Related Experiment Videos
Pyrogen retention by highly permeable synthetic membranes during in vitro dialysis
G Lonnemann1, L Sereni, H D Lemke
1Gemeinschaftspraxis, Eickenhof, Langenhagen, Germany.
Abstract:
Pyrogen permeability of the new highly permeable synthetic membrane polyethersulfone (DIAPES) was compared to polysulfone in vitro dialysis experiments with heparinized human donor blood in the blood compartment. After sterile dialysis for 5 min, dialysate was contaminated with a culture filtrate of Pseudomonas aeruginosa using high and moderate challenge doses (Limulus assay reactivity 20,000 EU/ml and 50 EU/ml, respectively). Whole blood samples were separated from the blood compartment during the sterile (5 min) and contaminated (60 min) phases of dialysis and incubated for 6 h at 37 degrees C. Blood samples were lysed, and interleukin-1beta and tumor necrosis factor alpha were measured by specific ELISAs. Moderate dialysate contamination (50 EU/ml) did not induce detectable cytokine production in whole blood. High challenge dose (20,000 EU/ml) induced whole blood interleukin-1beta and tumor necrosis factor alpha production in the blood compartment, which was higher with DIAPES than with polysulfone after 30 min. After 60 min, membrane-dependent differences were no longer detectable. Pyrogen concentrations in the dialysate decreased with time indicating adsorption of cytokine-inducing substances to the dialyzer membrane. Pyrogens adsorbed to dialyzer membranes were resuspended during recirculation of sterile phosphate-buffered saline in the dialysate compartment and retained cytokine-inducing activity as seen from whole blood incubation experiments. DIAPES and polysulfone adsorbed pyrogens in the presence of whole blood. Pyrogen adsorption to the membrane polymer and/or to the protein coat on the membrane prevented the passage of pyrogens in the presence of moderately contaminated dialysate. High grade dialysate contamination caused breakthrough of pyrogens into the blood with DIAPES and polysulfone. In order to reduce the risk of a dialysis-dependent inflammatory response, dialysate of high bacteriological quality (ultrapure dialysate) should be mandatory.
Insights
New synthetic membranes (DIAPES) showed higher pyrogen adsorption than polysulfone during dialysis. However, both membranes allowed pyrogen breakthrough with high contamination, necessitating ultrapure dialysate to prevent inflammatory responses.
Area of Science:
- Biomaterials Science
- Nephrology
- Immunology
Background:
- Dialysis-induced inflammatory responses are a concern.
- Synthetic membranes play a role in pyrogen passage.
- Understanding pyrogen-membrane interactions is crucial for patient safety.
Purpose of the Study:
- To compare the pyrogen permeability of a new synthetic membrane, DIAPES, with polysulfone.
- To evaluate the impact of pyrogen contamination on cytokine production in vitro.
- To assess the role of dialyzer membranes in pyrogen adsorption and breakthrough.
Main Methods:
- In vitro dialysis experiments using heparinized human donor blood.
- Contamination of dialysate with Pseudomonas aeruginosa culture filtrate at high and moderate doses.
- Measurement of interleukin-1beta and tumor necrosis factor alpha in whole blood samples via ELISA.
- Assessment of pyrogen adsorption and elution from dialyzer membranes.
Main Results:
- Moderate pyrogen contamination did not induce cytokine production.
- High contamination led to increased cytokine production, initially higher with DIAPES.
- Both DIAPES and polysulfone adsorbed pyrogens, preventing passage with moderate contamination.
- Pyrogen breakthrough into blood occurred with both membranes under high contamination.
- Adsorbed pyrogens retained activity and could be re-suspended.
Conclusions:
- DIAPES and polysulfone membranes exhibit pyrogen adsorption properties.
- High-grade dialysate contamination can lead to pyrogen breakthrough with both membranes.
- Ultrapure dialysate is essential to minimize the risk of dialysis-dependent inflammatory responses.