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Objective Real-life management of patients with hypertension and chronic kidney disease (CKD) among European Society of Hypertension Excellence Centres (ESH-ECs) is unclear : we aimed to investigate it. Methods A survey was conducted in 2023. The questionnaire contained 64 questions asking ESH-ECs representatives to estimate how patients with CKD are managed. Results Overall, 88 ESH-ECS representatives from 27 countries participated. According to the responders, renin-angiotensin system (RAS) blockers, calcium-channel blockers and thiazides were often added when these medications were lacking in CKD patients, but physicians were more prone to initiate RAS blockers (90% [interquartile range: 70–95%]) than MRA (20% [10–30%]), SGLT2i (30% [20–50%]) or (GLP1-RA (10% [5–15%]). Despite treatment optimisation, 30% of responders indicated that hypertension remained uncontrolled (30% (15–40%) vs 18% [10%–25%]) in CKD and CKD patients, respectively). Hyperkalemia was the most frequent barrier to initiate RAS blockers, and dosage reduction was considered in 45% of responders when kalaemia was 5.5–5.9 mmol/L. Conclusions RAS blockers are initiated in most ESH-ECS in CKD patients, but MRA and SGLT2i initiations are less frequent. Hyperkalemia was the main barrier for initiation or adequate dosing of RAS blockade, and RAS blockers’ dosage reduction was the usual management.

Patients with Crohn's disease are at increased risk for symptomatic nephrolithiasis. Stones in these patients are most commonly composed of calcium oxalate monohydrate or mixed calcium-oxalate and calcium-phosphate. Precipitation of both minerals depends on urinary pH, calcium, phosphate and oxalate excretion. The present manuscript reports on two patients with Crohn's disease and bowel resection, in whom the onset of symptomatic urolithiasis occurred after repeated infusions of ferric carboxymaltose – a drug, which is known to cause hyperphosphaturia. The present study shows that ferric carboxymaltose-induced hyperphosphaturia can be associated with kidney stone formation and symptomatic urolithiasis, especially in patients treated with calcitriol. Calcitriol has been shown to mitigate ferric carboxymaltose-induced secondary hyperparathyroidism and hyperphosphaturia, but is known to increase urinary calcium excretion. Chemical analysis of recovered stones revealed that they were mixed calcium oxalate and phosphate stones. Ring-like deposition of iron detected by spatially resolved elemental analysis using laser ablation-inductively coupled plasma mass spectrometry, showed that the stones also contained iron. Based on our findings, we propose that patients with inflammatory bowel disease requiring intravenous iron therapy should be carefully monitored for the development of hypophosphatemia and urolithiasis. If hypophosphatemia occurs in such patients, calcitriol should be used with caution.

Background: Statins are widely used to reduce the risk of cardiovascular disease (CVD). Patients with end-stage renal disease (ESRD) on hemodialysis have significantly increased risk of developing CVD. Statin treatment in these patients however did not show a statistically significant benefit in large trials on a patient cohort level. Methods: We generated gene expression profiles for statins to investigate the impact on cellular programs in human renal proximal tubular cells and mesangial cells in-vitro. We subsequently selected biomarkers from key statin-affected molecular pathways and assessed these biomarkers in plasma samples from the AURORA cohort, a double-blind, randomized, multi-center study of patients on hemodialysis or hemofiltration that have been treated with rosuvastatin. Patient clusters (phenotypes) were created based on the identified biomarkers using Latent Class Model clustering and the associations with outcome for the generated phenotypes were assessed using Cox proportional hazards regression models. The multivariable models were adjusted for clinical and biological covariates based on previously published data in AURORA. Results: The impact of statin treatment on mesangial cells was larger as compared with tubular cells with a large overlap of differentially expressed genes identified for atorvastatin and rosuvastatin indicating a predominant drug class effect. Affected molecular pathways included TGFB-, TNF-, and MAPK-signaling and focal adhesion among others. Four patient clusters were identified based on the baseline plasma concentrations of the eight biomarkers. Phenotype 1 was characterized by low to medium levels of the hepatocyte growth factor (HGF) and high levels of interleukin 6 (IL6) or matrix metalloproteinase 2 (MMP2) and it was significantly associated with outcome showing increased risk of developing major adverse cardiovascular events (MACE) or cardiovascular death. Phenotype 2 had high HGF but low Fas cell surface death receptor (FAS) levels and it was associated with significantly better outcome at 1 year. Conclusions: In this translational study, we identified patient subgroups based on mechanistic markers of statin therapy that are associated with disease outcome in patients on hemodialysis.

IntroductionCurrent guidelines recommend renin angiotensin system inhibitors (RASi) as key components of treatment of diabetic kidney disease (DKD). Additional options include sodium-glucose cotransporter-2 inhibitors (SGLT2i), glucagon-like peptide 1 receptor agonists (GLP1a), and mineralocorticoid receptor antagonists (MCRa). The identification of the optimum drug combination for an individual is difficult because of the inter-, and longitudinal intra-individual heterogeneity of response to therapy.ResultsUsing data from a large observational study (PROVALID), we identified a set of parameters that can be combined into a meaningful composite biomarker that appears to be able to identify which of the various treatment options is clinically beneficial for an individual. It uses machine-earning techniques to estimate under what conditions a treatment of RASi plus an additional treatment is different from the treatment with RASi alone. The measure of difference is the annual percent change (ΔeGFR) in the estimated glomerular filtration rate (ΔeGFR). The 1eGFR is estimated for both the RASi-alone treatment and the add-on treatment.DiscussionHigher estimated increase of eGFR for add-on patients compared with RASi-alone patients indicates that prognosis may be improved with the add-on treatment. The personalized biomarker value thus identifies which patients may benefit from the additional treatment.

