X-Linked hypophosphatemia. Data from a Spanish adult population cohort.

BACKGROUND: X-linked hypophosphatemia (XLH) represents the most prevalent cause of hereditary hypophosphatemia. X-linked hypophosphatemia causes an elevation of fibroblast growth factor 23 (FGF23), a hormone responsible for inducing hyperphosphaturia, and reduced active vitamin D synthesis. Challenges in diagnosis and the absence of well-defined clinical guidelines have resulted in higher rates of late diagnoses. While numerous reports focus on pediatric X-linked hypophosphatemia patients, studies in adults are limited. METHODS: Multicenter, cross-sectional, observational study of a cohort of adult patients diagnosed with X-linked hypophosphatemia. The study identified demographic, clinical, genetic, laboratory variables, treatments used, comorbidities, and complications. RESULTS: Twenty patients diagnosed with X-linked hypophosphatemia were collected. The median age at diagnosis was 11 (1-56) years and at data collection was 44 (21-68) years. Fifty percent of cases were diagnosed in adulthood. Main clinical manifestation was osteoarticular pain, in 75% of cases, and no relation to age at diagnosis, height, phosphorus, or parathyroid hormone (PTH) levels was observed (p > 0.05). Lower limb deformities were associated with reduced stature and earlier diagnosis (p < 0.05). Sixty percent of patients reported pain requiring chronic medication and no significant correlation was found with other variables. Anxiety and depression were found in an important number of patients. FGF23 levels were not related to any of the clinical variables studied (p > 0.05). DISCUSSION: This is the largest study on adult patients with X-linked hypophosphatemia in southern Europe. It may offer valuable insights into the natural progression and course of the condition in adults, which can aid in better clinical management.

Tacrolimus's Time Below Therapeutic Range Is Associated With Acute Pancreatic Graft Rejection and the Development of De Novo Donor-specific Antibodies.

Tacrolimus is pivotal in pancreas transplants but poses challenges in maintaining optimal levels due to recipient differences. This study aimed to explore the utility of time spent below the therapeutic range and intrapatient variability in predicting rejection and de novo donor-specific antibody (dnDSA) development in pancreas graft recipients. This retrospective unicentric study included adult pancreas transplant recipients between January 2006 and July 2020. Recorded variables included demographics, immunosuppression details, HLA matching, biopsy results, dnDSA development, and clinical parameters. Statistical analysis included ROC curves, sensitivity, specificity, and predictive values. A total of 131 patients were included. Those with biopsy-proven acute rejection (BPAR, 12.2%) had more time (39.9% ± 24% vs. 25.72% ± 21.57%, p = 0.016) and tests (41.95% ± 13.57% vs. 29.96% ± 17.33%, p = 0.009) below therapeutic range. Specific cutoffs of 31.5% for time and 34% for tests below the therapeutic range showed a high negative predictive value for BPAR (93.98% and 93.1%, respectively). Similarly, patients with more than 34% of tests below the therapeutic range were associated with dnDSA appearance (38.9% vs. 9.4%, p = 0.012; OR 6.135, 1.346-27.78). In pancreas transplantation, maintaining optimal tacrolimus levels is crucial. Suboptimal test percentages below the therapeutic range prove valuable in identifying acute graft rejection risk.

Comparison of efficacy and safety of the new generation helixone dialyzers.

INTRODUCTION: New generation helixone dialyzers has recently been developed as part of the ongoing effort to improve dialyzer hemocompatibility and avoid adverse reactions to synthetic dialyzers. This study aimed to assess the performance and albumin loss of this new dialyzer series in hemodiafiltration and compare it with the previous generation helixone series. MATERIAL AND METHODS: A prospective study was conducted in 19 patients. Each patient underwent eight dialysis sessions with the same routine dialysis parameters; only the dialyzer varied: FX60 CorDiax, FX CorAL 60, FX600 CorDiax, FX CorAL 600, FX80 CorDiax, FX CorAL 80, FX800 CorDiax, and FX CorAL 800. The reduction ratios (RR) of urea, creatinine, ß2-microglobulin, myoglobin, kappa-free immunoglobulin light chains (κFLC), prolactin, α1-microglobulin, α1-acid glycoprotein, lambda immunoglobulin light chains (λFLC), and albumin were compared intra-individually. Dialysate albumin loss was also measured. RESULTS: All treatments were well tolerated. The mean amount of replacement fluid ranged from 31 to 34 L. Comparison of dialysis treatments showed no differences between small molecules and even up to those the size of ß2-microglobulins. Little differences were found between myoglobin, κFLC, prolactin, α1-microglobulin, and λFLC RRs, and only FX80 CorDiax was slightly superior to the others. Mean dialysate albumin losses were similar, with less than 2.5 g lost in each dialyzer. The FX80 CorDiax showed slightly higher global removal scores than the other dialyzers evaluated, except for FX CorAL 800. CONCLUSION: The new generation helixone dialyzers series has been updated to minimise the risk of adverse reactions, while maintaining the effectiveness and albumin loss achieved by the previous most advanced helixone generation.

