Toray has created a new generation of dialyzers, the polysulphone (TS) UL series, and polymethylmethacrylate (PMMA) NF‐U series, which offer enhanced efficacy over the previous TS‐S series and NF‐H series. The aim of this study was to evaluate the safety and efficacy of these dialyzer series versus contrasted expanded hemodialysis (HDx) and postdilution hemodiafiltration (HDF). We conducted a prospective study in 12 patients. Each patient underwent six dialysis sessions: FX80 Cordiax in HD, Toraysulfone TS‐1.8 UL in HD, Theranova 400 in HDx, polymethylmethacrylate (PMMA) NF‐2.1 U in HDF, Toraysulfone TS‐2.1 UL in HDF, and FX80 Cordiax in HDF. The removal ratios (RRs) of urea, creatinine, ß2‐microglobulin, myoglobin, prolactin, α1‐microglobulin, α1‐acid glycoprotein, and albumin were compared intraindividually. Dialysate albumin loss was also measured. The RRs for β2‐microglobulin, myoglobin, prolactin, α1‐microglobulin, and α1‐acid glycoprotein were higher with the TS‐2.1 UL and FX80 Cordiax dialyzers in HDF than those obtained with HD treatments and NF‐2.1 U in HDF. The β2‐microglobulin, myoglobin, and prolactin RRs were also higher with HDx than those obtained with HD treatments. The myoglobin and prolactin RRs were higher with TS‐1.8 UL in HD than those obtained with helixone dialyzers in HD. Dialysate albumin loss was less than 3 g in all situations except in TS‐2.1 UL in HDF. The highest global removal score values were obtained with the TS‐2.1 UL and helixone dialyzers in HDF. Significant differences were found between all study situations. In conclusion, the new generation dialyzers, Toraysulfone TS Series UL and PMMA NF‐U series, show excellent behaviour and tolerance in HD and HDF, representing an upgrade versus their predecessor series. The higher permeability of the TS UL series has been proven with higher efficiency in HD and maximum performance in HDF. The new PMMA NF‐U series allows the use of HDF with good efficiency and complete safety.

Background Metabolic acidosis is a common problem in haemodialysis patients, but acidosis overcorrection has been associated with higher mortality. There is no clear definition of the optimal serum bicarbonate target or dialysate bicarbonate. This study analysed the impact of reducing dialysate bicarbonate from 35 to 32 mEq/L on plasma bicarbonate levels in a cohort of patients treated with online haemodiafiltration (OL-HDF). Methods We performed a prospective cohort study with patients in a stable chronic OL-HDF programme for at least 12 months in the Hospital Clinic of Barcelona. We analysed pre- and post-dialysis total carbon dioxide(TCO2) before and after dialysate bicarbonate reduction from 35 to 32 mEq/L, as well as the number of patients with a pre- and post-dialysis TCO2 within 19–25 and ≤29 mEq/L, respectively, after the bicarbonate modification. Changes in serum sodium, potassium, calcium, phosphorous and parathyroid hormone (PTH) were also assessed. Results We included 84 patients with a 6-month follow-up. At 6 months, pre- and post-dialysis TCO2 significantly decreased (26.78 ± 1.26 at baseline to 23.69 ± 1.92 mEq/L and 31.91 ± 0.91 to 27.58 ± 1.36 mEq/L, respectively). The number of patients with a pre-dialysis TCO2 >25 mEq/L was significantly reduced from 80 (90.5%) to 17 (20.2%) and for post-dialysis TCO2  >29 mEq/L this number was reduced from 83 (98.8%) to 9 (10.7%). PTH significantly decreased from 226.09 (range 172–296) to 182.50 (125–239)  pg/mL at 6 months (P < 0.05) and post-dialysis potassium decreased from 3.16 ± 0.30 to 2.95 ± 0.48 mEq/L at 6 months (P < 0.05). Sodium, pre-dialysis potassium, calcium and phosphorous did not change significantly. Conclusions Reducing dialysate bicarbonate concentration by 3 mEq/L significantly and safely decreased pre- and post-dialysis TCO2, avoiding acidosis overcorrection and improving secondary hyperparathyroidism control. An individualized bicarbonate prescription (a key factor in the adequate control of acidosis) according to pre-dialysis TCO2 is suggested based on these results.

