiltration was observed in 30.8% while Cystatin-C was elevated in 56.3% of β-TM. Patients having high serum Cystatin-C were older in age and having higher serum levels of aspartate aminotransferases and urea. Cystatin-C level was positively correlated with serum creatinine and urea and negatively correlated with glomerular filtration rate. Periodic assessment of Cystatin-C in patients with β-TM is recommended for early diagnosis of renal dysfunction especially during drug dosing prescription aiming to obtain the maximum effectiveness and safety. Controlling anemia by maintaining appropriate hemoglobin level with close monitoring of iron overload are also recommended to preserve renal function among β-TM patients.

Potential Value of TNF-α (-376 G/A) Polymorphism and Cystatin C (CysC) in the Diagnosis of Sepsis Associated Acute Kidney Injury (S-AK I) and Prediction of Mortality in Critically Ill patients

Sepsis Associated Kidney Injury represents a major health concern as it is frequently associated with increased risk of mortality and morbidity. We aimed to evaluate the potential value of TNF-α (-376 G/A) and cystatin C in the diagnosis of S-AKI and prediction of mortality in critically ill patients. This study included 200 critically ill patients and 200 healthy controls. Patients were categorized into 116 with acute septic shock and 84 with sepsis, from which 142 (71%) developed S-AKI. Genotyping of TNF-α (-376 G/A) was performed by RT-PCR and serum CysC was assessed by Enzyme Linked Immunosorbent Assay. Our results showed a highly significant difference in the genotype frequencies of TNF-α (-376 G/A) SNP between S-AKI and non-AKI patients (p < 0.001). Additionally, sCysC levels were significantly higher in the S-AKI group (p = 0.011). The combination of both sCysC and TNF-α (-376 G/A) together had a better diagnostic ability for S-AKI than sCysC alone (AUC = 0.610, 0.838, respectively). Both GA and AA genotypes were independent predictors of S-AKI (p= < 0.001, p = 0.002 respectively). Additionally, sCysC was significantly associated with the risk of S-AKI development (Odds Ratio = 1.111). Both genotypes and sCysC were significant predictors of non-survival (p < 0.001), suggesting their potential role in the diagnosis of S-AKI and prediction of mortality.

Potential therapeutic efficacy of pachymic acid in chronic kidney disease induced in rats: role of Wnt/β-catenin/renin-angiotensin axis

OBJECTIVES

Chronic kidney disease (CKD) is a major public health problem associated with high mortality. The therapeutic effects of pachymic in CKD management and its underlying mechanisms have not been studied. Therefore, we aimed to investigate the possible inhibitory effect of PA on renal Wnt/β-catenin signalling in CKD.

METHODS

CKD was induced in rats by doxorubicin (DOX; 3.5 mg/kg i.p., twice weekly for 3 weeks). Rats were treated orally with PA (10 mg/kg/day), LOS (10 mg/kg/day) or their combination (PA + LOS) for 4 weeks starting after the last dose of DOX.

KEY FINDINGS

DOX-induced renal injury was characterized by high serum cystatin-C, and urine albumin/creatinine ratio, renal content of podocin and klotho were decreased. Tumour necrosis factor-α, interleukin-6, interleukin-1β, Wnt1, active β-catenin/total β-catenin ratio and fibronectin along with mRNA expression of RENIN, ACE and AT1 were increased in renal tissues. Treatment with either PA or LOS ameliorated all DOX-induced changes. The combined treatment was more effective in improving all changes than monotherapy.

CONCLUSIONS

These results suggest a new therapeutic benefit of PA in ameliorating CKD in rats through its up-regulatory effect on renal klotho thereby preventing Wnt/β-catenin reactivation and RAS gene expression. PA/LOS combination provided an additional inhibition of Wnt/β-catenin signalling and its downstream targets.

