Serological evaluation of recombinant protein antigen Tp0608 for the diagnosis of syphilis

Objective: To evaluate the serological diagnosis value of recombinant protein antigen Tp0608 for syphilis. Method: 406 patients with various stages of syphilis were enrolled. A recombinant protein antigen Tp0608 was established and ELISA was used to detect patients with various stages of syphilis. The results were compared with the conventional rapid plasma reagin test (RPR) and Treponema pallidum particle agglutination test (TPPA). The sensitivity of Tp0608 recombinant protein and RPR+TPPA screening was 96.6 % and 93.1 % respectively for patients with various stages of syphilis. For patients who may have cross reactivity, the specificity of Tp0608 recombinant protein screening is 98.9 %, and the AUC of the ROC curve is 0.99; The specificity of RPR+TPPA screening was 97.3 %, and the AUC of the ROC curve was 0.96. The sensitivity and specificity of Tp0608 recombinant protein in syphilis screening are higher than conventional RPR+TPPA methods, especially in congenital syphilis and primary syphilis. Conclusion: The Tp0608 recombinant protein is a promising diagnostic antigen for syphilis screening, but its intracellular location and protective response have not been determined, and further verification is needed