2162. Treponema Pallidum, IgG antibodies

IgG antibodies to Treponema pallidum indicate current, chronic, or past infection. The test is used to confirm syphilis, assess the effectiveness of treatment, and for preventive screening – particularly during pregnancy, in donors, and before surgery.

Treponema pallidum is a spirochete that causes syphilis, a systemic infectious disease transmitted primarily through sexual contact, but also through transfusion and vertical (mother-to-child) transmission. The disease progresses through stages: primary, secondary, latent, and tertiary syphilis, each with its own clinical characteristics or a prolonged asymptomatic course.

IgG antibodies to T. pallidum appear approximately 3-4 weeks after infection and can persist for life, even after successful treatment. Their presence indicates a history of infection or the development of a chronic form. The IgG test is part of treponemal screening and is used as a basic method for detecting syphilis, particularly in asymptomatic cases or incidental detection during routine checkups.

Since IgG does not allow one to determine the disease's activity, its results are interpreted in conjunction with:

• IgM antibodies (acute or recent infection);
• non-treponemal tests (RPR, VDRL) – these decrease after treatment and are used to monitor progress;

With an initial positive IgG result, a confirmatory treponemal test is recommended – TPHA, TPPA, or immunoblot.

• If active or latent syphilis is suspected.
• In patients with a positive IgM or RPR test to confirm the diagnosis.
• For all pregnant women – mandatory screening to prevent congenital syphilis.
• For couples planning a pregnancy, IVF, or ICSI.
• For blood, organ, or tissue donors.
• For patients before surgical or invasive procedures.
• For retrospective assessment of infection status after casual or high-risk sexual contacts.
• For monitoring the effectiveness of syphilis treatment – ​​in combination with RPR/VDRL over time.

• Venous blood

In order to exclude factors that may affect the test results, we recommend to follow the preparation rules: