Aim: Development of test-system on the basis of immunochip for detection of IgG to Treponema pallidum.
Materials and methods: Recombinant T. pallidum antigens Tp47, Tp17, Tp15, TmpA were separately immobilized on activated slides as individual spots. The specific antibodies to T. pallidum in human serum were detected by indirect immunofluorescent assay on the immunochip using antispecies antibodies to human IgG. Fluorescent scanner was used to read results of testing. For each antigen threshold level of fluorescent signal and positivity coefficient were calculated. Assessment of specificity and sensitivity of the immunochip was performed on 400 human serum samples containing or not-containing antibodies to T. pallidum.
Results: From 200 positive serum samples 5 were interpreted as inconclusive because positive results on antigen Tp17 only were registered that was comparable with the results of immunoblotting. For each other 195 serum samples, positive result on 2 or more antigens was obtained. Specificity of the immunochip-based test-system was 100%.
Conclusion: Experimental immunochip-based test-system for differential serologic diagnostics of the syphilis was developed. Its sensitivity and specificity are comparable with that of ELISA-based test-system.