Prevalence of Fabry Disease in Patients on Dialysis in France.

Numerous prevalence studies on Fabry disease (FD, OMIM #301500) have been conducted in dialysis populations across the world with variable and controversial results. The FABRYDIAL study aimed to estimate the prevalence of FD in patients aged 18 to 74 years on chronic dialysis in France. This cross-sectional study was conducted in patients undergoing dialysis. One hundred and twenty-four dialysis centers participated. Patients with proven causes of nephropathy unrelated to FD were excluded. Alpha-galactosidase A activity was assayed in men, and both α-galactosidase A and lyso-Gb3 were assayed in women from dried blood spots. GLA gene sequencing was performed in case of abnormal values. If a variant was identified, a diagnosis validation committee was consulted for adjudication. Among the 6032 targeted patients, 3088 were included (73.6% of the eligible patients). Biochemical results were available for 2815 (1721 men and 1094 women). A genetic variant of GLA was identified in five patients: a benign c.937G>T/p.(Asp313Tyr) variant in two individuals, a likely benign c.427G>A/(p.Ala143Thr) variant, a likely benign c.416A>G/(p.Asn139Ser) variant, and a pathogenic c.1185dupG/p.Phe396Glyfs variant. Among the screened patients, the prevalence was 0.058% [0.010;0.328] in males, 0% [0.000;0.350] in females, and 0.035% [0.006;0.201] when both genders were pooled. Among all patients aged 18-74 years undergoing dialysis without a previously known cause of nephropathy unlinked to FD, the prevalence was 0.028% [0.006;0.121]. The prevalence of FD in a cohort of French dialysis patients was low. However, considering the prognostic impact of earlier diagnosis, signs of FD should be sought in patients with nephropathies of uncertain etiology.

Impact of Albumin Assays in the Diagnosis of Malnutrition in Hemodialysis Patients: A Cohort Study.

OBJECTIVE: In hemodialysis (HD) patients, malnutrition should be diagnosed by several assessment tools including a plasma albumin concentration of less than 3.8 g/dL or 3.5 g/dL using bromocresol green or immunonephelometry (IN), respectively. However, albumin measurement is not yet standardized and two alternative methods are also commonly used in laboratories: bromocresol purple (BCP) and immunoturbidimetry (IT). This study aimed to revisit the hypoalbuminemia thresholds for BCP and IT, in HD patients. METHODS: Plasma albumin was measured by the four analytical methods during the monthly HD nutritional assessment of 103 prospectively included patients. RESULTS: Significant differences in albumin levels were observed in HD patients depending on the method used. Using BCP or IT with the cut-off at 3.5 g/dL (determined for the general population) we obtained 33% and 9.7% of false hypoalbuminemia in comparison to IN (mean bias of -0.4 g/dL and -0.065 g/dL, respectively). The best hypoalbuminemia threshold for BCP was 3.05 g/dL and 3.4 g/dL for IT. Twenty percent of HD patients were classified as malnourished when albumin was determined by IN. Similar rates were obtained using the new hypoalbuminemia cut-offs for BCP (18.5%) and IT (19.5%). CONCLUSION: To avoid nutritional misclassification of HD patients, we should adjust hypoalbuminemia thresholds when BCP or IT methods are used in laboratories.

Efficacy of plasmapheresis and semi-selective immunoadsorption for removal of anti-HLA antibodies.

