Decreased Renal Gluconeogenesis Is a Hallmark of Chronic Kidney Disease.

INTRODUCTION: CKD is associated with alterations of tubular function. Renal gluconeogenesis is responsible for 40% of systemic gluconeogenesis during fasting, but how and why CKD affects this process and the repercussions of such regulation are unknown. METHODS: We used data on the renal gluconeogenic pathway from more than 200 renal biopsies performed on CKD patients and from 43 kidney allograft patients, and studied three mouse models, of proteinuric CKD (POD-ATTAC), of ischemic CKD, and of unilateral urinary tract obstruction. We analyzed a cohort of patients who benefitted from renal catheterization and a retrospective cohort of patients hospitalized in the intensive care unit. RESULTS: Renal biopsies of CKD and kidney allograft patients revealed a stage-dependent decrease in the renal gluconeogenic pathway. Two animal models of CKD and one model of kidney fibrosis confirm gluconeogenic downregulation in injured proximal tubule cells. This shift resulted in an alteration of renal glucose production and lactate clearance during an exogenous lactate load. The isolated perfused kidney technique in animal models and renal venous catheterization in CKD patients confirmed decreased renal glucose production and lactate clearance. In CKD patients hospitalized in the intensive care unit, systemic alterations of glucose and lactate levels were more prevalent and associated with increased mortality and a worse renal prognosis at follow-up. Decreased expression of the gluconeogenesis pathway and its regulators predicted faster histologic progression of kidney disease in kidney allograft biopsies. CONCLUSION: Renal gluconeogenic function is impaired in CKD. Altered renal gluconeogenesis leads to systemic metabolic changes with a decrease in glucose and increase in lactate level, and is associated with a worse renal prognosis.

[Collaboration in nephrology between Geneva and Yaoundé: a convincing example]. / Néphrologie solidaire : la coopération Genève-Yaoundé.

Chronic kidney disease (CKD) has a high prevalence in Cameroon and will become an important public health problem. Its management must be comprehensive, starting with CKD prevention to the implementation of renal replacement therapies best suited to the needs of patients and resources available in Cameroon. Practical interventions involving nephrology departments in both Africa and Europe can contribute to an improved management of CKD in Africa. The current collaboration between the Geneva University Hospitals and the Yaoundé teaching hospitals is a convincing example. It includes a clinical trial on the treatment of metabolic acidosis linked to CKD, assistance with the placement of hemodialysis catheters by sonography and the initiation of a kidney transplantation program with living donors.

La maladie rénale chronique (MRC) a une haute prévalence au Cameroun et va devenir un important problème de santé publique. Sa prise en charge doit être globale, partant de la prévention de la MRC jusqu'à la mise en place des techniques de suppléance extrarénale les plus adaptées aux besoins des patients et aux ressources disponibles localement. Des actions concrètes, dans le cadre d'une néphrologie solidaire, impliquant des services de néphrologie d'Afrique et d'Europe, peuvent y contribuer. La collaboration entre les Hôpitaux universitaires de Genève et ceux de Yaoundé en est un exemple probant, avec la mise en place d'un essai clinique sur le traitement de l'acidose métabolique liée à la MRC, une aide à la pose des cathéters de dialyse par sonographie et l'initiation d'un programme de transplantation rénale avec des donneurs vivants.

Renal water transport in health and disease.

