Effectiveness and safety of direct oral anticoagulants versus vitamin K antagonists in patients on chronic dialysis: a nationwide registry study.

BACKGROUND AND HYPOTHESIS: Clinical trials of direct oral anticoagulants (DOAC) are scarce and inconclusive in patients who are receiving dialysis, for whom DOAC are not labelled in Europe. In a French nationwide registry study of patients on chronic dialysis, we compared the effectiveness and safety of off-label DOAC use vs. approved vitamin K antagonist (VKA). METHODS: Data on patients on dialysis were extracted from the French Renal Epidemiology and Information Network (REIN) registry and merged with data from the French national healthcare system database (Système National des Données de Santé, SNDS). Patients on dialysis who had initiated treatment with an oral anticoagulant between January 1st, 2012, and December 31st, 2020, were eligible for inclusion. The primary safety outcome was the occurrence of major bleeding events and the primary effectiveness outcome was the occurrence of thrombotic events. Using propensity-score-weighted cause-specific Cox regression, we compared the safety and effectiveness outcomes for DOAC and VKA. RESULTS: 8,954 patients received an oral anticoagulant (483 DOAC and 8,471 VKA) for the first time after the initiation of dialysis. Over a median [interquartile range] follow-up period of 1.7 [0.8-3.2] years, 2,567 patients presented a first thromboembolic event and 1,254 patients had a bleeding event. After propensity score adjustment, the risk of a thromboembolic event was significantly lower in patients treated with a DOAC than in patients treated with a VKA (weighted hazard ratio (wHR) [95% confidence interval (CI)]: 0.66 [0.46; 0.94]. A non-significant trend toward a lower risk of major bleeding events was found in DOAC-treated patients, relative to VKA-treated patients (wHR [95%CI]: 0.68 [0.41; 1.12]). The results were consistent across subgroups and in sensitivity analyses. CONCLUSIONS: In a large group of dialysis patients initiating an oral anticoagulant, the off-label use of DOACs was associated with a significantly lower risk of thromboembolic events and a non-significantly lower risk of bleeding, relative to VKA use. This provides reassurance regarding the off-label use of DOACs in people on dialysis.

Impact of Preformed Donor-Specific Anti-HLA-Cw and Anti-HLA-DP Antibodies on Acute Antibody-Mediated Rejection in Kidney Transplantation.

Given the risk of rejection, the presence of preformed donor specific antibodies (DSA) contraindicates transplantation in most allocation systems. However, HLA-Cw and -DP DSA escape this censorship. We performed a multicentric observational study, in which the objective was to determinate risk factors of acute antibody-mediated rejection (aABMR) in recipients transplanted with preformed isolated Cw- or DP-DSA. Between 2010 and 2019, 183 patients were transplanted with a preformed isolated Cw- or DP-DSA (92 Cw-DSA; 91 DP-DSA). At 2 years, the incidence of aABMR was 12% in the Cw-DSA group, versus 28% in the DP-DSA group. Using multivariable Cox regression model, the presence of a preformed DP-DSA was associated with an increased risk of aABMR (HR = 2.32 [1.21-4.45 (p = 0.001)]) compared with Cw-DSA. We also observed a significant association between the DSA's MFI on the day of transplant and the risk of aABMR (HR = 1.09 [1.08-1.18], p = 0.032), whatever the DSA was. Interaction term analysis found an increased risk of aABMR in the DP-DSA group compared with Cw-DSA, but only for MFI below 3,000. These results may plead for taking these antibodies into account in the allocation algorithms, in the same way as other DSA.

Haemoglobin trajectories in chronic kidney disease and risk of major adverse cardiovascular events.

