MO652: Comparison of Two Medium Cut-Off Dialysers Versus Online Haemodiafiltration Regarding Albumin Loss and the Removal of a Broad Spectrum of Molecules
Authors: Martínez Miguel Patricia , Gimena Muñoz Rocio , Lizasoain Ignacio , López-Ongil Susana , Rodríguez-Puyol Diego , Manuel García-Segura Juan 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Ideally, the goal of haemodialysis (HD) is to maximize the removal of molecules smaller than 50 000 Daltons and minimize albumin loss. The techniques that seem to best achieve this purpose are online haemodiafiltration (HDF) and, recently, HD with medium cut-off membranes. On the other hand, we now have new methods, such as metabolomics, which allow us to detect potential new uraemic toxins in a non-targeted way. The aim of this study is to compare, in terms of efficacy and safety, online HDF using Fx800Cordiax, with 2 medium cut-off dialysers: Theranova 500 and the new Elisio21 HX dialyser.

METHOD
A total of 14 patients following a baseline treatment with online HDF using Fx800Cordiax were included. Each patient was considered his/her own control and was randomized to receive a consecutive 1-week haemodialysis treatment with Theranova 500 and Elisio 21HX. Pre- and post-HD blood samples were obtained on the middle day of the week with the three dialysers and proportional volumes of dialysate effluent were collected to quantify albumin loss during the session. We compared the reduction rate of differently sized molecules, as well as the variation rate in molecules smaller than 1000 Daltons, detected and quantified by NMR based chemometrics. For the analysis of differences, we used PLS-DA (Partial Least Squares-Discriminant Analysis) and ANOVA with multiple comparisons (Bonferroni).

RESULTS
The figure shows the result of the PLS-DA analysis carried out via the MetaboAnalyst web platform, showing, in terms of variable importance in projection (VIP) scores, the importance of different metabolites for the discrimination between the pre-HD and post-HD state regarding each of the three dialysis procedures. The metabolites that generate the 30 most important first signals or spectral bins are shown. The right-hand columns show the relative concentrations of the different metabolites on a colour-coded qualitative scale from red to blue. The predominance of dark blue in post-haemodialysis using online HDF (postCntr) indicates a greater elimination of metabolites with this technique, followed in efficacy by ElisioHX(postE), with a predominance of light blue and Theranova 500 (postT) in third place, with a predominance of orange. In any case, these are semi-quantitative differences. The table shows the reduction rate of different molecules and albumin losses.

CONCLUSION
In this study, haemodialysis with Theranova 500 has proven to be very similar in efficacy to online HDF, although with a significantly higher albumin loss. Haemodialysis with Elisio21HX resulted in lower removal of molecules around 20 000 Da compared to online HDF, but there was no significant difference compared to haemodialysis with Theranova 500. Albumin loss was significantly higher with Theranova 500 than with Elisio21HX. The semi-quantitative metabolomics study suggests that, in terms of clearance of low molecular weight metabolites (&lt;1 kDa), on-line HDF is more effective, followed by haemodialysis with Elisio HX and finally with Theranova 500.