Saving body water by optimal reabsorption of water filtered by the kidney leading to excretion of urine with concentrations of solutes largely above that of plasma allowed vertebrate species to leave the aquatic environment to live on solid ground. Filtered water is reabsorbed for 70% and 20% by proximal tubules and thin descending limbs of Henle, respectively. These two nephron segments express the water channel aquaporin-1 located along both apical and basolateral membranes. In the proximal tubule, the paracellular pathway accounts for at least 30% of water reabsorption, and the tight-junction core protein claudin-2 plays a key role in this permeability. The ascending limb of Henle and the distal convoluted tubule are impermeant to water and are responsible for urine dilution. The water balance is adjusted along the collecting system, i.e. connecting tubule and the collecting duct, under the control of arginine-vasopressin (AVP). AVP is synthesized by the hypothalamus and released in response to an increase in extracellular osmolality or stimulation of baroreceptors by decreased blood pressure. In response to AVP, aquaporin-2 water channels stored in subapical intracellular vesicles are translocated to the apical plasma membrane and raise the water permeability of the collecting system. The basolateral step of water reabsorption is mediated by aquaporin-3 and -4, which are constitutively expressed. Drugs targeting water transport include classical diuretics, which primarily inhibit sodium transport; the new class of SGLT2 inhibitors, which promotes osmotic diuresis and the non-peptidic antagonists of the V2 receptor, which are pure aquaretic drugs. Disturbed water balance includes diabetes insipidus and hyponatremias. Diabetes insipidus is characterized by polyuria and polydipsia. It is either related to a deficit in AVP secretion called central diabetes insipidus that can be treated by AVP analogs or to a peripheral defect in AVP response called nephrogenic diabetes insipidus. Diabetes insipidus can be either of genetic origin or acquired. Hyponatremia is a common disorder most often related to free water excess relying on overstimulated or inappropriate AVP secretion. The assessment of blood volume is key for the diagnosis and treatment of hyponatremia, which can be classified as hypo-, eu-, or hypervolemic.

Diffusion-magnetic resonance imaging predicts decline of kidney function in chronic kidney disease and in patients with a kidney allograft.

Kidney cortical interstitial fibrosis is highly predictive of kidney prognosis and is currently assessed by evaluation of a biopsy. Diffusion-weighted magnetic resonance imaging is a promising non-invasive tool to evaluate kidney fibrosis. We recently adapted diffusion-weighted imaging sequence for discrimination between the kidney cortex and medulla and found that the cortico-medullary difference in apparent diffusion coefficient (ΔADC) correlated with histological interstitial fibrosis. Here, we assessed whether ΔADC as measured with diffusion-weighted magnetic resonance imaging is predictive of kidney function decline and dialysis initiation in chronic kidney disease (CKD) and patients with a kidney allograft in a prospective study encompassing 197 patients. We measured ΔADC in 43 patients with CKD (estimated GFR (eGFR) 55ml/min/1.73m2) and 154 patients with a kidney allograft (eGFR 53ml/min/1.73m2). Patients underwent a kidney biopsy and diffusion-weighted magnetic resonance imaging within one week of biopsy; median follow-up of 2.2 years with measured laboratory parameters. The primary outcome was a rapid decline of kidney function (eGFR decline over 30% or dialysis initiation) during follow up. Significantly, patients with a negative ΔADC had 5.4 times more risk of rapid decline of kidney function or dialysis (95% confidence interval: 2.29-12.58). After correction for kidney function at baseline and proteinuria, low ADC still predicted significant kidney function loss with a hazard ratio of 4.62 (95% confidence interval 1.56-13.67) independent of baseline age, sex, eGFR and proteinuria. Thus, low ΔADC can be a predictor of kidney function decline and dialysis initiation in patients with native kidney disease or kidney allograft, independent of baseline kidney function and proteinuria.

ADD10 protects renal cells from cold injuries by improving energy metabolism.

Static cold storage (SCS) is currently the most widely used method for organ preservation, but a number of limitations are associated including tissue damage and restricted opportunity for organ repair. Thus, the development of improved hypothermic storage solutions is an urgent need. Herein, using a renal epithelial cell model (LLC-PK1), we tested the benefits of ADD10, a novel clinical grade antioxidant product, in reducing damages associated with ischemia-reperfusion (IR). Cells were stored up to 24h at 4 °C in University of Wisconsin (UW) solution without or in the presence of 1% ADD10 with following reperfusion up to 24h at 37 °C. The presence of ADD10 significantly decreased cells damages, cell death, and the level of reactive oxygen species (ROS) (P < 0.05). Concomitantly, ADD10 supplementation also favored an increased oxygen consumption rate (OCR) and improved bioenergetics of LLC-PK1 cells (P < 0.05). Finally, preliminary in vivo studies suggested a benefit of ADD10 on the renal function post-transplantation. In conclusion, these results demonstrate that the addition of ADD10 to the preservation solution not only efficiently protects renal cells during SCS, but also improves the functionality of cold-stored organs during transplantation.