Correlation of Serum Cystatin C with Renal Function in Gout Patients with Renal Injury

The gout-induced continuous deposition of urate in the kidney tissues is the main cause of renal injury, for which cystatin C (Cys C) is an important indicator. This research analyzed the correlation between general renal injury indicators and serum Cys C level, and further investigated the potential of Cys C in renal injury diagnosis. A total of 140 gout patients with renal injury (GRI) were recruited and grouped by their glomerular filtration rate (GFR). Urea nitrogen, uric acid, creatinine, and Cys C levels in the serum were evaluated. The diagnostic efficacy of serum Cys C was evaluated by the nonparametric receiver operating characteristic analysis. Serum Cys C level was increased with decreased GFR in GRI. Urea nitrogen, uric acid, and creatinine levels in the serum showed positive correlations with Cys C level. The area under the curve for serum Cys C was 0.8589 (P < 0.001). In conclusion, this research demonstrated that the serum Cys C level was a precise diagnostic marker for GFR and renal damage evaluation, and showed a significant diagnostic value for renal injury in patients with gout.

Prediction of drug-induced kidney injury in drug discovery

Drug induced kidney injury is one of the leading causes of failure of drug development programs in the clinic. Early prediction of renal toxicity potential of drugs is crucial to the success of drug candidates in the clinic. The dynamic nature of the functioning of the kidney and the presence of drug uptake proteins introduce additional challenges in the prediction of renal injury caused by drugs. Renal injury due to drugs can be caused by a wide variety of mechanisms and can be broadly classified as toxic or obstructive. Several biomarkers are available for in vitro and in vivo detection of renal injury. In vitro static and dynamic (microfluidic) cellular models and preclinical models can provide valuable information regarding the toxicity potential of drugs. Differences in pharmacology and subsequent disconnect in biomarker response, differences in the expression of transporter and enzyme proteins between in vitro to in vivo systems and between preclinical species and humans are some of the limitations of current experimental models. The progress in microfluidic (kidney-on-chip) platforms in combination with the ability of 3-dimensional cell culture can help in addressing some of these issues in the future. Finally, newer in silico and computational techniques like physiologically based pharmacokinetic modeling and machine learning have demonstrated potential in assisting prediction of drug induced kidney injury.

MDM2 inhibition improves cisplatin-induced renal injury in mice via inactivation of Notch/hes1 signaling pathway

OBJECTIVE

To explore the potential function of MDM2-mediated Notch/hes1 signaling pathway in cisplatin-induced renal injury.

METHODS

The acute renal injury models of mice after intraperitoneal injection of cisplatin in vivo, and the apoptotic models of human renal tubular epithelial (HK-2) cells induced by cisplatin in vitro, were conducted respectively. The renal function-related parameters were measured. The renal tissue pathological changes and apoptosis were observed by PAS staining and TUNEL staining, respectively. Cell viability and apoptosis were detected by MTT and flow cytometry. Notch/hes1 pathway-related proteins were tested by Western blotting.

RESULTS

After mice injected by cisplatin, the levels of Cr, BUN, urine cystatin C, urine NGAL and urine ACR were increased and GFR was decreased with the elevation of renal tubular injury scores, the upregulation of the expressions of MDM2, N1ICD, Hes1 and Cleaved caspase-3, as well as the enhancement of cell apoptosis accompanying decreased ratio of Bcl-2/Bax. However, these cisplatin-induced renal injuries of mice have been improved by MDM2 inhibition. Besides, the declined viability, increased cytotoxicity, and enhanced apoptosis were observed in cisplatin-induced HK-2 cells, with the activated Notch/hes1 pathway. Notably, the phenomenon was alleviated in cisplatin-induced HK-2 cells transfected with MDM2 shRNA, but was severer in those co-treated with AdMDM2. Moreover, Notch1 siRNA can reverse the injury of AdMDM2 on HK-2 cells.

CONCLUSION

Inhibiting MDM2 could reduce cell apoptosis through blocking Notch/hes1 signaling pathway, thus alleviating the acute renal injury caused by cisplatin.

