Long-term effects of citric acid-based bicarbonate haemodialysis on patient outcomes: a survival propensity score-matched study in western France.

BACKGROUND: Citric acid-based bicarbonate haemodialysis (CIT-HD) has gained more clinical acceptance over the last few years in France and is a substitute for other acidifiers [e.g. acetic acid (CH3COOH) and hydrochloric acid (HCl)]. This trend was justified by several clinical benefits compared with CH3COOH as well as the desire to avoid the consequences of the corrosive action of HCl, but a nationwide clinical report raised concerns about the long-term safety of CIT-HD. The aim of this study was to assess the long-term effects of CIT-HD exposure on patient outcomes in western France. METHODS: This is a population-based retrospective multicentre observational study performed in 1132 incident end-stage kidney disease patients in five sanitary territories in western France who started their renal replacement therapy after 1 January 2008 and followed up through 15 October 2018. Relevant data, collected prospectively with the same medical software, were anonymously aggregated for the purposes of the study. The primary goal of this study was to investigate the effects of citrate exposure on all-cause mortality. To provide a control group to CIT-HD one, propensity score matching (PSM) at 2:1 was performed in two steps: the first analysis was intended to be exploratory, comparing patients who received citrate ≤80% of the time (CIT-HD ≤80) versus those who received citrate >80% of the time (CIT-HD >80), while the second analysis was intended to be explanatory in comparing patients with 0% (CIT-HD0) versus 100% citrate time exposure (CIT-HD100). RESULTS: After PSM, in the exploratory part of the analysis, 432 CIT-HD ≤80 patients were compared with 216 CIT-HD >80 patients and no difference was found for all-cause mortality using the Kaplan-Meier model (log-rank 0.97), univariate Cox regression analysis {hazard ratio [HR] 1.01 [95% confidence interval (CI) 0.71-1.40]} and multivariate Cox regression analysis [HR 1.11 (95% CI 0.76-1.61)] when adjusted for nine variables with clinical pertinence and high statistical relevance in the univariate analysis. In the explanatory part of the analysis, 316 CIT-HD0 patients were then compared with 158 CIT-HD100 patients and no difference was found using the Kaplan-Meier model (log-rank 0.06), univariate Cox regression analysis [HR 0.69 (95% CI 0.47-1.03)] and multivariate Cox regression analysis [HR 0.87 (95% CI 0.57-1.33)] when adjusted for seven variables with clinical pertinence and high statistical relevance in the univariate analysis. CONCLUSIONS: Findings of this study support the notion that CIT-HD exposure ≤6 years has no significant effect on all-cause mortality in HD patients. This finding remains true for patients receiving high-volume online haemodiafiltration, a modality most frequently prescribed in this cohort.

All anti-vascular endothelial growth factor drugs can induce 'pre-eclampsia-like syndrome': a RARe study.

BACKGROUND: Specific therapies that target vascular endothelial growth factor (VEGF) and its receptors have improved the survival of patients with metastatic cancers, but can induce side effects. Renal side effects (proteinuria, hypertension and renal failure) are underestimated. METHODS: The French RARe (Reins sous traitement Anti-VEGF Registre) study collects data on patients with cancer who had a renal biopsy because of major renal side effects during treatment with anti-VEGF drugs. RESULTS: We collected 22 renal biopsies performed 16.2±10.6 months after the beginning of treatment; of which 21 had hypertension, mean proteinuria was 2.97±2.00 g/day and mean serum creatinine, 134±117 µmol/L. Thrombotic microangiopathy (TMA) was observed in 21 biopsy specimens, sometimes associated with acute tubular necrosis (ATN; n=4). TMA histological lesions were more important than the biological signs of TMA could suggest. Patients with ATN of >20% had higher serum creatinine levels than those with only TMA (231 versus 95 µmol/L). Nephrin, podocin and synaptopodin were variably down-regulated in all renal biopsies. VEGF was down-regulated in all glomeruli. CONCLUSION: This study underlines the importance of regular clinical and biological cardiovascular and renal checking during all anti-VEGF therapies for cancer for early detection of renal dysfunction. Collaboration between oncologists and nephrologists is essential. In such cases, renal biopsy might help in appreciating the severity of the renal lesions and after multidisciplinary discussion whether or not it is safe to continue the treatment.

Sodium Bicarbonate Prescription and Extracellular Volume Increase: Real-world Data Results from the AlcalUN Study.

