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Background: Primary hyperoxalurias (PH) are extremely rare genetic disorders characterized by clinical heterogeneity. Delay in diagnosing these conditions can have detrimental effects on patient outcomes. The primary objective of this study is to assess the current diagnostic delay for PH., Methods: This nationwide, observational and retrospective study included patients who received a genetic diagnosis of PH types 1, 2 and 3 between 1 January 2015 and 31 December 2019. Diagnostic delay was defined as the duration between the onset of symptoms and the time of genetic diagnosis., Results: A total of 52 patients (34 children and 18 adults) were included in the study, with 40 PH1 (77%), 3 PH2 (6%) and 9 PH3 (17%). At the time of diagnosis, 12 patients (23%) required dialysis. Among the PH1 patients, the predominant symptom at onset in adults was renal colic (79% of cases), whereas symptoms in children were more diverse (renal colic in 17% of cases). The diagnostic delay was significantly shorter in children compared with adults [median (interquartile range)]: 1.2 (0.1-3.0) versus 30 (17-36) years, respectively ( P  < .0001). RNA interference was utilized in 23 patients (58%). Five individuals (13%) underwent double liver-kidney transplantation, and five (13%) received isolated kidney transplantation, with lumasiran therapy in four patients. For PH2 and PH3 patients, the diagnostic delay ranges from 0 to 3 years, with renal colic as first symptom in 33% of cases., Conclusion: This extensive and recent cohort of PH underscores the considerable delay in diagnosing PH, particularly in adults, even in a country with a dedicated organization for enhancing the overall management of rare diseases. These findings reinforce the imperative for increased awareness among relevant specialties regarding the evaluation of urolithiasis., Competing Interests: R.P. received funding from Alnylam Pharmaceuticals to attend a national nephrology congress. C.A. received consulting fees for Alnylam and Novonordisk. N.B. received help for medical writing from Alnylam. S.B. received fees from AstraZeneca, Lilly, CSL Vifor, Bayer and IKI. I.B., K.C., C.D., M.G., F.H. and C.R.-R. declare no conflict of interest. E.L. patented Stiripentol to reduce urine oxalate excretion (WO2017140658A1) and received consulting fees from Biocodex Laboratory. J.B. received travel, consulting and speaker fees from Alnylam Pharmaceuticals, and consulting fees from Dicenra/Novonordisk Pharmaceuticals and Biocodex Pharmaceuticals. B.M. received consulting, travel and speaker fees from Alnylam Pharmaceuticals., (© The Author(s) 2024. Published by Oxford University Press on behalf of the ERA.)