Metabolomics of Plasma in XLH Patients with Arterial Hypertension: New Insights into the Underlying Mechanisms.

X-linked hypophosphatemia (XLH) is a rare genetic disorder that increases fibroblast growth factor 23 (FGF23). XLH patients have an elevated risk of early-onset hypertension. The precise factors contributing to hypertension in XLH patients have yet to be identified. A multicenter cross-sectional study of adult patients diagnosed with XLH. Metabolomic analysis was performed using ultra-performance liquid chromatography (UPLC) coupled to a high-resolution mass spectrometer. Twenty subjects were included, of which nine (45%) had hypertension. The median age was 44 years. Out of the total, seven (35%) subjects had a family history of hypertension. No statistically significant differences were found between both groups for nephrocalcinosis or hyperparathyroidism. Those with hypertension exhibited significantly higher levels of creatinine (1.08 ± 0.31 mg/dL vs. 0.78 ± 0.19 mg/dL; p = 0.01) and LDL-C (133.33 ± 21.92 mg/dL vs. 107.27 ± 20.12 mg/dL, p = 0.01). A total of 106 metabolites were identified. Acetylcarnitine (p = 0.03), pyruvate p = (0.04), ethanolamine (p = 0.03), and butyric acid (p = 0.001) were significantly different between both groups. This study is the first to examine the metabolomics of hypertension in patients with XLH. We have identified significant changes in specific metabolites that shed new light on the potential mechanisms of hypertension in XLH patients. These findings could lead to new studies identifying associated biomarkers and developing new diagnostic approaches for XLH patients.

Treatment of Chronic Heart Failure in Advanced Chronic Kidney Disease: The HAKA Multicenter Retrospective Real-World Study.

INTRODUCTION: Chronic heart failure (HF) has high rates of mortality and hospitalization in patients with advanced chronic kidney disease (aCKD). However, randomized clinical trials have systematically excluded aCKD population. We have investigated current HF therapy in patients receiving clinical care in specialized aCKD units. METHODS: The Heart And Kidney Audit (HAKA) was a cross-sectional and retrospective real-world study including outpatients with aCKD and HF from 29 Spanish centers. The objective was to evaluate how the treatment of HF in patients with aCKD complied with the recommendations of the European Society of Cardiology Guidelines for the diagnosis and treatment of HF, especially regarding the foundational drugs: renin-angiotensin system inhibitors (RASi), angiotensin receptor blocker/neprilysin inhibitors (ARNI), beta-blockers (BBs), mineralocorticoid receptor antagonists (MRAs), and sodium-glucose cotransporter-2 inhibitors (SGLT2i). RESULTS: Among 5,012 aCKD patients, 532 (13%) had a diagnosis of HF. Of them, 20% had reduced ejection fraction (HFrEF), 13% mildly reduced EF (HFmrEF), and 67% preserved EF (HFpEF). Only 9.3% of patients with HFrEF were receiving quadruple therapy with RASi/ARNI, BB, MRA, and SGLT2i, but the majority were not on the maximum recommended doses. None of the patients with HFrEF and CKD G5 received quadruple therapy. Among HFmrEF patients, approximately half and two-thirds were receiving RASi and/or BB, respectively, while less than 15% received ARNI, MRA, or SGLT2i. Less than 10% of patients with HFpEF were receiving SGLT2i. CONCLUSIONS: Under real-world conditions, HF in aCKD patients is sub-optimally treated. Increased awareness of current guidelines and pragmatic trials specifically enrolling these patients represent unmet medical needs.

