UCSF Navigation Bar

UCSF Departments of Pathology & Laboratory Medicine Home Page

Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

Internal Resources


Item Value
Available Stat? No
Test code RPRS
Performed by? Microbiology
Sendout? no
Price range $$
In House Availability test run once a week on Wednesday
Principle This test provides a qualitative determination of the presence of antibodies to Treponema pallidum. Patient serum, containing the specific antibody, will react with gel particles which are coated with T. pallidum antigen. The formation of a mat of agglutinated particles indicates a reactive specimen. The TP-PA test is reported as "reactive" or "nonreactive."

Interpretation The TP-PA test is used as a confirmatory test for sera from patients suspected to have syphilis. The MHA-TP (microhemagglutination for Treponema pallidum.) and the FTA-ABS are no longer used by SFGH or the SF Department of Public Health for confirmation. Studies have shown good correlation between the TP-PA and the MHA-TP as confirmatory tests. If primary syphilis is suspected and the TP-PA test is non-reactive, a second specimen from the patient should be submitted.

Treponemal antibody tests (TP-PA) are recommended as a diagnostic aid for patients with symptoms suggesting late syphilis regardless of results from non-treponemal antibody testing, which are less sensitive in such cases. However, the TP-PA is not recommended as a general screening test for syphilis or to monitor therapy. In most cases, once a treponemal antibody test is reactive, it will remain reactive for life. However, when treatment is begun early in primary disease, the TP-PA may not become reactive and about 10% of these patients who do become reactive will be nonreactive within two years.
Container type gold top gel tube
Amount to Collect 3 mL
Sample type Blood
Normal range nonreactive
Synonyms MHA-TP (Microhemagglutination for Treponema Pallidum);Microhemagglutination for Treponema Pallidum;Syphilis Testing;Treponema Pallidum Serology;Treponemal Confirmatory Test for Syphilis;
Stability 3 days at 4°C.
Additional information REQUISITION: Blood/Serum - Main Laboratory.
References Package insert. June. 2006. Serodia(R) TP-PA: Reagents for the Detection of Antibodies to Treponema pallidum. Fujirebio, Inc., Tokyo, Japan.
CPT coding 86781
Last Updated 4/7/2011 4:49:42 PM
Search Our Test Menu
UCSF home page UCSF home page About UCSF Search UCSF UCSF Medical Center