title: Prospective study of IgM to Toxoplasma gondii on Beckman Coulter's Access(TM) immunoassay system and comparison with Zeus ELISA and gull IFA assays.
abstract: We compared a new assay for Toxoplasma IgM on the Access analyzer (Beckman Coulter, Inc., Chaska, MN, USA), a random access instrument based on the principle of paramagnetic particle enzyme immunoassay with an enzyme-linked immunosorbent assay (ELISA) (Zeus Scientific, Inc., Raritan, NJ, USA) and an immunofluorescent assay (IFA) (Gull Laboratories, Inc., Salt Lake City, UT, USA). Four hundred fresh, unfrozen clinical samples from pregnant women (n = 154), HIV positive patients (n = 41), and patients in whom infection with Toxoplasma gondii was suspected (n = 200) were collected and assayed over a three month period. The specificity of the Access assay was compared to the consensus results. Results that were discrepant between the ELISA and IFA were resolved using a third IFA (Zeus). Once resolved, the specificity for the Access assay, the Zeus ELISA and the Gull IFA were 99.22%, 97.91%, and 99.45%, respectively. We conclude that the Access assay specificity is comparable to consensus results, minimizing false positive results; and because it is a random access instrument, it may be preferable over batch methods.
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.forename: B P
authors.initials: BP
authors.lastname: Turner
authors.forename: C E
authors.initials: CE
authors.lastname: Peyton
authors.forename: B S
authors.initials: BS
authors.lastname: Reisner
authors.forename: A O
authors.initials: AO
authors.lastname: Okorodudu
authors.forename: A A
authors.initials: AA
authors.lastname: Mohammad
authors.forename: G D
authors.initials: GD
authors.lastname: Hankins
authors.forename: A S
authors.initials: AS
authors.lastname: Weissfeld
authors.forename: J R
authors.initials: JR
authors.lastname: Petersen
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015200:Fluoroimmunoassay; D015658:HIV Infections / Q000150:complications; D006801:Humans; D007118:Immunoassay; D007075:Immunoglobulin M / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic; D014122:Toxoplasma / Q000276:immunology* / Q000302:isolation & purification; D014123:Toxoplasmosis / Q000175:diagnosis* / Q000209:etiology / Q000469:parasitology
chemical_list: D007075:Immunoglobulin M; D011933:Reagent Kits, Diagnostic