Evaluation of IMMUNOTICLES Auto3RPR and Auto3TP for Testing of Syphilis Infection / 임상검사와정도관리

ABSTRACT

BACKGROUND: The serologic tests for syphilis infection have been performed manually, but the procedures are time-consuming and interpretations may be subjective. Recently, automated assays were developed for rapid and efficient testing for syphilis infection. In this study, we evaluated the performances of IMMUNOTICLES Auto3 RPR and Auto3TP (A&T Corporation, Japan) using latex agglutination turbidimetry method. METHODS: Using 236 serum samples referred for syphilis at Ewha Womans University, Mokdong Hospital, between March 2004 and April 2007, we evaluated precision, linearity, detection limit and compared with the results of manual serologic tests, RPR (RPR card test, ASAN Pharmaceutical, Korea) and TPHA (ASAN-TPHA, ASAN Pharmaceutical). RESULTS: The within-run and between day precisions of Auto3RPR and Auto3TP were from 2.1% to 4.8%. The linearity was good up to 5.0 RU for Auto3RPR and to 250 TU for Auto3TP. Agreement of Auto3RPR with RPR was 65.7% (155/236) and 32.6% of patients (77/236) were RPR positive and Auto3RPR negative. RPR titers were less than 18 in 99% of these discrepant samples (76/77) and 65% (50/77) were latent infection and the others were false positive (32%, 27/77). Agreement of Auto3TP with TPHA was 97.1%. CONCLUSIONS: IMMUNOTICLES Auto3RPR and Auto3TP may be useful for rapid and efficient testing for syphilis. However, discrepant results were present in patients with low titer RPR positivity and method of reporting shoud be considered in individual clinical situation. In addition, linear range was not wide and further study is needed for reporting of quantitative results.