title: A novel ELISA using a recombinant outer membrane protein, rTp0663, as the antigen for serological diagnosis of syphilis.
abstract: BACKGROUND
  The lack of Treponema pallidum-specific antigens with highly accurate diagnosis makes the diagnosis of syphilis challenging.
  
  
  METHODS
  A soluble recombinant version of a new diagnostic protein Tp0663 has been produced. The serodiagnostic potential of this protein was assessed by screening 3326 serum samples simultaneously evaluated by rapid plasma reagin and T. pallidum particle agglutination tests. Kappa (κ) coefficients were used to compare the concordance between clinical diagnosis and the Tp0663-based ELISA or the ARCHITECT Syphilis TP chemiluminescent immunoassay (Abbott GmbH and Co. KG).
  
  
  RESULTS
  Using the results of clinical diagnosis as the gold standard, the sensitivity and specificity of Tp0663 were found to be 98.83% (95% confidence interval (CI) 96.61-99.60%) and 100% (95% CI 99.88-100%), respectively. In comparison, the ARCHITECT Syphilis TP assay was found to have a lower sensitivity (97.27%, 95% CI 94.46-98.67%) and specificity (99.61%, 95% CI 99.32-99.78%). In particular, the ARCHITECT Syphilis TP exhibited a false-positive rate of 0.39%. Moreover, the ELISA was in perfect agreement with the gold standard, with a κ value of 0.99, comparable to that of ARCHITECT Syphilis TP (0.96).
  
  
  CONCLUSIONS
  These results identified Tp0663 as a novel serodiagnostic candidate with great potential for developing novel tests for the diagnosis of syphilis.
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
authors.forename: Man
authors.initials: M
authors.lastname: Xu
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
authors.forename: Yafeng
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
authors.forename: Chuanhao
authors.initials: C
authors.lastname: Jiang
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China; Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China, Hengyang, China.
authors.forename: Yongjian
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
authors.forename: Xingxing
authors.initials: X
authors.lastname: Kuang
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
authors.forename: Feijun
authors.initials: F
authors.lastname: Zhao
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
authors.forename: Tiebing
authors.initials: T
authors.lastname: Zeng
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of University of South China, Hengyang, China.
authors.forename: Shuangquan
authors.initials: S
authors.lastname: Liu
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
authors.forename: Mingxing
authors.initials: M
authors.lastname: Liang
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China. Electronic address: yimouwu@sina.com.
authors.forename: Yimou
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000372:Agglutination Tests / Q000379:methods; D000942:Antigens, Bacterial / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D011994:Recombinant Proteins; D012680:Sensitivity and Specificity; D013587:Syphilis / Q000175:diagnosis*; D013588:Syphilis Serodiagnosis / Q000379:methods; D014210:Treponema pallidum / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D011994:Recombinant Proteins
keywords: ELISA; Recombinant antigen; Serodiagnosis; Syphilis; Tp0663; Treponema pallidum