BACKGROUND: In organ transplantation, apheresis is frequently used for removal of anti-HLA antibodies. However, it is unclear whether plasmapheresis (PP) or semi-selective immunoadsorption (IA) should be employed, and the optimal number of apheresis sessions required to reach post-treatment objectives is also unknown. METHODS: We enrolled 43 patients from Bordeaux University Hospital who were treated with PP (n = 29) or IA (n = 14) for antibody-mediated rejection or pre-transplant desensitization. Using Luminex single-antigen flow beads, we assessed the initial mean fluorescence intensity (MFI) of 1416 positive beads with MFIs obtained after 7 to 8 apheresis sessions (extended protocol) and, if a serum was available, after the first four sessions (short protocol). RESULTS: MFI reduction after extended apheresis protocol was stronger with IA [87% (61%-100%)] than with PP [73% (22%-100%)] (P < .001). Indeed, 59% of the beads had a final MFI < 2000 with IA, whereas only 38% with PP (P < .001). The efficacy of removal depended on initial MFI but not on HLA specificity. A short protocol of apheresis showed excellent results without superiority of IA over PP for antibodies with an initial MFI < 3000. For antibodies showing MFI ≥2000 after four sessions, the residual MFI predicted the effectiveness of four additional sessions. CONCLUSION: Monitoring the MFI of anti-HLA antibodies before and during apheresis protocol can guide physicians in the selection of apheresis technique and the number of sessions to be performed.

No Improvement of Hepatitis B Vaccination Response in Patients Dialysed with a Polymethylmethacrylate Membrane Compared to High-Flux Polysulfone: Results of the HEPADIAL Study.

BACKGROUND: An altered immune response and decreased vaccine response are observed in patients with chronic renal failure. A preliminary study of 15 non-immunised patients, despite appropriate previous hepatitis B vaccination, showed a 60% seroconversion rate after 3 months of dialysis with a polymethylmethacrylate (PMMA) membrane. This response was associated with circulating soluble CD40 (CD40s) decrease, a natural inhibitor of the humoral immune response. The aim of the study is to confirm these results in a randomised study. METHODS: We conducted a multicentre randomised intention-to-treat superiority clinical trial comparing polysulfone and a PMMA membrane in 2 parallel patient groups. The primary end point was the vaccine response rate, as defined by an anti-HBs antibodies titre of >10 IU/L, 1 month after the last vaccination with a double dose of Engerix B20®, performed at weeks 12, 16, 20, and 36. RESULTS: Twenty-five patients were randomised and included in an intention-to-treat analysis. They were dialysed on polysulfone (n = 11) or PMMA (n = 14) for 40 weeks. Fifty percent of the PMMA patients versus 54.5% of the polysulfone patients achieved seroconversion (p = 1.00). The median anti-HBs antibody titre in responders at week 40 was 496 (92-750) versus 395 (43-572) UI/mL for PMMA and polysulfone, respectively (p = 0.46). The median CD40s titre at week 12 was 306 (193-448) versus 491 (281-515) pg/mL (p = 0.21). The CD40s median variation between week 0 and week 12 was 5 (-105 to 90) versus 64 (-63 to 123) pg/mL (p = 0.55). The CD40s level at week 12 in non-responders was slightly inferior to that of the responders: median 193 (168-331) versus 413 (281-512) pg/mL (p = 0.08). CONCLUSION: We did not observe a better vaccine response with the PMMA membrane compared to high-flux polysulfone. The PMMA membrane did not decrease the CD40s more than the polysulfone membrane probably because the titre was previously low in the 2 groups.

Use of the Flixene vascular access graft as an early cannulation solution.

OBJECTIVE: The primary end points of this study were safety and efficacy of early cannulation of the Flixene graft (Maquet-Atrium Medical, Hudson, NH). Secondary end points were complications and patency. METHODS: This is a prospective single-center nonrandomized study. Study data included patient characteristics; history of vascular access; operative technique; interval between implantation and initial cannulation; complications; and patency at 1 month, 3 months, and every 6 months. Patency rates were estimated by the Kaplan-Meier method. RESULTS: Between January 2011 and September 2013, a total of 46 Flixene grafts were implanted in 44 patients (27 men) with a mean age of 63 years. The implantation site was the upper arm in 67% of cases, the forearm in 11%, and the thigh in 22%. Seven grafts were never cannulated during the study period. Of the remaining 39 grafts, 32 (82%) were successfully cannulated within the first week after implantation, including 16 (41%) on the first day. The median interval from implantation to initial cannulation was 2 days (interquartile range, 1-3 days). The median follow-up was 223.5 days (interquartile range, 97-600 days). Five hematomas occurred, but only one required surgical revision. Primary assisted and secondary patency rates were 65% and 86%, respectively, at 6 months and 56% and 86%, respectively, at 1 year. CONCLUSIONS: This study suggests that cannulation of the Flixene graft within 1 week after implantation is safe and effective. Early cannulation avoids or shortens the need for a temporary catheter. One-year patency rates appeared to be comparable to those achieved with conventional grafts, but long-term follow-up and randomized controlled studies will be needed to confirm this finding.

Performance of real-time PCR in suspected haemodialysis catheter-related bloodstream infection: a proof-of-concept study.

Background: Catheter-related bloodstream infections (CRBIs) remain a major cause of mortality in haemodialysis (HD) patients with central venous catheters (CVCs), especially because of the non-specific symptomatology and the delay in microbiological diagnosis with possible use of non-optimal empiric antibiotics. Moreover, empiric broad-spectrum antibiotics increase antibiotic resistance development. This study aims to evaluate the diagnostic performance of real-time polymerase chain reaction (rt-PCR) in suspected HD CRBIs compared with blood cultures. Methods: A blood sample for rt-PCR was collected simultaneously with each pair of blood cultures for suspected HD CRBI. The rt-PCR was performed on the whole blood, without any enrichment stage and with specific DNA primers: 16S (universal bacterial), Staphylococcus spp., Staphylococcus aureus and mecA. Each successive patient with a suspected HD CRBI in the HD centre of Bordeaux University Hospital was included. Performance tests were used to compare the result obtained in each rt-PCR assay with its corresponding routine blood culture. Results: Eighty-four paired samples were collected and compared for 40 suspected HD CRBI events in 37 patients. Among these, 13 (32.5%) were diagnosed as HD CRBI. All rt-PCRs except mecA (insufficient number of positive samples) showed high diagnostic performances within 3.5 h: 16S (sensitivity 100%, specificity 78%), Staphylococcus spp. (sensitivity 100%, specificity 97%), S. aureus (sensitivity 100%, specificity 99%). Based on the rt-PCR results, antibiotics could be more appropriately targeted, thus cutting anti-cocci Gram-positive therapy from 77% to 29%. Conclusions: The performance of rt-PCR in suspected HD CRBI events showed fast and high diagnostic accuracy. Its use would improve HD CRBI management with an antibiotic consumption decrease.

[Diagnosis and treatment of catheter-related bloodstream infection in hemodialysis: 10 years later]. / Diagnostic et prise en charge des bactériémies liées au cathéter d'hémodialyse : 10 ans après les dernières recommandations.

Patients in hemodialysis on central venous catheter as vascular access are at risk of infections. Catheter-related bloodstream infection is one of the most serious catheter-complications in hemodialysis patients. Its clinical and microbiological diagnosis is challenging. The implementation of empiric antibiotic therapy is based on old recommendations proposing the combination of a molecule targeting methicillin-resistant Staphylococcus aureus and a betalactamin active on P. aeruginosa, and also adapting this probabilistic treatment by carrying out a microbiological register on a local scale, which is rarely done. In our hemodialysis center at Bordeaux University Hospital, an analysis of the microorganisms causing all catheter-related bloodstream infection over the period 2018-2020 enabled us to propose, in agreement with the infectious disease specialists, an adapted probabilistic antibiotic therapy protocol. This approach allowed us to observe a low incidence of meticillinoresistance of Staphylococcus. For catheters inserted more than 6 months ago, we observed no Staphylococcus, no multi-resistant Pseudomonas, and only 2% of Enterobacteria resistant to cephalosporins. A frequent updating of the microbiological epidemiology of catheter-related bloodstream infection, in partnership with the infectious diseases team in each hemodialysis center, allowing an adaptation of the probabilistic antibiotic therapy, and seems to have a good feasibility. This strategy might favor the preservation of microbial ecology on an individual and collective scale in maintenance hemodialysis patients.

[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.

