title: Characterization of sera with discordant results from reverse sequence screening for syphilis.
abstract: Reverse sequence screening for syphilis (RSSS) (screening with treponemal tests, followed by confirmation with nontreponemal tests) has been increasingly adopted. CDC recommends confirmation of discordant results (reactive EIA/CIA and nonreactive nontreponemal test) with Treponema pallidum particle agglutination assay (TP-PA). We characterized sera with discordant results from RSSS with Architect Syphilis TP CIA. Among 15,713 screening tests using Architect Syphilis TP at Seoul National University Gangnam Center between October 2010 and May 2011, 260 (1.7%) showed reactive results. Rapid plasma reagin (RPR) and TP-PA were performed on 153 available sera among them. On sera with discordant results between Architect Syphilis TP and TP-PA, INNO-LIA Syphilis Score and FTA-ABS were performed. Among 153 sera, RPR was nonreactive in 126 (82.4%). Among them, TP-PA was positive in 103 (81.7%), indeterminate (±) in 7 (5.6%), and negative in 16 (12.7%). Out of 16 CIA(+)/RPR(-)/TP-PA(-) sera, INNO-LIA Syphilis Score and/or FTA-ABS were negative on 14 sera. Out of 7 CIA(+)/RPR(-)/TP-PA(±) sera, INNO-LIA Syphilis Score and FTA-ABS were positive/reactive in 6 sera. RSSS with confirmation by TP-PA on sera with discordant results between Architect Syphilis TP and RPR effectively delineated those discordant results and could be successfully adopted for routine checkup for syphilis.
authors.affiliation: Department of Laboratory Medicine, College of Medicine, Seoul National University, Seoul 110-744, Republic of Korea.
authors.forename: Kyunghoon
authors.initials: K
authors.lastname: Lee
authors.forename: Hyewon
authors.initials: H
authors.lastname: Park
authors.forename: Eun Youn
authors.initials: EY
authors.lastname: Roh
authors.forename: Sue
authors.initials: S
authors.lastname: Shin
authors.forename: Kyoung Un
authors.initials: KU
authors.lastname: Park
authors.forename: Myoung Hee
authors.initials: MH
authors.lastname: Park
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Song
mesh_terms: D000465:Algorithms; D000907:Antibodies, Bacterial / Q000097:blood; D006801:Humans; D007118:Immunoassay / Q000379:methods; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic; D011935:Reagins / Q000097:blood; D015203:Reproducibility of Results; D056910:Republic of Korea; D012680:Sensitivity and Specificity; D013587:Syphilis / Q000097:blood* / Q000175:diagnosis; D013588:Syphilis Serodiagnosis / Q000379:methods*; D014210:Treponema pallidum / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D011933:Reagent Kits, Diagnostic; D011935:Reagins