Inactivation of Wnt/β-catenin/renin angiotensin axis by tumor necrosis factor-alpha inhibitor, infliximab, ameliorates CKD induced in rats

Infliximab (IFX), a chimeric monoclonal antibody against tumor necrosis factor-α (TNF-α), is widely used to treat autoimmune diseases and chronic diseases associated with inflammation. TNF-α was reported to inhibit klotho, reactivate β-catenin and cause tubular cell injury in vitro. Whether the inhibition of TNF-α can regulate Wnt/β-catenin pathway via klotho in CKD in vivo is not studied yet. We aimed to investigate the impact of IFX on Wnt/β-catenin pathway in doxorubicin (DOX)-induced nephropathy. Doxorubicin (3.5 mg/kg; i.p., twice weekly for 3 weeks) increased serum cystatin-C, urine albumin/creatinine ratio (UACR), but depleted renal podocin. It markedly increased renal contents of TNF-α, interleukin-6 (IL-6), interleukin-1β (IL1β). DOX decreased the renal expression of klotho which in turn increased Wnt1, active β-catenin/total β-catenin ratio in renal tissue. Significant increase in renal gene expression of RENIN, ACE, and AT1 was observed. Moreover, renal fibronectin and collagen deposition increased in renal tissue. Treatment with either IFX (5 mg/kg, once; i.p.), losartan (LOS, 10 mg/kg/day, orally) or their combination significantly improved renal function, inhibited inflammatory cytokines and fibrosis. Renal TNF-α was negatively correlated with renal klotho. On the hand, it was positively correlated with renal Wnt1 and active β-catenin/total β-catenin ratio. The combined IFX and LOS treatment was the most effective in improving all studied parameters. In conclusion, this study proved, for the first time, the inhibitory effect of IFX on renal Wnt/β-catenin signaling in DOX-induced nephropathy in vivo by up-regulating renal klotho. Therefore, these results suggest a new role for IFX in chronic kidney disease via targeting renal Wnt/β-catenin/renin angiotensin axis.

Rapid Multianalyte Microfluidic Homogeneous Immunoassay on Electrokinetically Driven Beads

The simplicity of homogeneous immunoassays makes them suitable for diagnostics of acute conditions. Indeed, the absence of washing steps reduces the binding reaction duration and favors a rapid and compact device, a critical asset for patients experiencing life-threatening diseases. In order to maximize analytical performance, standard systems employed in clinical laboratories rely largely on the use of high surface-to-volume ratio suspended moieties, such as microbeads, which provide at the same time a fast and efficient collection of analytes from the sample and controlled aggregation of collected material for improved readout. Here, we introduce an integrated microfluidic system that can perform analyte detection on antibody-decorated beads and their accumulation in confined regions within 15 min. We employed the system to the concomitant analysis of clinical concentrations of Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Cystatin C in serum, two acute kidney injury (AKI) biomarkers. To this end, high-aspect-ratio, three-dimensional electrodes were integrated within a microfluidic channel to impart a controlled trajectory to antibody-decorated microbeads through the application of dielectrophoretic (DEP) forces. Beads were efficiently retained against the fluid flow of reagents, granting an efficient on-chip analyte-to-bead binding. Electrokinetic forces specific to the beads' size were generated in the same channel, leading differently decorated beads to different readout regions of the chip. Therefore, this microfluidic multianalyte immunoassay was demonstrated as a powerful tool for the rapid detection of acute life-threatening conditions.

Elevated serum creatinine in the context of HIV - who is the culprit? Over-the-counter supplements vs. antiretrovirals

We present a case of a 53-year-old male living with well-controlled HIV who, as part of routine monitoring, was noted to have an unexpected decline in renal function. His antiretrovirals were switched accordingly. It subsequently transpired that he had recently started taking creatine supplements in order to build muscle mass. He underwent specialist renal review and further investigation with a chromium-labelled scan which revealed his renal function was, in fact, stable. He continues under renal and HIV follow-up. It is now more widely recognised that creatine can affect renal function, and result in difficulty in interpretation of traditional renal blood tests. However, the further investigations that may be undertaken in such settings and HIV treatment considerations are not as widely reported. This case serves as a reminder to ensure over-the-counter and herbal supplements are part of routine questioning in HIV clinics, and outlines the specialist investigations that may be undertaken in cases of apparent renal decline.

