Treponema pallidum Antibody by TP-PA
Also known as: MHA
Use
The Treponema pallidum Antibody test by TP-PA is recommended by the CDC as a confirmatory test for syphilis. This test is primarily used when the initial screening tests, such as the RPR or VDRL, show reactive results. It is a helpful diagnostic tool especially for patients who manifest atypical symptoms in primary, secondary, or late syphilis stages. While TP-PA compares favorably with the FTA test, it may be slightly less sensitive in detecting untreated early primary syphilis cases. In cases of late syphilis, the test shows a 99% agreement with the FTA test.
Special Instructions
TP-PA provides a confirmatory testing option following initial reactive reagin tests. It should not be used for cerebrospinal fluid (CSF) testing as VDRL is preferred for CSF. TP-PA in CSF has not been validated and thus is not recommended.
Limitations
While TP-PA is highly effective as a confirmatory test for syphilis, it shows slightly reduced sensitivity in cases of untreated early primary syphilis compared to the FTA test. Additionally, it is not designed for use with CSF specimens, where VDRL is the preferred testing method. Therefore, the test may not be suitable for all syphilis testing contexts, especially concerning CSF evaluation.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 24312-1
- 24312-1
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.4 mL
Container
ARUP standard transport tube
Collection Instructions
Separate serum or plasma from cells ASAP or within 2 hours of collection.
Storage Instructions
Refrigerated
Causes for Rejection
CSF or other body fluids.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 2 weeks |
| Frozen | 1 year (avoid repeated freeze/thaw cycles) |