BACKGROUND: Trajectories of haemoglobin in patients with chronic kidney disease (CKD) have been poorly described. In such patients, we aimed to identify typical haemoglobin trajectory profiles and estimate their risks of major adverse cardiovascular events (MACE). METHODS: We used 5-year longitudinal data from the CKD-REIN cohort patients with moderate to severe CKD enrolled from 40 nationally representative nephrology clinics in France. A joint latent class model was used to estimate, in different classes of haemoglobin trajectory, the competing risks of (i) MACE + defined as the first event among cardiovascular death, non-fatal myocardial infarction, stroke or hospitalization for acute heart failure, (ii) initiation of kidney replacement therapy (KRT), and (iii) non-cardiovascular death. RESULTS: During the follow-up, we gathered 33 874 haemoglobin measurements from 3 011 subjects (median, 10 per patient). We identified five distinct haemoglobin trajectory profiles. The predominant profile (n = 1885, 62.6%) showed an overall stable trajectory and low risks of events. The four other profiles had nonlinear declining trajectories: early strong decline (n = 257, 8.5%), late strong decline (n = 75, 2.5%), early moderate decline (n = 356, 11.8%) and late moderate decline (n = 438, 14.6%). The four profiles had different risks of MACE, while the risks of KRT and non-cardiovascular death consistently increased from the haemoglobin decline. CONCLUSION: In this study, we observed that two third of patients had stable haemoglobin trajectory and low risks of adverse events. The other third had a nonlinear trajectory declining at different rates, with increased risks of events. A better attention to dynamic changes of haemoglobin in CKD should be paid.

Statin therapy and the incidence of atherosclerotic cardiovascular events after kidney transplantation.

BACKGROUND: Statins are recommended in kidney transplant recipients (KTRs) - a population with a high risk of major cardiovascular (CV) events. However, the literature data on the effectiveness of statins in KTRs are sparse and inconclusive. The present study's objective was to evaluate the association between statin exposure and atherosclerotic CV events in KTRs and the biochemical effectiveness of statins on the lipid profile. METHODS: 318 consecutive KTRs managed at a single center between 2006 and 2019 were retrospectively included. Those exposed to statins after transplantation were incident users. In all users, statins were indicated for primary CV prevention. Lipid profiles, the occurrence of any atherosclerotic CV events (stroke, myocardial infarction, other atherosclerotic CV events, and atherosclerotic CV deaths) were documented comprehensively. We applied Cox models that included statin exposure as a time-dependent covariate fitted with time-varying inverse probability treatment weighting (IPTW) to assess the effectiveness of statins on atherosclerotic CV events and on all CV events. We built linear mixed models to assess the biochemical effectiveness of statins. RESULTS: During a median [interquartile range] follow-up period of 6.0 [3.9-10.0] years, 27 atherosclerotic CV events occurred in 26 patients. In the Cox models fitted with time-varying IPTW, exposure to statins was not associated with a decrease in atherosclerotic CV events; the hazard ratio (HR) [95% confidence interval (CI)] was 1.16 [0.53-2.53] (p=0.700). In the linear mixed models, statin exposure was associated with significant decrease over time in triglyceride and low-density lipoprotein cholesterol concentrations (p < 0.001). These results were consistent when stratified for the intensity of statin therapy. CONCLUSION: Even though the lipid profile improved, statin exposure was not associated with a decrease in CV events in this real-life, single-center, retrospective, long-term follow-up study of a KTR cohort. Larger, controlled studies are needed to confirm or refute these results.

Tacrolimus Exposure Before and After a Switch From Twice-Daily Immediate-Release to Once-Daily Prolonged Release Tacrolimus: The ENVARSWITCH Study.

LCP-tacrolimus displays enhanced oral bioavailability compared to immediate-release (IR-) tacrolimus. The ENVARSWITCH study aimed to compare tacrolimus AUC0-24 h in stable kidney (KTR) and liver transplant recipients (LTR) on IR-tacrolimus converted to LCP-tacrolimus, in order to re-evaluate the 1:0.7 dose ratio recommended in the context of a switch and the efficiency of the subsequent dose adjustment. Tacrolimus AUC0-24 h was obtained by Bayesian estimation based on three concentrations measured in dried blood spots before (V2), after the switch (V3), and after LCP-tacrolimus dose adjustment intended to reach the pre-switch AUC0-24 h (V4). AUC0-24 h estimates and distributions were compared using the bioequivalence rule for narrow therapeutic range drugs (Westlake 90% CI within 0.90-1.11). Fifty-three KTR and 48 LTR completed the study with no major deviation. AUC0-24 h bioequivalence was met in the entire population and in KTR between V2 and V4 and between V2 and V3. In LTR, the Westlake 90% CI was close to the acceptance limits between V2 and V4 (90% CI = [0.96-1.14]) and between V2 and V3 (90% CI = [0.96-1.15]). The 1:0.7 dose ratio is convenient for KTR but may be adjusted individually for LTR. The combination of DBS and Bayesian estimation for tacrolimus dose adjustment may help with reaching appropriate exposure to tacrolimus rapidly after a switch.

