Description of a New Simple and Cost-Effective Molecular Testing That Could Simplify MUC1 Variant Detection

Introduction

Patients with autosomal dominant tubulointerstitial kidney disease (ADTKD) usually present with nonspecific progressive chronic kidney disease (CKD) with mild to negative proteinuria and a family history. ADTKD-MUC1 leads to the formation of a frameshift protein that accumulates in the cytoplasm, leading to tubulointerstitial damage. ADTKD-MUC1 prevalence remains unclear because MUC1 variants are not routinely detected by standard next-generation sequencing (NGS) techniques.

Methods

We developed a bioinformatic counting script that can detect specific genetic sequences and count the number of occurrences. We used DNA samples from 27 patients for validation, 11 of them were patients from the Lille University Hospital in France and 16 were from the Wake Forest Hospital, NC. All patients from Lille were tested with an NGS gene panel with our script and all patients from Wake Forest Hospital were tested with the snapshot reference technique. Between January 2018 and February 2023, we collected data on all patients diagnosed with MUC1 variants with this script.

Results

A total of 27 samples were tested anonymously by the BROAD Institute reference technique for confirmation and we were able to get a 100% concordance for MUC1 diagnosis. Clinico-biologic characteristics in our cohort were similar to those previously described in ADTKD-MUC1.

Conclusion

We describe a new simple and cost-effective method for molecular testing of ADTKD-MUC1. Genetic analyses in our cohort suggest that MUC1 might be the first cause of ADTKD. Increasing the availability of MUC1 diagnosis tools will contribute to a better understanding of the disease and to the development of specific treatments.

Extracorporeal Photopheresis Reduces Fibrotic and Inflammatory Transcriptomic Biological Marker of Chronic Antibody-mediated Kidney Rejection

Background

The benefit of extracorporeal photopheresis on the course of kidney transplant rejection is unknown. The aim of our study was to investigate the variations in transcriptomics on graft biopsies when extracorporeal photopheresis was used to treat chronic humoral rejection after kidney transplantation.

Methods

We retrospectively analyzed the mRNA expression of 770 genes of interest in graft biopsies performed before and after treatment. Eight patients received an average of 23 extracorporeal photopheresis sessions over 4 mo between the 2 biopsies.

Results

Transcriptomic analysis of the graft biopsies identified a significant (adjusted P < 0.05) increase in CAV1 mRNA in all patients and a significant decrease in CD19, IL21, PAX5, and SFTPA2 mRNAs in 7 of 8 patients.

Conclusions

In patients treated with extracorporeal photopheresis for chronic humoral rejection after renal transplantation, omic analysis of repeated biopsies shows a reduction in fibrotic and inflammatory transcriptomic biologicals markers.

Proteinuria reduction with SGLT2 inhibitors in a patient treated with tyrosine kinase inhibitor lenvatinib

We describe the case of a 66-year-old woman treated with tyrosine kinase inhibitor Lenvatinib for thyroid carcinoma who had persistent proteinuria above 2 g/24 h despite maximal dose of angiotensin-converting enzyme inhibitor. We initiated a treatment with SGLT2 inhibitor Dapagliflozin. Three months after Dapagliflozin initiation, her proteinuria decreased to 1 g/24 h, and after 6 months of follow-up was 0.6 g/24 h. To our knowledge, this is the first case of successful proteinuria reduction with SGLT2i in a patient treated with Lenvatinib. Specific renal effects of SGLT2i seem promising and their effects on tyrosine kinase inhibitor renal adverse effects need to be validated in clinical trials involving cancer patients.

Comprehensive conservative care: what doctors say, what patients hear

The demographic evolution of patients with advanced chronic kidney disease (CKD) has led to the advent of an alternative treatment option to kidney replacement therapy in the past couple of decades. The KDIGO controversies on Kidney Supportive Care called this approach "comprehensive conservative care" (CCC) and defined it as planned holistic patient-centered care for patients with CKD stage 5 that does not include dialysis. Although the benefit of this treatment option is now well-recognized, especially for the elderly, and comorbid and frail patients, its development remains limited in practice. While shared decision-making and advance care planning represent the cornerstones of the CCC approach, one of the main barriers in its development is the perfectible communication between nephrologists and patients, but also between all healthcare professionals involved in the care of advanced CKD patients. As a result, a significant gap has opened up between what doctors say and what patients hear. Indeed, although CCC is reported by nephrologists to be widely available in their facilities, few of their patients say that they have actually heard of it. The objectives of this review are to explore discrepancies between what doctors say and what patients hear, to identify the factors underlying this gap, and to formulate practical proposals for narrowing this gap in practice.

Comprehensive conservative care for the management of advanced chronic kidney disease: overview and perspectives

Comprehensive “conservative care” is defined as any active therapeutic procedure for the management of stage 5 chronic kidney disease without recourse to dialysis. This therapeutic option is discussed in elderly, frail patients whose anticipated life expectancy is reduced with dialysis. The decision for conservative management primarily relies on an informed choice by the patient and his caregivers. This holistic approach, focused on quality of life, requires a multidisciplinary approach. The goals are to slow the progression of kidney disease, prevent complications, anticipate the risks of decompensation, provide support for the patient and his caregivers to maintain the best possible quality of life at home. This article describes the principles of conservative management, highlights various barriers to this care pathway, and proposes potential solutions.