Oral alkalization with sodium bicarbonate (NaHCO3 ) or citrate is prescribed for conditions ranging from metabolic acidosis to nephrolithiasis. Although most nephrologists/urologists use this method routinely, extracellular volume (ECV) increase is the main feared adverse event reported for NaHCO3 . Thus far, no trial has specifically studied this issue in a real-world setting. AlcalUN (NCT03035812) is a multicentric, prospective, open-label cohort study with nationwide (France) enrollment in 18 (public and private) nephrology/urology units. Participants were adult outpatients requiring chronic (>1 month) oral alkalization by either NaHCO3 -containing or no-NaHCO3 -containing agents. The ECV increase (primary outcome) was judged based on body weight increase (ΔBW), blood pressure increase (ΔBP), and/or new-onset edema at the first follow-up visit (V1). From February 2017 to February 2020, 156 patients were enrolled. After a median 106 days of treatment, 91 (72%) patients reached the primary outcome. They had lower systolic (135 (125, 141) vs. 141 (130, 150), P = 0.02) and diastolic (77 (67, 85) vs. 85 (73, 90), P = 0.03) BP values, a higher plasma chloride (106.0 (105.0, 109.0) vs. 105.0 (102.0, 107.0), P = 0.02) at baseline, and a less frequent history of nephrolithiasis (32 vs. 56%, P = 0.02). Patients experienced mainly slight ΔBP (< 10 mmHg). The primary outcome was not associated (P = 0.79) with the study treatment (129 received NaHCO3 and 27 received citrate). We subsequently developed three different models of propensity score matching; each confirmed our results. Chronic oral alkalization with NaHCO3 is no longer associated with an ECV increase compared to citrate in real-life settings.

[Prolonged hemodialysis: Rationale, practical organization, results]. / Hémodialyse longue : rationnel, organisation pratique, résultats.

In France, long nocturnal dialyses, eight hours three-times a week, are sparsely proposed. However, numerous studies reported that this specific type of dialysis is associated to better blood pressure control, better cardiac remodeling, better mineral and nutritional balance as well as better life quality and survival rate. MATERIAL AND METHODS: In this study, we aimed at quantifying the benefits, risks and obstacles of developing night dialysis and at describing the results of a program that took place in Rennes from 2002 to 2019. Data were collected between 2008 and 2014 for eighteen case-patients and were compared to thirty-six controls that underwent conventional dialysis. Patients were paired according sex, age and year of dialysis start. RESULTS: The median age for dialysis start was 47.5 years [27-60] with a male prevalence (5/1). After six months, a significant difference was reported for postdialytic, systolic and diastolic pressure (respectively 126±15 vs 139±21 [P=0.04] and 72±9 vs 81±14 [P=0.02]) despite an antihypertensive reduction ranging from 2.4±1.4 to 1.3±0.9 per day at six months and 0.7±0.9 at one year (P=0.02). An increase of nPCR was evidenced at 6 and 9 months (P=0.02). At the end of the study, the phosphate level was maintained for both cohorts at the expense of an increased consumption of phosphate binder for the long nocturnal dialysis group (P=0.025). As a whole, 61% of the patients that pursued long night dialysis maintained a professional activity compared to only 30% for the controls (P=0.04). This highlights the advantages of night dialysis for maintaining employment but also the bias that represents the employment status in observational study on this specific topic.

[Psychological impact of lockdown and the COVID-19 epidemic on haemodialysis patients and carers in France]. / Répercussions psychologiques du confinement et de l'épidémie à COVID-19 chez les patients et soignants en hémodialyse en France.

INTRODUCTION: The health crisis linked to the COVID-19 epidemic has required lockdown measures in France and changes in practices in dialysis centers. The objective was to assess the depressive and anxiety symptoms during lockdown in hemodialysis patients and their caregivers. METHODS: We sent, during lockdown period, between April and May 2020, self-questionnaires to voluntary subjects (patients and caregivers), treated by hemodialysis or who worked in hemodialysis in one of the 14 participating centers in France. We analyzed their perception of dialysis sessions (beneficial or worrying), their stress level (VAS rated from 0 to 10), their anxiety and depressive symptoms (Hospital anxiety and depression scale). Factors associated with stress, anxiety and depression were analyzed with multiple linear regression models. RESULTS: 669 patients and 325 caregivers agreed to participate. 70 % of participants found it beneficial to come to dialysis during confinement. The proportions of subjects with a stress level ≥ 6 linked to the epidemic, confinement, fear of contracting COVID-19 and fear of infecting a loved one were respectively 23.9%, 26.2%, 33.4% and 42%. 39.2% presented with certain (13.7%) or doubtful (19.2%) anxious symptoms. 21.2% presented a certain (7.9%) or doubtful (13.3%) depressive symptomatology. Age, gender, history of psychological disorders and perception of dialysis sessions were associated with levels of stress, anxiety and depression. CONCLUSION: During the lockdown period, in France, the majority of hemodialysis patients and caregivers found it beneficial to come to dialysis. One in three subjects had anxiety symptoms and one in five subjects had depressive symptoms.

