Effect of blood microfilters on complement activity in human plasma

Area of Science:

• Biomaterials Science
• Immunology
• Medical Device Engineering

Background:

• Many blood-contacting medical devices are safe for cellular and coagulation aspects of blood.
• However, their potential to activate the complement system remains largely unevaluated.
• The complement system plays a crucial role in innate immunity and inflammation.

Purpose of the Study:

• To investigate the complement-activating potential of specific biomaterials used in blood microfilters.
• To quantify the generation of C3a, a marker of complement activation, by different filter materials.
• To compare the C3a generation between nylon/polypropylene and polyester/polypropylene filter combinations.

Main Methods:

• Incubation of heparinized plasma with blood microfilters composed of different material combinations (nylon/polypropylene and polyester/polypropylene).
• Measurement of C3a generation using validated immunoassays.
• Statistical analysis to determine the significance of observed C3a generation (p-values reported).

Main Results:

• Both nylon/polypropylene and polyester/polypropylene microfilters induced significant C3a generation in heparinized plasma.
• The nylon/polypropylene combination produced significantly higher levels of C3a (p < 0.01) compared to the polyester/polypropylene combination (p < 0.05).
• This indicates a material-dependent difference in complement activation.

Conclusions:

• Blood microfilters utilizing nylon/polypropylene or polyester/polypropylene materials can activate the complement system.
• The nylon/polypropylene combination demonstrates a greater capacity for complement activation.
• These findings highlight the importance of evaluating complement activation by medical devices used in cardiopulmonary bypass.