Search for a Treponema pallidum Antigen Test (SeTPAT) project Treponema pallidum-specific proteomic changes in patients with incident syphilis infection: an observation study in Belgium

The only validated tests available for assessing if syphilis has responded to therapy are the “non-treponemal” tests. These tests frequently give false positive and false negative results. Despite these problems, the “non-treponemal” tests are also one of the two categories of tests used in the initial diagnosis of syphilis. The search for a Treponema pallidum Antigen Test (SeTPAT) project aims to study the proteomic, immunological, serological and clinical changes associated with pre- and post-treatment syphilis infection in a way that will ultimately lead to the development of a new ELISA and rapid diagnostic test of T. pallidum antigenaemia. The general aim of this observational study is thus to quantify a set of target proteins with the highest diagnostic potential for the diagnosis of initial T. pallidum infection and T. pallidum persistence. A test which could directly detect the presence of T. pallidum antigens could represent a considerable advance over currently used tests in the diagnosis of initial syphilis infection, its response to therapy and in the diagnosis of syphilis reinfections. In this study, we plan to set up a prospective observational study of patients diagnosed with syphilis within a HIV positive cohort at the Institute of Tropical Medicine (Work Package 1 – WP1). Targeted proteomic studies including mass spectrometry will be used to assess which T.pallidum antigens have the greatest diagnostic potential for evaluating the initial diagnosis and response to therapy of T.pallidum infection (WP2). WP3 will use this information to construct a specific T.pallidum capture ELISA – using polyclonal antibodies from rabbit infection as the capture antibodies and monoclonal antibodies as the detection antibodies. We aim to translate this test into an ELISA that will take the place of, or complement, the “non-treponemal” tests in the initial diagnosis and subsequent follow up of patients with syphilis.

Trefwoorden:B780-tropische-geneeskunde