Latest Trends in Hemodiafiltration.

This review provides a detailed analysis of hemodiafiltration (HDF), its progress from an emerging technique to a potential conventional treatment for chronic hemodialysis patients, and its current status. The article covers the advances, methods, and clinical benefits of HDF, specifically focusing on its impact on cardiovascular health, survival rates, and overall well-being. The review also addresses questions about the safety of HDF and provides evidence to dispel concerns related to the elimination of beneficial substances and infection risks. Additionally, the article explores the potential implications of expanded hemodialysis (HDx) as an alternative to HDF, its classification, safety profile, and an ongoing trial assessing its non-inferiority to HDF. Supported by evidence from randomized controlled trials and observational studies, the review emphasizes the superiority of HDF as a hemodialysis modality and advocates for its positioning as the gold standard in treatment. However, it acknowledges the need for extensive research to define the role of HDx in comprehensive treatment approaches in individuals undergoing dialysis. The synthesis of current knowledge underscores the importance of ongoing exploration and research to refine hemodialysis practices for optimal patient outcomes.

Long-Term Outcomes of Incidental Liver Malignancies in Simultaneous Liver-Kidney Transplant Recipients.

BACKGROUND: The pretransplant diagnosis of liver malignancies in nodular cirrhotic livers remains a diagnostic challenge despite current advances. Although the prognostic impact of incidental hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (iCC) in liver transplant recipients is well documented, there are no data on the impact in simultaneous liver kidney transplant (LKT) recipients. METHODS: This is a single-center observational, retrospective study of all LKT performed from May 1993 to April 2022. Among these patients, demographic data, immunosuppressive therapy, rejection episodes, and prevalence of incidental HCC or iCC were evaluated. RESULTS: One hundred eight LKTs were performed and 6 were excluded. There were 13 patients with incidental carcinomas in the explanted liver: one of them with both an HCC and iCC, one with an iCC, and the remaining with an HCC. One case of iCC died. No other recurrences occurred. There were no cases of incidental HCC nor iCC in patients with a hereditary or metabolic LKT indication. We found no differences in the 5-year patient survival, and death-censored kidney and liver graft survival rates for those LKT with an incidental HCC and those without it (76.9% vs 84.2%, P = .5; 100% vs 91.6%, P = .28; and 100% vs 94.7%, P = 0.39, respectively). Finally, there were no significant associations between explant carcinoma and rejections of the liver (7.7% vs 17.9%, P = .34) or kidney graft (0% vs 16.8%, P = 0.11). CONCLUSION: Despite a high prevalence of incidental HCC or iCC, patient, kidney, and liver graft 5-year survival were unaffected by incidental HCC.

Most recently developed polyester polymer alloy dialyzer: A new medium cut-off membrane?

BACKGROUND: New versions of the polyester polymer alloy (PEPA) membrane have appeared over the years, with increases in both the pore size and the amount of polyvinylpyrrolidone (PVP) to optimize hydrophilicity performance. This study aimed to assess the efficacy of the most recently developed PEPA dialyzer, the FDY series, in hemodialysis (HD) modality in terms of uremic toxin removal and albumin loss and to compare it with that of several high-flux dialyzers currently used in HD and post-dilution hemodiafiltration (HDF) treatments. METHODS: A prospective study was carried out in 21 patients. All patients underwent six dialysis sessions with the same routine dialysis parameters; only the dialyzer and/or the dialysis modality varied: FX80 in HD, FDY 180 in HD, Clearum HS17 in HDF, Elisio 19H in HDF, Vitapes 180 in HDF, and FX80 in post-dilution HDF. The reduction ratios (RR) of urea, creatinine, ß2-microglobulin, myoglobin, κFLC, prolactin, α1-microglobulin, α1-acid glycoprotein, λFLC, and albumin were compared intraindividually. Dialysate albumin loss was also measured. RESULTS: Both membranes FDY and FX80 are high-flux dialyzers and are applied here in high-flux HD. The average RR of ß2-microglobulin was slightly lower in the two HD treatments than in the HDF treatments. Comparison of dialysis treatments revealed that the PEPA FDY dialyzer in the HD modality was more effective than the FX80 dialyzer in high-flux HD and was as effective as post-dilution HDF, especially in terms of myoglobin, κFLC, prolactin, α1-microglobulin, and λFLC RRs. The FDY treatments obtained similar albumin RR in blood and slightly higher dialysate albumin loss, although the values were clinically acceptable. CONCLUSIONS: The most recently developed PEPA dialyzers in the HD modality were as effective as all treatments in the HDF modality and were clearly superior to high-flux helixone HD treatment. These results confirm that this dialyzer should be categorized within the medium cut-off (MCO) membrane classification.