[Bicarbonate: From physiology to treatment for all clinicians]. / Bicarbonate : de la physiologie aux applications thérapeutiques pour tout clinicien.

Acid-base regulation is essential to maintain homeostasis in humans. Carbonic acid/bicarbonate (H2CO3/HCO3-) couple is the most predominant extracellular buffer to keep plasma pH within a physiological range. The ability to (re)generate such a buffer is a key milestone that necessitates to understand a precise physiology of both renal tubule and digestive tract. Here, we first reviewed renal and digestive cycles of bicarbonate in physiology. We also reviewed pathological findings where acid-base disequilibrium is involved and nutritional and/or alkali therapy could be necessary. Secondly, data from clinical trials were synthesized. Alkali therapy, oral and parenteral, from mineral-based water, masterful preparations or pharmaceutics drugs, is regularly used in a wide range of clinical findings, even if supporting data are (often) of a low level of evidence. Bicarbonate is primarily used during contrast-induced nephropathy, metabolic acidosis in chronic kidney disease or nephrolithiasis in which alkaline urine is necessary. Cast nephropathy, rhabdomyolysis and tumor lysis syndrome make usually physicians prescribe alkali therapy even if this prescription is only supported by physiopathological data without any proven clinical results. Finally, bicarbonate is essential in the composition of dialysate in both hemodialysis and peritoneal dialysis.

Drug-Induced Acute Interstitial Nephritis with Nifedipine.

Background. Acute interstitial nephritis (AIN) is a frequent cause of Acute Kidney Injury (AKI). Drug hypersensitivity is the most common etiology and the list of drugs that can induce AIN is not exhaustive yet. Case Report. Here, we describe the case of a 43-year-old man who was treated with nifedipine (Adalate®) for Raynaud's syndrome. After nifedipine introduction, serum creatininemia progressively increased from 91 to 188 µmol/L in a few months and AKI was diagnosed. Laboratory work-up results indicated the presence of tubular proteinuria and nonspecific inflammatory syndrome. Histological analysis found granulomatous interstitial nephropathy without necrosis in 20% of the kidney biopsy without immunofluorescent deposit. Nifedipine was stopped and corticosteroid treatment was started with a rapid but incomplete reduction of serum creatininemia level to 106 µmol/L. Conclusion. This is the first case of AIN caused by nifedipine.

Is Anticoagulation Discontinuation Achievable with Citrate Dialysate during HDF Sessions?

Citrate dialysate has been developed for few years to replace acetate and HCl concentrates. In Online Postdilution Hemodiafiltration (OL-POST-HDF), several issues are remaining concerning the possibility of stopping anticoagulation during sessions and the side effects of citrate solutions on calcium metabolism. This 1-year monocentric retrospective study included all patients exposed to citrate in OL-POST-HDF with nadroparin decrease for more than one month. Clotting events, serum calcium, PTH, hemoglobin, CRP, depuration parameters, and treatments administrated were recorded for analysis. 27 patients experienced nadroparin decrease and 5 did not receive nadroparin at the end of the study. Nadroparin decrease and withdrawal were both associated with more clotting events whereas the use of vitamin K antagonists was protective. No significant metabolic side effects were observed. Citrate dialysate does not allow anticoagulation discontinuation or decrease but has no significant side effects on mineral bone metabolism or erythropoiesis.

Sunitinib combined with angiotensin-2 type-1 receptor antagonists induces more necrosis: a murine xenograft model of renal cell carcinoma.