A Meta-Analysis on the Performance of Cystatin C- versus Creatinine-based eGFR Equations in Predicting Vancomycin Clearance

BACKGROUND

The objective of this study was to compare the performance of cystatin C- and creatinine-based estimated glomerular filtration rate (eGFR) equations in predicting the clearance of vancomycin.

METHODS

MEDLINE and Embase databases were searched from inception up to September 2019 to identify all studies that compared the predictive performance of cystatin C- and/or creatinine-based eGFR in predicting the clearance of vancomycin. The prediction errors (PEs) (the value of eGFR equations minus vancomycin clearance) were quantified for each equation and were pooled using a random-effects model. The root mean squared errors were also quantified to provide a metric for imprecision.

RESULTS

This meta-analysis included evaluations of seven different cystatin C- and creatinine-based eGFR equations in total from 26 studies and 1,234 patients. The mean PE (MPE) for cystatin C-based eGFR was 4.378 mL min^-1 (95% confidence interval [CI], -29.425, 38.181), while the creatinine-based eGFR provided an MPE of 27.617 mL min^-1 (95% CI, 8.675, 46.560) in predicting clearance of vancomycin. This indicates the presence of unbiased results in vancomycin clearance prediction by the cystatin C-based eGFR equations. Meanwhile, creatinine-based eGFR equations demonstrated a statistically significant positive bias in vancomycin clearance prediction.

CONCLUSION

Cystatin C-based eGFR equations are better than creatinine-based eGFR equations in predicting the clearance of vancomycin. This suggests that utilising cystatin C-based eGFR equations could result in better accuracy and precision to predict vancomycin pharmacokinetic parameters.

The role of specific biomarkers, as predictors of post-operative complications following flexible ureterorenoscopy (FURS), for the treatment of kidney stones: a single-centre observational clinical pilot-study in 37 patients

BACKGROUND

The number of patients diagnosed and subsequently treated for kidney stones is increasing, and as such the number of post-operative complications is likely to increase. At present, little is known about the role of specific biomarkers, following flexible ureterorenoscopy (FURS) for the surgical treatment of kidney stones. The main aim of the study was to evaluate the role of kidney and infection biomarkers, in patients undergoing FURS.

METHODS

Included were 37 patients (24 males, 13 females), who underwent elective FURS, for the treatment of kidney stones. Venous blood samples were collected from each patient: pre-operatively, and at 30 min, 2 and 4 h post-operatively. Changes to kidney (NGAL, Cystatin-C) and infection (MPO, PCT) biomarkers was quantified by means of ELISA, Biomerieux mini-vidas and Konelab 20 analysers.

RESULTS

Four patients developed post-operative complications (3 - UTIs with urinary retention, 1 - urosepsis. NGAL concentration increased significantly following FURS (p = 0.034). Although no significant changes were seen in Cystatin C, MPO and PCT (p ≥ 0.05) some key clinical observation were noted. Limiting factors for this study were the small number of patients recruited and restriction in blood sampling beyond 4 h.

CONCLUSIONS

Although not confirmative, changes seen to biomarkers such as Cystatin C, NGAL and MPO in our observational clinical pilot-study may warrant further investigation, involving larger cohorts, to fully understand the role of these biomarkers and their potential association with post-operative complications which can develop following FURS.

Safety of a Combined WB-EMS and High-Protein Diet Intervention in Sarcopenic Obese Elderly Men

Purpose

Whole-body electromyostimulation (WB-EMS) especially in combination with a high-protein supplementation has been established as an efficient treatment against sarcopenia. However, there are several case reports of rhabdomyolysis after WB-EMS application. Thus, we asked if this training could potentially lead to deteriorations of the cardiac as well as the renal function.

