Abstract: Background and Objectives:Human anti-mouse antibodies (HAMAs) are relatively common in human serum and may interfere with therapeutic and diagnostic mouse monoclonal antibodies (MoAbs). We developed a simple particle agglutination test (PaGIA) for the detection of HAMAs. Design and Methods:Red-dyed high density particles were coated with monoclonal mouse IgG. These particles were incubated in the reaction chamber of a gel-card together with serum samples obtained from healthy blood donors (n=32), and patients with clinically proven autoimmune thrombocytopenia (AITP; n=26). Positive reactions were defined by a layer of particles on top of the gel or agglutinated particles dispersed throughout the gel matrix. Furthermore, MoAb-coated particles were subjected to flow cytometry and the results were compared with the new HAMA PaGIA. Results:HAMAs were detectable in 33% of serum samples tested (n=58). Results from flow cytometric analysis revealed a high parallel to those obtained by the PaGIA. Interestingly, we observed an increased incidence of HAMAs in AITP patients (42%) compared to healthy blood donors (26%). Interpretation and Conclusion:The new HAMA PaGIA allows a specific and easy, rapid detection of HAMAs and is suitable for large scale testing.