Introduction: Type 2 diabetes and its complications represent a huge burden to public health. With this prospective, observational cohort study, we aimed to estimate and to compare the incidence rate (IR) of renal and cardiovascular outcomes and all-cause mortality in patients with type 2 diabetes in different European countries. Methods: The renal endpoint was a composite of a sustained decline in estimated GFR of at least 40%, a sustained increase in albuminuria of at least 30% including a transition in albuminuria class, progression to kidney failure with replacement therapy, or death from renal causes. The cardiovascular endpoint was a composite of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. Results: 3,131 participants from four European countries (Austria, Hungary, The Netherlands, and Scotland) with a median follow-up time of 4.4 years were included. IRs were adjusted for several risk factors including sex, age, estimated GFR, albuminuria, HbA1c, blood pressure, and duration of type 2 diabetes. Across countries, the adjusted IR for the renal endpoint was significantly higher in Hungary and Austria, and the adjusted IR for the cardiovascular endpoint was significantly higher in Scotland and Austria. All-cause mortality was significantly higher in Scotland compared to all other countries. Conclusion: Our findings show how the longitudinal outcome of patients with type 2 diabetes varies significantly across European countries even after accounting for the distribution of underlying risk factors.

Renin–angiotensin–aldosterone system (RAAS) inhibitors are standard care in patients with hypertension, heart failure or chronic kidney disease (CKD). Although we have studied the RAAS for decades, there are still circumstances that remain unclear. In this review, we describe the evolution of the RAAS and pose the question of whether this survival trait is still necessary to humankind in the present age. We elucidate the benefits on cardiovascular health and kidney disease of RAAS inhibition and present promising novel medications. Furthermore, we address why more studies are needed to establish a new standard of care away from generally prescribing ACEi or ARB toward an improved approach to combine drugs tailored to the needs of individual patients.

IntroductionPatients with immune-mediated glomerular diseases are considered at high risk for severe COVID-19 outcomes. However, conclusive evidence for this patient population is scarce.MethodsWe created a global registry and retrospectively collected clinical data of patients with COVID-19 and a previously diagnosed immune-mediated glomerular disease to characterize specific risk factors for severe COVID-19 outcomes.ResultsFifty-nine patients with a history of immune-mediated glomerular diseases were diagnosed with COVID-19 between 01.03.2020 and 31.08.2021. Over a mean follow-up period of 24.79 ± 18.89 days, ten patients (16.9%) developed acute kidney injury. Overall, 44.1% of patients were managed in an outpatient setting and therefore considered as having “non-severe” COVID-19, while 55.9% of patients had severe COVID-19 requiring hospitalization including worse outcomes. Comparing both groups, patients with severe COVID-19 were significantly older (53.55 ± 17.91 versus 39.77 ± 14.95 years, p = .003), had lower serum albumin levels at presentation (3.00 ± 0.80 g/dL versus 3.99 ± 0.68 g/dL, p = .016) and had a higher risk of developing acute kidney injury (27% versus 4%, p = .018). Male sex (p

We investigated for the first time the effect of combination therapy of renin–angiotensin system inhibition (RASi) and sodium–glucose co-transporter-2 inhibitors (SGLT2is) on endotrophin (ETP), a pro-fibrotic signaling molecule reflecting collagen type VI formation, measured in the plasma of persons with type 2 diabetes (T2D). ETP was measured using the PRO-C6 ELISA in 294 individuals from the “Drug combinations for rewriting trajectories of renal pathologies in type 2 diabetes” (DC-ren) project. In the DC-ren study, kidney disease progression was defined as a >10% decline in the estimated glomerular filtration rate (eGFR) to an eGFR < 60 mL/min/1.73 m2. Among the investigated circulating markers, ETP was the most significant predictor of future eGFR. Combination therapy of RASi and SGLT2is led to a significant reduction in ETP levels compared to RASi monotherapy (p for slope difference = 0.002). Higher levels of baseline plasma ETP were associated with a significantly increased risk of kidney disease progression (p = 0.007). In conclusion, plasma ETP identified individuals at higher risk of kidney disease progression. The observed decreased levels of plasma ETP with combination therapy of RASi and SGLT2is in persons with T2D may reflect a reduced risk of kidney disease progression following treatment with SGLT2is.

Exosomes have emerged as a valuable repository of novel biomarkers for human diseases such as chronic kidney disease (CKD). From a healthy control group, we performed microRNA (miRNA) profiling of urinary exosomes and compared it with a cell culture model of renal proximal tubular epithelial cells (RPTECs). Thereby, a large fraction of abundant urinary exosomal miRNAs could also be detected in exosomes derived from RPTECs, indicating them as a suitable model system for investigation of CKD. We subsequently analyzed exosomes from RPTECs in pro-inflammatory and pro-fibrotic states, mimicking some aspects of CKD. Following cytokine treatment, we observed a significant increase in exosome release and identified 30 dysregulated exosomal miRNAs, predominantly associated with the regulation of pro-inflammatory and pro-fibrotic-related pathways. In addition to miRNAs, we also identified 16 dysregulated exosomal mitochondrial RNAs, highlighting a pivotal role of mitochondria in sensing renal inflammation. Inhibitors of exosome biogenesis and release significantly altered the abundance of selected candidate miRNAs and mitochondrial RNAs, thus suggesting distinct sorting mechanisms of different non-coding RNA (ncRNA) species into exosomes. Hence, these two exosomal ncRNA species might be employed as potential indicators for predicting the pathogenesis of CKD and also might enable effective monitoring of the efficacy of CKD treatment.

