#3205 A 2-YEAR STUDY FOR CHANGE OF PLASMA BIOMARKERS INCLUDING LARGER MIDDLE MOLECULES IN DIALYTIC PATIENTS USING DIALYZERS WITH MEDIUM CUT-OFF MEMBRANES
Authors: Jung Jong Hwan , Ahn Seon-Ho 
Published: June 2023

Abstract

Background and Aims
Uremic toxins with middle molecular weight usually develop uremic symptoms. The larger middle molecules are regarded as causative molecules of uremic symptoms. Medium cut-off (MCO) membrane newly developed can remove larger middle molecules which can be not removed through high flux membrane and hemodiafiltration. Larger middle molecules are mainly related to cardiovascular complications. Therefore, long-term use of MCO membrane may have beneficial effects in dialytic patients, in terms of lowering concentrations of larger middle molecules associated with cardiovascular complications. Now, we report interesting 2-year results of long-term use of MCO membrane in dialytic patients.

Method
Thirty-four patients undergoing hemodialysis were prospectively analyzed during 24 months. We randomly divided enrolled patients into two groups: control and MCO group. Patients in the control group used dialyzer with high flux membrane and patients in MCO group used MCO membrane. We measured plasma levels of biomarkers with 3 or 6-month to investigate efficacy of the MCO membrane for small (3-month interval) to larger middle molecules (6-month interval). Particularly, we performed comparative analysis with larger middle molecules in both groups. We calculated reduction ratio of biomarkers per one session at 24-month.

Results
The levels of larger middle molecules at baseline did not show significant difference between two groups. However, compared with the control group, plasma sclerostin levels at 6-month and 12-month in MCO group did not increased significantly compared to baseline levels. Plasma sclerostin were lower in MCO group throughout 2 year, but the significant difference of plasma sclerostin levels between two groups unfortunately disappeared after 12 months. The levels of other biomarkers including FGF23, leptin and GDF15, also did not show significant difference between two groups. However, β2MG levels in MCO group compared to control group decreased significantly throughout 2 years (MCO group: 18-month, p = 0.01 and 24-month, p &lt;0.001, respectively; control group: 18-month, p = 0.003 and 24-month, p &lt;0.067, respectively). Interestingly, even in MCO group, there was no statically significant decrease in total protein and albumin levels after 24 months (p = 0.429 and p = 0.101, respectively) (Figure 1). The reduction ratio of larger middle molecules compared to small molecules per one session prominently increased in MCO group (sclerostin, p &lt; 0.001; GDF15, p &lt;0.001; FGF23, p &lt;0.01; RBP4, p &lt;0.01; phosphate, p = 0.821; calcium, p = 0.827; CRP, p = 0.729 and β2MG, p = 0.286, respectively) (Figure 2).

Conclusion
Conclusively, in MCO group, the significant change of plasma sclerostin associated with cardiovascular complications after 12 months disappeared. However, in MCO group compared to control group, there was a continuous decrease of β2MG and RBP4 throughout study period. In addition, the clearance of larger middle molecules is also prominently high in MCO group. Interestingly, there were also no significant differences of albumin between 24-month and baseline in MCO group. Therefore, the MCO membrane can be a good tool for controlling uremic symptoms or sings without protein loss even when used for a relatively long time in dialytic patients.