Syphilis: Treponemal Antibodies, Treponema pallidum Particle Agglutination (TPPA)

Serum

1 mL

0.5 mL (Note: This volume does not allow for repeat testing.)

Gel-barrier tube or serum transfer tube

This test detects antibodies to Treponema pallidum and can be used in conjunction with a nontreponemal assay to aid in the diagnosis of syphilis infection. This test is not recommended as a stand-alone test for general screening purposes for syphilis, nor should it be used to evaluate response to therapy. To screen for and diagnose syphilis infection, a reflex cascade that includes both RPR and a treponemal-specific assay should be utilized per current guidelines.

As with all serological tests for syphilis, interpretation of results obtained with TPPA test must be used in conjunction with the patient's clinical symptoms, medical history and other clinical and/or laboratory findings. Treponemal antibodies typically remain detectable long term following infection and therefore should not be used to evaluate response to therapy.

The syphilis TPPA may be reactive in <1% of normal or healthy persons; these biological false-positive results are often transient and their cause is unknown.

Treponemal antibody tests may be reactive in persons exposed to yaws or pinta.

Samples from patients with HIV, leprosy, toxoplasmosis, H. pylori or drug addiction may on occasion produce false-positive or inconclusive results.

Agglutination