BACKGROUND: Angiotensin-2 type-1 receptor antagonists not are only antihypertensive drugs but also can inhibit VEGF production. We hypothesised that adding telmisartan to sunitinib could potentiate the antiangiogenic effects. MATERIAL AND METHODS: 786-O cell lines were injected in nude mice. After tumor development, mice were divided into 4 groups: the first was the control group (DMSO), the second group was treated with sunitinib alone, the third group was treated with telmisartan alone, and the fourth group was treated with the combination. Drugs were orally administered every day for four weeks. Animals were sacrificed after treatment. Blood and tumor tissues were collected for analysis by immunohistochemistry, Western Blot, and ELISA methods. RESULTS: All animals developed a ccRCC and ten in each group were treated. Using a kinetic model, tumors tended to grow slower in the combination group compared to others (P = 0.06). Compared to sunitinib alone, the addition of telmisartan significantly increased tissue necrosis (P = 0.038). Central microvascular density decreased (P = 0.0038) as well as circulating VEGF (P = 0.003). There was no significant variation in proliferation or apoptosis markers. CONCLUSION: The combination of sunitinib and telmisartan revealed an enhancement of the blockage of the VEGF pathway on renal tumor resulting in a decrease in neoangiogenesis and an increase in necrosis.

[Prospective study of drug-induced interstitial nephritis in eleven French nephrology units]. / Médicaments à l'origine d'insuffisances rénales aiguës allergiques en France en 2013.

OBJECTIVE: Certain medications have been associated with drug-induced acute interstitial nephritis (AIN), but few prospective studies have been published. This prospective observational study aims to record and assess incidents of drug-induced AIN observed over a period of one year in nephrology units in France. The goal is to determine which medications are involved in AIN and to expound the clinical and biological presentation, management, and evolution of AIN. METHODS: Between April 2012 and April 2013, drug-associated cases of AIN were prospectively recorded in 24 patients registered in 11 nephrology units that belong to the Société de Néphrologie de l'Ouest (SNO). Data sheets, including suspected and concomitant drug(s), kidney function assessment, biological disturbances, clinical signs, histological data, management, and evolution, were collected by the Rennes Regional Pharmacovigilance Center and recorded in the French pharmacovigilance database. RESULTS: In order, the most frequently involved medications in the AIN cases were: vitamin K antagonists (33.3% of the cases, almost exclusively fluindione), antibiotics (20.8% of cases) non-steroidal anti-inflammatory drugs (20.8% of cases), and proton pump inhibitors (16.7% of cases). The mean delay of onset to AIN was 8.3 weeks. At the time of diagnosis, mean serum creatinine was 366 µM, higher for vitamin K antagonists (VKAs), except in the case of warfarin. During the course of an AIN event, 70% of patients had complete blood count and/or urine analysis abnormalities, 55% had clinical signs of systemic hypersensitivity, and 13% of patients had hepatic disorders. Renal biopsies were performed in 54% of patients; however, only 37% of patients requiring therapeutic anticoagulation underwent a biopsy. Suspected drugs were discontinued in all patients and the majority was treated with oral corticosteroids. Renal function often continued to be impaired after an AIN event. At baseline, 25% of patients had chronic kidney disease (CKD); after an AIN event, 67% of patients were noted to have CKD. CONCLUSION: Physicians need to be aware of the possibility of drug-induced acute interstitial nephritis as a common cause of acute kidney injury (AKI). This study supports increased vigilance when prescribing three therapeutic classes frequently associated with AIN: antibiotics, NSAIDs and PPIs (especially in instances of polypharmacy), which were associated with two thirds of the AIN cases in this study. Fluindione, an oral anticoagulant exclusively marketed in Luxembourg and France where it constitutes the vast majority of VKA prescriptions, was associated with one third of the AIN cases alone, making it a common possible culprit of drug-induced AIN, warranting particular attention.

[Angiotensin-2 type 1 receptors (AT1R) and cancers]. / Récepteurs de type 1 à l'angiotensine-2 (AT1R) et cancers.

Recently, several meta-analysis suggested an increased risk of cancers linked to the use of antagonists of angiotensin-2 receptors or inhibitors of angiotensinogen converting enzyme. The results of epidemiological studies are conflicting. Meta-analysis as well as retrospective studies are not reliable and biased, since they have never been designed to explore any pro- or antitumoral effect. We lack of prospective studies that could take off the doubt on these drugs. Nevertheless, all experimental researches pointed out potent antitumoral properties. Indeed, direct antiproliferative and neo-angiogenic inhibition have been described on tumor cell cultures as well as on animal models. Moreover, we are convinced that the use of antagonists of angiotensin-2 receptors and inhibitors of angiotensinogen converting enzyme may be then of clinical use in the near future in association with classical antitumor drugs. In this review, we proposed to explore these data by a thorough analysis of recent literature associating epidemiological and experimental studies.