Abstract: Objective To compare and analyze the difference between colloidal gold method and particle agglutination test in the detection of Treponema pallidum antibody and toluidine red antibody. Methods A total of 100 patients who were examined in Guizhou Armed Police Corps Hospital due to suspected syphilis from January 2019 to January 2022 were selected as the study objects. The gold standard positive was that the blood, cerebrospinal fluid VDRL and FTA ABS were all positive. The detection efficiency of colloidal gold method, particle agglutination test and toluidine red test for Treponema pallidum antibody was examined by blind method and compared between groups. Results The positive results of VDRL and FTA ABS in blood and cerebrospinal fluid of patients were regarded as gold standard positive. Among 100 suspected syphilis patients, 83 were positive, 17 were negative; 81 were positive by colloidal gold method; 19 were negative, 83 were positive by particle agglutination test; 17 were negative, 53 were positive by toluidine red, 47 were negative. The diagnostic accuracy of colloidal gold method was 94.00%, sensitivity was 95.18%, specificity was 88.24%, missed diagnosis rate was 4.82%, misdiagnosis rate was 11.76%; diagnostic accuracy of particle agglutination test was 94.00%; sensitivity was 96.39%, specificity was 82.35%, missed diagnosis rate was 3.61%, misdiagnosis rate was 17.65%; diagnostic accuracy of toluidine red was 56.00%, sensitivity was 55.42%, specificity was 58.82%, missed diagnosis rate was 44.58%, misdiagnosis rate was 41.18%. The ROC curves of colloidal gold method, particle agglutination test and toluidine red test for the diagnosis of Treponema pallidum antibody were drawn respectively, and the AUC was 0.907 (P<0.001), 0.894 (P<0.001) and 0.571 (P=0.356). Conclusion The colloidal gold method, particle agglutination test and toluidine red test have certain diagnostic efficacy for Treponema pallidum antibody, but the diagnostic accuracy, sensitivity and specificity of the colloidal gold method and particle agglutination test are higher than those of the toluidine red test, which can be considered for the differential diagnosis of syphilis patients in clinical practice.

Key words: colloidal gold method, particle agglutination test, toluidine red test, treponema pallidum antibody, diagnostic performance