Changes of lipoprotein(a) levels with endogenous steroid hormones.

BACKGROUND: Lipoprotein(a) [Lp(a)] is an LDL-like molecule that is likely causal for cardiovascular events and Lp(a) variability has been shown to be mostly of genetic origin. Exogenous hormones (hormone replacement therapy) seem to influence Lp(a) levels, but the impact of endogenous hormone levels on Lp(a) is still unknown. The aim of the study was to assess the effect of endogenous steroid hormone metabolites on Lp(a). METHODS: Lipoprotein(a) levels were measured in 1,021 participants from the Swiss Kidney Project on Genes in Hypertension, a family-based, multicentre, population-based prospective cohort study. Endogenous levels of 28 steroid hormone precursors were measured in 24-h urine collections from 883 individuals. Of the participants with Lp(a) data, 1,011 participants had also genotypes available. RESULTS: The participants had an average age of 51 years and 53% were female. Median Lp(a) levels were 62 mg/L, and the 90th percentile was 616 mg/L. The prevalence of a Lp(a) elevation ≥700 mg/L was 3.2%. Forty-three per cent of Lp(a) variability was explained respectively by: age (2%, p < .001), LDL-C (1%, p = .001), and two SNPs (39%, p value<2⋅10-16 ). Of the 28 endogenous steroid hormones assessed, androstenetriol, androsterone, 16α-OH-DHEA and estriol were nominatively associated with serum Lp(a) levels in univariable analyses and explained 0.4%-1% of Lp(a) variability, but none of them reached significance in multivariable models. CONCLUSIONS: In this contemporary population-based study, the prevalence of a Lp(a) elevation ≥700 mg/L was 3.2%. The effect of endogenous steroid hormone levels of Lp(a) variability was small at best, suggesting a negligible impact on the wide range of Lp(a) variability.

Epidemiology, thrombolytic management, and outcomes of acute stroke among patients with chronic kidney disease: a systematic review and meta-analysis.

BACKGROUND: The relative frequency of ischaemic versus haemorrhagic stroke among patients with chronic kidney disease (CKD) has not been clearly described. Moreover, no recent meta-analysis has investigated the outcomes of patients with CKD treated with thrombolysis for acute ischaemic stroke. We conducted a systematic review and meta-analysis to estimate the proportion of stroke subtypes and the outcomes of thrombolysis in CKD. METHODS: A PubMed, EMBASE and Cochrane literature research was conducted. The primary outcome was the proportion and incidence of ischaemic versus haemorrhagic strokes among patients with CKD. In addition, we assessed the impact of CKD on disability, mortality and bleeding among patients with acute ischaemic stroke treated with thrombolysis. The pooled proportion and the risk ratio were estimated using a random-effects model. RESULTS: Thirty-nine observational studies were included: 22 on the epidemiology of stroke types and 17 on the outcomes of thrombolysis in this population. In the main analysis (>99 281 patients), ischaemic stroke was more frequent than haemorrhagic among patients with CKD [78.3%, 95% confidence interval (CI) 73.3-82.5%]. However, among patients with kidney failure, the proportion of ischaemic stroke decreased and was closer to that of haemorrhagic stroke (59.8%, 95% CI 49.4-69.4%). CKD was associated with worse clinical outcomes in patients with acute ischaemic stroke compared with patients with preserved kidney function. CONCLUSIONS: The relative frequency of haemorrhagic stroke seems to increase as kidney function declines. Among patients with acute ischaemic stroke treated with thrombolysis, presence of CKD is associated with higher disability, mortality and bleeding, compared with patients with preserved kidney function.

Dietary sodium intake does not alter renal potassium handling and blood pressure in healthy young males.