Factors That Predict a Sustained Humoral Response to COVID-19 Vaccines in Kidney Transplant Recipients.

INTRODUCTION: Kidney transplant recipients (KTRs) produce a weak humoral response to coronavirus disease 2019 (COVID-19) vaccines. However, the factors associated with the quality of the serological response to three doses of COVID-19 vaccine have not been unambiguously identified. METHODS: We included KTRs followed in the Nephrology Department at Amiens University Hospital (Amiens, France) between June and December 2021 who had received three doses of a COVID-19 mRNA vaccine (or two doses plus an episode of polymerase chain reaction-confirmed COVID-19). The lack of a humoral response was defined as an antibody titer below 7.1 binding antibody units (BAU)/mL, and an optimal response was defined as an antibody titer above 264 BAU/mL. RESULTS: Of the 371 patients included, 246 (66.3%) were seropositive, and 97 (26.1%) had an optimal response. In a multivariate analysis, the only factor associated with seropositivity was a history of COVID-19 [odds ratio (OR) 87.2; 95% confidence interval (CI) (7.88-965.0); p < 0.0001], while the main factors associated with non-response were female sex [OR 0.28; 95%CI (0.15-0.51); p < 0.0001], less than 36 months between kidney transplantation and vaccination [OR 0.26; 95%CI (0.13-0.52); p < 0.0001], a higher creatinine level [OR 0.33; 95%CI (0.19-0.56); p < 0.0001], the use of tacrolimus [OR 0.23; 95%CI (0.12-0.45); p < 0.0001], the use of belatacept [OR 0.01; 95%CI (0.001-0.20); p = 0.002] and three-drug immunosuppression [OR 0.39; 95%CI (0.19-0.78); p = 0.015]. A history of COVID-19 was associated with an optimal response [OR 4.03; 95%CI (2.09-7.79); p < 0.0001], while an older age at vaccination [OR 0.97; 95%CI (0.95-0.99); p = 0.002], less than 36 months between kidney transplantation and vaccination [OR 0.35; 95%CI (0.18-0.69); p = 0.002], a higher creatinine level [OR 0.60; 95%CI (0.38-0.93); p = 0.02], three-drug immunosuppression [OR 0.45; 95%CI (0.27-0.76); p = 0.003] were associated with a poorer response. CONCLUSION: We identified factors associated with a humoral response to a COVID-19 mRNA vaccine in KTRs. These findings might help physicians to optimize vaccination in KTRs.

Prognostic value of complement serum C3 level and glomerular C3 deposits in anti-glomerular basement membrane disease.

Background and objectives: Activation of the complement system is involved in the pathogenesis of anti-glomerular basement membrane (anti-GBM) disease. Glomerular deposits of complement 3 (C3) are often detected on kidney biopsies. The primary objective of this study was to analyze the prognostic value of the serum C3 level and the presence of C3 glomerular deposits in patients with anti-GBM disease. Methods: We conducted a retrospective cohort study of 150 single-positive patients with anti-GBM disease diagnosed between 1997 and 2017. Patients were categorized according to the serum C3 level (forming a low C3 (C3<1.23 g/L) and a high C3 (C3≥1.23 g/L) groups) and positivity for C3 glomerular staining (forming the C3+ and C3- groups). The main outcomes were kidney survival and patient survival. Results: Of the 150 patients included, 89 (65%) were men. The median [interquartile range (IQR)] age was 45 [26-64]. At diagnosis, kidney involvement was characterized by a median [IQR] peak serum creatinine (SCr) level of 578 [298-977] µmol/L, and 106 (71%) patients required dialysis. Patients in the low C3 group (72 patients) had more severe kidney disease at presentation, as characterized by higher prevalences of oligoanuria, peak SCr ≥500 µmol/L (69%, vs. 53% in the high C3 group; p=0.03), nephrotic syndrome (42%, vs. 24%, respectively; p=0.02) and fibrous forms on the kidney biopsy (21%, vs. 8%, respectively; p=0.04). Similarly, we observed a negative association between the presence of C3 glomerular deposits (in 52 (41%) patients) and the prevalence of cellular forms (83%, vs. 58% in the C3- group; p=0.003) and acute tubulo-interstitial lesions (60%, vs. 36% in the C3- group; p=0.007). When considering patients not on dialysis at diagnosis, the kidney survival rate at 12 months was poorer in the C3+ group (50% [25-76], vs. 91% [78-100] in the C3- group; p=0.01), with a hazard ratio [95% confidence interval] of 5.71 [1.13-28.85] (p=0.04, after adjusting for SCr). Conclusion: In patients with anti-GBM disease, a low serum C3 level and the presence of C3 glomerular deposits were associated with more severe disease and histological kidney involvement at diagnosis. In patients not on dialysis at diagnosis, the presence of C3 deposits was associated with worse kidney survival.

