Comparative study of five analytical methods for screening of antibodies against treponema pallidum / 中华检验医学杂志

ABSTRACT

Objectives To evaluate the value of Treponema pallidum (TP) antibody analytical methods for syphilis screening.Methods A total of 4870 samples of Peking University First Hospital from May to October 2010 were detected of antibodies against TP by chemiluminescent microparticle immunoassay (CMIA),ELISA,rapid plasma reagin test (RPR),Treponema pallidum particle agglutination assay (TPPA) and dot-immunoblotting test (dot-IBT).The positive rates were compared by McNemar test for paired data;Using dot-IBT as gold standard,the sensitivity,specificity and total accordance rate of the other four methods were analyzed.Results In 4870 screening samples,the positive rate of dot-IBT was 2.5％(122/4870).The positive rate of CMIA and RPR was 3.1％(149/4870) and 1.2％(58/4870),respectively.According to McNemar test for paired data,there was significant difference when compared with dot-IBT (P ＜0.01).The positive rate of ELISA and TPPA was 2.4％ (119/4870) and 2.4％ (116/4870),respectively.There was no significant difference when compared with dot-IBT (P ＞ 0.05).When the dot-IBT results for the standard,CMIA has highest sensitivity,96.7％ (118/122),the specificity was 99.6％(4705/4724).The sensitivity and specificity of ELISA was 93.4％ (114/122) and 99.9％ (4720/4724),respectively,TPPA was 91.0％ (111/122) and 99.9％ (4721/4724),respectively,and RPR was 46.7％(57/122) and 100.0％ (4724/4724),respectively.The accordance rate of CMIA,ELISA,TPPA and RPR with the dot-IBT was 99.5％ (4823/4846),99.8％ (4834/4846),99.7％ (4832/4846) and 98.7％(4781/4846).When the TPPA results for the standard,sensitivity of CMIA was 96.6％ (112/116),the specificity was 99.2％ (4717/4754).The sensitivity and specificity of ELISA was 98.3 ％ (114/116) and 99.9％ (4749/4754),respectively,and RPR was 47.4％ (55/116) and 99.9％ (4751/4754),respectively.The accordance rate of CMIA,ELISA and RPR with the dot-IBT was 99.2％ (4829/4870),99.9％ (4863/4870) and 98.7％ (4806/4870).Conclusions Because of the low sensitivity of RPR,it is not fit for screening test.There are high sensitivity and specificity for detection of TP antibody using CMIA and ELISA,so they could be used as a screening test for TP.Due to the complexity of the operating steps,TPPA can be used to further confirm the test.