PrEP Use Only: T. pallidum (Syphilis) Cascade (Reverse Cascade)

Casandra

Casandra Test Code LC53699Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 082360CPT Code 86780

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

Clinical Use

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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

PrEP use only. This test contains a CPT code modifier for the CARES Act. Reactive and equivocal samples reflex to RPR at an additional charge.

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.

Test Details