Syphilis antibodies that have been positive for more than 10 years usually do not turn negative. Syphilis antibodies are mainly composed of two types: specific antibodies and non-specific antibodies. Whether or not a positive syphilis antibody can be converted depends on the type of antibody. 1. Syphilis-specific antibodies: they are mainly produced against the syphilis spirochetes, such as TPPA and TPHA. Once positive, specific antibodies are usually non-convertible and last for life. 2. Syphilis non-specific antibodies: non-specific antibodies are an indicator of disease activity. After effective treatment in the early stages of infection, the syphilis titer can gradually decrease and become negative. Syphilis antibody positivity for more than 10 years generally means that the specific antibody is positive for more than 10 years. Therefore, specific antibody positivity for more than 10 years generally does not turn negative.