Hemolysis is associated with altered heparan sulfate of the endothelial glycocalyx and with local complement activation in thrombotic microangiopathies

The complement system plays a key role in the pathophysiology of kidney thrombotic microangiopathies (TMA), as illustrated by atypical hemolytic uremic syndrome. But complement abnormalities are not the only drivers of TMA lesions. Among other potential pathophysiological actors, we hypothesized that alteration of heparan sulfate (HS) in the endothelial glycocalyx could be important. To evaluate this, we analyzed clinical and histological features of kidney biopsies from a monocentric, retrospective cohort of 72 patients with TMA, particularly for HS integrity and markers of local complement activation. The role of heme (a major product of hemolysis) as an HS-degrading agent in vitro, and the impact of altering endothelial cell (ECs) HS on their ability to locally activate complement were studied. Compared with a positive control, glomerular HS staining was lower in 57 (79%) patients with TMA, moderately reduced in 20 (28%), and strongly reduced in 37 (51%) of these 57 cases. Strongly reduced HS density was significantly associated with both hemolysis at the time of biopsy and local complement activation (C3 and/or C5b-9 deposits). Using primary endothelial cells (HUVECs, Glomerular ECs), we observed decreased HS expression after short-term exposure to heme, and that artificial HS degradation by exposure to heparinase was associated with local complement activation. Further, prolonged exposure to heme modulated expression of several key genes of glycocalyx metabolism involved in coagulation regulation (C5-EPI, HS6ST1, HS3ST1). Thus, our study highlights the impact of hemolysis on the integrity of endothelial HS, both in patients and in endothelial cell models. Hence, acute alteration of HS may be a mechanism of heme-induced complement activation.

Barriers to conservative care from patients' and nephrologists' perspectives: the CKD-REIN study

BACKGROUND

Conservative care is increasingly considered an alternative to kidney replacement therapy for kidney failure management, mostly among the elderly. We investigated its status and the barriers to its implementation from patients' and providers' perspectives.

METHODS

We analysed data from 1204 patients with advanced chronic kidney disease (CKD) [estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2] enrolled at 40 nationally representative nephrology clinics (2013-16) who completed a self-administered questionnaire about the information they received and their preferred treatment option, including conservative care, if their kidneys failed. Nephrologists (n = 137) also reported data about their clinics' resources and practices regarding conservative care.

RESULTS

All participating facilities reported they were routinely able to offer conservative care, but only 37% had written protocols and only 5% had a person or team primarily responsible for it. Overall, 6% of patients were estimated to use conservative care. Among nephrologists, 82% reported they were fairly or extremely comfortable discussing conservative care, but only 28% usually or always offered this option for older (>75 years) patients approaching kidney failure. They used various terminology for this care, with conservative management and non-dialysis care mentioned most often. Among patients, 5% of those >75 years reported receiving information about this option and 2% preferring it.

CONCLUSIONS

Although reported by nephrologists to be widely available and easily discussed, conservative care is only occasionally offered to older patients, most of whom report they were not informed of this option. The lack of a person or team responsible for conservative care and unclear information appear to be key barriers to its implementation.

The Versatile Role of miR-21 in Renal Homeostasis and Diseases

MicroRNAs (miRNAs) are small, non-coding RNA species that control gene expression and confer robustness to biological processes. Over the last two decades, their important roles during kidney development, homeostasis and the treatment of diseases have been established, in particular during the onset and progression of various forms of acute and chronic renal disorders. In recent years, miR-21, one of the best-characterized miRNAs to date, has received much attention in renal physiology in particular given its high degree of conservation and expression in kidneys, as well as its potent pathogenic role in various debilitating renal diseases. This review summarizes the current knowledge on miR-21’s involvement in both renal homeostasis and diseases, in particular its double-edged-sword role in acute versus chronic kidney injuries. Finally, we also discuss the potential of miR-21 as a biomarker and therapeutic target in renal diseases.

Vaccination and COVID-19 Dynamics in Dialysis Patients

BACKGROUND AND OBJECTIVES

Dialysis patients have a high mortality risk after coronavirus disease 2019 (COVID-19) and an altered immunologic response to vaccines, but vaccine clinical effectiveness remains unknown in this population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using Bayesian multivariable spatiotemporal models, we estimated the association between vaccine exposure and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) severe infections (with hospital admission) in dialysis patients from simultaneous incidence in the general population. For dialysis patients, cases were reported within the French end-stage kidney disease REIN registry from March 11, 2020, to April 29, 2021, and vaccine exposure (first dose) was reported in weekly national surveys since January 2021. Cases in the general population were obtained from the national exhaustive inpatient surveillance system (SI-VIC database), and vaccination coverage (first dose) was obtained from the national surveillance system (VAC-SI database).

RESULTS

During the first wave, incidence in dialysis patients was approximately proportional to the general population. However, we showed a lower relative incidence for dialysis patients during the second wave (compared with that observed in nondialysis patients), suggesting an effect of prevention measures. Moreover, from the beginning of the vaccination rollout, incidence in dialysis patients was lower compared with predictions based on the first and second waves. Adding vaccination coverages in dialysis and nondialysis patients as predictors allowed the reported cases to be fit correctly (3685 predicted cases, 95% confidence interval, 3552 to 3816, versus 3620 reported). Incidence rate ratios were 0.37 (95% confidence interval, 0.18 to 0.71) for vaccine exposure in dialysis patients and 0.50 (95% confidence interval, 0.40 to 0.61) per 10% higher in vaccination coverage in the same-age general population, meaning that vaccine exposure in dialysis patients and the general population was independently associated with lower hospitalization rate of dialysis patients.

CONCLUSIONS

Our findings suggest that vaccination may yield a protective effect against severe forms of COVID-19 in dialysis patients, despite altered immunologic vaccine responses.

Early Renal Recovery after the First Flare of Pauci-Immune Glomerulonephritis

INTRODUCTION

Renal involvement is a severe manifestation of antineutrophil cytoplasmic antibody-associated vasculitis. Patients often progress to end-stage renal disease. The potential for renal recovery after the first flare has seldom been studied. Our objectives were to describe the evolution of the estimated glomerular filtration rate (eGFR) and identify factors associated with the change in the eGFR between diagnosis and the follow-up at 3 months (ΔeGFRM0-M3).