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Background and Aims a growing number of octogenarians or older patients are being admitted to the intensive care unit (ICU). The aim of this study was to assess factors associated with acute renal replacement therapy (ARRT) requirement in these patients and the impact of ARRT on the 90-day ICU mortality. Also we aimed to identify prognostic factors associated with mortality risk in the group of patients that required ARRT. Method retrospective study of octogenarian or older patients admitted to the ICUs of Hospital Clínic de Barcelona from June 2007 to April 2019. Patients on chronic dialysis treatment or kidney transplant, and patients with limitation of therapeutic support or admitted for less than 48 hours were excluded. Results 217 patients were included in the study, of which 36.4% required ARRT. Use of vasoactive drugs and Sequential Organ Failure Assessment (SOFA) score on admission were higher in ARRT patients (p=0.009 and <0.001). Basal estimated glomerular filtration rate (eGFR) was lower in the ARRT cohort (p<0.001). Hospital and ICU length of stay were longer in the ARRT cohort (p<0.001). Ninety-day mortality was 58.2% in the ARRT cohort and 55.8% in the control cohort, without statistical differences. In the survival analysis, only female sex and non-renal SOFA ≥6.5 were significantly associated with mortality (p= 0.005 and 0.002 respectively) in the ARRT cohort. Conclusion mortality was not significatively increased in the octogenarian population that required and got ARRT respect to those who did not require it. Scores like SOFA can help in the process of decision making about initiation of ARRT.

Background and Aims Anti-glomerular basement membrane (anti-GBM) disease is an aggressive and rare glomerulopathy characterized by rapidly progressive loss of kidney function, leading to end stage kidney disease (ESKD) in a significant amount of cases. The main objective of our study was to determine whether anti-GBM titer correlated with the rate of activity in renal biopsy and long-term kidney survival in patients with anti-GBM, hence identifying patients who would potentially benefit from more intensive treatments. Method A retrospective analysis was performed on the cases of anti-GBM from our center that had both a positive biopsy and serology, from 2007 to 2019. Epidemiological data, anti-GBM levels on admission, kidney function at admission, discharge and follow-up, treatment and kidney biopsy findings were collected. All biopsies were reevaluated by a single, blinded pathologist and nephrologist. Based on a recent study by van Daalen et al, a chronicity and activity histopathological score was developed. The score was divided in glomerular and interstitial sections. In the glomerular section, a sclerotic pattern (>50% of glomeruli) was given 0 points in activity and 3 in chronicity, a mixed pattern was given 1 point in activity and chronicity, and a crescentic pattern (>50% with cellular crescents) was given 3 points in activity and 0 in chronicity. In the interstitial section, the presence of fibrosis and atrophy was given between 0 and 3 points in chronicity and the presence of tubulitis or interstitial infiltrate were given points in activity (0 to 1 and 0 to 3 respectively). The presence of neutrophils in the infiltrate was given one extra point in activity. Spearman correlation was performed between anti-GBM levels and our biopsy score. Results Twelve cases were identified, with a median Anti-GBM titer at admission of 292 U/mL (IQR 40-1517). Ten patients were treated with cyclophosphamide, 1 with rituximab plus cyclophosphamide and 1 with only rituximab. All patients received treatment with metilprednisona and plasma exchange with a median number of sessions of 8 (range: 6-12). Only one patient was not in ESKD during follow-up (35 months), so correlation with long-term kidney survival could not be performed. On the other hand, high antibody titers correlated with more activity on biopsy (correlation coefficient 0.592, p= 0.042) and less chronicity (correlation coefficient -0.657, p= 0.02). Conclusion These results suggest that patients who present with higher titers have more acute inflammation and less chronicity in renal parenchima, and therefore could benefit from more intensive treatment that changes the natural history of this aggressive disease. It would be interesting to study this score in larger and multicentric cohorts in order to produce more definitive conclusions.