(1) Background: Kidney and cardiovascular diseases are responsible for a large fraction of population morbidity and mortality. Early, targeted, personalized intervention represents the ideal approach to cope with this challenge. Proteomic/peptidomic changes are largely responsible for the onset and progression of these diseases and should hold information about the optimal means of treatment and prevention. (2) Methods: We investigated the prediction of renal or cardiovascular events using previously defined urinary peptidomic classifiers CKD273, HF2, and CAD160 in a cohort of 5585 subjects, in a retrospective study. (3) Results: We have demonstrated a highly significant prediction of events, with an HR of 2.59, 1.71, and 4.12 for HF, CAD, and CKD, respectively. We applied in silico treatment, implementing on each patient’s urinary profile changes to the classifiers corresponding to exactly defined peptide abundance changes, following commonly used interventions (MRA, SGLT2i, DPP4i, ARB, GLP1RA, olive oil, and exercise), as defined in previous studies. Applying the proteomic classifiers after the in silico treatment indicated the individual benefits of specific interventions on a personalized level. (4) Conclusions: The in silico evaluation may provide information on the future impact of specific drugs and interventions on endpoints, opening the door to a precision-based medicine approach. An investigation into the extent of the benefit of this approach in a prospective clinical trial is warranted.

Type II diabetes mellitus (T2DM) accounts for approximately 90% of all diabetes mellitus cases in the world. Glucagon-like peptide-1 receptor (GLP-1R) agonists have established an increased capability to target directly or indirectly six core defects associated with T2DM, while the underlying molecular mechanisms of these pharmacological effects are not fully known. This exploratory study was conducted to analyze the effect of treatment with GLP-1R agonists on the urinary peptidome of T2DM patients. Urine samples of thirty-two T2DM patients from the PROVALID study (“A Prospective Cohort Study in Patients with T2DM for Validation of Biomarkers”) collected pre- and post-treatment with GLP-1R agonist drugs were analyzed by CE-MS. In total, 70 urinary peptides were significantly affected by GLP-1R agonist treatment, generated from 26 different proteins. The downregulation of MMP proteases, based on the concordant downregulation of urinary collagen peptides, was highlighted. Treatment also resulted in the downregulation of peptides from SERPINA1, APOC3, CD99, CPSF6, CRNN, SERPINA6, HBA2, MB, VGF, PIGR, and TTR, many of which were previously found to be associated with increased insulin resistance and inflammation. The findings indicate potential molecular mechanisms of GLP-1R agonists in the context of the management of T2DM and the prevention or delaying of the progression of its associated diseases.

Abstract Background Chronic kidney disease (CKD) is a well-established complication in people with diabetes mellitus. Roughly one quarter of prevalent patients with diabetes exhibit a CKD stage of 3 or higher and the individual course of progression is highly variable. Therefore, there is a clear need to identify patients at high risk for fast progression and the implementation of preventative strategies. Existing prediction models of renal function decline, however, aim to assess the risk by artificially grouped patients prior to model building into risk strata defined by the categorization of the least-squares slope through the longitudinally fluctuating eGFR values, resulting in a loss of predictive precision and accuracy. Methods This study protocol describes the development and validation of a prediction model for the longitudinal progression of renal function decline in Caucasian patients with type 2 diabetes mellitus (DM2). For development and internal-external validation, two prospective multicenter observational studies will be used (PROVALID and GCKD). The estimated glomerular filtration rate (eGFR) obtained at baseline and at all planned follow-up visits will be the longitudinal outcome. Demographics, clinical information and laboratory measurements available at a baseline visit will be used as predictors in addition to random country-specific intercepts to account for the clustered data. A multivariable mixed-effects model including the main effects of the clinical variables and their interactions with time will be fitted. In application, this model can be used to obtain personalized predictions of an eGFR trajectory conditional on baseline eGFR values. The final model will then undergo external validation using a third prospective cohort (DIACORE). The final prediction model will be made publicly available through the implementation of an R shiny web application. Discussion Our proposed state-of-the-art methodology will be developed using multiple multicentre study cohorts of people with DM2 in various CKD stages at baseline, who have received modern therapeutic treatment strategies of diabetic kidney disease in contrast to previous models. Hence, we anticipate that the multivariable prediction model will aid as an additional informative tool to determine the patient-specific progression of renal function and provide a useful guide to early on identify individuals with DM2 at high risk for rapid progression.

BackgroundKnowledge of the biological variation of serum or plasma creatinine (Cr) and the estimated glomerular filtration rate (eGFR) is important for understanding disease dynamics in Chronic Kidney Disease (CKD). The aim of our study was to determine the magnitude of random fluctuation of eGFR by determining its reference change value (RCV).MethodsWe performed a systematic review and meta-analysis of studies on biological variation of Cr. Relevant studies were identified by systematic literature search on PubMed. Additional studies were retrieved from the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Biological Variation Database. Random-effects meta-analysis was conducted to derive an overall estimate of intra-individual variation of creatinine (CVICr). Based on our estimate of CVICr and RCV for Cr, the RCV for the eGFR was determined.ResultsAmong identified studies, 37 met our inclusion criteria. Meta-analysis of all studies yielded a CVICr of 5.2% (95% confidence interval [CI] 4.6–5.8%), however high between-study heterogeneity (I2 = 82.3%) was found. Exclusion of outliers led to a significant reduction of heterogeneity while still including 85% of all studies and resulted in a slightly lower CVICr of 5.0% (95% CI 4.7–5.4%). Assuming an analytical variation of CVA 1.1%, we found an overall RCV for eGFR of ±16.5%. After exclusion of outlier studies, we found a minimum conservative RCV for eGFR of ±12.5%.ConclusionThe RCV of the eGFR represents a valuable tool for clinicians to discern true changes in kidney function from random fluctuation.

Membranous nephropathy (MN) is the most common cause of primary nephrotic syndrome among adults. The identification of phospholipase A2 receptor (PLA2R) as target antigen in most patients changed the management of MN dramatically, and provided a rationale for B-cell depleting agents such as rituximab. The efficacy of rituximab in inducing remission has been investigated in several studies, including 3 randomized controlled trials, in which complete and partial remission of proteinuria was achieved in approximately two-thirds of treated patients. Due to its favorable safety profile, rituximab is now considered a first-line treatment option for MN, especially in patients at moderate and high risk of deterioration in kidney function. However, questions remain about how to best use rituximab, including the optimal dosing regimen, a potential need for maintenance therapy, and assessment of long-term safety and efficacy outcomes. In this review, we provide an overview of the current literature and discuss both strengths and limitations of “the new standard.”

