P1051ASINGLE SESSION AND WEEKLY BETA 2 MICROGLOBULIN REMOVAL DURING SHORT FREQUENT HEMODIALYSIS USING PHYSIDIA TECHNOLOGY
Authors: Thomas Michel , Vincent Eric , Todorova Veliana 
Published: June 2020

Abstract

Background and Aims
S3 Physidia monitor is a dedicated system for short frequent hemodialysis at home based on push pull dialysis mode. Clinical data is provided to show the Beta 2 microglobulin elimination, used as a model for middle molecule removal. The aim of the study is to compare Beta 2 microglobulin removal between hemodialysis systems with low dialysate flow rate and conventional hemodialysis or hemodiafiltration.

Method
Analyzed data is collected during multicentric clinical study performed to evaluate the safety and performances level with S3 Physidia system.
This clinical investigation has been conducted in accordance with the Good Clinical Practices (Helsinki Declaration), every patient was informed by the investigator and has signed the consent form prior to the completion of the study. The project has been approved by the local Committee and authorities.
Anonymized data of 10 patients (age: 55.3 +/- 12.3 years, weight: 72.8 +/- 17.2 kg) is collected during 126 dialysis sessions (blood flow rate: 293 +/- 24 ml/min, dialysate flow rate: 190 +/- 14 ml/min).
The convection volume (Ultrafiltration and back filtration generated by the push pull technique) is between 1 to 8 l per session (dialyzer used: Smartflux HFP190).
For each session, Beta 2 microglobulin (β2M) removal rate is calculated by using pre and post dialysis β2M blood concentrations. Post concentration is corrected by using Bergström formula to take into account the hemoconcentration and rebound. Both single session (2hours) and weekly (12 hours/week) β2m removal rates were calculated.
Single session and weekly β2m removal levels are compared to published data with conventional hemodialysis or post dilution hemodiafiltration.
Weekly dialysis performance is evaluated according to the standardized Kt / V (sdt) according to the Gotch calculation method.

Results
Using S3 daily hemodialysis, weekly dialysis diffusive performance for urea (standardized Kt / V is 2.56 +/- 0.39, higher than KDIGO recommendations for frequent dialysis (min 2.1).
β2M removal rate per session is 52.9 +/- 6.6 % with pre dialytic concentration average value of 25 mg/l corresponding to 73 mg of β2M removed per session. Calculated weekly β2M removal is 438 mg.
These results are compared to β2M removal obtained by standard treatment procedures (ref1) and by short frequent hemodialysis using diffusive low dialysate flow (Nx Stage system One, ref 2).
During conventional hemodialysis (4h, 3 sessions per week), the β2M removal rate is between 60 to 80 % corresponding to a removal of 300 to 380 mg/week (ref 1)
During high volume post dilution hemofiltration (4h, 3 sessions per week, convection &gt; 20 l per session), the average β2M removal rate is 80% corresponding to a removal of 380 mg/week (ref 1)
With Nx Stage device, without convective component, single session β2M removal rate is between 40 and 50 % depending on blood flow rate (maximum obtained with blood flow rate 400 ml/min) (ref 2)
Ref 1: J. Potier et al, Int J Artif Organs. 2016 Nov 11;39(9):460-470
Ref 2 : M. Leclerc et al, Blood Purif 2018;46:279–285

Conclusion
β2M reduction rate obtained with the S3 Physidia system is greater than 50%, removing any dowry concerning the performance of a low dialysate flow rate system. The convective component, provided by the push pull technique, must be confirmed, but these initial results are encouraging (reduction rate &gt; 50% despite a relatively low blood flow rate).
Due to the frequency, the quantity of β2M weekly removed is higher than that obtained with conventional treatment methods.