Background: A novel class of membranes, medium cut-off (MCO) membranes, has recently been designed to achieve interesting removal capacities for middle and large middle molecules in hemodialysis (HD) treatments. The few studies published to date have reported contradictory results regarding middle-sized molecules when comparing MCO dialyzers versus dialyzers used in online hemodiafiltration (OL-HDF). Methods: A prospective, single-center study was carried out in 22 patients. Each patient underwent 9 dialysis sessions with routine dialysis parameters, one with an MCO dialyzer in HD and the other 8 with different dialyzers in OL-HDF. The removal ratio (RR) of urea, creatinine, β₂-microglobulin, myoglobin, prolactin, α₁-microglobulin, α₁-acid glycoprotein, and albumin was intraindividually compared. Albumin loss in dialysate was measured. We propose a global removal score ([urea_RR + β₂-microglobulin_RR + myoglobin_RR + prolactin_RR + α₁-microglobulin_RR + α₁-acid glycoprotein_RR]/6 – albumin_RR) as a new tool for measuring dialyzer effectiveness. Results: No significant differences in the RRs of small and middle molecular range molecules were observed between the MCO vs. OL-HDF dialyzers (range 60–80%). Lower RRs were found for α₁-microglobulin and α₁-acid glycoprotein without significant differences. The albumin RR was < 11% and dialysate albumin loss was < 3.5 g in all situations without significant differences. The global removal score was 54.9 ± 4.8% with the MCO dialyzer without significant differences. Conclusions: Removal of a wide range of molecular weights, calculated with the proposed global removal score, was almost equal with the MCO dialyzer in HD treatment compared with 8 high-flux dialyzers in high-volume OL-HDF without relevant changes in albumin loss. The global removal score could be a new tool to evaluate the effectiveness of dialyzers and/or different treatment modalities.

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.

Accurate quantification of indoxyl sulfate (IndS) and p-cresyl sulfate (pCS) is essential for understanding their role in chronic kidney disease (CKD) progression and for developing strategies to mitigate their harmful effects, including cardiovascular morbidity and renal fibrosis. Advances in liquid chromatography–high-resolution mass spectrometry (LC–HRMS) enable the integration of powerful diagnostic tools into clinical laboratories. Along with accurate quantification, precise mass measurements allow for untargeted compound identification. Methods. An LC–HRMS was validated for quantifying IndS and pCS in human serum, following EMA guidelines. The method involved protein precipitation with methanol, micro-LC for chromatographic separation, and detection based on accurate mass, with simultaneous high-resolution full-scan acquisition. Clinical samples from patients with varying degrees of renal insufficiency and samples obtained before and after hemodiafiltration were analyzed. Results. The method demonstrated acceptable linearity, precision, and accuracy. The measurement range for both analytes was from 100 to 40,000 ng/mL. Serum levels of IndS and pCS correlated with decreased renal function. After hemodiafiltration, there was a significant reduction of IndS (50%) and pCS (43%). Simultaneous untargeted analysis allowed to identify metabolites significantly underexpressed after hemodiafiltration. Conclusions. An accurate LC–HRMS method was validated for the quantification of IndS and pCS serum levels in patients with CKD, providing insights into toxin dynamics and enabling untargeted metabolic evaluation.