Background: Long-term studies have demonstrated a slight increased risk for end-stage renal disease (ESRD) for living kidney donors (LKD). In France, living kidney donation doubled within the past 10 years. We investigated the change in characteristics of LKD between 2007 and 2017 and the adequacy of follow-up., Methods: Data were obtained from the national registry for LKD. We compared characteristics of LKD between two study periods: 2007-11 and 2012-17, and stratified donors by age and relation to recipient. We aggregated four characteristics associated with higher ESRD risk [young age, first-degree relation to recipient, obesity, low glomerular filtration rate (GFR) for age] in a single risk indicator ranging from 0 to 4., Results: We included 3483 donors. The proportion of unrelated donors >56 years of age increased significantly. The proportion of related donors <56 years of age decreased significantly. The body mass index and proportion of obese donors did not change significantly. The proportion of donors with low estimated GFR for age decreased significantly from 5% to 2.2% (P < 0.001). The proportion of donors with adequate follow-up after donation increased from 19.6% to 42.5% (P < 0.001). No donor had a risk indicator equal to 4, and the proportion of donors with a risk indicator equal to 0 increased significantly from 19.2% to 24.9% (P < 0.001)., Conclusions: An increase in living kidney donation in France does not seem to be associated with the selection of donors at higher risk of ESRD and the proportion of donors with adequate annual follow-up significantly increased., (© The Author(s) 2019. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Background: Recent years have seen increasing use of rituximab (RTX) for various types of primary and secondary glomerulopathies. However, there are no studies that specifically address the risk of infection related to this agent in patients with these conditions., Methods: We reviewed the outcomes of all patients who received RTX therapy for glomerular disease between June 2000 and October 2011 in eight French nephrology departments. Each case was analysed for survival, cause of death if a non-survivor and/or the presence of infectious complications, including severe or opportunistic infection occurring within the 12 months following RTX infusion., Results: Among 98 patients treated with RTX, 25 presented with at least one infection. We report an infection rate of 21.6 per 100 patient-years. Five patients died within 12 months following an RTX infusion, of whom four also presented with an infection. The median interval between the last RTX infusion and the first infectious episode was 2.1 months (interquartile range 0.5-5.1). Most infections were bacterial (79%) and pneumonia was the most frequent infection reported (27%). The presence of diabetes mellitus (P = 0.006), the cumulative RTX dose (P = 0.01) and the concomitant use of azathioprine (P = 0.03) were identified as independent risk factors. Renal failure was significantly associated with an increased infection risk by bivariate analysis (P = 0.03) and was almost significant by multivariate analysis (P = 0.05). Nephrotic syndrome did not further increase the risk of infection and/or death., Conclusion: The risk of infection after RTX-based immunosuppression among patients with glomerulopathy must be considered and patients should receive close monitoring and appropriate infection prophylaxis, especially in those with diabetes and high-dose RTX regimens.

Patients with chronic kidney disease (CKD) represent an increasing proportion of the population undergoing percutaneous coronary intervention (PCI) and up to 40% of the patients treated for acute coronary syndrome (ACS). Several studies and registries in the setting of ACS and elective PCI have reported a negative association between CKD and mortality, stent thrombosis, post-procedural ischaemic events and bleeding events. Pharmacological inhibition of the adenosine diphosphate receptor by thienopyridines or ticagrelor and disruption of the cyclooxygenase pathway by aspirin constitute the current standards of care to prevent thrombotic complications following stent-based PCI. In CKD patients, the avoidance of anti-platelet therapy may be driven by the lack of clinical trial data to support its efficacy, by errors or omissions, or by a reluctance to use this therapy in a population characterized by its enhanced bleeding risk. However, there is growing evidence to suggest that a severely decreased glomerular filtration rate per se, independent of the presence of diabetes mellitus, is an important determinant of high residual platelet reactivity under a clopidogrel maintenance dose. Recent reports have emphasized that the impact of impaired platelet inhibition by thienopyridines is of paramount importance in CKD patients, with an enhanced mortality rate in low-responder patients. Pharmacodynamic studies indicate the phosphodiesterase 3 inhibitor, cilostazol, the third generation thienopyridine prasugrel and the reversible P2Y12 antagonist ticagrelor to be potent strategies to overcome this biological resistance. In clinical practice, platelet function testing should be considered in CKD patients undergoing PCI, especially in those who experience thrombotic events despite dual therapy. Newer agents should be contemplated in patients who display higher residual platelet aggregability after standard treatment. Among these, the non-thienopyridine P2Y12 receptor antagonist ticagrelor, which does not require biotransformation, could be the drug of choice in CKD patients with ACS. In this population, ticagrelor has been found to reduce mortality and ischaemic events with an acceptable bleeding risk.

