Evaluation of a Treponema IgG ELISA alone and in combination with an IgM ELISA as substitutes for Treponema pallidum particle agglutination (TPPA) as confirmatory tests in a two-tier diagnostic algorithm for diagnosis of syphilis infection

Abstract

The Treponema pallidum particle agglutination (TPPA) has been used for decades for serological diagnostics of syphilis but is no longer available. Therefore, we evaluated the Treponema IgG ELISA (TpG) alone and in combination with the Treponema IgM ELISA (TpG+M, both from Euroimmun) as possible substitutes for TPPA as a confirmatory test in a two-tier syphilis screening algorithm. Furthermore, we investigated whether a TPPA titer of 5,120 which is used as cut-off for therapeutic decision in pregnant women in Germany can be transferred to an appropriate cut-off value of the TpG.

Keywords

• syphilis
• serology
• treponema
• tppa
• elisa
• pregnancy