BACKGROUND: The effects of sodium (Na+) intakes on renal handling of potassium (K+) are insufficiently studied. METHODS: We assessed the effect of Na+ on renal K+ handling in 16 healthy males assigned to three 7-day periods on low salt diet [LSD, 3 g sodium chloride (NaCl)/day], normal salt diet (NSD, 6 g NaCl/day) and high salt diet (HSD, 15 g NaCl/day), with constant K+ intake. Contributions of distal NaCl co-transporter and epithelial Na+ channel in the collecting system on K+ and Na+ handling were assessed at steady state by acute response to 100 mg oral hydrochlorothiazide and with addition of 10 mg of amiloride to hydrochlorothiazide, respectively. RESULTS: Diurnal blood pressure slightly increased from 119.30 ± 7.95 mmHg under LSD to 123.00 ± 7.50 mmHg (P = 0.02) under HSD, while estimated glomerular filtration rate increased from 133.20 ± 34.68 mL/min under LSD to 187.00 ± 49.10 under HSD (P = 0.005). The 24-h K+ excretion remained stable on all Na+ intakes (66.28 ± 19.12 mmol/24 h under LSD; 55.91 ± 21.17 mmol/24 h under NSD; and 66.81 ± 20.72 under HSD, P = 0.9). The hydrochlorothiazide-induced natriuresis was the highest under HSD (30.22 ± 12.53 mmol/h) and the lowest under LSD (15.38 ± 8.94 mmol/h, P = 0.02). Hydrochlorothiazide increased kaliuresis and amiloride decreased kaliuresis similarly on all three diets. CONCLUSIONS: Neither spontaneous nor diuretic-induced K+ excretion was influenced by Na+ intake in healthy male subjects. However, the respective contribution of the distal convoluted tubule and the collecting duct to renal Na+ handling was dependent on dietary Na+ intake.

Relationship between renal function and blood pressure dipping status in renal transplant recipients: a longitudinal study.

BACKGROUND: Hypertension (HT) is associated with adverse outcomes in kidney transplant (KTX) recipients. Blunting of physiological decrease in nighttime compared to daytime blood pressure (non-dipping status) is frequent in this setting. However, weather non-dipping is independently associated with renal function decline in KTX patients is unknown. METHODS: We retrospectively screened KTX outpatients attending for a routine ambulatory blood pressure monitoring (ABPM) (T1) at a single tertiary hospital. Patients had two successive follow-up visits, 1 (T2) and 2 (T3) years later respectively. Routine clinical and laboratory data were collected at each visit. Mixed linear regression models were used with estimated glomerular filtration rate (eGFR) as the dependent variable. RESULTS: A total of 123 patients were included with a mean follow-up of 2.12 ± 0.45 years after ABPM. Mean age and eGFR at T1 were 56.0 ± 15.1 and 54.9 ± 20.0 mL/min/1.73m2 respectively. 61 patients (50.4%) had sustained HT and 81 (65.8%) were non-dippers. In multivariate analysis, systolic dipping status was positively associated with eGFR (p = 0.009) and compared to non-dippers, dippers had a 10.4 mL/min/1.73m2 higher eGFR. HT was negatively associated with eGFR (p = 0.003). CONCLUSIONS: We confirm a high prevalence of non-dippers in KTX recipients. We suggest that preserved systolic dipping is associated with improved renal function in this setting independently of potential confounders, including HT and proteinuria. Whether modification of dipping status by chronotherapy would preserve renal function remains to be tested in clinical trials.

[Climate change and clinical implications]. / Changement climatique et enjeux cliniques.

Climate change and global warming present major clinical challenges. We focus on cardiovascular and renal clinical consequences. The physiological adaptations and physiopathological effects are described, especially in vulnerable populations. The clinical consequences during heat waves, are mainly cardiovascular with stroke, acute ischemic heart disease and sudden death increased by up to 40%. Likewise, episodes of acute renal failure, electrolyte disturbances and kidney stones disease increase. The chronic consequences should not be overlooked, as the risk of heart failure also increases in high ambient temperature regions and there is also some evidence of an increase in chronic kidney disease in tropical zones. Physicians must be aware of these consequences as they will be involved in their management in the future.