Quantitative determination of plasma free and total concentrations of antivitamin K drugs using a new sensitive and rapid LC-MS/MS method: Application in hemodialysis patients.

BACKGROUND AND AIMS: Vitamin K antagonists (VKAs) are the first-line anticoagulants used in end stage renal disease. This population experiences a significant variability in their International Normalized Ratio (INR) over time. There is a need for methods allowing the study of the pharmacokinetics of free and total concentrations of VKAs to explain INR variability. MATERIALS AND METHODS: We developed and validated a high-performance liquid chromatography-tandem mass spectrometry method allowing the quantification of warfarin and fluindione free and total plasma concentrations. Chromatographic separation was achieved in a raptor biphenyl column and the spectrometry acquisition was set in multiple reaction monitoring mode after negative electrospray ionization. We then applied it in describing the plasma free and total concentrations of VKAs in samples from 50 hemodialysis patients. RESULTS: The developed method is rapid, sensitive and specific. Our cohort results showed a correlation between free and total VKA concentrations. The free VKA concentrations tended to be higher in patients with higher INR. Although VKAs are highly albumin-bound drugs, albumin concentration did not totally explain the high inter-individual total VKA concentrations variability. CONCLUSION: This opens the door to further studies to understand the factors involved in their variability.

Chronic kidney disease is a key risk factor for aortic stenosis progression.

BACKGROUND: Rapid progression of aortic stenosis (AS) has been observed in patients undergoing dialysis, but existing cross-sectional evidence is contradictory in non-dialysis-dependent chronic kidney disease (CKD). The present study sought to evaluate whether CKD is associated with the progression of AS over time in a large cohort of patients with AS. METHODS: We retrospectively studied all consecutive patients diagnosed with AS [peak aortic jet velocity (Vmax) ≥2.5 m/s] and left ventricular ejection fraction ≥50% in the echocardiography laboratories of two tertiary centers between 2000 and 2018. The estimated glomerular filtration rate (eGFR) (mL/min/1.73 m2) was calculated from serum creatinine values. Patients were divided into five CKD stages according to the baseline eGFR. Annual rates of change in the aortic valve area (AVA) were determined by a linear mixed-effects model. RESULTS: Among the 647 patients included, 261 (40%) had CKD. After a median follow-up of 2.9 (interquartile range 1.8-4.8) years, the mean overall rate of change in AVA was -0.077 (95% confidence interval -0.082; -0.073) cm2/year. There was an inverse relationship between the progression rate and kidney function. The more severe the CKD stage, the greater the AVA narrowing (P < .001). By multivariable linear regression analysis, the eGFR was also negatively associated (P < .001) with AS progression. An eGFR strata below 45 mL/min/1.73 m2 was associated with higher odds of rapid progression of AS than normal kidney function. During the clinical follow-up, event-free survival (patients free of aortic valve replacement or death) decreased as CKD progressed. Rapid progression of AS in patients with kidney dysfunction was associated with worse outcomes. CONCLUSIONS: Patients with CKD exhibit more rapid progression of AS over time and require close monitoring. The link between kidney dysfunction and rapid progression of AS is still unknown and requires further research.

Indoxyl-sulfate activation of the AhR- NF-κB pathway promotes interleukin-6 secretion and the subsequent osteogenic differentiation of human valvular interstitial cells from the aortic valve.

