What it measures
RPR and VDRL tests measure antibodies that rise while syphilis is active. The result is a titre, which shows how far the blood can be diluted and still react, so it tracks the level of activity over time.
Why people test it
- Used after a positive syphilis antibody test to see whether the infection is current.
- Repeated after antibiotics, as a falling titre shows the infection has responded.
- Used to look for a new infection in someone who has had syphilis before.
Typical range
Reported as non-reactive, or as a titre where a higher titre means a stronger reaction. Methods vary between labs, so titres are best compared between results from the same lab, and your report shows how the lab reads the result.
Finger-prick or vein?
Offered as a vein draw only.