Les changements climatiques liés au réchauffement planétaire comportent des enjeux cliniques majeurs. Nous nous concentrerons sur les enjeux cardiovasculaires et rénaux. Les adaptations physiologiques et effets physiopathologiques sont décrits, particulièrement chez des populations vulnérables. Les conséquences cliniques des vagues de chaleur sont en grande majorité cardiovasculaires. Les accidents vasculaires cérébraux, cardiopathies ischémiques aiguës et morts subites sont augmentés jusqu'à 40 %. De même, les épisodes d'insuffisance rénale aiguë, les troubles électrolytiques et les lithiases rénales augmentent. Le risque d'insuffisance cardiaque et le nombre d'insuffisances rénales chroniques augmentent également dans les régions tropicales. Les médecins doivent être conscients de ces conséquences pour lesquelles ils seront impliqués à l'avenir.

[Clinical use of tolvaptan: a 2021 review]. / Histoire d'eau : le tolvaptan dans tous ses états.

Along with the arrival of the first vasopressin-receptor V2R inhibitor, the indications for its use have increased. We review here and focus on polycystic kidney disease (PKD) and hyponatremia. Tolvaptan is the first drug available to slow down the progression of PKD in patients with rapid progressing disease. However, the benefits are moderate and the side effects are important, making important to share the decision of treatment together with the patient. Hyponatremia with preserved extra-cellular volume or associated with edema may be reversed by tolvaptan. Patients with SIADH or hyponatremia and edema might benefit from this treatment under strict monitoring. Overall, vaptans are helpful in several conditions, but remain tools that must be used under close control.

Depuis l'arrivée des inhibiteurs des récepteurs rénaux à la vasopressine V2, les indications à leur utilisation ont explosé. Nous revoyons ici certaines d'entre elles, en particulier la polykystose rénale et l'hyponatrémie. Première molécule à ralentir la progression de la polykystose rénale, le tolvaptan est réservé à des patients très motivés, dont la maladie progresse rapidement. En effet, les bénéfices sont modérés et les effets secondaires importants. La décision de traiter doit donc être partagée avec le patient. L'hyponatrémie à volume conservé ou liée à des œdèmes peut être corrigée par le tolvaptan. Les patients avec syndrome de sécrétion inappropriée d'hormone antidiurétique ou avec œdèmes peuvent en bénéficier sous certaines conditions et sous stricte surveillance. Le tolvaptan permet d'améliorer plusieurs pathologies, mais exige une étroite surveillance.

[IgA nephropathy : update]. / Nouveautés dans la néphropathie à IgA.

IgA nephropathy is the most common primary glomerulopathy worldwide. However, it remains underdiagnosed because of its clinical heterogeneity. Its diagnosis is currently based on kidney biopsy and there are no clinically validated serological tests. Its pathogenesis is based on an anomaly in the glycosylation of type A immunoglobulins and a progression punctuated by multiple triggering events (hits). The conservative approach of using corticosteroid therapy and/or more selective immunosuppression in certain clinical situations remains the state-of-the-art treatment. New therapeutic perspectives seem promising but must be validated.

La néphropathie à immunoglobulines A est la glomérulopathie primaire la plus fréquente dans le monde. Elle reste néanmoins sous-diagnostiquée de par son hétérogénéité clinique. Son diagnostic repose actuellement sur la biopsie rénale et il n'existe pas de tests sérologiques cliniquement validés. Sa pathogenèse repose sur une anomalie de la glycosylation des immunoglobulines de type A et une progression rythmée par des événements déclencheurs multiples. L'approche conservatrice reste la pierre angulaire du traitement avec recours à la corticothérapie et/ou une immunosuppression plus sélective dans certaines situations cliniques. De nouvelles perspectives thérapeutiques semblent prometteuses, mais doivent être validées.

[SGLT2 inhibitors in diabetic and non-diabetic nephropathies]. / Inhibiteurs du SGLT2 dans les néphropathies diabétiques et non diabétiques.

SGLT2 inhibitors (SGLT2i) will change the clinical practice of nephrology with their therapeutic cardiorenal and antidiabetic properties. By inhibiting proximal tubular sodium and glucose reabsorption, these new drugs decrease intraglomerular pressures. Over the last 5 years several breakthrough studies have demonstrated the SGLT2i protective effects on outcomes such as cardiovascular mortality, hospital admission for heart failure, sustained decreases in eGFR in patients with diabetic nephropathy and the development of ESKD. With the new DAPA-CKD study revealing protective effects of SGLT2i in CKD patients without diabetes, therapeutic recommendations will now have to evolve towards including these drugs in the chronic management of all most proteinuric CKD patients.

