Résumé
Objective To investigate the incidence of prozone phenomenon of rapid plasma reagin (RPR) test in syphilis serolog-ic testing and its correlation with the intensity of chemiluminescent microparticle immunoassay (CMIA) results.Methods A total of 101493 patients in our hospital from January 2014 to December 2015 were performed syphilis serologic testing by CMIA ,RPR and treponema pallidum particle agglutination (TPPA).The incidence rate of prozone phenomenon in RPR testing was evaluated.Its in-fluencing factors were investigated by using the Logistic regression.Results Among 101493 serum samples ,2180 cases were posi-tive by CMIA and 767 cases were positive by RPR ,the incidence rate of prozone phenomenon was 3.3% (26/767)in RPR.The Lo-gistic regression results indicated that the incidence of prozone phenomenon was significantly correlated with CMIA S /CO values and RPR titer ,but had no correlation with sex ,age and seasonality.Conclusion Although the incidence of prozone phenomenon is low in syphilis serologic testing ,but it is enough important.The patients with higher S/CO value in CMIA test have a higher inci-dence rate of RPR prozone phenomenon.
Résumé
Objective To identify the advantages and disadvantages of the rapid plasma reagin test (RPR), chemiluminescence immunoassay (CLIA) and Treponema pallidum particle agglutination test (TPPA) for detecting syphilis. Methods A total of 1,808 serum specimens were detected by RPR and CLIA; the negative specimens as detected by CLIA and by RPR were redetected by TPPA. Results There were 170 syphilis patients among the 1,808 patients. The sensitivity and positive predictive value of RPR were both significantly lower than those of CLIA and TPPA (P0. 05). However, the negative predictive value of RPR was significantly lower than that of CLIA (P0. 05), however, the positive predictive value of CLIA was significantly lower than that of TPPA (P<0. 05). Biologically false positive results could be found for all the 3 methods and false negative results could be found for RPR and TPPA (P<0. 05). Conclusion CLIA and TPPA are superior to RPR in diagnosing syphilis. The procedure of diagnosing syphilis may need to be adjusted, and syphilis should be diagnosed by combining the medical history, symptom and lab results.