Assessment of complement activation during extracorporeal circulation by measurement of complement split C3d

Area of Science:

• Nephrology
• Immunology
• Biomaterials Science

Background:

• Hemodialysis involves extracorporeal circulation, potentially activating the complement system.
• Dialyzer membranes vary in biocompatibility, influencing patient response.
• Leukopenia and complement activation are key indicators of hemodialysis-related inflammatory responses.

Purpose of the Study:

• To investigate the impact of different dialyzer membranes on complement activation markers.
• To establish a relationship between dialyzer membrane properties and hemodialysis-induced leukopenia.
• To evaluate plasma C3d as a cumulative marker for complement activation during hemodialysis.

Main Methods:

• Comparison of various dialyzer membranes.
• Measurement of leukocyte count.
• Quantification of plasma C3d, C5a/C5ades-Arg, and total hemolytic complement levels.

Main Results:

• A correlation was observed between C5a/C5ades-Arg formation in the dialyzer and hemodialysis-induced leukopenia.
• Arterial plasma C3d served as a reliable cumulative marker for complement activation.
• C3d generation kinetics in the artificial kidney mirrored C5a/C5ades-Arg formation.
• Total hemolytic complement decreased transiently with all membranes but did not indicate biocompatibility.

Conclusions:

• Plasma C3d determination is a more efficient method for assessing complement activation during hemodialysis compared to previous techniques.
• Dialyzer membrane choice influences complement activation and leukopenia.
• C3d is a valuable biomarker for monitoring hemodialysis-related complement activation.