| Autor: |
Fakile YF; Centers for Disease Control and Prevention, Atlanta, Georgia, USA yfakile@cdc.gov., Jost H; Centers for Disease Control and Prevention, Atlanta, Georgia, USA., Hoover KW; Centers for Disease Control and Prevention, Atlanta, Georgia, USA., Gustafson KJ; Sexually Transmitted Disease Control Branch, Division of Communicable Disease Control, Center for Infectious Diseases, California Department of Public Health, Richmond, California, USA., Novak-Weekley SM; Southern California Permanente Medical Group Regional Reference Laboratories, North Hollywood, California, USA., Schapiro JM; Kaiser Permanente Northern California Regional Laboratory, Berkeley, California, USA., Tran A; San Francisco Department of Public Health, San Francisco, California, USA., Chow JM; Southern California Permanente Medical Group Regional Reference Laboratories, North Hollywood, California, USA., Park IU; Southern California Permanente Medical Group Regional Reference Laboratories, North Hollywood, California, USA.; Department of Family and Community Medicine, School of Medicine, University of California-San Francisco, San Francisco, California, USA. |
| Abstrakt: |
Automated treponemal immunoassays are used for syphilis screening with the reverse-sequence algorithm; discordant results (e.g., enzyme immunoassay [EIA] reactive and reactive plasma reagin [RPR] nonreactive) are resolved with a second treponemal test. We conducted a study to determine automated immunoassay signal strength values consistently correlating with reactive confirmatory treponemal testing. We conducted a cross-sectional analysis of four automated immunoassays (BioPlex 2200 microbead immunoassay [MBIA], Liaison chemiluminescence immunoassay [CIA], Advia-Centaur CIA, and Trep-Sure EIA) and three manual assays ( Treponema pallidum particle agglutination [TP-PA], fluorescent treponemal antibody absorption [FTA-ABS] test, and Inno-LIA line immunoassay). We compared signal strength values of automated immunoassays and positive and negative agreement. Among 1,995 specimens, 908 (45.5%) were true positives (≥4/7 tests reactive) and 1,087 (54.5%) were true negatives (≥4/7 tests nonreactive). Positive agreement ranged from 86.1% (83.7 to 88.2%) for FTA-ABS to 99.7% (99.0 to 99.9%) for Advia-Centaur CIA; negative agreement ranged from 86.3% (84.1 to 88.2%) for Trep-Sure EIA to 100% for TP-PA (99.6 to 100%). Increasing signal strength values correlated with increasing reactivity of confirmatory testing ( P < 0.0001 for all automated immunoassays by Cochran-Armitage test for trend). All automated immunoassays had signal strength cutoffs corresponding to ≥4/7 reactive treponemal tests. BioPlex MBIA and Liaison CIA had signal strength cutoffs correlating with ≥99% and 100% TP-PA reactivity, respectively. The Advia-Centaur CIA and Trep-Sure EIA had signal strength cutoffs correlating with at least 95% TP-PA reactivity. All automated immunoassays had signal strength cutoffs correlating with at least 95% FTA-ABS reactivity. Assuming that a 95% level of confirmation is adequate, these signal strength values can be used in lieu of confirmatory testing with TP-PA and FTA-ABS. |