Frailty in hemodialysis patients: results of a screening program and multidisciplinary interventions.

Background: The number of frail patients of advanced age with end-stage kidney disease (ESKD) undergoing hemodialysis is increasing globally. Here we evaluated a frailty screening program of ESKD patients starting hemodialysis, and subsequent multidisciplinary interventions. Methods: This was a prospective observational study of ESKD patients in a hemodialysis program. Patients were evaluated for frailty (Fried frail phenotype) before and after a 12-month period. Patients followed standard clinical practice at our hospital, which included assessment and multidisciplinary interventions for nutritional (malnutrition-inflammation score, protein-energy wasting), physical [short physical performance battery (SPPB)] and psychological status. Results: A total of 167 patients (mean ± standard deviation age 67.8 ± 15.4 years) were screened for frailty, and 108 completed the program. At screening, 27.9% of the patients were frail, 40.0% pre-frail and 32.1% non-frail. Nutritional interventions (enrichment, oral nutritional supplements, intradialytic parenteral nutrition) resulted in stable nutritional status for most frail and pre-frail patients after 12 months. Patients following recommendations for intradialytic, home-based or combined physical exercise presented improved or stable in SPPB scores after 12 months, compared with those that did not follow recommendations, especially in the frail and pre-frail population (P = .025). A rate of 0.05 falls/patient/year was observed. More than 60% of frail patients presented high scores of sadness and anxiety. Conclusions: Frailty screening, together with coordinated interventions by nutritionists, physiotherapists, psychologists and nurses, preserved the health status of ESKD patients starting hemodialysis. Frailty assessment helped in advising patients on individual nutritional, physical or psychological needs.

Tricuspid regurgitation, right ventricular function, and renal congestion: a cardiorenal triangle.

There is a growing interest in the evaluation of tricuspid regurgitation due to its increasing prevalence and detrimental impact on clinical outcomes. Historically, it has been coined the "forgotten" defect in the field of valvular heart disease due to the lack of effective treatments to improve prognosis. However, the development of percutaneous treatment techniques has led to a new era in its management, with promising results and diminished complication risk. In spite of these advances, a comprehensive exploration of the pathophysiological mechanisms is essential to establish clear indications and optimal timing for medical and percutaneous intervention. This review will address the most important aspects related to the diagnosis, pathophysiology and treatment of tricuspid regurgitation from a cardiorenal perspective, with a special emphasis on the interaction between right ventricular dysfunction and the development of hepatorenal congestion.

Results of Salt Intake Restriction Monitored with the New Sodium Control Biosensor.

INTRODUCTION: Adherence to a low-sodium (Na) diet is crucial in patients under hemodialysis, as it improves cardiovascular outcomes and reduces thirst and interdialytic weight gain. Recommended salt intake is lower than 5 g/day. The new 6008 CAREsystem monitors incorporate a Na module that offers the advantage of estimating patients' salt intake. The objective of this study was to evaluate the effect of dietary Na restriction for 1 week, monitored with the Na biosensor. METHODS: A prospective study was conducted in 48 patients who maintained their usual dialysis parameters and were dialyzed with a 6008 CAREsystem monitor with activation of the Na module. Total Na balance, pre-/post-dialysis weight, serum Na (sNa), changes in pre- to post-dialysis sNa (ΔsNa), diffusive balance, and systolic and diastolic blood pressure were compared twice, once after 1 week of patients' usual Na diet and again after another week with more restricted Na intake. RESULTS: Restricted Na intake increased the percentage of patients on a low-Na diet (<85 Na mmol/day) from 8% to 44%. Average daily Na intake decreased from 149 ± 54 to 95 ± 49 mmol, and interdialytic weight gain was reduced by 460 ± 484 g per session. More restricted Na intake also decreased pre-dialysis sNa and increased both intradialytic diffusive balance and ΔsNa. In hypertensive patients, reducing daily Na by more than 3 g Na/day lowered their systolic blood pressure. CONCLUSIONS: The new Na module allowed objective monitoring of Na intake, which in turn could permit more precise personalized dietary recommendations in patients under hemodialysis.

