Syphilis Antibody, IgG, Serum Clinical Information Discusses
physiology, pathophysiology, and general clinical aspects, as
they relate to a laboratory test Syphilis is a disease caused by
infection with the spirochete Treponema pallidum. The infection
is systemic and the disease is characterized by periods of
latency. These features, together with the fact that Treponema
pallidum cannot be isolated in culture, mean that serologic
techniques play a major role in the diagnosis and follow-up of
treatment for syphilis. Historically, the serologic testing
algorithm for syphilis included an initial nontreponemal
screening test, such as the rapid plasma reagin (RPR) or the
venereal disease research laboratory (VDRL) tests. Because these
tests measure the host's antibody response to nontreponemal
antigens, they lack specificity. Therefore, a positive result by
RPR or VDRL requires confirmation by a treponemal-specific test,
such as the fluorescent treponemal antibody-absorbed (FTA-ABS)
or microhemagglutination assay