Characterization of Fabry Disease cardiac involvement according to longitudinal strain, cardiometabolic exercise test, and T1 mapping.

In Anderson-Fabry disease (FD), we sought to evaluate relation between left ventricular (LV) hypertrophy, longitudinal strain (LS), myocardial T1 mapping and cardiopulmonary exercise parameters, and their prognostic value in term of cardiovascular outcomes. In this prospective, observational, monocentric study called "FABRY-Image", we evaluated consecutive adult FD patients by echocardiography, cardiac magnetic resonance, and cardiopulmonary exercise testing. We investigated regional LS, the relations between LV hypertrophy, LS, T1 mapping, and VO2 peak and VE/VCO2, and the prediction of cardiovascular events during follow-up. From 2016 to 2019, we included 35 FD patients (44 ± 17 years, 40% male), that were compared with 20 controls. In FD patients, global, basal and mid-LV LS, as well as mean T1 were significantly altered compared to controls (p < 0.05) with relative apical LS sparing. LV wall thickness was particularly related to mean of basal LS (r = - 0.73), to T1 (r = - 0.48), and to VE/VCO2 (r = 0.45). Mean of basal LS was well related to myocardial T1 (r = 0.59). A good relation was observed between VO2 peak and global LS (r = 0.39) while VE/VCO2 slope was more related to maximal LV wall thickness (r = 0.45), and T1 (r = - 0.61). During a median follow-up of 2.4 years, 6/31 patients presented de novo atrial fibrillation or stroke. In Cox univariate analyses, LV wall thickness, basal LS, T1 value, and VE/VCO2 were significantly predictive of occurrence of de novo atrial fibrillation or stroke (p < 0.05). Our study shows an apical LS sparing in FD patients as observed in amyloidosis, and a close relation between LV hypertrophy, LS, T1 mapping, and VE/VCO2 which are all associated to the occurrence of de novo atrial fibrillation or TIA/stroke during follow-up. These results need to be confirmed by future multicentric studies.

Cardiac Rhythm Disturbances in Hemodialysis Patients: Early Detection Using an Implantable Loop Recorder and Correlation With Biological and Dialysis Parameters.

OBJECTIVES: The aim of this study was to identify using implantable loop recorder (ILR) monitoring the mechanisms leading to sudden death (SD) in patients undergoing hemodialysis (HD). BACKGROUND: SD accounts for 11% to 25% of death in HD patients. METHODS: Continuous rhythm monitoring was performed using the remote monitoring capability of the ILR device in patients undergoing HD at 8 centers. Clinical, biological, and technical HD parameters were recorded and analyzed. RESULTS: Seventy-one patients (mean age 65 ± 9 years, 73% men) were included. Left ventricular ejection fraction was <50% in 16%. Twelve patients (17%) had histories of atrial fibrillation or flutter at inclusion. During a mean follow-up period of 21.3 ± 6.9 months, 16 patients died (14% patient-years), 7 (44%) of cardiovascular causes. Four SDs occurred, with progressive bradycardia followed by asystole. The incidence of patients presenting with significant conduction disorder and with ventricular arrhythmia was 14% and 9% patient-years, respectively. In multivariate survival frailty analyses, a higher risk for conduction disorder was associated with plasma potassium >5.0 mmol/l, bicarbonate <22 mmol/l, hemoglobin >11.5 g/dl, pre-HD systolic blood pressure >140 mm Hg, the longer interdialytic period, history of coronary artery disease, previous other arrhythmias, and diabetes mellitus. A higher risk for ventricular arrhythmia was associated with potassium <4.0 mmol/l, no antiarrhythmic drugs, and previous other arrhythmias. With ILR monitoring, de novo atrial fibrillation or flutter was diagnosed in 14 patients (20%). CONCLUSIONS: ILR may be considered in HD patients prone to significant conduction disorders, ventricular arrhythmia, or atrial fibrillation or flutter to allow early identification and initiation of adequate treatment. Therapeutic strategies reducing serum potassium variability could decrease the rate of SD in these patients. (Implantable Loop Recorder in Hemodialysis Patients [RYTHMODIAL]; NCT01252823).