Efficacy and Safety of the Medium Cut-Off Elisio HX Dialyzer.

INTRODUCTION: The medium cut-off Elisio HX dialyzer by Nipro became commercially available in Europe in 2021, but there are still no reports of in vivo data. This study aimed to evaluate the safety and efficacy of it compared with previously evaluated hemodialysis (HD), expanded HD (HDx), and postdilution hemodiafiltration (HDF) treatments. METHODS: A prospective study was carried out on 18 patients who underwent 5 dialysis sessions: FX80 Cordiax in HD, Elisio H19 in HD, Elisio HX19 in HDx, Theranova 400 in HDx, and FX80 Cordiax in HDF. The reduction ratios of urea, creatinine, ß2-microglobulin, myoglobin, kappa FLC, prolactin, α1-microglobulin, α1-acid glycoprotein, lambda FLC, and albumin were compared. Dialysate albumin loss was measured. RESULTS: The comparison between the different dialysis modalities revealed no difference for small molecules, but HDx and HDF were significantly more efficient than HD for medium and large molecule removal. The efficacy of Elisio HX19 dialyzer in HDx was similar to the Theranova 400, superior to both dialyzers in HD, and slightly lower than HDF. Albumin losses in dialysate with HD dialyzers were less than 1 g, but between 1.5 and 2.5 g in HDx and HDF. The global removal score (GRS) values with HDx treatments were statistically significantly higher than those with HD. The highest GRS was obtained with the helixone dialyzer in HDF. CONCLUSIONS: The new MCO dialyzer, Elisio HX, performs with excellent behavior and tolerance. It represents an upgrade compared to their predecessor and is very close to the removal capacity of HDF treatment.

Creatine Kinase Elevation in Autosomal Dominant Polycystic Kidney Disease Patients on Tolvaptan Treatment.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary cause of end-stage kidney disease. Currently, tolvaptan is the only treatment that has proven to delay disease progression. The most notable side effect of this therapy is drug-induced liver injury; however, recently, there have been two reports of creatine kinase (CK) elevation in ADPKD patients on tolvaptan treatment. We set out to monitor and determine the actual incidence of CK elevation and evaluate its potential association with other clinical factors. METHODS: This is an observational retrospective multicenter study performed in rapidly progressive ADPKD patients on tolvaptan treatment from Barcelona, Spain. Laboratory tests, demographics, treatment dose, and reported symptoms were collected from October 2018 to March 2021. RESULTS: Ninety-five patients initiated tolvaptan treatment during follow-up. The medication had to be discontinued in 31 (32.6%) patients, primarily due to aquaretic effects (12.6%), elevated liver enzymes (8.4%), and symptomatic or persistently elevated CK levels (3.2%). Moreover, a total of 27 (28.4%) patients had elevated CK levels, with most of them being either transient (12.6%), mild and asymptomatic (4.2%), or resolved after dose reduction (3.2%) or temporary discontinuation (2.1%). CONCLUSION: We pre-sent the largest cohort that has monitored CK levels in a real-life setting, finding them elevated in 28.4% of patients. More research and monitoring will help us understand the clinical implications and the pathophysiological mechanism of CK elevation in this population.

Acute hepatitis post arteriovenous graft thrombectomy of hemodialysis vascular access.

The following paper reports the case of a woman on in-center hemodialysis through an arteriovenous graft, who attended with an acute vascular access thrombosis. Post percutaneous thrombectomy, the patient presented a rare case of self-limited acute hepatitis secondary to the revascularization procedure. We explain the probable trigger for this complication, its pathophysiology, management, and evolution.

Conductivity variations and changes in serum sodium concentration during dialysis related to monitor switching.

