Novel strategy for overcoming interference from anti-CD47 agents in pretransfusion testing

Area of Science:

• Immunology
• Transfusion Medicine
• Biotechnology

Background:

• CD47 acts as a crucial immune checkpoint in various cancers.
• Anti-CD47 therapies face challenges due to panreactivity, causing interference in pretransfusion compatibility testing by binding to red blood cells.

Purpose of the Study:

• To develop and evaluate immunomagnetic beads (IMBs) for adsorbing anti-CD47 monoclonal antibodies (mAbs).
• To mitigate the interference of anti-CD47 mAbs in pretransfusion compatibility testing.

Main Methods:

• Creation of two types of IMBs: IMB-OVCAR3 (coated with OVCAR3 cell lysate protein) and IMB-CD47 (coated with recombinant CD47 protein).
• Screening of IMB-OVCAR3 using flow cytometry and immunofluorescence staining.
• Adsorption of anti-CD47 mAbs from plasma using IMBs, followed by gel column agglutination testing and flow cytometry to assess interference removal.
• Analysis of IMB effects on irregular antibody screening and adsorption capacity over time.

Main Results:

• Successfully prepared IMBs efficiently adsorbed anti-CD47 mAbs from plasma within 30 seconds.
• IMBs significantly reduced anti-CD47 mAb interference in both simulated and clinical samples.
• IMBs demonstrated no adsorption of irregular antibodies, preserving test specificity.
• Both IMB formulations maintained their adsorption capacity for up to 3 weeks when stored in a preservation solution.

Conclusions:

• IMB-OVCAR3 and IMB-CD47 are effective tools for removing CD47 interference in transfusion compatibility testing.
• These IMBs offer a novel solution for accurate blood compatibility assessments in transfusion laboratories.
• The developed IMBs ensure reliable pretransfusion testing by specifically targeting and removing anti-CD47 mAb interference.