Materials and Methods

One hundred sarcopenic obese men aged 70 years and older were randomly balanced (1-1-1) and allocated to one of the three study arms. During 16 weeks of intervention, these groups either performed WB-EMS and took a protein supplement (WB-EMS&P), solely received the protein supplement (Protein) or served as control group (CG). WB-EMS consisted of 1.5×20 min (85 Hz, 350 μs, 4 s of strain to 4 s of rest) applied with moderate-to-high intensity while moving. We further generated a daily protein intake of 1.7-1.8 g/kg/body mass per day. At baseline and 8-10 days after completion of the intervention, blood was drawn and biomarkers of muscle, cardiac and renal health were assessed.

Results

Hereby, we found slight but significant elevations of creatine kinase (CK) levels in the WB-EMS group pointing to minor damages of the skeletal muscle (140 U/l [81-210], p < 0.001). This was accompanied by a significant, low-grade increase of creatine kinase-muscle brain (CK-MB, 0.43 ng/mL [-0.29-0.96], p < 0.01) and high-sensitivity troponin T (hsTnT, 0.001 ng/mL. [0.000-0.003], p < 0.001) but without a higher risk of developing heart failure according to N-terminal prohormone of brain natriuretic peptide (NT-proBNP, -5.7 pg/mL [-38.8-24.6], p = 0.17). Estimated glomerular filtration rate (eGFR) was impaired neither by the high-protein supplementation alone nor in combination with WB-EMS (CG 76.0 mL/min/1.73 m² [71.9-82.2] vs Protein 73.2 mL/min/1.73 m² [63.0-78.9] vs WB-EMS&P 74.6 mL/min/1.73 m² [62.8-84.1], p = 0.478).

Conclusion

In conclusion, even in the vulnerable group of sarcopenic obese seniors, the combination of WB-EMS with a high-protein intake revealed no short-term, negative impact on the eGFR, but potential consequences for the cardiovascular system need to be addressed in future studies.

Earlier Detection of Glomerular Dysfunction in β-Thalassemia Major Patients

Chronic transfusions program in β-thalassemia patients will inevitably lead to iron overload with a significant morbidity and mortality. Glomerular filtration rate (GFR) is progressively declined in relation to iron overload as well as chronic anemia. Objective is to define levels of Cystatin C in transfusion dependent β-thalassemia major patients as a sensitive marker for detection of earlier glomerular dysfunction in addition to understand the effect of iron overload, chelating therapy and hepatitis infection. A cross sectional study conducted at Al-Basrah Hemoglobinopathy Centre for the period from September 2017 to January 2018 to enroll 75 β-thalassemia major patients. Data collected included duration of the disease, total transfusion requirement, details of chelation therapy and its therapeutic index. In addition to blood urea, serum creatinine and Cystatin C with estimated GFR (eGFR). The mean Cystatin C was 1.075 mg/L where 66.6% of patients had abnormal renal function which is higher proportion than those with renal (42.6%) detected according to serum creatinine level Cystatin C was significantly higher in patients who received desferrioxamine as compared to those received deferasirox (p = 0.007), in accordance with GFR which is significantly higher in patients receiving the latter chelation therapy (p = 0.009). A significant inverse relationship between Cystatin C, and GFR, while positive relationship between ferritin and Cystatin C (p = 0.0001, 0.001 respectively). Cyctatin C is better for detection and monitoring of glomerular dysfunction in B thalassemia major patient which is already not uncommon complications for the disease and iron chelation therapy.

The French national protocol for Kennedy's disease (SBMA): consensus diagnostic and management recommendations

Background

Kennedy’s disease (KD), also known as spinal and bulbar muscular atrophy (SBMA), is a rare, adult-onset, X-linked recessive neuromuscular disease caused by CAG expansions in exon 1 of the androgen receptor gene (AR). The objective of the French national diagnostic and management protocol is to provide evidence-based best practice recommendations and outline an optimised care pathway for patients with KD, based on a systematic literature review and consensus multidisciplinary observations.