Glomerulonephritis is characterized by the proliferation and apoptosis of mesangial cells (MC). The parathyroid-hormone related protein (PTHrP) is a locally active cytokine that affects these phenomena in many cell types, through either paracrine or intracrine pathways. The aim of this study was to evaluate the effect of both PTHrP pathways on MC proliferation and apoptosis. In vitro studies were based on MC from male transgenic mice allowing PTHrP-gene excision by a CreLoxP system. MC were also transfected with different PTHrP constructs: wild type PTHrP, PTHrP devoid of its signal peptide, or of its nuclear localization sequence. The results showed that PTHrP deletion in MC reduced their proliferation even in the presence of serum and increased their apoptosis when serum-deprived. PTH1R activation by PTHrP(1-36) or PTH(1-34) had no effect on proliferation but improved MC survival. Transfection of MC with PTHrP devoid of its signal peptide significantly increased their proliferation and minimally reduced their apoptosis. Overexpression of PTHrP devoid of its nuclear localization sequence protected cells from apoptosis without changing their proliferation. Wild type PTHrP transfection conferred both mitogenic and survival effects, which seem independent of midregion and C-terminal PTHrP fragments. PTHrP-induced MC proliferation was associated with p27(Kip1) down-regulation and c-Myc/E2F1 up-regulation. PTHrP increased MC survival through the activation of cAMP/protein kinase A and PI3-K/Akt pathways. These results reveal that PTHrP is a cytokine of multiple roles in MC, acting as a mitogenic factor only through an intracrine pathway, and reducing apoptosis mainly through the paracrine pathway. Thus, PTHrP appears as a probable actor in MC injuries.

Background: Short-term intensified dosing using enteric-coated mycophenolate sodium (EC-MPS) reduces rejection after kidney transplantation without compromising safety and may facilitate steroid avoidance., Methods: In a 6-month, multicentre open-label trial, 222 de novo kidney transplant recipients at low-immunological risk were randomized to steroid avoidance or maintenance steroids with interleukin (IL)-2 receptor antibody (IL-2RA) induction, EC-MPS (2160 mg/day to Week 6, 1440 mg/day thereafter) and cyclosporine., Results: The primary end point; treatment failure at Month 6 [biopsy-proven acute rejection (BPAR), graft loss, death or loss to follow-up], occurred in 17.9% (20/112) of steroid-avoidance patients and 14.5% (16/110) of controls (difference 3.4%, 95% confidence interval -6.3 to 13.1, P = 0.47 for superiority testing). BPAR occurred in 11.6 and 7.3% of patients in the steroid-avoidance and control arms, respectively (P = 0.27). Creatinine clearance was similar at Month 6 (steroid-avoidance 56 ± 18 mL/min/1.73 m(2), controls 60 ± 22 mL/min/1.73 m(2), P = 0.34). Cytomegalovirus infection, as reported by investigators, occurred in 12.5% of steroid-avoidance patients and 22.7% of controls (P = 0.045)., Conclusions: A regimen of early intensified EC-MPS dosing with calcineurin inhibitor and IL-2RA induction permits oral steroid avoidance in adult kidney transplant patients at low-immunological risk without compromising efficacy at 6 months' follow-up.

Background: Although several risk factors associated with complications after renal biopsy (RB) have been identified, the gold standard for RB procedures remains to be defined. Practices vary widely among nephrologists, depending on personal experience and the availability of particular techniques. The purpose of our study was to depict the main aspects of the practice of RB in adults in France., Methods: Members of the Société de Néphrologie in France were asked to participate in a questionnaire survey on RB procedures., Results: Eighty-eight nephrologists from 74 units (27 in teaching hospitals, 35 in public general hospitals and 12 in private centres) participated in our study. Native kidney and graft biopsies were performed in 73 and 35 units, respectively. RB activity was highly variable among units, ranging from several hundred to <10 per year. Transjugular renal biopsy was judged to be smoothly accessible in 28 out of 73 units (38.4%). Significant variations in practices were observed regarding patient information before RB, assessment of haemorrhagic risk factors, management of patients with antiplatelet agents and haemorrhagic risk factors, and radiological guidance. Early discharge (<12 h) was the rule in 3 (4.1%) units for native kidney biopsies and in 10 (28.6%) units for graft biopsies., Conclusions: Our study is the first to provide a representative picture of 'everyday' RB practices in a country. Important variations in procedures were observed. Our study may represent a preliminary step for the elaboration of guidelines for all aspects of RB practices.

