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Published on: July 19, 2018
Reprocessed (high-flux) Polyflux dialyzers resist trans-membrane endotoxin passage and attenuate inflammatory markers
Geoffrey S Teehan1, Daqing Guo, Mary C Perianayagam
1Dialysis Research Laboratory, Division of Nephrology, Tufts-New England Medical Center, Boston, Mass., USA.
Background:
Bacterial contamination of dialysis water can contribute to the chronic microinflammatory state observed in dialysis patients. This study characterized the selective permeability of new and peroxyacetic acid/acetic acid/hydrogen peroxide (Renalin) reprocessed high-flux, polyarylethersulfone-polyvinylpyrrolidone (Polyflux-17R) dialyzers after exposure to endotoxin-contaminated dialysate during in vitro dialysis. Clinical correlation with pre-dialysis levels of systemic markers of inflammation, and clearance of middle molecules was also assessed in vivo.
Methods:
Six hemodialysis (HD) patients were enrolled in the study. After reuses 0, 1, 5, 10, and 15, the dialyzers were reclaimed and submitted to an in vitro dialysis circuit using standard dialysate and blood from healthy volunteers. New and reprocessed dialyzers were sequentially exposed to escalating doses of Pseudomonas aeruginosa endotoxin in the dialysate compartment, and whole blood tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) production was used as an index of reverse passage of endotoxin. In vivo, IL-6, C-reactive protein (CRP) and serum amyloid A (SAA) levels were measured to assess the impact of reprocessing on the systemic inflammatory response. Finally, pre- and post-dialysis samples were collected to measure urea and beta(2)-microglobulin (beta(2)-M) clearances.
Results:
During in vitro dialysis, blood-side endotoxin levels were undetectable following dialysate contamination. TNF-alpha production remained unchanged (p = NS), and IL-6 production fell significantly on reuses 0, 1, 10, and 15 (p = 0.03) suggesting membrane adsorption, as a result of reuse-dependent surface binding. In vivo, whereas IL-6 and SAA levels did not significantly differ (p = 0.90 and 0.59, respectively), CRP levels fell near significantly, over the course of 15 reuses (p = 0.06). In vivo, beta(2)-M clearance was not affected by the reuse technique (p = 0.28).
Conclusions:
This study provides in vitro and in vivo evidence arguing that high-flux Polyflux dialyzers provide more than adequate dialysis, while preventing the in vitro back-diffusion of bacterial endotoxin despite 15 reuses with Renalin. Clinically, this may translate into an attenuation of the microinflammatory milieu.
Insights
Reprocessed Polyflux dialyzers effectively prevent endotoxin back-diffusion, maintaining dialysis adequacy and potentially reducing inflammation in hemodialysis patients despite multiple uses.
Area of Science:
- Nephrology
- Biomaterials Science
- Infectious Disease Control
Background:
- Bacterial contamination in dialysis water contributes to chronic inflammation in hemodialysis patients.
- High-flux Polyflux dialyzers (Polyflux-17R) were evaluated for selective permeability after reprocessing.
- Reprocessing involved peroxyacetic acid/acetic acid/hydrogen peroxide (Renalin).
Purpose of the Study:
- To characterize the selective permeability of reprocessed Polyflux dialyzers against endotoxin.
- To assess the impact of dialyzer reuse on endotoxin passage and inflammatory markers.
- To evaluate clinical correlation with inflammation markers and middle molecule clearance.
Main Methods:
- Six hemodialysis patients underwent dialyzer reuse up to 15 times.
- In vitro dialysis assessed endotoxin passage using Pseudomonas aeruginosa endotoxin.
- Tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) production measured reverse endotoxin passage.
- In vivo, IL-6, C-reactive protein (CRP), and serum amyloid A (SAA) levels were monitored.
- Urea and beta(2)-microglobulin (beta(2)-M) clearances were measured.
Main Results:
- No endotoxin detected on the blood side during in vitro dialysis.
- IL-6 production decreased significantly with reuse, indicating membrane adsorption.
- In vivo, CRP levels showed a near-significant decrease over 15 reuses.
- Beta(2)-microglobulin clearance remained unaffected by dialyzer reuse.
Conclusions:
- Reprocessed high-flux Polyflux dialyzers prevent endotoxin back-diffusion effectively, even after 15 reuses with Renalin.
- The study provides in vitro and in vivo evidence of dialyzer safety and efficacy.
- Clinical outcomes may include an attenuation of the microinflammatory state in dialysis patients.