METHODS

This was a retrospective study over the period 2003-2018 of incident patients in the Nord-Pas-de-Calais (France). The primary outcome was the ΔeGFRM0-M3.

RESULTS

One hundred and seventy-seven patients were included. The eGFR at 3 months was significantly higher than at diagnosis (mean ± standard deviation, 40 ± 24 vs. 28 ± 26 mL/min/1.73 m2, p < 0.001), with a ΔeGFRM0-M3 of 12 ± 19 mL/min/1.73 m2. The eGFR at 12 months was higher than at 3 months (44 ± 13 vs. 40 ± 24 mL/min/1.73 m2, p = 0.003). The factors significantly associated with the ΔeGFRM0-M3 in multivariate analysis were the percentage of cellular crescents and neurological involvement. The mean increase in the eGFR was 2.90 ± 0.06 mL/min/1.73 m2 for every 10-point gain in the percentage of cellular crescents.

CONCLUSIONS

Early renal recovery after the first flare of pauci-immune glomerulonephritis occurred mainly in the first 3 months of treatment. The percentage of cellular crescents was the main independent predictor of early renal recovery.

Association between acute graft pyelonephritis and kidney graft survival: A single-center observational study

The association between acute graft pyelonephritis (AGPN) and graft failure in kidney transplant recipients (KTR) remains controversial. In this single-center observational study, we aimed to assess the incidence of AGPN as a time-dependent posttransplantation event. We also examined the association between the diagnosis of AGPN and graft outcomes. In total, we evaluated 1480 patients who underwent kidney transplantation between January 2007 and December 2017. During a median follow-up of 5.04 years, we observed 297 AGPN episodes that occurred in 158 KTR. To evaluate the association between AGPN and clinical outcomes, we performed Cox proportional hazards regression analyses in which AGPN was entered as a time-dependent covariate. AGPN was independently associated with an increased risk of graft loss (hazard ratio = 1.66; 95% confidence interval [CI]: 1.05-2.64, p < .03) and a persistently decreased eGFR (fixed effect on intercept: -2.29 ml/min/1.73 m² ; 95% CI: from -3.23 to -1.35, p < .01). However, neither mortality nor biopsy-proven acute rejection was found to correlate with AGPN. Moreover, recurrent AGPN episodes did not appear to have an additive detrimental impact on graft loss. These data represent a promising step in understanding whether AGPN prevention may decrease the risk of graft loss in KTR.

Impact of Tacrolimus Daily Dose Limitation in Renal Transplant Recipients Expressing CYP3A5: A Retrospective Study

The pharmacokinetic variability of tacrolimus can be partly explained by CYP3A5 activity. Our objective was to evaluate a tacrolimus sparing policy on renal graft outcome according to CYP3A5 6986A>G genetic polymorphism. This retrospective study included 1114 recipients with a median follow-up of 6.3 years. Genotyping of the 6986A>G allelic variant corresponding to CYP3A5*3 was systematically performed. One year after transplantation, tacrolimus blood trough concentration (C0) target range was 5–7 ng/mL. However, daily dose was capped to 0.10 mg/kg/day regardless of the CYP3A5 genotype. A total 208 CYP3A5*1/- patients were included. Despite a higher daily dose, CYP3A5*1/- recipients exhibited lower C0 during follow-up (p < 0.01). Multivariate analysis did not show any significant influence of CYP3A5*1/- genotype (HR = 0.70, 0.46–1.07, p = 0.10) on patient-graft survival. Glomerular Filtration Rate (GFR) decline was significantly lower for the CYP3A5*1/- group (p = 0.02). The CYP3A5*1/- genotype did not significantly impact the risk of biopsy-proven acute rejection (BPAR) (HR = 1.01, 0.68–1.49, p = 0.97) despite significantly lower C0. Based on our experience, a strategy of tacrolimus capping is associated with a better GFR evolution in CYP3A5*1/- recipients without any significant increase of BPAR incidence. Our study raised some issues about specific therapeutic tacrolimus C0 targets for CYP3A5*1/- patients and suggests to set up randomized control studies in this specific population.

New Insights into Acute-on-Chronic Kidney Disease in Nephrology Patients: The CKD-REIN Study

BACKGROUND

Acute-on-chronic kidney disease (ACKD) is poorly understood and often overlooked. We studied its incidence, circumstances, determinants, and outcomes in patients with CKD.

METHODS

We used the Kidney Disease Improving Global Outcomes criteria to identify all-stage acute kidney injury (AKI) events in 3033 nephrology outpatients with CKD stage 3-5 participating in the CKD-REIN cohort study (2013-2020), and cause-specific Cox models to estimate hazard ratios (HR, 95% confidence intervals [CI]) of AKI-associated risk factors.

RESULTS

At baseline, 22% of the patients (mean age 67 years, 65% men, mean eGFR 32 ml/min/1.73m2) had a history of AKI. Over a 3-year follow-up, 443 had at least one AKI event: 27% were stage 2 or 3, and 11% required dialysis; 74% involved hospitalization including 47% acquired as hospital inpatients; a third were not reported in hospital discharge reports. Incidence rates were 10.1 and 4.8 per 100 person-years in patients with and without an AKI history, respectively. In 2375 patients without this history, male sex, diabetes, cardiovascular disease, cirrhosis, several drugs, low eGFR, and serum albumin levels were significantly associated with a higher risk of AKI, as were low birth weight (<2500 g) (adjusted HR, 1.98; 95%CI, 1.35 to 2.91) and hemoglobin level (HR 1.21; 1.12 to 1.32 per 1 g/dl decrease). Within one year, only 63% of the patients had recovered their previous kidney function, 13.7% had started kidney replacement therapy, and 12.7% had died.