Objectives: To assess the association of public interest in coronavirus infections with the actual number of infected cases for selected countries across the globe. Methods: We performed a Google TrendsTM search for “Coronavirus” and compared Relative Search Volumes (RSV) indices to the number of reported COVID-19 cases by the European Center for Disease Control (ECDC) using time-lag correlation analysis. Results: Worldwide public interest in Coronavirus reached its first peak end of January when numbers of newly infected patients started to increase exponentially in China. The worldwide Google TrendsTM index reached its peak on the 12th of March 2020 at a time when numbers of infected patients started to increase in Europe and COVID-19 was declared a pandemic. At this time the general interest in China but also the Republic of Korea has already been significantly decreased as compared to end of January. Correlations between RSV indices and number of new COVID-19 cases were observed across all investigated countries with highest correlations observed with a time lag of −11.5 days, i.e. highest interest in coronavirus observed 11.5 days before the peak of newly infected cases. This pattern was very consistent across European countries but also holds true for the US. In Brazil and Australia, highest correlations were observed with a time lag of −7 days. In Egypt the highest correlation is given with a time lag of 0, potentially indicating that in this country, numbers of newly infected patients will increase exponentially within the course of April. Conclusions: Public interest indicated by RSV indices can help to monitor the progression of an outbreak such as the current COVID-19 pandemic. Public interest is on average highest 11.5 days before the peak of newly infected cases.

A patient with renal glucosuria due to a congenital knock-out of the sodium-glucose cotransporter 2 (SGLT-2) protein because of a compound heterozygous mutation in the SLC5A2 gene may provide a natural model mimicking the effects of long-term SGLT-2 inhibitor therapy, which has been shown to exert kidney-protective effects beyond its antidiabetic properties. One possible mechanism for the protective effects of SGLT-2 inhibitor therapy might be the activation of tubuloglomerular feedback by increased outflow of sodium, chloride, and glucose to distal parts of the nephron, including the macula densa. Subsequently, afferent arteriolar vasoconstriction is induced and blood flow, intraglomerular filtration pressure, and glomerular filtration rate (GFR) all decline. However, prolonged tubuloglomerular feedback activation could change the sensitivity of tubuloglomerular feedback and hence decrease the beneficial effects of SGLT-2 inhibition on kidney function. Tubuloglomerular feedback is mediated by the Na+/K+/2Cl− cotransporter. Hence furosemide, which blocks this cotransporter, is a medical option to test tubuloglomerular feedback because GFR should increase after administration of this loop diuretic. In our patient with long-term activated tubuloglomerular feedback due to SGLT-2 mutations, we show that the sensitivity of tubuloglomerular feedback is maintained, demonstrated by an increase in GFR measured using iohexol clearance following furosemide administration. This observation supports the idea that long-term SGLT-2 inhibitor therapy is kidney protective through a functional tubuloglomerular feedback. Index Words: SGLT-2 Inhibitor, glomerular filtration rate, tubuloglomerular feedback, kidney protection, iohexol clearance

Abstract Background Acquired or genetic abnormalities of the complement alternative pathway are the primary cause of C3glomerulopathy(C3G) but may occur in immune-complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) as well. Less is known about the presence and role of C4nephritic factor(C4NeF) which may stabilize the classical pathway C3-convertase. Our aim was to examine the presence of C4NeF and its connection with clinical features and with other pathogenic factors. Results One hunfe IC-MPGN/C3G patients were enrolled in the study. C4NeF activity was determined by hemolytic assay utilizing sensitized sheep erythrocytes. Seventeen patients were positive for C4NeF with lower prevalence of renal impairment and lower C4d level, and higher C3 nephritic factor (C3NeF) prevalence at time of diagnosis compared to C4NeF negative patients. Patients positive for both C3NeF and C4NeF had the lowest C3 levels and highest terminal pathway activation. End-stage renal disease did not develop in any of the C4NeF positive patients during follow-up period. Positivity to other complement autoantibodies (anti-C1q, anti-C3) was also linked to the presence of nephritic factors. Unsupervised, data-driven cluster analysis identified a group of patients with high prevalence of multiple complement autoantibodies, including C4NeF. Conclusions In conclusion, C4NeF may be a possible cause of complement dysregulation in approximately 10–15% of IC-MPGN/C3G patients.

Fibrinogen-like 2 (FGL2) was recently found to be associated with fibrosis in a mouse model of kidney damage and was proposed as a potential therapeutic target in chronic kidney disease (CKD). We assessed the association of renal FGL2 mRNA expression with the disease outcome in two independent CKD cohorts (NEPTUNE and Innsbruck CKD cohort) using Kaplan Meier survival analysis. The regulation of FGL2 in kidney biopsies of CKD patients as compared to healthy controls was further assessed in 13 human CKD transcriptomics datasets. The FGL2 protein expression in human renal tissue sections was determined via immunohistochemistry. The regulators of FGL2 mRNA expression in renal tissue were identified in the co-expression and upstream regulator analysis of FGL2-positive renal cells via the use of single-cell RNA sequencing data from the kidney precision medicine project (KPMP). Higher renal FGL2 mRNA expression was positively associated with kidney fibrosis and negatively associated with eGFR. Renal FGL2 mRNA expression was upregulated in CKD as compared with healthy controls and associated with CKD progression in the Innsbruck CKD cohort (p-value = 0.0036) and NEPTUNE cohort (p-value = 0.0048). The highest abundance of FGL2 protein in renal tissue was detected in the thick ascending limb of the loop of Henle and macula densa, proximal tubular cells, as well as in glomerular endothelial cells. The upstream regulator analysis identified TNF, IL1B, IFNG, NFKB1, and SP1 as factors potentially inducing FGL2-co-expressed genes, whereas factors counterbalancing FGL2-co-expressed genes included GLI1, HNF1B, or PPARGC1A. In conclusion, renal FGL2 mRNA expression is elevated in human CKD, and higher FGL2 levels are associated with fibrosis and worse outcomes.

