Rapid Plasma Reagin (RPR - Titre Test) - Syphilis – BC268
🔬 Syphilis Screening & MonitoringReport: Same Day
Sample Type: Blood (Serum)
Test Code: BC268
The RPR (Rapid Plasma Reagin) with Titre is a quantitative blood test used to screen for syphilis and monitor treatment. It not only detects the presence of reagin antibodies but also measures their level (titer). This level is crucial for assessing disease activity and confirming a cure after treatment.
✔ A quantitative screening test for syphilis.
✔ The titer level is essential for monitoring response to antibiotic therapy.
✔ A four-fold drop in the titer is the primary indicator of a successful cure.
✔ A reactive result requires confirmation with a specific treponemal test (e.g., TPHA).
The Power of the Titer: From Screening to Monitoring
The RPR test is a non-treponemal test, meaning it detects antibodies produced against substances released by cells damaged by the syphilis bacterium. While a simple RPR can give a "Reactive" or "Non-reactive" result, the RPR with Titre provides a much more valuable, quantitative number.
What is a Titer?
A titer is a measure of how much of an antibody is in the blood. In the lab, the patient's blood serum is diluted in a series (1:2, 1:4, 1:8, 1:16, 1:32, etc.). The test is performed on each dilution. The titer is the highest dilution at which the reactive (positive) result is still visible. A higher titer (e.g., 1:128) indicates a greater concentration of antibodies than a lower titer (e.g., 1:8).
Why the Titer is Crucial for Treatment
The RPR titer is the gold standard for monitoring the effectiveness of syphilis treatment. After successful treatment with antibiotics, the cell damage stops, and the body's production of reagin antibodies decreases. This is reflected in the RPR titer.
- Successful Cure: A four-fold or greater drop in the RPR titer (e.g., a change from 1:64 to 1:16) within 6-12 months after treatment is the primary indicator of a cure.
- Treatment Failure or Reinfection: If the titer fails to decrease or starts to rise again after an initial drop, it suggests that the treatment was not successful or that the person has been reinfected.
Because of this, doctors will order serial RPR with Titre tests at specific intervals after treatment to track the patient's recovery.
Frequently Asked Questions (FAQ)
A regular RPR test may just give a positive/negative result. The RPR with Titre is a quantitative test that measures the level of antibodies. This level, or titer, is essential for monitoring how well treatment is working.
A titer of 1:32 means that the reagin antibodies were still detectable even after your blood serum was diluted 32 times. It indicates a higher concentration of antibodies than a titer of 1:8, for example, and suggests an active or recent infection.
Your doctor is monitoring the titer to confirm a cure. After successful treatment, your RPR titer should show a significant (at least four-fold) drop over several months. This is the best way to prove that the treatment worked.
Not necessarily. The RPR test can have false positives. Any initial reactive RPR result, regardless of the titer, must be confirmed with a more specific test like TPHA to make a definitive diagnosis of syphilis.