CONCLUSIONS

The study highlights the high rate of hospital-acquired AKI events in patients with CKD, and their underreporting at hospital discharge. It also reveals low birth weight and anemia as possible new risk factors in CKD patients.

Impact of air pollution on renal outcomes: a systematic review and meta-analysis protocol

INTRODUCTION

Chronic kidney disease is a serious and a frequent disease associated with a high risk of morbi-mortality. Although several risk factors have already been well addressed, mostly diabetes and hypertension, many remain underappreciated, such as chronic exposure to air pollution.

METHODS AND ANALYSIS

We will search EMBASE, PubMed, Web of Science, Cochrane Library and CINAHL database, from inception to 31 March 2020, for relevant records using a combination of keywords related to the type of exposure (ozone, carbon monoxide, nitrogen oxides and dioxide, sulfur dioxide, PM_2.5, PM_coarse and PM₁₀) and to the type of outcome (chronic kidney disease, end-stage renal/kidney disease, kidney failure, proteinuria/albuminuria, renal function, renal transplant, kidney graft, kidney transplant failure, nephrotic syndrome and kidney cancer). The review will be reported according to the guidelines of the Meta-analysis Of Observational Studies in Epidemiology. Two independent reviewers will select studies without design or language restrictions, using original data and investigating the association between exposure to one or more of the prespecified air pollutants and subsequent risk of renal outcomes. Using random-effects meta-analyses, we will present pooled summary statistics (HR, OR or beta-coefficients with their respective 95% CI) associated with a standardised increase in each pollutant level. The results will be presented by air pollutant and outcome. Heterogeneity will be assessed using the χ² test on Cochran's Q statistic and quantified by calculating I². The Egger's test and visual inspection of funnel plots will be used to assess publication bias.

ETHICS AND DISSEMINATION

Since primary data are not collected in this study, ethical approval is not required. This review is expected to provide relevant data on the associations between various air pollutants' exposure and renal outcomes. The final report will be published in an international peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42020187956.

Donor-to-recipient transmission and reactivation in a kidney transplant recipient of an inherited chromosomally integrated HHV-6A: Evidence and outcomes

Human herpesvirus (HHV)-6A can be inherited and chromosomally integrated (iciHHV-6A), and donor-to-recipient transmission has been reported in solid organ transplant. However, when HHV-6A reactivation happens after transplant, the source of HHV-6A is often not evident and its pathogenicity remains unclear. Here, we present an exhaustive case of donor-to-recipient transmission and reactivation of iciHHV-6A through kidney transplant. The absence of HHV-6A genome from the nails of the recipient excluded a recipient-related iciHHV-6A. Viral loads > 7 log₁₀ copies/10⁶ cells in donor blood samples and similarities of U38, U39, U69, and U100 viral genes between donor, recipient, and previously published iciHHV-6A strains are proof of donor-related transmission. Detection of noncoding HHV-6 snc-RNA14 using fluorescence in situ hybridization analysis and immunofluorescence staining of HHV-6A gp82/gp105 late proteins on kidney biopsies showed evidence of reactivation in the transplanted kidney. Because HHV-6A reactivation can be life threatening in immunocompromised patients, we provide several tools to help during the complete screening and diagnosis.

[Renal granulomatous nephritis: Histopathological point of view]

Granulomatous interstitial nephritis (NIG) is a rare form of interstitial nephritis that can be related to acute or chronic clinical presentation. NIG is characterized by granulomas located to the renal interstitium and composed of either epithelioid histiocytes with giant cells and/or of foreign body reaction. The symptoms are unspecific and associate varying degrees of renal failure with abnormal urinanalysis. Extra-renal signs may point to systemic disease. Pathological examination from kidney percutaneous biopsy or surgical resection is required to assert NIG diagnosis and to guide the etiological research. The main causes of NIG are sarcoidosis, drug reactions, mycobacterial infections and crystalline nephropathies. Sarcoidosis is characterized by non-necrotic and well-formed giant cell epithelioid interstitial granulomas. Drug reactions have less well-defined granulomas with inconstant eosinophils. The presence of caseous necrosis within giant cell and epithelioid granulomas leads to infectious NIG diagnosis (tuberculosis and fungal infection). Identification of crystals within foreign body reaction can be improved by polarized light study. Xanthogranulomatous pyelonephritis and malakoplakia are rarer causes of NIG characterized by patches of histiocytes associated with inconstant giant cells. Differential diagnoses of NIG are represented by granulomatous reactions centered on glomeruli and vessels (vasculitis and emboli of cholesterol crystals). Less than 10% of NIG are idiopathic. The prognosis and the treatment vary according to the cause. The factors of poor renal prognosis are chronic irreversible tubulo-interstitial injury (tubular atrophy and interstitial fibrosis).

Angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, β-blockers or both in incident end-stage renal disease patients without cardiovascular disease: a propensity-matched longitudinal cohort study

BACKGROUND

End-stage renal disease (ESRD) patients even without known cardiovascular (CV) disease have high mortality rates. Whether neurohormonal blockade treatments improve outcomes in this population remains unknown. The aim of this study was to assess the effect of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARBs), β-blockers or both in all-cause mortality rates in incident ESRD patients without known CV disease starting renal replacement therapy (RRT) between 2009 and 2015 in the nationwide Réseau Epidémiologie et Information en Néphrologie registry.

METHODS

Patients with known CV disease and those who started emergency RRT, stopped RRT or died within 6 months were excluded. Propensity score matching models were used. The main outcome was all-cause mortality.