Background: High-volume online hemodiafiltration (OL-HDF) has proven to be the most efficient dialysis modality and to offer better clinical outcomes in patients on hemodialysis. Longer and more frequent dialysis sessions have demonstrated clinical and survival benefits. Methods: A single-center observational study of the first one hundred patients on nocturnal every-other-day OL-HDF was conducted with the aim of reporting the experience with this treatment schedule and evaluating analytical and clinical outcomes as well as the patient and technique survival. Results: Nocturnal OL-HDF on alternate days was highly accepted, with no adverse symptoms, good clinical tolerance, and maintained active work in 62%. Kt, and the convective volume increased from 67.6 ± 12 L to 105.4 ± 11.7 L, and from 27.1 ± 4.6 L to 48.1 ± 6.4 L, respectively, from the baseline to 24 months. An improved calcium–phosphate balance and blood pressure control were observed, as the use of phosphate binders and antihypertensive medications decreased from 76.7% to 3.3% and from 56.7% to 28.3%, respectively. Furthermore, 58.3% of patients required phosphate supplementation in the dialysis fluid to prevent intradialytic hypophosphatemia. Additionally, doses of iron and erythropoiesis-stimulating agents were reduced. The global patient survival was 94% at the end of the follow-up. It was higher in those on the transplant waiting list, with 98.1% survival compared to 84.6% in non-wait-listed patients at 24 months. The main reason for treatment discontinuation was kidney transplantation, accounting for 78.4% of the 88 withdrawals, while death was the leading cause of discontinuation in non-listed patients (41.6%). Conclusions: Nocturnal every-other-day OL-HDF is a well-tolerated dialysis regimen that offers significant clinical benefits, which may positively impact morbidity and mortality. Additionally, it allows patients to integrate the treatment into their social and occupational lives.

The dialysis membrane based on a hydrophilic polymer (Hydrolink NV) was designed to enhance the movement of adsorbed water at the blood–membrane interface, aiming to achieve antithrombogenic and antifouling effects. This study aimed to assess the performance and albumin loss of the Hydrolink NV dialyzer in hemodialysis (HD) and post-dilution hemodiafiltration (HDF) with different infusion flows (Qis) and compare it with the hydrophilic FX CorAL dialyzer in post-dilution HDF. A prospective study was carried out in 20 patients. Patients underwent five dialysis sessions with the same routine dialysis parameters: four sessions with the Toraylight NV 2.1 (HD, post-dilution HDF with 50, 75 or auto-substitution Qi) and one with the FX CorAL 800 (post-dilution HDF with auto-substitution Qi). The reduction ratios’ (RRs’) wide range of molecular weight molecules were assessed and the dialysate albumin loss was quantified. The lowest β₂-microglobulin, indoxyl-sulfate, and p-cresyl sulfate RR values were observed with the Toraylight NV 2.1 in HD, and they improved progressively with an increased Qi, without differences being observed between the two dialyzers in auto-substitution. A different removal profile was observed in terms of myoglobin, kFLC, prolactin, α₁-microglobulin, α₁-acid glycoprotein, and λFLC, whose RRs also improved progressively with an increased Qi but were significantly higher with the Toraylight NV than the CorAL in the same convective condition. There were significant differences in the albumin dialysate losses, with the highest value obtained with the Toraylight NV in auto-substitution HDF, with more than 50% of patients surpassing 5 g per session. The Toraylight NV dialyzer has great potential for efficacy but should be used at the optimal convective volume (Qi not exceeding 75 mL/min or FF not exceeding 25%) to avoid excessive albumin loss.

Objectives: The communication of critical results (CR) is considered an essential role in clinical laboratories to ensure patient safety. This is especially relevant to outpatients, who are non-hospitalized and more difficult to locate. In our laboratory, there is a specific protocol for CR management that sets up the communication pathway to adequately provide these results to clinicians. The aim of this study is to evaluate the impact of CR reporting on outpatient care. Methods: This is a retrospective study focused on CR for biochemistry parameters in a clinical laboratory of a Spanish tertiary hospital during 2019. A total of 156 CR were determined and properly provided to clinicians. We collected CR, age, gender, and the requesting department. We also collected the medical action data resulting from the communication of the CR. Results: Seventy-six outpatients (49%) were properly treated because of effective CR communication. Hypoglycemia was the most frequent event (33%), however, the greatest clinical impact was observed for patients with hyponatremia (100%), hyperkalemia (62%), hypokalemia (60%), and hypercalcemia (57%). Based on these findings, we evaluated new glucose alert thresholds depending on whether or not the outpatient was diabetic (1.7 and 2.2 mmol/L, respectively). Based on these new thresholds, we established a CR reporting protocol with 69% effectiveness in outpatients. Conclusions: We demonstrate that CR communication in outpatients has a significant clinical impact. To increase the effectiveness of the CR reporting protocol, we propose to adjust alert thresholds according to pathology, department, and patient population.