DETECTION OF HETEROPHILE ANTIBODIES USING A MULTIPLEX FLOW IMMUNOASSAY

Background:  Infectious mononucleosis (IM) is a common syndrome characterized by a clinical triad of fever, pharyngitis, and lymphadenopathy.  Although several different microbial pathogens cause IM-like disease, approximately 90% of cases are caused by infection with Epstein-Barr virus (EBV).  The diagnosis of IM is generally made based on characteristic clinical findings and the detection of heterophile antibodies.  Current assays (rapid agglutination and immunochromatographic) used to test for heterophile antibodies are effective in 80-85% of cases of IM.  However, these methods require manual testing and are subjective, allowing for potential variability in the interpretation of results. 

Methods:  With the need for automated testing and objective interpretation of results, we evaluated the performance of the BioPlex™ 2200 heterophile IgM assay (Bio-Rad Laboratories, Hercules, CA), using 494 serum specimens submitted to our laboratory for routine heterophile testing by Colorcard Mono™ (Inverness Medical, Princeton, NJ).  Specimens showing discordant results were tested by a third heterophile assay (Status Mono™, LifeSign LLC, Somerset, NJ). 

Results:  Following the resolution of discordant results, the BioPlex 2200 heterophile IgM assay demonstrated a sensitivity and specificity of 96.7% and 98.8%, respectively. 

Conclusions:  Our findings showed that the BioPlex 2200 heterophile IgM assay yielded comparable results to those obtained by routine testing using hemagglutination.  The BioPlex 2200 is a fully automated, random access analyzer that tests for EBV-specific and heterophile antibodies in a multiplex reaction, allowing for a more rapid and high-throughput analysis of the EBV serologic response.