Biocompatibility of dialysis membranes: a comparative study

Area of Science:

• Biomaterials Science
• Immunology
• Nephrology

Background:

• Hemodialysis is a life-sustaining treatment for kidney failure.
• Certain hemodialysis membranes can trigger adverse immune responses, including leukopenia.
• Complement activation, specifically C5a generation, is implicated in these reactions.

Purpose of the Study:

• To investigate the relationship between different hemodialysis membrane materials and the resulting white blood cell count changes.
• To assess the extent of complement activation, measured by plasma C5a anaphylatoxin levels, induced by various dialyzer membranes.
• To determine if C5a generation correlates with hemodialysis-induced leukopenia and to evaluate membrane biocompatibility.

Main Methods:

• Hemodialysis was performed using dialyzers with cuprophane, ethylenevinylalcohol, polycarbonate, polymethylmethacrylate, acrylonitrile, polysulfone, and polyacrylonitrile membranes.
• White blood cell counts were monitored during hemodialysis.
• Plasma C5a anaphylatoxin levels were measured to quantify complement activation.

Main Results:

• Cuprophane membranes induced significant leukopenia and high C5a generation.
• Ethylenevinylalcohol, polycarbonate, polymethylmethacrylate, and acrylonitrile membranes caused moderate leukopenia and mild C5a generation, with some showing no time-dependency.
• Polysulfone and polyacrylonitrile membranes did not induce leukopenia or increase C5a levels.

Conclusions:

• Complement-derived anaphylatoxin C5a generation plays a significant role in hemodialysis-induced leukopenia.
• The biocompatibility of hemodialysis membranes can be estimated by evaluating their leukopenic effect and C5a generation potential.
• Polysulfone and polyacrylonitrile membranes appear to be more biocompatible due to minimal immune activation.