BackgroundFactor H-related protein 5 (FHR-5) is a member of the complement Factor H protein family. Due to the homology to Factor H, the main complement regulator of the alternative pathway, it may also be implicated in the pathomechanism of kidney diseases where Factor H and alternative pathway dysregulation play a role. Here, we report the first observational study on CFHR5 variations along with serum FHR-5 levels in immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) and C3 glomerulopathy (C3G) patients together with the clinical, genetic, complement, and follow-up data.MethodsA total of 120 patients with a histologically proven diagnosis of IC-MPGN/C3G were enrolled in the study. FHR-5 serum levels were measured in ELISA, the CFHR5 gene was analyzed by Sanger sequencing, and selected variants were studied as recombinant proteins in ELISA and surface plasmon resonance (SPR).ResultsEight exonic CFHR5 variations in 14 patients (12.6%) were observed. Serum FHR-5 levels were lower in patients compared to controls. Low serum FHR-5 concentration at presentation associated with better renal survival during the follow-up period; furthermore, it showed clear association with signs of complement overactivation and clinically meaningful clusters.ConclusionsOur observations raise the possibility that the FHR-5 protein plays a fine-tuning role in the pathogenesis of IC-MPGN/C3G.

BackgroundLiver transplantation (LT) is the only curative treatment for end-stage liver disease. Less than 10% of global transplantation needs are met worldwide, and the need for LT is still increasing. The death rates on the waiting list remain too high. ObjectiveIt is, therefore, critical to raise awareness among the public and health care providers and in turn increasingly acquire donors. MethodsWe performed a Google Trends search using the search terms liver transplantation and liver transplant on October 15, 2020. On the basis of the resulting monthly data, the annual average Google Trends indices were calculated for the years 2004 to 2018. We not only investigated the trend worldwide but also used data from the United Network for Organ Sharing (UNOS), Spain, and Eurotransplant. Using pairwise Spearman correlations, Google Trends indices were examined over time and compared with the total number of liver transplants retrieved from the respective official websites of UNOS, the Organización Nacional de Trasplantes, and Eurotransplant. ResultsFrom 2004 to 2018, there was a significant decrease in the worldwide Google Trends index from 78.2 in 2004 to 20.5 in 2018 (–71.2%). This trend was more evident in UNOS than in the Eurotransplant group. In the same period, the number of transplanted livers increased worldwide. The waiting list mortality rate was 31% for Eurotransplant and 29% for UNOS. However, in Spain, where there are excellent awareness programs, the Google Trends index remained stable over the years with comparable, increasing LT numbers but a significantly lower waiting list mortality (15%). ConclusionsPublic awareness in LT has decreased significantly over the past two decades. Therefore, novel awareness programs should be initialized.

Aim: This study aimed to identify from different stakeholders the benefits and obstacles of implementing precision medicine in diabetic kidney disease (DKD) and to build consensus about a way forward in order to treat, prevent, or even reverse this disease.Methods: As part of an ongoing effort of moving implementation of precision medicine in DKD forward, a two-day consensus-building meeting was organized with different stakeholders involved in drug development and patient care in DKD, including patients, patient representatives, pharmaceutical industry, regulatory agencies representatives, health technology assessors, healthcare professionals, basic scientists, and clinical academic researchers. The meeting consisted of plenary presentations and discussions, and small group break-out sessions. Discussion topics were based on a symposium, focus groups and literature search. Benefits, obstacles and potential solutions toward implementing precision medicine were discussed. Results from the break-out sessions were presented in plenary and formed the basis of a broad consensus discussion to reach final conclusions. Throughout the meeting, participants answered several statement and open-ended questions on their mobile device, using a real-time online survey tool. Answers to the statement questions were analyzed descriptively. Results of the open-ended survey questions, the break-out sessions and the consensus discussion were analyzed qualitatively.Results and conclusion: Seventy-one participants from 26 countries attended the consensus-building meeting in Amsterdam, April 2019. During the opening plenary on the first day, the participants agreed with the statement that precision medicine is the way forward in DKD (n = 57, median 90, IQR [75–100]). Lack of efficient tools for implementation in practice and generating robust data were identified as significant obstacles. The identified benefits, e.g., improvement of the benefit-risk ratio of treatment, offer substantive incentives to find solutions for the identified obstacles. Earlier and increased multi-stakeholder collaboration and specific training may provide solutions to alter clinical and regulatory guidelines that lie at the basis of both obstacles and solutions. At the end of the second day, the opinion of the participants toward precision medicine in DKD was somewhat more nuanced (n = 45, median 83, IQR [70–92]) and they concluded that precision medicine is an important way forward in improving the treatment of patients with DKD.