Les inhibiteurs du cotransporteur du sodium-glucose de type 2 (iSGLT2) révolutionnent la pratique clinique en néphrologie par le biais de leurs effets antidiabétique, cardio et néphroprotecteur. Ces molécules inhibent la réabsorption du glucose et du sodium au niveau du tubule proximal, ce qui résulte en une baisse de la pression intraglomérulaire. Plusieurs grandes études ont démontré l'effet protecteur des iSGLT2 sur la mortalité cardiovasculaire, le taux d'hospitalisation pour une insuffisance cardiaque et le ralentissement de la progression de la néphropathie diabétique. La sortie de DAPA-CKD va certainement modifier les recommandations thérapeutiques pour la prise en charge de l'insuffisance rénale chronique (IRC) non diabétique, en démontrant un effet néphroprotecteur majeur chez les IRC protéinuriques d'origine non diabétique également.

[Living donor nephrectomy]. / Prélèvement de rein chez le donneur vivant.

Kidney living donor is the best treatment of terminal kidney failure. Donors are remarkably altruistic. The first concern of the medical team is not to harm the donor and respect their will to give their kidney. The technological evolution towards mini-invasive approaches has largely contributed to a better post-operative recovery. The evolution of this trend has led us to use laparoscopic robot-assisted kidney harvesting as the optimal standard. This work describes our pathway to this option.

Recevoir un rein par un donneur vivant est à ce jour le meilleur traitement de l'insuffisance rénale terminale. Les donneurs font un geste remarquablement altruiste. Le but primaire de l'équipe médicale est de pouvoir soigner un patient insuffisant rénal grâce au don d'organe sans nuire au donneur. Les avancées technologiques vers des approches mini-invasives ont contribué à l'amélioration de la prise en charge des donneurs en augmentant considérablement leur confort postopératoire et en réduisant drastiquement les durées moyennes d'hospitalisation. La procédure standard aux HUG à ce jour est la laparoscopie robot-assistée. Cet article retrace l'évolution mini-invasive du don de rein dans le service.

Dialysis initiation improves calcification propensity.

BACKGROUND: Cardiovascular morbidity and mortality is high in patients starting dialysis and could be related to modifications of calcification inducers and inhibitors by dialysis, promoting cardiovascular events. The impact of dialysis initiation on serum calcification propensity evolution and arterial stiffness is unknown. We therefore prospectively determined the evolution of the one-half maximal transition time (T50) value and its main determinants as well as pulse wave velocity over the first 3 months of dialysis initiation. METHODS: We analysed the evolution of T50, fetuin-A and mineral metabolism parameters before dialysis initiation (M0) and monthly until Month 3 (M3) in incident patients starting haemodialysis (HD) or peritoneal dialysis (PD) in two tertiary Swiss university hospitals. Arterial stiffness was assessed by pulse tonometry at M0 and M3 and biological parameters were compared between M0 and M3 and before/after HD. Linear mixed models were used to assess parameter evolution over time, taking into account repeated measures and other influencing variables. RESULTS: Forty-six patients on HD and 12 on PD were followed. Among them, 45 were male (78%) with a median age of 67 years (25th-75th quartile range 54-77). T50 significantly increased between M0 and M3 from 183 (120-266) to 246 min (175-330) (P < 0.001). Fetuin-A, calcium and magnesium also increased while phosphate decreased. Factors associated with T50 changes over time were fetuin-A, phosphate and magnesium (P < 0.001). Fetuin-A changes were associated with inflammation-related factors (albumin, C-reactive protein) but not calcium and phosphate levels. Arterial stiffness was not significantly modified over 3 months. PD and HD initiation showed similar trends. CONCLUSIONS: Dialysis initiation significantly improves calcification propensity and fetuin-A levels. These modifications do not explain the high mortality related to dialysis initiation. The clinical relevance of using T50 values to initiate dialysis awaits further studies.