RESULTS

A total of 13 741 patients were included in this analysis. The median follow-up time was 24 months. When compared with matched controls without antihypertensive treatment, treatment with ACEi/ARBs, β-blockers and ACEi/ARBs + β-blockers was associated with an event-rate reduction per 100 person-years: ACEi/ARBs 7.6 [95% confidence interval (CI) 7.1-8.2] versus matched controls 9.5 (8.8-10.1) [HR 0.76 (95% CI 0.69-0.84)], β-blocker 7.1 (6.6-7.7) versus matched controls 9.5 (8.5-10.2) [HR 0.72 (0.65-0.80)] and ACEi/ARBs + β-blockers 5.8 (5.4-6.4) versus matched controls 7.8 (7.2-8.4) [HR 0.68 (0.61-0.77)].

CONCLUSIONS

Neurohormonal blocking therapies were associated with death rate reduction in incident ESRD without CV disease. Whether these relationships are causal will require randomized controlled trials.

The Long Noncoding RNA DNM3OS Is a Reservoir of FibromiRs with Major Functions in Lung Fibroblast Response to TGF-β and Pulmonary Fibrosis

Rationale: Given the paucity of effective treatments for idiopathic pulmonary fibrosis (IPF), new insights into the deleterious mechanisms controlling lung fibroblast activation, the key cell type driving the fibrogenic process, are essential to develop new therapeutic strategies. TGF-β (transforming growth factor-β) is the main profibrotic factor, but its inhibition is associated with severe side effects because of its pleiotropic role. Objectives: To determine if downstream noncoding effectors of TGF-β in fibroblasts may represent new effective therapeutic targets whose modulation may be well tolerated. Methods: We investigated the whole noncoding fraction of TGF-β-stimulated lung fibroblast transcriptome to identify new genomic determinants of lung fibroblast differentiation into myofibroblasts. Differential expression of the long noncoding RNA (lncRNA) DNM3OS (dynamin 3 opposite strand) and its associated microRNAs (miRNAs) was validated in a murine model of pulmonary fibrosis and in IPF tissue samples. Distinct and complementary antisense oligonucleotide-based strategies aiming at interfering with DNM3OS were used to elucidate the role of DNM3OS and its associated miRNAs in IPF pathogenesis. Measurements and Main Results: We identified DNM3OS as a fibroblast-specific critical downstream effector of TGF-β-induced lung myofibroblast activation. Mechanistically, DNM3OS regulates this process in trans by giving rise to three distinct profibrotic mature miRNAs (i.e., miR-199a-5p/3p and miR-214-3p), which influence SMAD and non-SMAD components of TGF-β signaling in a multifaceted way. In vivo, we showed that interfering with DNM3OS function not only prevents lung fibrosis but also improves established pulmonary fibrosis. Conclusions: Pharmacological approaches aiming at interfering with the lncRNA DNM3OS may represent new effective therapeutic strategies in IPF.

Prevention of Cisplatin-Induced Acute Kidney Injury: A Systematic Review and Meta-Analysis

PURPOSE

Cisplatin-induced acute kidney injury (CIA) is a serious adverse event that affects 20-40% of exposed patients, despite any implemented precaution to avoid it. The aim of this work was therefore to identify a relevant nephroprotective method for CIA.

METHODS

We searched Pubmed, Embase, and Web of Science from 1 January 1978 to 1 June 2018, without language restriction. All studies (observational and interventional) assessing a CIA prevention method for adults receiving at least one course of cisplatin were eligible. The primary outcome was acute nephrotoxicity, as defined by the AKI-KDIGO classification (2012). The odds ratio and corresponding 95% confidence interval were used to assess the associations. We used narrative synthesis in case of heterogeneity regarding intervention, population, or outcome. When possible, a random-effects model was used to pool studies. The heterogeneity between studies was quantified (I²), and multiple meta-regressions were carried out to identify potential confounders.

RESULTS

Within 4520 eligible studies, 51 articles fulfilling the selection criteria were included in the review, assessing 21 different prevention methods. A meta-analysis could only be performed on the 15 observational studies concerning magnesium supplementation (1841 patients), and showed a significant nephroprotective effect for all combined grades of CIA (OR 0.24, [0.19-0.32], I² = 0.0%). This significant nephroprotective effect was also observed for grades 2 and 3 CIA (OR 0.22, [0.14-0.33], I² = 0.0% and OR 0.25, [0.08-0.76], I² = 0.0%, respectively).

CONCLUSION

While no method of prevention had so far demonstrated its indisputable efficacy, our results highlight the potential protective effect of magnesium supplementation on cisplatin-induced acute nephrotoxicity.

TRIAL REGISTRATION

This study is registered in PROSPERO, CRD42018090612.

Prognostic significance of the renal resistive index in the primary prevention of type II diabetes

The renal resistive index has been demonstrated to predict the progression of renal disease and recurrence of major cardiac events in high-risk cardiovascular patients, in addition to other comorbidities. We aimed to assess the prognostic significance of the renal resistive index in type 2 diabetic patients for primary prevention. From 2008 to 2011, patients with type 2 diabetes underwent cardiovascular evaluation, including renal resistive index assessment by renal Doppler ultrasound. The incidence of all-cause death, cardiovascular events, dialysis requirement or a twofold increase in creatinine was recorded. Survival curves were estimated by the Kaplan-Meier method. Two hundred sixty-six patients were included; 50% of the patients were men, an HbA1C level of 8.1 ± 1.7% (65 ± 13.6 mmol/mol) and a serum creatinine level of 8 [7-9] mg/L. The mean 24-hour systolic blood pressure, 24-hour diastolic blood pressure, and 24-hour pulse pressure were 133.4 ± 16.7, 76.5 ± 9.4, and 56.9 ± 12.4 mm Hg, respectively. The median renal resistive index was 0.7 [0.6-0.7] with a threshold of 0.7 predictive of monitored events. After adjustment of the 24-hour pulse pressure, age and 24-hour heart rate, a renal resistive index ≥0.70 remained associated with all-cause death (hazard ratio: 3.23 (1.16-8.98); P = .025) and the composite endpoint of major clinical events (hazard ratio: 2.37 (1.34-4.18); P = .003). An elevated renal resistive index with a threshold of 0.7 is an independent predictor of a first cardiovascular or renal event in type 2 diabetic patients. This simple index should be implemented in the multiparametric staging of diabetes.