Abstract Background Ear, nose and throat involvement in granulomatosis with polyangiitis (GPA) is frequently the initial disease manifestation. Previous investigations have observed a higher prevalence of Staphylococcus aureus in patients with GPA, and chronic nasal carriage has been linked with an increased risk of disease relapse. In this cross-sectional study, we investigated changes in the nasal microbiota including a detailed analysis of Staphylococcus spp. by shotgun metagenomics in patients with active and inactive granulomatosis with polyangiitis (GPA). Shotgun metagenomic sequence data were also used to identify protein-encoding genes within the SEED database, and the abundance of proteins then correlated with the presence of bacterial species on an annotated heatmap. Results The presence of S. aureus in the nose as assessed by culture was more frequently detected in patients with active GPA (66.7%) compared with inactive GPA (34.1%). Beta diversity analysis of nasal microbiota by bacterial 16S rRNA profiling revealed a different composition between GPA patients and healthy controls (P = 0.039). Beta diversity analysis of shotgun metagenomic sequence data for Staphylococcus spp. revealed a different composition between active GPA patients and healthy controls and disease controls (P = 0.0007 and P = 0.0023, respectively), and between healthy controls and inactive GPA patients and household controls (P = 0.0168 and P = 0.0168, respectively). Patients with active GPA had a higher abundance of S. aureus, mirroring the culture data, while healthy controls had a higher abundance of S. epidermidis. Staphylococcus pseudintermedius, generally assumed to be a pathogen of cats and dogs, showed an abundance of 13% among the Staphylococcus spp. in our cohort. During long-term follow-up of patients with inactive GPA at baseline, a higher S. aureus abundance was not associated with an increased relapse risk. Functional analyses identified ten SEED protein subsystems that differed between the groups. Most significant associations were related to chorismate synthesis and involved in the vitamin B12 pathway. Conclusion Our data revealed a distinct dysbiosis of the nasal microbiota in GPA patients compared with disease and healthy controls. Metagenomic sequencing demonstrated that this dysbiosis in active GPA patients is manifested by increased abundance of S. aureus and a depletion of S. epidermidis, further demonstrating the antagonist relationships between these species. SEED functional protein subsystem analysis identified an association between the unique bacterial nasal microbiota clusters seen mainly in GPA patients and an elevated abundance of genes associated with chorismate synthesis and vitamin B12 pathways. Further studies are required to further elucidate the relationship between the biosynthesis genes and the associated bacterial species.

Diabetic kidney disease (DKD) is a complex and multifactorial disorder associated with deregulations in a large number of different biological pathways on the molecular level. Using the 2 established biomarkers, estimated glomerular filtration rate (eGFR) and albuminuria will not allow allocating patients to tailored therapy. Molecular multimarker panels as sensors for the deregulation of the various disease mechanisms combined with a better understanding of how investigational as well as approved drugs interfere with these disease processes forms the basis for platform trials in DKD. In these platform trials, patients with DKD are assigned to the most suitable treatment arm based on their molecular marker profile. Close monitoring of biomarkers after treatment initiation together with assessment of renal function and “off-target” effects will allow identification of therapy responders, with nonresponders shifted to the next-best treatment arm based on their molecular profile. In this viewpoint article, we summarize evidence on the variation of DKD disease progression as well as the response to therapy and outline procedures to model disease pathophysiology supporting biomarker panel construction. Finally, the use of biomarkers in clinical trial setup is discussed. Keywords: biomarker panel, clinical trial design, diabetic kidney disease, pathophysiology, predictive marker

Aging is a major driver for chronic kidney disease (CKD) and the counterbalancing of aging processes holds promise to positively impact disease development and progression.In this study we generated a signature of renal age-associated genes (RAAGs) based on six different data sources including transcriptomics data as well as data extracted from scientific literature and dedicated databases. Protein abundance in renal tissue of the 634 identified RAAGs was studied next to the analysis of affected molecular pathways. RAAG expression profiles were furthermore analysed in a cohort of 63 CKD patients with available follow-up data to determine association with CKD progression. 23 RAAGs were identified showing concordant regulation in renal aging and CKD progression. This set was used as input to computationally screen for compounds with the potential of reversing the RAAG/CKD signature on the transcriptional level. Among the top-ranked drugs we identified atorvastatin, captopril, valsartan, and rosiglitazone, which are widely used in clinical practice for the treatment of patients with renal and cardiovascular diseases. Their positive impact on the RAAG/CKD signature could be validated in an in-vitro model of renal aging.In summary, we have (i) consolidated a set of RAAGs, (ii) determined a subset of RAAGs with concordant regulation in CKD progression, and (iii) identified a set of compounds capable of reversing the proposed RAAG/CKD signature. Keywords: Renal aging, Chronic kidney disease progression, Computational compound screening, Drug repurposing, Anti-aging

Abstract Donor organ quality affects long term outcome after renal transplantation. A variety of prognostic molecular markers is available, yet their validity often remains undetermined. A network-based molecular model reflecting donor kidney status based on transcriptomics data and molecular features reported in scientific literature to be associated with chronic allograft nephropathy was created. Significantly enriched biological processes were identified and representative markers were selected. An independent kidney pre-implantation transcriptomics dataset of 76 organs was used to predict estimated glomerular filtration rate (eGFR) values twelve months after transplantation using available clinical data and marker expression values. The best-performing regression model solely based on the clinical parameters donor age, donor gender, and recipient gender explained 17% of variance in post-transplant eGFR values. The five molecular markers EGF, CD2BP2, RALBP1, SF3B1, and DDX19B representing key molecular processes of the constructed renal donor organ status molecular model in addition to the clinical parameters significantly improved model performance (p-value = 0.0007) explaining around 33% of the variability of eGFR values twelve months after transplantation. Collectively, molecular markers reflecting donor organ status significantly add to prediction of post-transplant renal function when added to the clinical parameters donor age and gender.

