Different complement and granulocyte activation in patients dialyzed with PMMA dialyzers

Area of Science:

• Nephrology
• Immunology
• Biochemistry

Background:

• Maintenance hemodialysis is a critical treatment for end-stage renal disease.
• Hollow fiber dialyzers are commonly used, with polymethylmethacrylate (PMMA) being a frequent material.
• Dialysis can trigger inflammatory responses, including complement activation and leukocyte activation.

Purpose of the Study:

• To investigate the extent of granulocyte degranulation during hemodialysis with PMMA dialyzers.
• To assess the relationship between granulocyte activation markers and complement activation products (C3a, C5a).
• To evaluate the impact of PMMA dialyzers on inflammatory markers in hemodialysis patients.

Main Methods:

• Measurement of plasma levels of complement components C3a and C5a.
• Quantification of granulocyte markers: lactoferrin, myeloperoxidase, and elastase in complex with alpha 1-proteinase inhibitor (E-alpha 1PI).
• Analysis of these markers in 10 patients undergoing maintenance hemodialysis with PMMA hollow fiber dialyzers before and during the procedure.

Main Results:

• Significant increases in plasma lactoferrin (166.5 to 712.5 ng/ml), myeloperoxidase (59.0 to 210.5 ng/ml), and E-alpha 1PI (114.2 to 681.8 ng/ml) were observed during dialysis.
• Plasma levels of C3a and C5a also increased, but to a lesser extent (C3a: 179.8 to 276.2 ng/ml; C5a: 55.7 to 101.1 ng/ml).
• The data suggest substantial granulocyte degranulation occurred despite limited complement activation.

Conclusions:

• Hemodialysis with PMMA hollow fiber dialyzers induces significant granulocyte degranulation.
• Granulocyte activation markers rise considerably during dialysis, indicating cellular response.
• The observed degranulation occurs independently of significant complement system activation and initial granulocytopenia.