Calcium state estimation by total calcium: the evidence to end the never-ending story

Background Total blood calcium (TCa) is routinely used to diagnose and manage mineral and bone metabolism disorders. Numerous laboratories adjust TCa by albumin, though literature suggests there are some limits to this approach. Here we report a large retrospective study on agreement rate between ionized calcium (iCa) measurement and TCa or albumin-adjusted calcium measurements. Methods We retrospectively selected 5055 samples with simultaneous measurements of iCa, TCa, albumin and pH. We subgrouped our patients according to their estimated glomerular filtration rate (eGFR), albumin levels and pH. We analyzed each patient's calcium state with iCa as reference to determine agreement rate with TCa and albumin-adjusted calcium using Payne, Clase, Jain and Ridefelt formulas. Results The Payne formula performed poorly in patients with abnormal albumin, eGFR or pH levels. In patients with low albumin levels or blood pH disorders, Payne-adjusted calcium may overestimate the calcium state in up to 80% of cases. Similarly, TCa has better agreement with iCa in the case of hypoalbuminemia, but performed similarly to the Payne formula in patients with physiological albumin levels. The global agreement rate for Clase, Jain and Ridefelt formulas suggests significant improvement compared to Payne calcium adjustment but no significant improvement compared to TCa. Conclusions Total and albumin-adjusted calcium measurement leads to a misclassification of calcium status. Moreover, accurate calcium state determination depends on blood pH levels, whose measurement requires the same pre-analytical restrictions as iCa measurement. We propose that iCa should instead become the reference method to determine the real calcium state.

Cadmium-Induced Renal Cell Toxicity Is Associated With MicroRNA Deregulation

Cadmium is an environmental pollutant well known for its nephrotoxic effects. Nevertheless, mechanisms underlying nephrotoxicity continue to be elucidated. MicroRNAs (miRNAs) have emerged in recent years as modulators of xenobiotic-induced toxicity. In this context, our study aimed at elucidating whether miRNAs are involved in renal proximal tubular toxicity induced by cadmium exposure. We showed that cadmium exposure, in 2 distinct renal proximal tubular cell models (renal proximal tubular epithelial cell [RPTEC]/human telomerase reverse transcriptase [hTERT] and human kidney-2), resulted in cytotoxicity associated with morphological changes, overexpression of renal injury markers, and induction of apoptosis and inflammation processes. Cadmium exposure also resulted in miRNA modulation, including the significant upregulation of 38 miRNAs in RPTEC/hTERT cells. Most of these miRNAs are known to target genes whose coding proteins are involved in oxidative stress, inflammation, and apoptosis, leading to tissue remodeling. In conclusion, this study provides a list of dysregulated miRNAs which may play a role in the pathophysiology of cadmium-induced kidney damages and highlights promising cadmium molecular biomarkers that warrants to be further evaluated.

Community-Acquired Acute Kidney Injury Induced By Drugs In Older Patients: A Multifactorial Event

Purpose

Community-acquired acute kidney injury (CA-AKI) is a frequent and severe adverse drug reaction (ADR) among older patients. The combination of drugs and other CA-AKI risk factors was barely evaluated. The objectives of our study were to both accurately identify CA-AKI induced by drugs in older patients, and to describe their combination with other risk factors.

Patients and methods

We conducted a retrospective, single-center study in a general hospital over a two-year period. An automated detection identified CA-AKI according to KDIGO criteria, amongst 4,767 eligible inpatient stays among patients aged 75 years or older. Two independent experts reviewed all CA-AKI events to adjudicate drug involvement (Naranjo scale), identify inappropriate prescriptions (STOPP criteria), evaluate avoidability (Hallas criteria) and identify combined risk factors.

Results

An expert review confirmed 713 CA-AKI (15.0% of inpatient stays) and determined that 419 (58.8%) CA-AKI were induced by drugs. A multifactorial cause (i.e., at least one drug with a precipitating factor) was found in 63.2% of drug-induced CA-AKI. Most of the drug-induced events were avoidable (66.8%), mainly in relation to a multifactorial cause.

Conclusion

Drug-induced CA-AKI were frequent, multifactorial events in hospitalized older patients and their prevention should focus on combinations with precipitating factors.

[Kidney disease care for the elderly]

In our aging population, kidney disease management needs to take into account the frailty of the elderly. Standardized geriatric assessments can be proposed to help clinicians apprehend this dimension in their daily practice. These tools allow to better identify frail patients and offer them more personalized and harmless treatments. This article aims to focus on the kidney diseases commonly observed in elderly patients and analyze their specific nephrogeriatric care modalities. It should be noticed that all known kidney diseases can be also observed in the elderly, most often with a quite similar clinical presentation. This review is thus focused on the diseases most frequently and most specifically observed in elderly patients (except for monoclonal gammopathy associated nephropathies, out of the scope of this work), as well as the peculiarities of old age nephrological care.

The prognostic impact of cirrhosis on patients receiving maintenance haemodialysis

BACKGROUND

Further study is needed on the prognostic impact of cirrhosis on haemodialysis patients.

AIM

To evaluate cirrhosis' impact according to severity on survival and to provide therapeutic guidelines for haemodialysis cirrhotic patients.