Background/Aims: The prevalence of diabetes mellitus type 2 and kidney disease in these patients varies widely between European countries. Methods: In addition to store bio-samples the “Prospective cohort study in patients with type 2 diabetes mellitus for validation of biomarkers” collects information on history, physical status, laboratory measurements and medication in 4000 patients with diabetes mellitus type 2, being taken care of at the primary level of healthcare in 5 European countries (Austria, Hungary, Netherlands, Poland and Scotland). Next to comparing the rate of loss of eGFR between the countries, a further objective of the PROVALID study is to determine the 5-year cumulative incidence of renal and cardiovascular outcomes. Results: The mean age of the population recruited is 62.9±10 years, 54.6% are male and the mean BMI is 30.9±5.4 kg/m2. Metabolic control (median HBA1c 6.8 % (6.2; 7.5)) is achieved via administration of metformin in 67.4% of the patients and insulin in 30.3%. Median systolic and diastolic blood pressure at recruitment is 135 (125; 146) and 80 (72; 85) mmHg, 65.4% of subjects received RAAS blocking agents. Mean eGFR is 80.7±29.2 ml/min/1.73m2 and median baseline albumin/creatinine ratio 8.3 mg (IQR: 3.8 and 25.1). Conclusion: PROVALID will provide information on incidence and progression of renal and cardiovascular disease and therapy in patients with type 2 diabetes mellitus in different European countries. Thus, in contrast to many other cohort studies we will be able to associate national clinical practise pattern with outcome in this highly vulnerable patient population.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disorder leading to deterioration of kidney function and end stage kidney disease (ESKD). A number of molecular processes are dysregulated in ADPKD but the exact mechanism of disease progression is not fully understood. We measured protein biomarkers being linked to ADPKD-associated molecular processes via ELISA in urine and serum in a cohort of ADPKD patients as well as age, gender and eGFR matched CKD patients and healthy controls. ANOVA and t-tests were used to determine differences between cohorts. Spearman correlation coefficient analysis was performed to assess coregulation patterns of individual biomarkers and renal function. Urinary epidermal growth factor (EGF) and serum apelin (APLN) levels were significantly downregulated in ADPKD patients. Serum vascular endothelial growth factor alpha (VEGFA) and urinary angiotensinogen (AGT) were significantly upregulated in ADPKD patients as compared with healthy controls. Arginine vasopressin (AVP) was significantly upregulated in ADPKD patients as compared with CKD patients. Serum VEGFA and VIM concentrations were positively correlated and urinary EGF levels were negatively correlated with urinary AGT levels. Urinary EGF and AGT levels were furthermore significantly associated with estimated glomerular filtration rate (eGFR) in ADPKD patients. In summary, altered protein concentrations in body fluids of ADPKD patients were found for the mechanistic markers EGF, APLN, VEGFA, AGT, AVP, and VIM. In particular, the connection between EGF and AGT during progression of ADPKD warrants further investigation.

SGLT2 inhibitor-related nephroprotection is—at least partially—mediated by anti-inflammatory drug effects, as previously demonstrated in diabetic animal and human studies, as well as hyperglycemic cell culture models. We recently presented first evidence for anti-inflammatory potential of empagliflozin (Empa) under normoglycemic conditions in human proximal tubular cells (HPTC) by demonstrating Empa-mediated inhibition of IL-1β-induced MCP-1/CCL2 and ET-1 expression on the mRNA and protein level. We now add corroborating evidence on a genome-wide level by demonstrating that Empa attenuates the expression of several inflammatory response genes in IL-1β-induced (10 ng/mL) normoglycemic HPTCs. Using microarray-hybridization analysis, 19 inflammatory response genes out of >30.000 human genes presented a consistent expression pattern, that is, inhibition of IL-1β (10 ng/mL)-stimulated gene expression by Empa (500 nM), in both HK-2 and RPTEC/TERT1 cells. Pathway enrichment analysis demonstrated statistically significant clustering of annotated pathways (enrichment score 3.64). Our transcriptomic approach reveals novel genes such as CXCL8/IL8, LOX, NOV, PTX3, and SGK1 that might be causally involved in glycemia-independent nephroprotection by SGLT2i.

Chronic kidney disease (CKD) is a progressive pathological condition marked by a gradual loss of kidney function. Treatment of CKD is most effective when diagnosed at an early stage and patients are still asymptomatic. However, current diagnostic biomarkers (e.g., serum creatinine and urine albumin) are insufficient for prediction of the pathogenesis of the disease. To address this need, we applied a cell-SELEX (systematic evolution of ligands by exponential enrichment) approach and identified a series of DNA aptamers, which exhibit high affinity and selectivity for cytokine-stimulated cells, resembling some aspects of a CKD phenotype. The cell-SELEX approach was driven toward the enrichment of aptamers that internalize via the endosomal pathway by isolating the endosomal fractions in each selection cycle. Indeed, we demonstrated co-localization of selected aptamers with lysosomal-associated membrane protein 1 (LAMP-1), a late endosomal and lysosomal marker protein, by fluorescence in situ hybridization. These findings are consistent with binding and subsequent internalization of the aptamers into cytokine-stimulated cells. Thus, our study sets the stage for applying selected DNA aptamers as theragnostic reagents for the development of targeted therapies to combat CKD. Keywords: cell-SELEX, DNA aptamers, chronic kidney disease, inflammatory kidney disease, cytokines

SGLT2 inhibitors (SGLT2i) slow the progression of chronic kidney disease; however, evidence for the underlying molecular mechanisms is scarce. We investigated SGLT2i-mediated effects on differential gene expression in two independent human proximal tubular cell (HPTC) lines (HK-2 and RPTEC/TERT1) at the mRNA and protein levels under normoglycemic conditions, utilizing IL-1β as a pro-inflammatory mediator. Microarray hybridization identified 259 genes that were uniformly upregulated by IL-1β (10 mg/mL) and downregulated by empagliflozin (Empa) (500 nM) after 24 h of stimulation in two independent HPTC lines (n = 2, each). The functional annotation of these genes identified eight pathway clusters. Among 12 genes annotated to the highest ranked cluster (enrichment score, 3.51), monocyte chemoattractant protein-1/CC-chemokine ligand 2 (MCP-1/CCL2) and endothelin-1 (ET-1) were selected for verification at mRNA and protein levels based on their established involvement in the early pathogenesis of chronic kidney disease: IL-1β upregulated basal MCP-1/CCL2 (15- and 19-fold) and ET-1 (3- and 8-fold) mRNA expression, while Empa downregulated basal MCP-1/CCL2 (0.6- and 0.5-fold) and ET-1 (0.3- and 0.2-fold) mRNA expression as early as 1 h after stimulation and for at least 24 h in HK-2 and RPTEC/TERT1 cells, respectively. The co-administration of Empa inhibited IL-1β-mediated MCP-1/CCL2 (0.2-fold, each) and ET-1 (0.2-fold, each) mRNA expression as early as 1 h after ligand stimulation and for at least 24 h in both HPTC lines, respectively. This inhibitory effect of Empa on basal and IL-1β-mediated MCP-1/CCL2 and ET-1 mRNA expression was corroborated at the protein level. Our study presents novel evidence for the interference of SGLT2 inhibition with tubular inflammatory response mechanisms under normoglycemic conditions that might account for SGLT2i-mediated nephroprotection.

