Which statement correctly identifies a non-treponemal test for syphilis?

Which statement correctly identifies a non-treponemal test for syphilis?

• A. VDRL and RPR
• B. RPR only
• C. VDRL
• D. FTA-ABS

Answer: (A)

Non-treponemal tests for syphilis detect antibodies to cardiolipin-lecithin-cholesterol complexes released from damaged host tissue, not antibodies to the bacteria itself. VDRL and RPR are examples of these tests. Because they target a host lipid-complex antigen, they are less specific for syphilis and can yield false positives in other conditions, but they’re useful for initial screening and for monitoring treatment response since their antibody titers tend to decline with successful therapy. Treponemal tests, like FTA-ABS, detect antibodies specific to Treponema pallidum and usually remain positive for life, which is why non-treponemal tests are often used for screening and monitoring, followed by treponemal testing to confirm.

Non-treponemal tests for syphilis detect antibodies to cardiolipin-lecithin-cholesterol complexes released from damaged host tissue, not antibodies to the bacteria itself. VDRL and RPR are examples of these tests. Because they target a host lipid-complex antigen, they are less specific for syphilis and can yield false positives in other conditions, but they’re useful for initial screening and for monitoring treatment response since their antibody titers tend to decline with successful therapy. Treponemal tests, like FTA-ABS, detect antibodies specific to Treponema pallidum and usually remain positive for life, which is why non-treponemal tests are often used for screening and monitoring, followed by treponemal testing to confirm.