BACKGROUND: Calcific aortic stenosis (CAS) is more prevalent, occurs earlier, progresses faster and has worse outcomes in patients with chronic kidney disease (CKD). The uremic toxin indoxyl sulfate (IS) is powerful predictor of cardiovascular mortality in these patients and a strong promoter of ectopic calcification whose role in CAS remains poorly studied. The objective of this study was to evaluate whether IS influences the mineralization of primary human valvular interstitial cells (hVICs) from the aortic valve. METHODS: Primary hVICs were exposed to increasing concentrations of IS in osteogenic medium (OM). The hVICs' osteogenic transition was monitored by qRT-PCRs for BMP2 and RUNX2 mRNA. Cell mineralization was assayed using the o-cresolphthalein complexone method. Inflammation was assessed by monitoring NF-κB activation using Western blots as well as IL-1ß, IL-6 and TNF-α secretion by ELISAs. Small interfering RNA (siRNA) approaches enabled us to determine which signaling pathways were involved. RESULTS: Indoxyl-sulfate increased OM-induced hVICs osteogenic transition and calcification in a concentration-dependent manner. This effect was blocked by silencing the receptor for IS (the aryl hydrocarbon receptor, AhR). Exposure to IS promoted p65 phosphorylation, the blockade of which inhibited IS-induced mineralization. Exposure to IS promoted IL-6 secretion by hVICs, a phenomenon blocked by silencing AhR or p65. Incubation with an anti-IL-6 antibody neutralized IS's pro-calcific effects. CONCLUSION: IS promotes hVIC mineralization through AhR-dependent activation of the NF-κB pathway and the subsequent release of IL-6. Further research should seek to determine whether targeting inflammatory pathways can reduce the onset and progression of CKD-related CAS.

Management of anaemia in French dialysis patients: results from a large epidemiological retrospective study.

Background: Limited real-world data are available in Europe, especially France, regarding the therapeutic management of anaemia in patients with dialysis-dependent chronic kidney disease (DD CKD). Methods: This retrospective, longitudinal, observational study was based on medical records from the MEDIAL database of not-for-profit dialysis units in France. From January to December 2016, we included eligible patients (≥18 years), with a diagnosis of CKD and receiving maintenance dialysis. Patients with anaemia were followed up for 2 years after inclusion. Patient demographic data, anaemia status, CKD-related anaemia treatments, and treatment outcomes including laboratory test results were evaluated. Results: Of 1632 DD CKD patients identified from the MEDIAL database, 1286 had anaemia; 98.2% of patients with anaemia were receiving haemodialysis at index date (ID). Of patients with anaemia, 29.9% had haemoglobin (Hb) levels of 10-11 g/dL and 36.2% had levels of 11-12 g/dL at ID. Furthermore, 21.3% had functional iron deficiency and 11.7% had absolute iron deficiency. The most commonly prescribed treatments at ID for patients with DD CKD-related anaemia were intravenous (IV) iron with erythropoietin-stimulating agents (ESAs) (65.1%). Among patients initiating ESA treatment at ID or during follow-up, 347 (95.3%) reached the Hb target of 10-13 g/dL and maintained response within the target Hb range for a median duration of 113 days. Conclusions: Despite combined use of ESAs and IV iron, duration within the Hb target range was short, suggesting that anaemia management can be further improved.

Drugs associated with incident fragility fractures in kidney transplant recipients.

Background: The risk of fragility fractures is high in kidney transplant recipients, and steroids are reportedly a major cause. Other drugs known to induce fragility fractures have been studied in the general population but not in kidney transplant recipients. Here, we investigated the association between exposure over time to drugs that can injure bone (namely vitamin K antagonists, insulin, loop diuretics, proton pump inhibitors, opioids, selective serotonin reuptake inhibitors, antiepileptics and benzodiazepines) and incident fractures and changes over time in T-scores in this population. Methods: A total of 613 consecutive kidney transplant recipients were included between 2006 and 2019. Drug exposures and incident fractures during the study period were comprehensively documented, and dual-energy X-ray absorptiometry was performed regularly. The data were analyzed using Cox proportional hazards models with time-dependent covariates and linear mixed models. Results: Incident fractures occurred in 63 patients, giving a fracture incidence of 16.9 per 1000 person-years. Exposures to loop diuretics [hazard ratio (95% confidence interval) 2.11 (1.17-3.79)] and opioids [5.94 (2.14-16.52)] were associated with incident fractures. Exposure to loop diuretics was associated with a decrease over time in the T-score for the lumbar spine (P = .022) and for the wrist (P = .028). Conclusions: This study suggests that the exposure to loop diuretics and opioids increases the risk of fracture in kidney transplant recipients.