Validation of the corticomedullary difference in magnetic resonance imaging-derived apparent diffusion coefficient for kidney fibrosis detection: a cross-sectional study.

BACKGROUND: Kidney cortical interstitial fibrosis (IF) is highly predictive of renal prognosis and is currently assessed by the evaluation of a biopsy. Diffusion magnetic resonance imaging (MRI) is a promising tool to evaluate kidney fibrosis via the apparent diffusion coefficient (ADC), but suffers from inter-individual variability. We recently applied a novel MRI protocol to allow calculation of the corticomedullary ADC difference (ΔADC). We here present the validation of ΔADC for fibrosis assessment in a cohort of 164 patients undergoing biopsy and compare it with estimated glomerular filtration rate (eGFR) and other plasmatic parameters for the detection of fibrosis. METHODS: This monocentric cross-sectional study included 164 patients undergoing renal biopsy at the Nephrology Department of the University Hospital of Geneva between October 2014 and May 2018. Patients underwent diffusion-weighted imaging, and T1 and T2 mappings, within 1 week after biopsy. MRI results were compared with gold standard histology for fibrosis assessment. RESULTS: Absolute cortical ADC or cortical T1 values correlated poorly to IF assessed by the biopsy, whereas ΔADC was highly correlated to IF (r=-0.52, P < 0.001) and eGFR (r = 0.37, P < 0.01), in both native and allograft patients. ΔT1 displayed a lower, but significant, correlation to IF and eGFR, whereas T2 did not correlate to IF nor to eGFR. ΔADC, ΔT1 and eGFR were independently associated with kidney fibrosis, and their combination allowed detection of extensive fibrosis with good specificity. CONCLUSION: ΔADC is better correlated to IF than absolute cortical or medullary ADC values. ΔADC, ΔT1 and eGFR are independently associated to IF and allow the identification of patients with extensive IF.

Impact of superimposed nephrological care to guidelines-directed management by primary care physicians of patients with stable chronic kidney disease: a randomized controlled trial.

BACKGROUND: Optimal clinical care of patients with chronic kidney disease (CKD) requires collaboration between primary care physicians (PCPs) and nephrologists. We undertook a randomised trial to determine the impact of superimposed nephrologist care compared to guidelines-directed management by PCPs in CKD patients after hospital discharge. METHODS: Stage 3b-4 CKD patients were enrolled during a hospitalization and randomised in two arms: Co-management by PCPs and nephrologists (interventional arm) versus management by PCPs with written instructions and consultations by nephrologists on demand (standard care). Our primary outcome was death or rehospitalisation within the 2 years post-randomisation. Secondary outcomes were: urgent renal replacement therapy (RRT), decline of renal function and decrease of quality of life at 2 years. RESULTS: From November 2009 to the end of June 2013, we randomised 242 patients. Mean follow-up was 51 + 20 months. Survival without rehospitalisation, GFR decline and elective dialysis initiation did not differ between the two arms. Quality of life was also similar in both groups. Compared to randomised patients, those who either declined to participate in the study or were previously known by nephrologists had a worse survival. CONCLUSION: These results do not demonstrate a benefit of a regular renal care compared to guided PCPs care in terms of survival or dialysis initiation in CKD patients. Increased awareness of renal disease management among PCPs may be as effective as a co-management by PCPs and nephrologists in order to improve the prognosis of moderate-to-severe CKD. TRIAL REGISTRATION: This study was registered on June 29, 2009 in clinicaltrials.gov (NCT00929760) and adheres to CONSORT 2010 guidelines.

[Ethylene glycol intoxication requires a multidisciplinary approach]. / L'intoxication à l'éthylène glycol nécessite une approche multidisciplinaire.

Cheap and easy to access, ethylene glycol is used in the synthesis of antifreezes. Intoxication has potentially irreversible morbid consequences. Ingestion of a small amount can lead to death. Due to its ubiquitous distribution and potential complications, it is of paramount importance for the practitioner to recognize its manifestations and metabolic complications in order to implement its therapy in partnership with the nephrologist and the intensivist. A successful treatment depends on rapid and multidisciplinary management, as reviewed in this article.

