Using standard serology blood tests to diagnose latent syphilis

Abstract

Goal. To conduct a comparative assessment of the results of regulated serological tests obtained as a result of blood tests in patients suffering from latent syphilis. Materials and methods. The authors examined 187 patient medical records with newly diagnosed latent syphilis in FGBU GNTsDK (State Research Center for Dermatology, Venereology and Cosmetology), Health Ministry of the Russian Federation, in 2006-2015. The results of patient blood tests were analyzed with the use of non-treponemal (microprecipitation test/RPR) and treponemal (passive hemagglutination test, immune-enzyme assay (IgA, IgM, IgG), IFabs, immunofluorescence test and Treponema pallidum immobilization test) serology tests. Results. According to the results of blood tests of latent syphilis patients, the largest number of positive results was obtained as a result of treponemal serology tests such as immune-enzyme assay (100%), passive hemagglutination test (100%) and IFabs (100%). The greatest number of negative results was observed in non-treponemal (microprecipitation test/RPR) serology tests: in 136 (72.7%) patients; evidently positive results (4+) test results were obtained in 8 (4.3%) patients only. According to the results of a comparative analysis of blood tests in patients suffering from latent syphilis obtained with the use of treponemal serology tests, the greatest number of evidently positive results (4+) was noted for the passive hemagglutination test (67.9%). Negative treponemal test results were obtained with the use of the immunofluorescence test and Treponema pallidum immobilization test (21.9% and 11.8% of cases, respectively). Moreover, weakly positive results prevailed for the immunofluorescence test: in 65 (34.7%) patients. Conclusion. These data confirm that the following treponemal tests belong to the most reliable ones for revealing patients suffering from latent syphilis: immune-enzyme assay, passive hemagglutination test and IFabs.