A better understanding of the pathophysiology of autoimmune disorders is desired to allow tailored interventions. Despite increased scientific interest a direct pathogenic factor in autoimmune renal disease has been described only in a minority like membranous nephropathy or ANCA-associated vasculitis. Nonetheless the initial step leading to the formation of these antibodies is still obscure. In this review we will focus on the possible role of microbial factors in this context. Staphylococcus aureus may be a direct pathogenetic factor in granulomatosis with polyangiitis (GPA). Chronic bacterial colonization or chronic infections of the upper respiratory tract have been proposed as trigger of IgA vasculitis and IgA nephropathy. Interventions to remove major lymphoid organs, such as tonsillectomy, have shown conflicting results but may be an option in IgA vasculitis. Interestingly no clear clinical benefit despite similar local colonization with bacterial strains has been detected in patients with IgA nephropathy. In systemic lupus erythematosus injection of bacterial lipopolysaccharide induced progressive lupus nephritis in mouse models. The aim of this review is to discuss and summarize the knowledge of microbial antigens in autoimmune renal disease. Novel methods may provide insight into the involvement of microbial antigens in the onset, progression, and prognosis of autoimmune kidney disorders.

Chronic nephrotoxicity of immunosuppressives is one of the main limiting factors in the long-term outcome of kidney transplants, leading to tissue fibrosis and ultimate organ failure. The cytokine TGF-β is considered a key factor in this process. In the human renal fibroblast cell line TK-173, the macrolide calcineurin inhibitor tacrolimus (FK-506) induced TGF-β-like effects, manifested by increased expression of NAD(P)H-oxidase 4 (Nox4), transgelin, tropomyosin 1, and procollagen α1(V) mRNA after three days. The macrolide mTOR inhibitor rapamycin had similar effects, while cyclosporine A did not induce fibrose-related genes. Concentration dependence curves were sigmoid, where mRNA expression was induced already at low nanomolar levels of tacrolimus, and reached saturation at 100-300 nM. The effects were independent of extracellular TGF-β as confirmed by the use of neutralizing antibodies, and thus most likely caused by aberrant TGF-β receptor signaling, where binding of tacrolimus to the regulatory FKBP12 protein results in a "leaky" TGF-β receptor. The myofibroblast marker α-smooth muscle actin was neither induced by tacrolimus nor by TGF-β1, indicating an incomplete activation of TK-173 fibroblasts under culture conditions. Tacrolimus- and TGF-β1-induced Nox4 protein upregulation was confirmed by Western blotting, and was accompanied by a rise in intracellular H2O2 concentration. Si-RNA mediated knock-down of Nox4 expression prevented up-regulation of procollagen α1(V) mRNA in tacrolimus-treated cells, but induced procollagen α1(V) expression in control cells. Nox4 knock-down had no significant effect on the other genes tested. TGF-β is a key molecule in fibrosis, and the constant activation of aberrant receptor signaling by tacrolimus might contribute to the long-term development of interstitial kidney fibrosis in immunosuppressed patients. Nox4 levels possibly play a regulatory role in these processes.

Novel prognostic markers for progression of kidney disease are needed to distinguish patients who might benefit from a more aggressive nephroprotective therapy. Expression of the proteoglycan versican was evaluated in renal transcriptomics profiles and in an independent set of 74 renal biopsies. Versican levels were correlated to histologic damage scores and to renal outcome, and versican expression and regulation was evaluated in vitro. In transcriptomics profiles of renal tissue versican was positively correlated with (i) histological parameters in kidney biopsies, (ii) progressive decline of renal function in proteinuric kidney diseases, and (iii) impaired renal function and histology scores in diabetic nephropathy. In an independent cohort of 74 biopsies of glomerular diseases renal RNA levels of versican isoforms V0 and V1, but not V2 and V3 correlated significantly with creatinine after a mean follow up time of 53 months. Versican isoforms V0 and V1 together with serum creatinine at time of biopsy and the degree of glomerulosclerosis predicted 20% and 24% of the variability of creatinine at follow up, which was significantly more than serum creatinine and histological parameters alone (16%). However, when patients with acute kidney failure at time of biopsy (n = 5) were excluded, the additive predictive value of versican V1 was only marginally higher (35%) than creatinine and glomerulosclerosis alone (34%). Versican isoforms V0 and V1 were primarily expressed in vitro in proximal tubule cells and in fibroblasts. The results in humans were confirmed in three rodent models of kidney disease, in which renal versican expression was significantly upregulated as compared to corresponding controls. These data show for the first time an association of renal versican isoform V0 and V1 expression with progressive renal disease.

The cardiorenal syndrome refers to the coexistence of kidney and cardiovascular disease, where cardiovascular events are the most common cause of death in patients with chronic kidney disease. Both, cardiovascular as well as kidney diseases have been extensively analyzed on a molecular level, resulting in molecular features and associated processes indicating a cross-talk of the two disease etiologies on a pathophysiological level. In order to gain a comprehensive picture of molecular factors contributing to the bidirectional interplay between kidney and cardiovascular system, we mined the scientific literature for molecular features reported as associated with the cardiorenal syndrome, resulting in 280 unique genes/proteins. These features were then analyzed on the level of molecular processes and pathways utilizing various types of protein interaction networks. Next to well established molecular features associated with the renin-angiotensin system numerous proteins involved in signal transduction and cell communication were found, involving specific molecular functions covering receptor binding with natriuretic peptide receptor and ligands as well known example. An integrated analysis of identified features pinpointed a protein interaction network involving mediators of hemodynamic change and an accumulation of features associated with the endothelin and VEGF signaling pathway. Some of these features may function as novel therapeutic targets.