Background: Hypertension is a risk factor for the two leading causes of death in renal transplant recipients: cardiovascular disease (CVD) and graft failure. Despite this, the optimum medication for post-transplant hypertension is unclear., Methods: The Study on Evaluation of Candesartan Cilexetil after Renal Transplantation (SECRET) was an international multicentre, double-blind, randomized investigation of the angiotensin II type 1 receptor blocker (ARB) candesartan cilexetil versus placebo in renal allograft recipients originally designed to study 700 patients for 3 years. The candesartan dose was escalated from 4 to 16 mg daily, followed by addition of co-medication, if needed, with the aim of achieving a diastolic blood pressure (BP) <85 mmHg. The primary efficacy variable was a composite of all-cause mortality, cardiovascular morbidity and graft failure., Results: SECRET was stopped prematurely as the primary event rate was much lower than expected. At that point, 502 patients were enrolled; 255 received candesartan and 247 placebo. Thirteen primary events had occurred in each group. Control of both systolic and diastolic BP was better in the candesartan group. Urinary protein excretion and protein/creatinine ratio decreased on candesartan but increased on placebo. Serum creatinine and potassium were increased in candesartan patients, but these changes were generally small., Conclusions: SECRET provides insights into the design and conduct of studies in this area and evidence for the utility of candesartan, which showed good safety and tolerability, improved BP control and decreased proteinuria in renal transplant recipients.

Background: Since 1996, the allocation of grafts in France has been based on a hierarchical three-level system: national, regional and local. The objective of this study was to determine whether the shipment of cadaveric kidneys according to these new exchange rules affects allograft outcome in the Eastern region of France., Methods: This retrospective study analysed all renal transplants performed in the four centres of the French Eastern region during 3 years (1996 to 1998). All patients were followed up until death, return to dialysis, last information date or the end of June 2003. Information regarding the donors, recipients and treatments, as well as patient and graft outcome, was recorded. Factors associated with graft loss were analysed using Cox proportional hazard methods., Results: 542 transplants were analysed, 287 (53%) kidneys were transplanted locally, 229 (42.2%) kidneys coming from exchanges within the region and 26 (4.8%) from another region. There were statistically significant differences between the four centres for donors' and recipient' characteristics and for immunosuppressive treatment, but there was no difference between centres regarding patient survival (94.4% at 5 years), graft survival (83.7% at 5 years) or death-censored graft survival (87.8% at 5 years). Compared to locally transplanted grafts, shipped grafts had significantly better human leukocyte antigen (HLA) matching (2.5 +/- 1.3 versus 2.1 +/- 1.0 matches, P = 0.0005 but a longer cold ischaemia time (23.2 +/- 7.9 versus 19.2 +/- 7.8 h, P < 0.0001). Three independent factors were associated with a reduced graft survival: at least one acute rejection, delayed graft function and a shipped graft., Conclusion: The results of this study suggest that the shipment of cadaveric renal allografts in a regional distribution system is associated with better HLA matching but is a significant predictor of graft loss at 5 years. It would be advisable to restrict graft sharing to patients whose access to transplantation is limited, taking special care to avoid any additional factors having a detrimental effect on the outcome.

Background: Recurrence of nephrotic syndrome (NS) after renal transplantation for primary focal segmental glomerulosclerosis (FSGS) is a frequent and still unpredictable complication. However, risk factors for recurrence have not yet been clearly identified., Methods: Data from 33 patients who underwent 35 renal transplantations for FSGS in two French centres are reported., Results: Recurrent NS occurred in 12 transplant recipients (34%). A significantly higher number of patients in the group with recurrence (R group) compared with the group without recurrence (NR group) received cyclosporine for FSGS treatment before transplantation (83.3% vs 43.4%, P<0.02). Donors of R group recipients were significantly older than those of the non-NR group recipients (42.8 years vs 35 years, P<0.05). A higher number of patients from the R group required post-transplantation dialysis (33.3% vs 17.4%, P = 0.002). Surprisingly, acute rejection occurred more frequently in patients of the NR group compared with the R group, although the difference was not significant. Among the 12 patients with NS relapse, 9 were treated with plasmapheresis. Graft loss related to recurrence occurred in 6 cases. The 5-year graft survival was significantly lower in patients with recurrent NS compared with patients without recurrence (57% vs 82%, P<0.001)., Conclusion: This study confirms the benefit to identify in the future clinical or biological predictive risk factors for NS recurrence after renal transplantation. It also indicates that donor age is a reliable risk factor for recurrence in adult recipients and suggests for the first time a possible opposite relationship between recurrent FSGS and acute rejection.