Safety of Roxadustat Versus Erythropoiesis-Stimulating Agents in Patients with Anemia of Non-dialysis-Dependent or Incident-to-Dialysis Chronic Kidney Disease: Pooled Analysis of Four Phase 3 Studies.

INTRODUCTION: This study was conducted to elucidate the safety of roxadustat, an oral medication, in patients with non-dialysis-dependent (NDD) or incident dialysis dialysis-dependent (ID-DD) chronic kidney disease (CKD). METHODS: Safety results from four phase 3, randomized, open-label studies comparing roxadustat to an erythropoiesis-stimulating agent (ESA) in men and women with NDD or ID-DD CKD with anemia were pooled and evaluated. Endpoints were time to major adverse cardiovascular event (MACE; myocardial infarction, stroke, and all-cause mortality) and MACE+ (MACE plus congestive heart failure or unstable angina requiring hospitalization), all-cause mortality, and treatment-emergent adverse events (TEAEs). MACE and MACE+ were evaluated for non-inferiority at 1.8- and 1.3-margins using hazard ratios (HRs) and 95% confidence intervals (CIs). TEAEs were descriptively summarized. RESULTS: In total, 2142 patients were evaluated (1083 roxadustat; 1059 ESA). Roxadustat was comparable to ESA for risk of MACE (HR 0.79, 95% CI 0.61-1.02), MACE+ (HR 0.78, 95% CI 0.62-0.98), and all-cause mortality (HR 0.78, 95% CI 0.57-1.05). TEAEs were comparable between roxadustat and ESA groups, including any TEAE [incidence rate per 100 (IR/100) patient-exposure years 56.1 vs. 53.5], TEAEs leading to study drug discontinuation (IR/100 patient-exposure years 6.7 vs. 5.1), and TEAEs leading to death (IR/100 patient-exposure years 6.9 vs. 7.4). CONCLUSION: There was no evidence of increased risk of cardiovascular events or mortality with roxadustat compared with ESA in patients with anemia who have NDD or ID-DD CKD. Although TEAEs occurred commonly in both the roxadustat and ESA groups, patients infrequently discontinued the study drug because of an adverse event. CLINICAL TRIAL REGISTRATION NUMBERS: DOLOMITES, 1517-CL-0610 [NCT02021318]; HIMALAYAS, FGCL-4592-063 [NCT02052310]; SIERRAS, FGCL-4592-064 [NCT02273726]; and ROCKIES, D5740C00002 [NCT02174731].

Indoxyl sulfate impairs erythropoiesis at BFU-E stage in chronic kidney disease.

Chronic kidney disease (CKD) is a global health condition characterized by a progressive deterioration of kidney function. It is associated with high serum levels of uremic toxins (UT), such as Indoxyl Sulfate (IS), which may participate in the genesis of several uremic complications. Anemia is one of the major complications in CKD patients that contribute to cardiovascular disease, increase morbi-mortality, and is associated with a deterioration of kidney failure in these patients. Our study aimed to characterize the impact of IS on CKD-related erythropoiesis. Using cellular and pre-clinical models, we studied cellular and molecular effects of IS on the growth and differentiation of erythroid cells. First, we examined the effect of clinically relevant concentrations of IS (up to 250 µM) in the UT7/EPO cell line. IS at 250 µM increased apoptosis of UT7/EPO cells at 48 h compared to the control condition. We confirmed this apoptotic effect of IS in erythropoiesis in human primary CD34+ cells during the later stages of erythropoiesis. Then, in IS-treated human primary CD34+ cells and in a (5/6 Nx) mice model, a blockage at the burst-forming unit-erythroid (BFU-E) stage of erythropoiesis was also observed. Finally, IS deregulates a number of erythropoietic related genes such as GATA-1, Erythropoietin-Receptor (EPO-R), and ß-globin. Our findings suggest that IS could affect cell viability and differentiation of erythroid progenitors by altering erythropoiesis and contributing to the development of anemia in CKD.