Verapamil and mild hyperkalemia in hemodialysis patients: a potentially hazardous association.

During the past 3 years, 3 patients undergoing intermittent hemodialysis (or about to do so) in our hospital developed a third-degree atrioventricular block while being treated with verapamil for blood pressure or supraventricular arrhythmia. In the 3 cases, mild hyperkalemia was concomitant. The medical history of these patients revealed no intrinsic cause of atrioventricular conduction disturbance. We report herein the 3 cases and draw attention to the risks of atrioventricular block in this particular context.

Early evolution of nutritional status and body composition after kidney transplantation.

BACKGROUND: Previous series have dealt with nutritional status after kidney transplantation. However, few studies have described the outcome of body composition after kidney transplantation. METHODS: A total of 44 cadaver kidney transplant recipients (28 men and 16 women) were followed prospectively during the first post-transplant year. Biochemical nutritional markers, dietary records, anthropometric measurements, and body composition were assessed at kidney transplantation and 3, 6, and 12 months later. RESULTS: By the end of the first year, serum albumin level was not significantly different from initial values. Prealbumin and retinol binding protein decreased from 42.3 +/- 10.2 mg/dL to 30.4 +/- 6.3 mg/dL and from 1.96 +/- 0.61 g/dL to 0.65 +/- 0.2 g/dL (P < 0.0001). Separating patients by gender showed that dietary caloric and protein intake increased in women only. At the end of the follow-up period, mean weight change was +5.4 kg in women (P = 0.009) and -0.9 kg in men (not significant). Body composition analyses showed that in women total fat and lean masses increased (+2.1 kg, P = 0.05, and +2.4 kg, P = 0.006), whereas in men total fat mass decreased (-1.4 kg, P = 0.04), and total lean mass tended to increase (+0.5 kg, not significant). Percentage change in total bone mass was +1.4% in women (not significant) and -2.1% in men (P = 0.05). In multivariate analyses, an independent impact of female gender on weight gain was observed, although increased fat mass was related only to energy intake. Increased total lean mass was related to low steroid doses and the absence of acute rejection and delayed graft function. Bone loss was related to male gender and high steroid doses. CONCLUSION: Changes in body composition during the first year after kidney transplantation are modulated by gender, energy intake, steroid doses, the occurrence of acute rejection, and delayed graft function.

Potential role of the soluble form of CD40 in deficient immunological function of dialysis patients: new findings of its amelioration using polymethylmethacrylate (PMMA) membrane.

Even though numerous studies have helped to better delineate abnormalities of either innate or adaptive immune system in end-stage renal disease (ESRD) patients, understanding immune dysfunctions in ESRD patients remains a very complex puzzle with missing pieces. In this context, we showed that the soluble form of CD40 (sCD40) is elevated in ESRD patients and is associated with a lack of response to hepatitis B vaccination. Interestingly, although most dialysis membranes are unable to clear sCD40, we demonstrated that polymethylmethacrylate (PMMA) BK-F membranes (Toray Medical Company, Japan) allow a dramatic diminution of the molecule. We took advantage of this observation to address the question of the potential usefulness of PMMA membrane (BK-F series) in the improvement of humoral immune response of ESRD patients. We, thus, present our recent data highlighting the potential role of BK-F membrane in the improvement of hepatitis B vaccination of ESRD patients who failed to mount a protective immune response despite one or more well-conducted anterior vaccination. Taken as a whole, our findings reinforced the concept of seeing dialysis membranes not just as a simple diffusive device but as a tool to tailor dialysis procedure to improve the global quality of life of ESRD patients. This opens a wide area of investigation, notably for the management of immunological dysfunction of ESRD patients.

An in vitro study of epoetin beta intravenous injection site at the end of hemodialysis.

