PrEP Use Only: T. pallidum (Syphilis) Cascade (Reverse Cascade)
Also known as: HIV PrEP, Pre-exposure prophylaxis screening for syphilis, Treponema pallidum antibody with reflex
Use
PrEP use only: This test is for baseline testing and monitoring for syphilis in patients administered HIV PrEP. This test aligns with the CDC-supported reverse serologic testing algorithm for syphilis using a combination of both treponemal and nontreponemal antibody tests. The reverse syphilis testing algorithm begins with a treponemal antibody assay. Positive samples reflex to RPR (nontreponemal). If the RPR is positive, RPR titer will be determined. If the RPR is negative, a second treponemal antibody assay will be performed to confirm the presence of treponemal antibodies. Interpretation of results obtained must take into account patient symptoms and clinical history.
Special Instructions
Not provided.
Limitations
Treponemal antibodies typically persist for life despite treatment; thus, this assay cannot be used to monitor response to treatment or assess treatment outcomes. False positive treponemal antibody results have been observed in individuals with nonsyphilis treponemal infections such as bejel, pinta, and yaws.
Methodology
Immunoassay
Biomarkers
Treponema pallidum antibody
Antibody
LOINC Codes
- 47236-5 - T palldm IgG+IgM SerPl Ql IA
- 47236-5 - T palldm IgG+IgM SerPl Ql IA
- 20507-0 - RPR Ser Ql
- 31147-2 - RPR Ser-Titr
- 24312-1 - T palldm Ab Ser Ql Aggl
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Red-top tube or gel-barrier tube
Storage Instructions
Room temperature
Causes for Rejection
Hemolysis; lipemia; gross bacterial contamination; plasma specimen
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |
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