Validation of the INNO-LIA syphilis kit as a confirmatory assay for Treponema pallidum antibodies.

Institute Alfred Fournier, 75014 Paris, France.
Journal of Clinical Microbiology (Impact Factor: 4.07). 01/2000; 38(1):215-9.
Source: PubMed

ABSTRACT The commercially available diagnostic tests for syphilis are mostly based on the use of extracted antigens of Treponema pallidum. Pronounced cross-reactivities with other spirochete antigens are often reported. The aim of this study was to validate a novel multiparametric assay (the assay performed with the kit) INNO-LIA Syphilis for the confirmation of syphilis antibodies in a set of 840 documented human serum samples. All serum samples were previously tested at the French World Health Organization reference center for venereal diseases (Institute Alfred Fournier, Paris, France), with a consensus result provided for each sample. The study was conducted in two phases, with each phase involving a validation set (500 well-documented serum samples) and an exploratory set (340 serum samples) of serum samples, respectively. By measuring the sensitivity and specificity, we compared the result of the new assay with the consensus result on the basis of the results of a variable number of classical serological methods and clinical information when available. A sensitivity of 99.6% (95% confidence internal [CI], 98.5 to 99.9%) and a specificity of 99.5% (95% CI, 98.1 to 99.9%) were found for the new line immunoassay. Six of seven samples with indeterminate results by classical serology tested positive with the INNO-LIA Syphilis kit. This single multiparametric assay provides reliable confirmatory diagnostic information that must currently be obtained by the performance and interpretation of results of a combination of serological assays.

0 0
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Recent trends in Western Europe show an increase in sexually transmitted infections. Surveillance data in Switzerland confirm this rising trend. Notifications of syphilis cases nearly doubled in the year 2002 and almost tripled in 2003. This trend necessitates an early correct diagnosis making reliable screening tests mandatory. In the presented study a particle gel immunoassay (ID-PaGIA syphilis antibody test, Diamed) using recombinant treponemal antigens TpN15, TpN17 and TpN47 was evaluated as a screening test in comparison to the currently used Treponema pallidum particle agglutination test (Serodia-TPPA, Fujirebio). Serum samples were obtained from a cross-sectional sero-epidemiological study among men who have sex with men. Samples were tested with the PaGia and the TPPA. In the case of equivocal results a titrated TPPA of an external laboratory was used as a confirmation test. In total 650 serum samples (48 seropositive patients, 602 negative) were evaluated. The PaGIA showed a sensitivity of 0.89 (43/48) and the TPPA of 0.83 (40/48). This difference was not statistically relevant (p = 0.4). The particle gel assay showed a significantly higher specificity (1.0) compared to the TPPA (0.98) (p = 0.004). The PaGIA showed a sensitivity comparable to that of other treponemal tests with an even better specificity. Advantages of the PaGIA are the fast reaction time of only 20 min and the simplicity of the procedure with minimal technical equipment.
    Infection 02/2009; 37(1):26-8. · 2.44 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Following a laboratory audit, a significant number of Treponema pallidum particle agglutination assay (TPPA)-negative sera were identified when TPPA was used as a confirmatory assay of syphilis enzyme immunoassay (EIA) screening-reactive sera (SSRS). Sera giving such discrepant results were further characterized to assess their significance. A panel of 226 sera was tested by the Abbott Murex ICE Syphilis EIA and then by the Newmarket Syphilis EIA II. TPPA testing was performed on 223 sera. Further testing by the Venereal Disease Research Laboratory (VDRL) test, the Mercia Syphilis IgM EIA, the fluorescent treponemal antibody (FTA-ABS) assay, and INNO-LIA immunoblotting was undertaken in discrepant cases. One hundred eighty-seven of 223 (83.8%) SSRS were TPPA reactive, while 26 (11.6%) sera which were reactive in both the ICE and Newmarket EIAs were nonreactive by TPPA. The majority (68%) of the TPPA-discrepant sera were from HIV-positive patients and did not represent early acute cases, based on previous or follow-up samples, which were available for 22/26 samples. FTA-ABS testing was performed on 24 of these sera; 14 (58.3%) were FTA-ABS positive, and 10 (41.7%) were FTA-ABS negative. Twenty-one of these 26 sera were tested by INNO-LIA, and an additional 4 FTA-ABS-negative samples were positive. In this study, significant numbers (18/26) of SSRS- and TPPA-negative sera were shown by further FTA-ABS and LIA (line immunoblot assay) testing to be positive. The reason why certain sera are negative by TPPA but reactive by treponemal EIA and other syphilis confirmatory assays is not clear, and these initial findings should be further explored.
    Clinical and vaccine Immunology: CVI 11/2010; 17(11):1718-22. · 2.60 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The introduction of automated treponemal enzyme immunoassays and chemiluminescence assays (EIA/CA) tests has led some laboratories in the United States to use new syphilis screening algorithms that start with a treponemal test. We compared the economic and health outcomes of this new algorithm with the standard algorithm from the perspective of the United States health system. We used a cohort decision analysis to estimate the expected costs and effects (including follow-ups and overtreatment) of the 2 algorithms from a health-care system perspective. In the standard algorithm, rapid plasma reagin (RPR) is followed (if reactive) by EIA/CA (Nontreponemal-First). In the new algorithm, EIA/CA is followed (if reactive) by RPR. If the RPR is negative, Treponema pallidum passive particle agglutination assay (TP-PA) test is used (Treponemal-First). For a cohort of 200,000 individuals (1000 current infections and 10,000 previous infections), the net costs were $1.6 m (Treponemal-First) and $1.4 m (Nontreponemal-First). The Treponemal-First option treated 118 more cases (986 vs. 868) but resulted in a substantially higher number of follow-ups (11,450 vs. 3756) and overtreatment (964 vs. 38). Treating the additional 118 cases might prevent 1 case of tertiary syphilis. The estimated cost-effectiveness ratios were $1671 (Treponemal-First) and $1621 (Nontreponemal-First) per case treated. The overtreatment was a function of the specificity of the EIA/CA and the lack of independence of EIA/CA and TP-PA. The Treponemal-First option costs slightly more and results in more unnecessary treatment.
    Sexually transmitted diseases 01/2011; 38(1):1-7. · 2.58 Impact Factor

Full-text (2 Sources)

Available from
May 28, 2013