Background: Hypertension and hyperuricaemia are common side-effects of cyclosporin A (CsA) treatment in renal transplant recipients. While it is well established that the calcium channel blocker amlodipine can control CsA-induced hypertension effectively in this patient population, recent evidence suggests amlodipine might also reduce hyperuricaemia. The present study was designed to compare the effects of the calcium channel blocker amlodipine (5-10 mg/day) and the beta-adrenoceptor antagonist tertatolol (5-10 mg/day) on CsA-induced hyperuricaemia in post-renal transplant recipients with hypertension., Methods: Forty-eight hypertensive renal transplant recipients on a stable dose of CsA were randomized in a double-blind, parallel-group manner to receive either amlodipine (n = 24) or tertatolol (n = 24) for 60 days. The primary outcome measure was the change from baseline in serum uric acid concentration. Secondary analyses of efficacy were based on changes in renal function and blood pressure., Results: Amlodipine significantly decreased serum uric acid levels from 483 +/- 99 to 431 +/- 110 microM/l (P < 0.001), while tertatolol significantly increased uric acid from 450 +/- 98 to 476 +/-84 microM/l (P = 0.006). Amlodipine also significantly increased glomerular filtration rate (P = 0.0048) and the clearance rate of uric acid (P = 0.023) and it reduced the fractional proximal tubular reabsorption of sodium (P < 0.001), compared with tertatolol. Renal plasma flow and filtered fraction were unaffected by both treatments, as was trough CsA blood concentration. Amlodipine lowered systolic blood pressure to a significantly greater extent than did tertatolol (P = 0.007). The time-dependent profile of diastolic blood pressure did not differ significantly between treatment groups. Both drugs were well tolerated., Conclusions: Amlodipine could be more appropriate than tertatolol for CsA-induced hypertension and hyperuricaemia in renal transplant recipients.

Background: Among hereditary fevers characterized by recurrent attacks of fever and organ localized inflammation, familial Mediterranean fever (FMF), and tumour necrosis factor receptor superfamily 1A (TNFRSF1A) receptor associated periodic syndrome (TRAPS) are diseases with identified genes that can be associated with renal amyloidosis of the AA type. In this study we have characterized FMF and TRAPS genotypes in 38 unrelated patients suffering from amyloidosis AA and recurrent inflammatory attacks., Methods: Mutations of the MEFV and TNFRSF1A genes, responsible respectively for FMF and TRAPS, were searched for by amplifying, using polymerase chain reaction (PCR), genomic DNA, and direct sequencing., Results: Twenty-seven patients (71%) carried mutations in MEFV (22 patients with two mutations, two patients with a single mutation) or TNFRSF1A genes (three patients). Patients with MEFV mutations belonged to the classical at-risk ethnic group for FMF: Sephardic Jews, Turks, Armenians, and Arabs from the Maghreb. The main genotype encountered was M694V/M694V (19/22), one Turkish patient was M680I/M680I, and two Arab patients from the Maghreb were M694I/M694I. We found three Caucasian patients with the C55S, C70Y, R92Q mutations in the TNFRSF1A gene., Conclusions: In this series we observed that FMF is the main cause of AA amyloidosis in Sephardic Jews and Turks. MEFV and TNFRSF1A mutations were found in only 6 of 14 Arab patients from the Maghreb. We found three families (one Caucasian and two from Maghreb) with AA amyloidosis without MEFV or TNFRSF1A mutations, suggesting that other genetic cause(s) exist(s). The characterization of mutations in MEFV and TNFRSF1A is important for the therapeutic behaviour of AA amyloidosis associated with inherited recurrent fever.