Results

The initial evaluation, confirmation of the diagnosis, and management should ideally take place in a tertiary referral centre for motor neuron diseases, and involve an experienced multidisciplinary team of neurologists, endocrinologists, cardiologists and allied healthcare professionals. The diagnosis should be suspected in an adult male presenting with slowly progressive lower motor neuron symptoms, typically affecting the lower limbs at onset. Bulbar involvement (dysarthria and dysphagia) is often a later manifestation of the disease. Gynecomastia is not a constant feature, but is suggestive of a suspected diagnosis, which is further supported by electromyography showing diffuse motor neuron involvement often with asymptomatic sensory changes. A suspected diagnosis is confirmed by genetic testing. The multidisciplinary assessment should ascertain extra-neurological involvement such as cardiac repolarisation abnormalities (Brugada syndrome), signs of androgen resistance, genitourinary abnormalities, endocrine and metabolic changes (glucose intolerance, hyperlipidemia). In the absence of effective disease modifying therapies, the mainstay of management is symptomatic support using rehabilitation strategies (physiotherapy and speech therapy). Nutritional evaluation by an expert dietician is essential, and enteral nutrition (gastrostomy) may be required. Respiratory management centres on the detection and treatment of bronchial obstructions, as well as screening for aspiration pneumonia (chest physiotherapy, drainage, positioning, breath stacking, mechanical insufflation-exsufflation, cough assist machnie, antibiotics). Non-invasive mechanical ventilation is seldom needed. Symptomatic pharmaceutical therapy includes pain management, endocrine and metabolic interventions. There is no evidence for androgen substitution therapy.

Conclusion

The French national Kennedy’s disease protocol provides management recommendations for patients with KD. In a low-incidence condition, sharing and integrating regional expertise, multidisciplinary experience and defining consensus best-practice recommendations is particularly important. Well-coordinated collaborative efforts will ultimately pave the way to the development of evidence-based international guidelines.

An ultrasensitive Cystatin C renal failure immunosensor based on a PPy/CNT electrochemical capacitor grafted on interdigitated electrode

An interdigitated immunosensor for Cystatin C detection based on polypyrrole/carbon nanotube electrochemical capacitor is described. Cystatin C (CysC) is powerful biomarker for early acute renal failure and one predictive for cardiovascular risk, sepsis, cancer and death. Recently, electrochemical immunosensors based on interdigitated electrodes (IDE) have been successfully focused on development of point-of-care testing, due to their miniaturization facilities and higher sensitivity as compared with the screen-printed electrochemical sensing. Herein, a polypyrrole/carbon nanotube nanoyhibrid film was grafted on two gold fingers by electropolymerization obtaining a supercapacitor. Anti-CysC antibodies were immobilized on the IDE by covalent entrapment via ethylenediamine bifunctional agent, followed by glycine blocking in acid and alkaline medium. Under low frequency, capacitive effect of antigen-antibody interaction were observed by double layer capacitance, and analytical responses of this IDE immunosensor to CysC serum were obtained by changes on phase angle a linear range up to 300 ng/mL. The cutoff was calculated for serum samples showing a total reducing of non-specific binding at approximately 28 ng/mL CysC. This immunosensor based on interdigitated electrode (IDE) is a potential tools as portable device,with possibility to use as a practical and rapid test for CysC diagnostic in samples of serum.

Creatinine Deiminase: Characterization, Using in Enzymatic Creatinine Assay, and Production of the Enzyme

The goal of the review is description of the main characteristics of creatinine deiminase (CDI), an important bioanalytical tool for creatinine (Crn) assay. Crn is an essential metabolite for diagnostics of kidney disfunction and some other diseases, a biomarker to control the hemodialysis procedure, as well as an important analyte for sport medicine (estimation of general physiological status of athletes). We have described the important sources for CDI isolation, cloning of the corresponding gene, the construction of microbial recombinant strains, overproducing CDI, and characteristics of the enzyme from different microorganisms. There are reviewing also the new bioanalytical methods for quantitative determination of Crn, including enzymatic ones based on using CDI.