Evaluation of a Multiplex Flow Immunoassay for Detection of Epstein-Barr Virus-Specific Antibodies

Abstract

Conventional methods for the detection of Epstein-Barr virus (EBV)-specific antibodies include the immunofluorescence assay (IFA) and enzyme immunoassay (EIA). While sensitive and specific, these methods are labor-intensive and require separate assays for each analyte. This study evaluated the performance of a multiplex bead assay (BioPlex 2200; Bio-Rad Laboratories, Hercules, CA) for the simultaneous detection of immunoglobulin G (IgG) and IgM class antibodies to the EBV viral capsid antigen (VCA) and IgG class antibodies to Epstein-Barr virus nuclear antigen-1 (EBNA-1). Serum specimens (n ‫؍‬ 1,315) submitted for routine EBV-specific antibody testing by EIA (Grifols-Quest, Inc., Miami, FL) were also tested by the multiplex bead assay using the BioPlex 2200 automated analyzer. Specimens showing discordant results were tested by IFA. Following IFA resolution, the BioPlex VCA IgM, VCA IgG, and EBNA-1 IgG assays demonstrated 97.9%, 91.4%, and 96.9% agreement, respectively, with the results obtained by EIA. Furthermore, the BioPlex assays showed an overall agreement of 94.1% with the EIA when the specimens were categorized by disease state (susceptible, acute, or past infection) based on the EBV-specific antibody profiles. These findings indicate that the BioPlex EBV assays demonstrate a performance comparable to that of the conventional EIA, while allowing for a more rapid (2.3 h for 100 samples versus 4.5 h by the EIA) and higher-throughput (ϳ400 samples per 9 h versus 200 samples by the EIA) analysis of the EBV-specific antibody response. Epstein-Barr virus (EBV) is the primary agent of infectious mononucleosis (IM), a common syndrome characterized by fever, pharyngitis, and lymphadenopathy. Most individuals become infected during childhood, and it is estimated that nearly 95% of the adult population worldwide is seropositive for the virus (20). While the majority of infections result in either asymptomatic or mild disease, serious complications, including B-and T-cell lymphomas, nasopharyngeal carcinoma, and central nervous system involvement, may occur, especially in immunocompromised hosts (14).The diagnosis of IM is made, in most cases, on the basis of characteristic clinical manifestations or the detection of heterophile antibodies (24). However, a determination of the EBVspecific antibody response may be required for young children (especially those Ͻ4 years old) (26) and for adults suspected of having heterophile-negative IM. Testing for immunoglobulin M (IgM) and IgG class antibodies to the viral capsid antigen (VCA) and for IgG class antibodies to Epstein-Barr virus nuclear antigen-1 (EBNA-1) allows for a discrimination between recent and remote infection (8,18,21,22). Levels of antibodies (IgM and/or IgG) to VCA are typically elevated during the acute phase of IM (19,22,26), with anti-VCA IgM levels showing a steady decline 4 to 6 weeks after symptom onset (16). In contrast, anti-VCA IgG persists indefinitely, and its detection along with that of anti-EBNA-1 IgG suggests past exposure to the virus (25)...

Comparison of Three Automated Immunoassay Methods for the Determination of Epstein-Barr Virus-Specific Immunoglobulin M

“…(5) 1 (0) 1 (0) 1 (0) 1 Anti-intrinsic factor antibodies (6) 0 (0) 0 (0) 1 (1) 0 Chronic lymphocytic leukemia (16) 1 (1) (9) 2 (1) 0 (0) 3 (2) 1 Acute herpes simplex virus (4) 0 (0) 0 (0) 0 (0) 0 Borrelia burgdorferi IgM (18) 2 (2) 1 (1) 3 (3) 0 Syphilis (22) 1 (0) 1 (0) 0 (0) 2 Acute parvovirus B19 (15) 0 (0) 0 (0) 0 (0) 0 Acute rubella virus (15) 7 (6) 2 (1) 2 (1) 1 Acute CMV (20) 11 (2) 8 (1) 12 (3) 10 Total (293) 28 (12) 21 (6) 28 (11) 20 a The number of false-positive (false ϩ ) EBV IgM results is shown in parentheses, e.g., "2 (1)" should be interpreted as two positive EBV IgM results, one of which was false positive. The results from the present study are in agreement with previous reports on the performance of BioPlex and Liaison (4,7,14). There are, however, minor differences between the various publications on BioPlex and Liaison, and these are probably not only attributable to sample size in the different studies but also to sample selection and the choice of reference method.…”

“…The ideal EBV-specific IgM assay should not only be sensitive and specific; in the modern laboratory automation, throughput, speed, accessibility, standardization, ease of use, and flexibility also play an important role. In the past decade, several immunoassay methods have been commercialized that may be able to meet most of these criteria (4,7,14).…”

Evidence-Based Approach for Interpretation of Epstein-Barr Virus Serological Patterns

“…This suggests that the interpretive patterns shown here are specific to use with BioPlex results. However, in this study and two previous studies (3,7), there was very strong (92 to 97%) concordance between BioPlex 2200 and predicate assay results. Therefore, Tables 4 and 6 may also be useful for interpretation of EBV serologic results generated with other assays, but further studies obviously are needed to support that hypothesis.…”

“…However, the association between a particular EBV diagnosis and serological patterns is based largely on assumptions. While utilization of multiplex technology for the detection of EBV antibodies has been evaluated recently (1,3,7,9,12), this is the first evidence-based study of its kind aiming to match a large number of clinical diagnoses with EBV serological patterns. Here, we analyzed almost 1,850 specimens, generating Ͼ10,000 individual serological test results, and reviewed the medical records of more than 800 patients.…”

“…Bio-Rad Laboratories (Hercules, CA) recently introduced a multiplex platform (BioPlex 2200) that can measure all five of these antibodies from one sample in two reaction vessels. We and others recently evaluated this platform with regard to its performance against various predicate assays and showed that it performed quite well (3,7).…”