[Management of iron deficiency in chronic kidney disease: Review and proposed algorithm]. / Prise en charge de la carence martiale au cours de la maladie rénale chronique : mise au point et proposition d'un algorithme.

Iron deficiency is very common in chronic kidney disease, even before the dialysis stage. It is an independent factor of morbidity and mortality in patients with non-dialysis chronic kidney disease. During chronic kidney disease, iron deficiency is defined by a transferrin saturation <20% and/or a serum ferritin <100 µg/L. In France, about half of non-dialysis chronic kidney disease patients have absolute iron deficiency (transferrin saturation <20% and serum ferritin <100 µg/L) and/or functional iron deficiency (transferrin saturation <20% and serum ferritin >100 µg/L). Despite this, iron deficiency is usually not investigated. In fact, more than 60% of nephrologists do not assess iron status at least once a year. In addition, iron deficiency is rarely treated: only 12% of patients are prescribed oral or intravenous iron. Early detection and treatment are fundamental and should be systematic. In order to help improve the management of iron deficiency among non-dialysis chronic kidney disease patients, we propose an algorithm that takes into account current recommendations and the most recent data from the literature. Initial blood test requires the measurement of hemoglobin concentration, transferrin saturation and serum ferritin. A transferrin saturation <20% establishes the diagnosis of iron deficiency and the serum ferritin level points towards an absolute or functional deficiency. The combination of both values makes it possible to adapt the treatment, particularly in an inflammatory context where oral iron is not effective.

Serum Calcification Propensity Represents a Good Biomarker of Vascular Calcification: A Systematic Review.

Vascular calcification contributes to cardiovascular morbidity and mortality. A recently developed serum calcification propensity assay is based on the half-transformation time (T50) from primary calciprotein particles (CPPs) to secondary CPPs, reflecting the serum's endogenous capacity to prevent calcium phosphate precipitation. We sought to identify and review the results of all published studies since the development of the T50-test by Pasch et al. in 2012 (whether performed in vitro, in animals or in the clinic) of serum calcification propensity. To this end, we searched PubMed, Elsevier EMBASE, the Cochrane Library and Google Scholar databases from 2012 onwards. At the end of the selection process, 57 studies were analyzed with regard to the study design, sample size, characteristics of the study population, the intervention and the main results concerning T50. In patients with primary aldosteronism, T50 is associated with the extent of vascular calcification in the abdominal aorta. In chronic kidney disease (CKD), T50 is associated with the severity and progression of coronary artery calcification. T50 is also associated with cardiovascular events and all-cause mortality in CKD patients, patients on dialysis and kidney transplant recipients and with cardiovascular mortality in patients on dialysis, kidney transplant recipients, patients with ischemic heart failure and reduced ejection fraction, and in the general population. Switching from acetate-acidified dialysate to citrate-acidified dialysate led to a longer T50, as did a higher dialysate magnesium concentration. Oral administration of magnesium (in CKD patients), phosphate binders, etelcalcetide and spironolactone (in hemodialysis patients) was associated with a lower serum calcification propensity. Serum calcification propensity is an overall marker of calcification associated with hard outcomes but is currently used in research projects only. This assay might be a valuable tool for screening serum calcification propensity in at-risk populations (such as CKD patients and hemodialyzed patients) and, in particular, for monitoring changes over time in T50.

Glomerulonephritis with non-Randall-type, non-cryoglobulinaemic monoclonal immunoglobulin G deposits (PGNMID and ITG).