L'éthylène glycol (EG), bon marché et facile d'accès, est notamment utilisé dans la synthèse des antigels. Une intoxication à l'EG a des conséquences morbides potentiellement irréversibles et est associée à une mortalité non négligeable. Du fait des complications et de sa distribution en libre-service, il convient pour le praticien des urgences d'en reconnaître les manifestations, notamment métaboliques, afin d'en assumer le traitement en partenariat avec l'intensiviste et le néphrologue. Le succès dépend d'une reconnaissance rapide et d'une prise en charge multidisciplinaire dont une approche est suggérée dans cet article.

[The kidneys†: possible victims of global warming†?] / Les reins†: cibles du réchauffement climatique†?

Over the last decades, an increasing number of cases of chronic and end-stage kidney disease has been observed in Central America and Asia. This kidney disease mainly affects young farmers without classic renal risk factors. The clinical presentation includes a progressive decrease of the glomerular filtration rate, minimal proteinuria and the presence of tubulo-interstitial nephritis at renal biopsy. A close link with global warming is suspected for this disease, called (according to its location) meso-american nephropathy, Sri Lanka nephropathy or chronic kidney disease of unknown etiology. Others have suggested that intake of water contaminated with pesticides may be responsible. This article provides an overview of this new kidney disease. Measures to prevent acute kidney injury during heat waves in Switzerland are also discussed.

Au cours des dernières décennies, on observe un nombre croissant de cas d'insuffisance rénale chronique et terminale en Amérique centrale et en Asie. Celle-ci touche surtout des jeunes agriculteurs sans autre facteur de risque rénal. La symptomatologie inclut une baisse progressive de la filtration glomérulaire, et une protéinurie minime, avec à la biopsie une néphrite tubulo-interstitielle. Un lien étroit avec le réchauffement climatique a été évoqué pour cette maladie nommée selon la région néphropathie mésoaméricaine, sri lankaise ou néphropathie d'étiologie inconnue. Une autre hypothèse est la consommation d'eau contaminée par des pesticides. Dans cet article, nous ferons le point sur cette nouvelle maladie rénale. La prévention de l'insuffisance rénale aiguë pendant les périodes de forte chaleur en Suisse est également discutée.

Serum phosphate optimal timing and range associated with patients survival in haemodialysis: the COSMOS study.

BACKGROUND: Serum phosphate is a key parameter in the management of chronic kidney disease-mineral and bone disorder (CKD-MBD). The timing of phosphate measurement is not standardized in the current guidelines. Since the optimal range of these biomarkers may vary depending on the duration of the interdialytic interval, in this analysis of the Current management of secondary hyperparathyroidism: a multicentre observational study (COSMOS), we assessed the influence of a 2- (midweek) or 3-day (post-weekend) dialysis interval for blood withdrawal on serum levels of CKD-MBD biomarkers and their association with mortality risk. METHODS: The COSMOS cohort (6797 patients, CKD Stage 5D) was divided into two groups depending upon midweek or post-weekend blood collection. Univariate and multivariate Cox's models adjusted hazard ratios (HRs) by demographics and comorbidities, treatments and biochemical parameters from a patient/centre database collected at baseline and every 6 months for 3 years. RESULTS: There were no differences in serum calcium or parathyroid hormone levels between midweek and post-weekend patients. However, in post-weekend patients, the mean serum phosphate levels were higher compared with midweek patients (5.5 ± 1.4 versus 5.2 ± 1.4 mg/dL, P < 0.001). Also, the range of serum phosphate with the lowest mortality risk [HR ≤ 1.1; midweek: 3.5-4.9 mg/dL (95% confidence interval, CI: 2.9-5.2 mg/dL); post-weekend: 3.8-5.7 mg/dL (95% CI: 3.0-6.4 mg/dL)] showed significant differences in the upper limit (P = 0.021). CONCLUSION: Midweek and post-weekend serum phosphate levels and their target ranges associated with the lowest mortality risk differ. Thus, clinical guidelines should consider the timing of blood withdrawal when recommending optimal target ranges for serum phosphate and therapeutic strategies for phosphate control.