ABSTRACT
Objective To evaluate the specificity of Architect chemiluminescence immunoassay ( CLIA) for diagnosis of syphilis in the clinical screening test.Methods 65 774 syphilis specific antibody results in the Beijing Tongren Hospital were retrospectively analyzed.In this study, Architect CLIA for diagnosis of syphilis was used as a screening test for the pre-operative patients from August 2011 to July 2012.All the repeatedly reactive samples were tested by the tolulized red unheated serum test ( TRUST) and Treponema pallidum particle agglutination ( TPPA) assay.Samples with with discordant results were verified by western blot ( WB) Finally, all the results were statistically analyzed by software SPSS 17.0.Results Among 65 774 samples, 940 (1.43%) were found to be repeatedly reactive using the Architect CLIA.Of these sera, 330 ( 35.11%) were reactive and 610 ( 64.89%) were nonreactive by TRUST.Because a TRUST titer of 1:1was not always sufficient to confirm a TPPA reactive result, all the samples with CLIA reactive results were finally performed by TPPA assays.The results showed that 843 ( 89.68%) were positive and 97 (10.32%) were negative.After arbitrated by the WB, out of 97 TPPA negative sera, 18 (18.56%) were positive;7(7.22%) were indeterminate and 72(74.23%) were negative.Conclusions The specificity of Architect CLIA for diagnosis of syphilis was 99.89%.The results showed that confirmation by TPPA on sera with screening test for syphilis by Architect CLIA effectively decreased the false-positive results and could be suitable for a routine supplementary for syphilis.However, if necessary, the WB should be further utilized.