Background: Glomerulonephritis (GN) with non-Randall-type, non-cryoglobulinaemic monoclonal immunoglobulin G deposits encompasses rare diseases [proliferative GN with non-organized deposits (PGNMID) and immunotactoid GN] that cannot be distinguished without ultrastructural analysis by electron microscopy (EM). Methods: Here, we report and analyse the prognosis of 41 EM-proven (PGNMID for 39/41) and 22 non-EM-proven/DNAJB9-negative cases, diagnosed between 2001 and 2019 in 12 French nephrology centres. Results: Median (interquartile range) serum creatinine (SCr) at presentation was 150 (92-256) µmol/L. The predominant histological pattern was membranoproliferative GN (79%), with IgG3 (74%) kappa (78%) deposits the most frequently observed. Disease presentation and patient management were similar between EM-proven and non-EM-proven cases. A serum monoclonal spike was detected for 21 patients and 10 had an underlying haematological malignancy. First-line therapy was mixed between clone-targeted therapy (n = 33), corticosteroids (n = 9) and RAAS inhibitors (n = 19). After 6 months, nine patients achieved complete and 23 partial renal recovery. In univariate analysis, renal recovery was associated with baseline SCr (odds ratio 0.70, P = 0.07). After a median follow-up of 52 (35-74) months, 38% of patients had progressed to end-stage kidney disease independently associated with baseline SCr [hazard ratio (HR) 1.41, P = 0.003] and glomerular crescentic proliferation (HR 4.38, P = 0.004). Conclusions: Our results confirm that non-cryoglobulinaemic and non-Randall GN with monoclonal IgG deposits are rarely associated with haematological malignancy. The prognosis is uncertain but may be improved by early introduction of a specific therapy.

Use of the Capture-Recapture Method to Estimate the Frequency of Community- and Hospital-Acquired Drug-Induced Acute Kidney Injuries in French Databases.

Drug-induced acute kidney injury (AKI) can occur both in primary care (i.e., community-acquired AKI (CA-AKI)) and in hospital settings (i.e., hospital-acquired AKI (HA-AKI)). The reported prevalence of these events varies markedly from one study to another, mainly due to differences in the study design. To estimate the frequency of drug-induced AKIs (both CA-AKIs and HA-AKIs) observed in a French university hospital, we applied the capture-recapture method to 1) the French national pharmacovigilance database (FPVD) and 2) a cohort of hospitalized patients with drug-induced AKIs (documented by analyzing the French national hospital discharge database and the patients' electronic medical records). Drug-induced AKIs were determined according to the Naranjo algorithm and then categorized as CA-AKIs or HA-AKIs. A total number of 1,557 episodes of AKI were record during the study period, of them, the estimated total number of drug-induced AKIs was 593 [95% confidence interval (CI): 485-702], and the estimated prevalence was 38.1% [95%CI: 35.67-40.50]. The prevalences of HA-AKIs and CA-AKIs were similar (39.4% [36.24-42.54] and 37.4% [33.67-41.21], respectively). Only 6.1% of the drug-induced AKIs were recorded in the FPVD, and the proportions of recorded HA-AKIs and CA-AKI differed markedly (3.0% vs. 10.5%, respectively). One of the most frequently involved drug classes were antibiotics in the HA-AKI subgroup (13.0%) and antineoplastics in the CA-AKI subgroup (8.3%). Application of the capture-recapture method to two incomplete data sources can improve the ability to identify and quantify adverse drug reactions like AKIs. The frequency of drug-induced AKI is relatively high and is probably underestimated. The clinical management of an AKI might depend on where it originated.

[Current status of persistent chronic hyperkalaemia in France: An expert consensus based on a Delphi approach]. / État des lieux sur l'hyperkaliémie chronique persistante en France : consensus d'experts par une approche Delphi.

INTRODUCTION: In France, no consensus document on the management of persistent hyperkalaemia is currently available. Variability in clinical practices has been observed. METHODS: A consensus statement on the definition and the management of persistent hyperkalaemia was developed by a Delphi panel of French nephrologists between December 2019 (26 voting participants among 40 invited panellists in first round) and June 2020 (20 voting participants among 26 panellists in second round). RESULTS: Persisting hyperkalaemia not controlled with current treatment strategies may be defined as the occurrence of two or more hyperkalaemia episodes within a year despite the administration of cation-exchange resins or loop diuretics during the same year. Some patient characteristics (diabetes, chronic kidney disease from stage 3B to stage 5 without dialysis, chronic heart failure) are associated with an increased risk of developing persistent hyperkalaemia. There is a medical need for the management of persistent hyperkalaemia in patients treated with renin-angiotensin-aldosterone system inhibitors that is not met by current treatment strategies (including available cation-exchange resins). CONCLUSIONS: The panel expressed a need for new treatment strategies validated by clinical trials.