INTRODUCTION: The sodium gradient during hemodialysis sessions is one of the key factors in sodium balance in patients with dialysis-dependent chronic kidney disease; however, until the appearance of the new monitors with sodium modules, the differences between prescribed and measured sodium have been understudied. The present study aimed to compare the impact on the measured conductivity and the initial and final plasma sodium after changing the 5008 Cordiax to the new 6008 Cordiax monitor. MATERIAL AND METHODS: 106 patients on hemodialysis were included. Each patient underwent 2 dialysis sessions in which only the monitor was varied. The variables collected were dialysate, sodium and bicarbonate prescribed, real conductivity, initial and final plasma sodium measured, and the calculated sodium gradient (ΔPNa). RESULTS: The change of dialysis monitor showed small but statistically significant differences in the initial (138.14mmol/L with 5008 vs. 138.81mmol/L with 6008) and final plasma sodium (139.58mmol/L vs. 140.97mmol/L), as well as in the actual conductivity obtained (13.97 vs. 14.1mS/cm). The ΔPNa also increased significantly. CONCLUSION: The change from 5008 to 6008 monitor is associated with increased conductivity, leading the patient to end the sessions with higher plasma sodium and ΔPNa. Knowing and confirming this change will allow us to individualize the sodium prescription and avoid possible undesirable effects. It could be the preliminary study to explore the new sodium biosensor incorporated into the new generation of monitors.

The metabolomic differential plasma profile between dialysates. Pursuing to understand the mechanisms of citrate dialysate clinical benefits.

Background: Currently, bicarbonate-based dialysate needs a buffer to prevent precipitation of bicarbonate salts with the bivalent cations, and acetate at 3-4 mmol/L is the most used. However, citrate is being postulated as a preferred option because of its association with better clinical results by poorly understood mechanisms. In that sense, this hypothesis-generating study aims to identify potential metabolites that could biologically explain these improvements found in patients using citrate dialysate. Methods: A unicentric, cross-over, prospective untargeted metabolomics study was designed to analyze the differences between two dialysates only differing in their buffer, one containing 4 mmol/L of acetate (AD) and the other 1 mmol/L of citrate (CD). Blood samples were collected in four moments (i.e., pre-, mid-, post-, and 30-min-post-dialysis) and analyzed in an untargeted metabolomics approach based on UPLC-Q-ToF mass spectrometry. Results: The 31 most discriminant metabolomic variables from the plasma samples of the 21 participants screened by their potential clinical implications show that, after dialysis with CD, some uremic toxins appear to be better cleared, the lysine degradation pathway is affected, and branched-chain amino acids post-dialysis levels are 9-10 times higher than with AD; and, on its part, dialysis with AD affects acylcarnitine clearance. Conclusion: Although most metabolic changes seen in this study could be attributable to the dialysis treatment itself, this study successfully identifies some metabolic variables that differ between CD and AD, which raise new hypotheses that may unveil the mechanisms involved in the clinical improvements observed with citrate in future research.

Comparison of four medium cut-off dialyzers.

Background: Recently, several pharmaceutical companies have developed new medium cut-off (MCO) dialyzers for expanded hemodialysis (HDx). This study aimed to compare the safety and efficacy of four MCO dialyzers, against each other and versus high-flux hemodialysis (HD) and post-dilution hemodiafiltration (HDF). Methods: A prospective study was carried out on 23 patients who underwent six dialysis sessions: two sessions with the FX80 Cordiax in HD and HDF, and four HDx sessions with the Phylther 17-SD, Vie-18X, Elisio HX19 and Theranova 400 dialyzers. The reduction ratios (RRs) of urea, creatinine, ß2-microglobulin, myoglobin, kappa free immunoglobulin light chain (κFLC), prolactin, α1-microglobulin, α1-acid glycoprotein, lambda (λFLC) and albumin were compared. Dialysate albumin loss was also measured. Results: The differences in efficacy between the evaluated dialyzers were minimal in small molecules and even up to the size of ß2-microglobulin. The main differences were found between myoglobin, κFLC, prolactin, α1-microglobulin and λFLC RRs, in which all four MCO dialyzers, with similar efficacy, were clearly superior to HD and slightly inferior to HDF treatment. Albumin losses in the dialysate with HD dialyzers were <1 g and between 1.5 and 2.5 g in HDx and HDF. The global removal score values were similar in all four HDx treatments, and again significantly higher than those with HD. Conclusions: The results of the four MCO dialyzers evaluated in this study showed good efficiency, with no significant performance differences between them while being completely safe in terms of albumin loss. Likewise, the study confirms the superiority of HDx over high-flux HD with an efficacy close to that of post-dilution HDF.