A novel ELISA using a recombinant outer membrane protein, rTp0663, as the antigen for serological diagnosis of syphilis

Man Xu; Yafeng Xie; Chuanhao Jiang; Yongjian Xiao; Xingxing Kuang; Feijun Zhao; Tiebing Zeng; Shuangquan Liu; Mingxing Liang; Li Li; Chuan Wang; Yimou Wu

doi:10.1016/j.ijid.2015.12.013

A novel ELISA using a recombinant outer membrane protein, rTp0663, as the antigen for serological diagnosis of syphilis

Int J Infect Dis. 2016 Feb:43:51-57. doi: 10.1016/j.ijid.2015.12.013. Epub 2015 Dec 31.

Authors

Affiliations

¹ 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.
² 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.
³ Department of Clinical Laboratory, The First Affiliated Hospital of University of South China, Hengyang, China.
⁴ 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.

PMID: 26747418
DOI: 10.1016/j.ijid.2015.12.013

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).

Conclusion: These results identified Tp0663 as a novel serodiagnostic candidate with great potential for developing novel tests for the diagnosis of syphilis.

Keywords: ELISA; Recombinant antigen; Serodiagnosis; Syphilis; Tp0663; Treponema pallidum.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Agglutination Tests / methods
Antigens, Bacterial / immunology*
Bacterial Outer Membrane Proteins / immunology*
Enzyme-Linked Immunosorbent Assay / methods*
Humans
Recombinant Proteins
Sensitivity and Specificity
Syphilis / diagnosis*
Syphilis Serodiagnosis / methods
Treponema pallidum / immunology*

Substances

Antigens, Bacterial
Bacterial Outer Membrane Proteins
Recombinant Proteins