Background and objectives: High-titer cold autoagglutinins (CA) interfere with the detection of alloantibodies against red-blood-cell antigens. The diagnostic procedure is extremely difficult, especially under pressure of time. It was the purpose of the study to find out whether quantitative IgG purification from serum or plasma by affinity chromatography facilitates the detection of IgG alloantibodies in the presence of high-titer IgM CA.
Materials and methods: Serum: IgM-chi CA, 0 degrees C titer = 65,000; five anti-IgG reactive alloantibodies. Affinity chromatography: HiTrap protein G 1-ml affinity column (Pharmacia Biotech, Uppsala, Sweden).
Results: All IgG alloantibodies were detectable in the eluate after affinity chromatography without interference of IgM CA.
Conclusion: IgG alloantibodies in the presence of high-titer IgM CA can be easily and rapidly detected under routine conditions by quantitative IgG purification from serum or plasma by affinity chromatography.