The aim of this study (SITEPO) is to evaluate the influence of the intravenous injection site (drip chamber injection site, venous injection site or venous fistula needle) on plasma concentration of epoetin beta (Neorecormon, Roche), a recombinant Human Erythropoietin (rHuEPO), at the end of in vitro hemodialysis sessions. No practical administration guidelines are available. Twenty 1-h dialysis sessions are performed. Before each dialysis, the circuit is filled with 270ml, of heparinized total human blood whose hematocrit is adjusted to 35%. A common dosage of epoetin beta in clinical practice (3000IU) is studied for the three injection sites and for reference experiments in which rHuEPO is not injected into the dialysis circuit. Plasma concentrations of erythropoietin are measured by ELISA. The physiologically endogenous erythropoietin concentration is systematically determined and removed from the total epoetin beta concentration. Average epoetin beta plasma levels returned are not significantly different between the three injection sites and no significant rHuEPO loss is observed after injection into the drip chamber, the venous injection site and the venous fistula needle compared with reference experiments. The three intravenous injection sites of rHuEPO can be used at the end of dialysis without significant epoetin beta loss.

Long-term outcome on renal replacement therapy in patients who previously received a keto acid-supplemented very-low-protein diet.

BACKGROUND: The consequences of a supplemented very-low-protein diet remain a matter of debate with regard to patient outcome before or after the onset of renal replacement therapy. OBJECTIVE: We evaluated the long-term clinical outcome during maintenance dialysis and/or transplantation in patients who previously received a supplemented very-low-protein diet. DESIGN: We assessed the outcome of 203 patients who received a supplemented very-low-protein diet for >3 mo (inclusion period: 1985-2000) and started dialysis after a mean diet duration of 33.1 mo (4-230 mo). RESULTS: The survival rate in the whole cohort was 79% and 63% at 5 and 10 y, respectively. One hundred two patients continued with chronic dialysis during the entire follow-up, and 101 patients were grafted at least once. Patient outcomes were similar to those of the French Dialysis Registry patients for the dialysis group and similar to the 865 patients who were transplanted in Bordeaux during the same period for the transplant group. There was no correlation between death rate and duration of diet. CONCLUSIONS: The lack of correlation between death rate and duration of diet and the moderate mortality rate observed during the first 10 y of renal replacement therapy confirm that a supplemented very-low-protein diet has no detrimental effect on the outcome of patients with chronic kidney disease who receive renal replacement therapy.

Nutrition in hemodialysis patients previously on a supplemented very low protein diet.

BACKGROUND: Nutritional safety of protein-restricted diets in patients with chronic renal failure is controversial. In the present study, we have assessed the evolution of nutritional status after initiation of hemodialysis in patients previously treated by a supplemented very low protein diet (SVLPD). METHODS: Nutritional data were prospectively collected during the first year of hemodialysis from 15 consecutive patients treated with a SVLPD (0.3 g protein/kg/day supplemented with essential amino acids, calcium, iron, and vitamins) and compared to 15 age- and gender-matched end-stage renal disease (ESRD) patients previously on a less-restricted diet (0.90 +/- 0.21 g protein/kg/day) who started hemodialysis during the same period. Dual-energy x-ray absorptiometry (DEXA) was used to assess body composition at 0, 6, and 12 months. Hemodialysis prescriptions, biologic data and 3-day food records were collected every 3 months. RESULTS: Protein intake was higher than 1.2 g/kg/day in both groups as soon as 3 months after the start of hemodialysis. Albumin and prealbumin increased significantly during the first 6 months in all patients. Body mass index (BMI) increased in all patients (+0.97 +/- 1.31 kg/m2; P < 0.001) reflecting a gain in fat mass in the overall population (+2.36 +/- 2.94 kg/m2; P < 0.001) while lean body mass remained stable overall. CONCLUSION: Once on hemodialysis, SVLPD patients rapidly increased protein intake. Nutritional status improved in all patients, with a gain in fat mass in all, and a gain in lean body mass in SVLPD men only. These data indicate that treatment with a SVLPD prior to hemodialysis initiation is nutritionally safe.