Improvement for identification of heterophile antibody interference and AFP hook effect in immunoassays with multiplex suspension bead array system.

BACKGROUND: A variety of immunoassays including multiplex suspension bead array have been developed for tumor marker detections; however, these assays could be compromised in their sensitivity and specificity by well-known heterophile antibody interference and hook effect. METHODS: Using Luminex® multiplex suspension bead arrays, we modified protocols with two newly-developed solutions that can identify heterophile antibody interference and AFP hook effect. Effectiveness of the two solutions was assessed in serum samples from patients. RESULTS: Concentrations of 9 tumor markers in heterophile antibody positive samples assayed with Solution A, containing murine monoclonal antibodies and mouse serum, were significantly reduced when compared with those false high signals assayed without Solution A (all p<0.01). With incorporation of Solution H (fluorescent beads linked with AFP antigen), a new strategy for identification of AFP hook effect was established, and with this strategy AFP hook effect was identified effectively in serum samples with very high levels of AFP. CONCLUSIONS: Two proprietary solutions improve the identification of heterophile antibody interference and AFP hook effect. With these solutions, multiplex suspension bead arrays provide more reliable testing results in tumor marker detection where complex clinical serum samples are used.