Biocompatibility of white cell filters as evaluated by complement activation

Area of Science:

• Biomedical Engineering
• Immunology
• Hematology

Background:

• White cell filters are crucial in blood component therapy to remove leukocytes.
• Assessing the biocompatibility of these filters, particularly their impact on the complement system, is essential for patient safety.
• Complement activation can lead to adverse inflammatory reactions.

Purpose of the Study:

• To evaluate the biocompatibility of nine different white cell filters.
• To determine if filtration activates the complement system in red cell concentrates (RBCs) and platelet concentrates (PCs).
• To identify any specific filters or conditions that may induce complement activation.

Main Methods:

• Plasma specimens from RBC and PC units were collected before and after filtration through nine different white cell filters.
• Complement activation products, including C3 activation products and terminal complement complex, were analyzed.
• Filtration was performed on both RBC concentrates and platelet concentrates.

Main Results:

• No significant increase in complement activation products was observed for most filters after filtering RBC and PC units.
• One filter, Imugard IG-500, showed a rise in C3 activation products when filtering multiple PCs.
• Imugard E caused a significant rise in C3 activation products when filtering plasma, unlike other filters.
• Platelet concentrates exhibited high baseline and storage-dependent C3 activation products, likely due to room temperature processing.

Conclusions:

• The majority of the tested white cell filters demonstrate good biocompatibility, as they do not activate the complement system.
• Specific filters (Imugard IG-500 and Imugard E) showed some potential for complement activation under certain conditions.
• Further investigation into complement activation in platelet concentrates is warranted, considering processing methods and storage.