Comparison of detection methods of syphilis antibodies

Objective To explore the sensitivity and specificity of different methods in detecting the antibody of treponema pallidum (TP). Methods The antibody of TP in 68 positive and 80 negative specimen were detected using treponema pallidum particle agglutination assay (TPPA), TP-ELISA and rapid plasma reagin assay (RPR), respectively. The sensitivity and specificity of the three methods were compared. Results The sensitivity of TPPA, TP-ELISA, RPR were 97.1%, 94.1%, 80.9%, and the specificity was 97.5%, 91.3%, 88.8%, respectively. The positive predictive value were 97.1%, 90.1%, 85.9%, and the negative predictive value were 97.5%, 94.8%, 84.5%, respectively. Compared with TPPA with relative good sensitivity and specificity, RPR had significantly lower sensitivity and specificity (P0.01, P0.05). Conclusion TPPA is suitable not for large-scale screening of blood, but confirmation test of syphilis antibody in positive specimens. TP-ELISA is the ideal method for screening of syphilis. RPR is suitable for the detection of non-specific antibodies, observation of clinical efficacy and sieve test.