METHODS

Patients with end-stage renal failure treated with haemodialysis were included retrospectively from 01/01/2000 to 31/12/2004 and prospectively from 01/01/2005 to 31/12/2014 in our French Region. Clinical data, presence of cirrhosis and its severity were recorded at the beginning of haemodialysis. The primary endpoint was 2-year survival.

RESULTS

Seven thousand three hundred and fifty-four patients (96%) without cirrhosis and 304 patients (4%) with cirrhosis were included. Two-year survival in noncirrhotic patients was higher than in cirrhotic patients (71.7% vs 54.4%, P < 0.0001). Patients with decompensated cirrhosis had a worse 2-year outcome (44.1%) as compared to compensated cirrhotic (62.8%, P = 0.002) and noncirrhotic patients (71.7%, P < 0.0001). Compensated and decompensated cirrhosis were independent predictive factors of 2-year mortality. In sensitivity analysis restricted to cirrhotic patients, 2-year survival of Child-Pugh A patients was higher than in Child-Pugh B and C patients (65.5% vs 27.7% vs 0%, P < 0.0001). Development of predictive models based either on severity scores (MELD and Child-Pugh) and extrahepatic comorbidities allowed correct classification of around 70% of patients in terms of mortality and may help to better stratify mortality risk in this population.

CONCLUSIONS

Cirrhosis is independently associated with mortality in haemodialysis patients. Patients with severe cirrhosis have a poor 2-year outcome. Severity of cirrhosis and presence of extrahepatic comorbidities should be considered when deciding to initiate renal replacement therapy.

Knockout of receptor for advanced glycation end-products attenuates age-related renal lesions

Pro‐aging effects of endogenous advanced glycation end‐products (AGEs) have been reported, and there is increasing interest in the pro‐inflammatory and ‐fibrotic effects of their binding to RAGE (the main AGE receptor). The role of dietary AGEs in aging remains ill‐defined, but the predominantly renal accumulation of dietary carboxymethyllysine (CML) suggests the kidneys may be particularly affected. We studied the impact of RAGE invalidation and a CML‐enriched diet on renal aging. Two‐month‐old male, wild‐type (WT) and RAGE^−/− C57Bl/6 mice were fed a control or a CML‐enriched diet (200 μg CML/g_food) for 18 months. Compared to controls, we observed higher CML levels in the kidneys of both CML WT and CML RAGE^−/− mice, with a predominantly tubular localization. The CML‐rich diet had no significant impact on the studied renal parameters, whereby only a trend to worsening glomerular sclerosis was detected. Irrespective of diet, RAGE^−/− mice were significantly protected against nephrosclerosis lesions (hyalinosis, tubular atrophy, fibrosis and glomerular sclerosis) and renal senile apolipoprotein A‐II (ApoA‐II) amyloidosis (p < 0.001). A positive linear correlation between sclerosis score and ApoA‐II amyloidosis score (r = 0.92) was observed. Compared with old WT mice, old RAGE^−/− mice exhibited lower expression of inflammation markers and activation of AKT, and greater expression of Sod2 and SIRT1. Overall, nephrosclerosis lesions and senile amyloidosis were significantly reduced in RAGE^−/− mice, indicating a protective effect of RAGE deletion with respect to renal aging. This could be due to reduced inflammation and oxidative stress in RAGE^−/− mice, suggesting RAGE is an important receptor in so‐called inflamm‐aging.

Isolated v-lesion in kidney transplant recipients: Characteristics, association with DSA, and histological follow-up

Isolated v-lesion (IvL) represents a rare and challenging situation in renal allograft biopsies because it is unknown whether IvL truly represents rejection, antibody- or T cell-mediated, or not. This multicentric retrospective study describes the clinicopathological features of IvL with an emphasis on the donor-specific antibody (DSA) status, histological follow-up, and graft survival. Inclusion criteria were the presence of v-lesion with minimal interstitial (i ≤ 1) and microvascular inflammation (g + ptc≤1). C4d-positive biopsies were excluded. We retrospectively found 33 IvL biopsies in 33 patients, mainly performed in the early posttransplantation period (median time 27 days) and clinically indicated in 66.7%. A minority of recipients (5/33, 15.2%) had DSA at the time of biopsy. IvL was treated by anti-rejection therapy in 21 cases (63.6%), whereas 12 (36.4%) were untreated. Seventy percent of untreated patients and 66% of treated patients showed favorable histological evolution on subsequent biopsy. Kidney graft survival in IvL was significantly higher than in a matched cohort of antibody-mediated rejection with arteritis. In conclusion, IvL is not primarily antibody-mediated and may show a favorable evolution. The heterogeneity of IvL pathophysiology on early biopsies should prompt DSA testing as well as close clinical and histological follow-up in all patients with IvL.

Intratubular amyloid in light chain cast nephropathy is a risk factor for systemic light chain amyloidosis

Light chain cast nephropathy is the most common form of kidney disease in patients with multiple myeloma. Light chain casts may occasionally show amyloid staining properties, that is, green birefringence after Congo red staining. The frequency and clinical significance of this intratubular amyloid are poorly understood. Here, we retrospectively assessed the clinicopathological features of 60 patients with histologically proven light chain cast nephropathy with a specific emphasis on intratubular amyloid, especially, its association with extrarenal systemic light chain amyloidosis. We found intratubular amyloid in 17 cases (17/60, 28%) and it was more frequent in patients with λ light chain gammopathy (13/17 in the 'intratubular amyloid' group vs 19/43 in the 'no intratubular amyloid' group, P=0.02). Pathological examination of extrarenal specimens showed that intratubular amyloid was significantly associated with the occurrence of systemic light chain amyloidosis (5/13 in the 'intratubular amyloid' group vs 0/30 in the 'no intratubular amyloid' group, P=0.001). Our results indicate that first, intratubular amyloid is not a rare finding in kidney biopsies of patients with light chain cast nephropathy, and, second, it reflects an amyloidogenic capacity of light chains that can manifest as systemic light chain amyloidosis. Thus, intratubular amyloid should be systematically screened for in kidney biopsies from patients with light chain cast nephropathy and, if detected, should prompt a work-up for associated systemic light chain amyloidosis.

