title: Multiplex detection of IgM and IgG class antibodies to Toxoplasma gondii, rubella virus, and cytomegalovirus using a novel multiplex flow immunoassay.
abstract: The goal of this study was to evaluate the BioPlex 2200 Toxoplasma, rubella, and cytomegalovirus (CMV) (ToRC) IgG and IgM multiplex immunoassays (Bio-Rad Laboratories, Hercules, CA) and compare the results to those of conventional testing by enzyme immunoassay (EIA) and enzyme-linked fluorescent assay (ELFA). Serum specimens (n = 600) submitted for routine ToRC IgG and IgM testing by EIA (SeraQuest, Doral, FL; Diamedix, Miami, FL) or ELFA (Vidas; bioMérieux, Durham, NC) were also tested by the BioPlex ToRC multiplex immunoassays. Samples showing discordant results were retested by both methods, with further discrepancies being arbitrated by a third assay. Following repeat testing, the BioPlex Toxoplasma, rubella, and CMV IgG assays demonstrated agreements of 98.7 (592/600 specimens), 93.3 (560/600 specimens), and 98.3% (590/600 specimens), respectively, while the ToRC IgM assays yielded agreements of 91.2 (547/600 specimens), 87.3 (524/600 specimens), and 95.2% (571/600 specimens), respectively. The BioPlex ToRC IgG assays provided results comparable to EIA/ELFA results, with kappa coefficients showing near-perfect agreement for the Toxoplasma (κ = 0.94) and CMV (κ = 0.97) IgG assays and substantial agreement for the rubella IgG assay (κ = 0.66). The BioPlex ToRC IgM assays showed lower specificity with only slight agreement for Toxoplasma IgM (κ = 0.07), poor agreement for rubella IgM (κ = -0.03), and moderate agreement for CMV IgM (κ = 0.55). Both the BioPlex IgG and IgM assays reduced turnaround time (1.7 h versus 5.5 h by EIA/ELFA for 100 specimens) and eliminated the necessity to manually pipette or aliquot specimens prior to testing.
authors.affiliation: Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, SDSC 1-526, Rochester, MN 55905, USA. binnicker.matthew@mayo.edu
authors.forename: M J
authors.initials: MJ
authors.lastname: Binnicker
authors.forename: D J
authors.initials: DJ
authors.lastname: Jespersen
authors.forename: J A
authors.initials: JA
authors.lastname: Harring
mesh_terms: D000913:Antibodies, Protozoan / Q000097:blood*; D000914:Antibodies, Viral / Q000097:blood*; D019411:Clinical Laboratory Techniques / Q000379:methods; D003587:Cytomegalovirus / Q000276:immunology; D003586:Cytomegalovirus Infections / Q000175:diagnosis*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D011933:Reagent Kits, Diagnostic; D012409:Rubella / Q000175:diagnosis*; D012412:Rubella virus / Q000276:immunology; D014122:Toxoplasma / Q000276:immunology; D014123:Toxoplasmosis / Q000175:diagnosis*
chemical_list: D000913:Antibodies, Protozoan; D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011933:Reagent Kits, Diagnostic