#5216 DIALYSIS MODALITIES, URAEMIC TOXINS AND MICROINFLAMMATION: CAN WE DO MORE? Free

Patients on hemodialysis (HD) have a high morbidity and mortality from cardiovascular disease (CVD). Despite advances in HD -new membranes, such as medium cut-off (MCO) or techniques that combine diffusion+convection+adsorption such as hemofiltration with ultrafiltrate regeneration- (HFR)-, only online hemodiafiltration (OL-HDF) has been shown to improve survival in these patients. It is important to investigate whether the new HD filters/techniques help to improve the clearance of uremic toxins that are difficult to eliminate (those bound to proteins) and molecules associated with microinflammation in uremic patients, due to the important role they play in the development of CVD.

To study whether different HD membrane-techniques improve the clearance of uremic toxins and/or parameters associated with the microinflammation present in these patients.

12 stable patients on HD were included, with a minimum time on HD of 3 months. Each patient underwent 4 random HD sessions in which only the dialysis membrane and/or the modality were changed. They underwent an HD session with a high-flux polyphenylene membrane, another session with this same filter in OL-HDF, another with MCO membrane, and another with HFR-H. All sessions were held in a short period. In all of them, pre- and post-dialysis blood samples were taken to assess the clearance of both conventional uremic toxins and protein-bound toxins (indoxyl-sultate and p-cresol), as well as molecules associated with the microinflammation process (proinflammatory monocytes: CD14+/CD16++ and proinflammatory cytokines).

When evaluating the effect of the different HD techniques on the percentage of proinflammatory monocytes, a relevant, although not significant, decrease was observed in the OL-HDF and HFR-H techniques. Likewise, when evaluating the profile of markers of inflammatory activity, such as IL-12B, IL-17C, CD8A or TNFRSF9, a significant decrease was observed after the dialysis session in HFR-H compared to the rest of the techniques analyzed.

After analyzing the results of our study, the HD technique that combines convection+adsorption+diffusion (with a novelty high permeability filter), HFR-H, is the only one that has shown significantly greater clearance of proinflammatory cytokines, as well as a greater elimination of activated monocytes and protein-bound toxins, although without reaching statistical significance. These results, although preliminary, are promising and open up a new line of research to improve CVD in HD patients.