[Socioeconomic inequalities and kidney transplantation]

Studies at the population level must take into account the effect of social insecurity and socioeconomic inequalities on the patient outcomes. Socioeconomic inequalities depend on many determinants that are socially determined. In renal transplantation, these social determinants are not registered in the databases. The European Deprivation Index (EDI) is a composite index of social vulnerability with a French version. The EDI is an ecological measure of deprivation including the individual perception of basic needs for daily life that is called "subjective poverty". The Townsend index, Carstairs index and the Index of Multiple Deprivation are other ecological index available. It has been demonstrated in the United States that socioeconomic indicators of deprivation were associated with both the access to the waiting list for renal transplantation and transplantation failure. In France, socioeconomic deprivation may also affect the access to the waiting list and outcome of transplantation. This article is a review about deprivation and renal transplantation.

Targeting miR-21 decreases expression of multi-drug resistant genes and promotes chemosensitivity of renal carcinoma

Renal cell carcinoma, the most common neoplasm of adult kidney, accounts for about 3% of adult malignancies and is usually highly resistant to conventional therapy. MicroRNAs are a class of small non-coding RNAs, which have been previously shown to promote malignant initiation and progression. In this study, we focused our attention on miR-21, a well described oncomiR commonly upregulated in cancer. Using a cohort of 99 primary renal cell carcinoma samples, we showed that miR-21 expression in cancer tissues was higher than in adjacent non-tumor tissues whereas no significant difference was observed with stages, grades, and metastatic outcome. In vitro, miR-21 was also overexpressed in renal carcinoma cell lines compared to HK-2 human proximal tubule epithelial cell line. Moreover, using Boyden chambers and western blot techniques, we also showed that miR-21 overexpression increased migratory, invasive, proliferative, and anti-apoptotic signaling pathways whereas opposite results were observed using an anti-miR-21-based silencing strategy. Finally, we assessed the role of miR-21 in mediating renal cell carcinoma chemoresistance and further showed that miR-21 silencing significantly (1) increased chemosensitivity of paclitaxel, 5-fluorouracil, oxaliplatin, and dovitinib; (2) decreased expression of multi-drug resistance genes; and (4) increased SLC22A1/OCT1, SLC22A2/OCT2, and SLC31A1/CTR1 platinum influx transporter expression. In conclusion, our results showed that miR-21 is a key actor of renal cancer progression and plays an important role in the resistance to chemotherapeutic drugs. In renal cell carcinoma, targeting miR-21 is a potential new therapeutic strategy to improve chemotherapy efficacy and consequently patient outcome.

[New scores in renal transplantation: How can we use them?]

In renal transplant medicine, several scores have been recently developed in order to help decision-making in clinical practice. The aim of this update is to focus on these new scores that allow to better estimate the quality of the renal transplant, to refine the allocation policy, to help registration of old recipients on the waiting list, or to evaluate the risk to develop end-stage renal failure after living donation.

Genome-Wide Association Study of Acute Renal Graft Rejection

Acute renal rejection is a major risk factor for chronic allograft dysfunction and long-term graft loss. We performed a genome-wide association study to detect loci associated with biopsy-proven acute T cell-mediated rejection occurring in the first year after renal transplantation. In a discovery cohort of 4127 European renal allograft recipients transplanted in eight European centers, we used a DNA pooling approach to compare 275 cases and 503 controls. In an independent replication cohort of 2765 patients transplanted in two European countries, we identified 313 cases and 531 controls, in whom we genotyped individually the most significant single nucleotide polymorphisms (SNPs) from the discovery cohort. In the discovery cohort, we found five candidate loci tagged by a number of contiguous SNPs (more than five) that was never reached in iterative in silico permutations of our experimental data. In the replication cohort, two loci remained significantly associated with acute rejection in both univariate and multivariate analysis. One locus encompasses PTPRO, coding for a receptor-type tyrosine kinase essential for B cell receptor signaling. The other locus involves ciliary gene CCDC67, in line with the emerging concept of a shared building design between the immune synapse and the primary cilium.

[Community pharmacists' interventions to prevent and screen chronic kidney disease patients]

Chronic kidney disease (CKD) is a major concern of public health. The pharmacist is known as a health practitioner involved in prevention and therapeutic education. Our study aimed at defining the impact of community pharmacists' interventions for preventing and screening CKD. In our observational prospective study of 5 months conducted in 109 community pharmacy, we included 2 groups of patients: A (therapeutic optimization): CKD patients and B (CKD screening): population at risk. In group A, we included 354 patients, mainly women (51.2%), in stage 3 of CKD, mean age 73 years old, with hypertension alone (40.6%) or associated with diabetes (44%). About 70% of the patients had a follow up by a nephrologist and 45% of them were good adherent according to the Morisky-Green self-report. However, approximately 20% of patients did not have nephroprotective treatments in their regimen although they were on stage 3 or 4 CKD patients, and about half of them were not aware of medical situations at risk. Concerning group B, 532 patients were included. The pharmaceutical interventions screened 10% of patients with a GFR<60mL/min/1.73m². The community pharmacists' interventions helped to optimize the therapeutic management of CKD patients and in the early screening of patients at risk. More studies are needed to extrapolate our observations to a larger population.