What does RPR (Rapid Plasma Reagin) test show?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 8, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

The RPR (Rapid Plasma Reagin) test is a blood test that screens for syphilis infection by detecting antibodies produced in response to the bacterium Treponema pallidum.

What the RPR Test Shows

The RPR test is considered a non-treponemal test, meaning it doesn't directly detect the syphilis bacterium but rather detects antibodies that react to substances released when cells are damaged by the infection.

  • A positive RPR result indicates possible syphilis infection but requires confirmation with a more specific treponemal test like the FTA-ABS or TP-PA.
  • The RPR test is also valuable for monitoring treatment effectiveness, as antibody levels (measured as titers) typically decrease after successful treatment.
  • False positive results can occur in certain conditions including pregnancy, autoimmune diseases, viral infections, and advanced age.

Key Points About the RPR Test

  • The test is simple to perform, relatively inexpensive, and provides quick results, making it useful for initial syphilis screening in various healthcare settings.
  • It is essential to interpret RPR results in the context of clinical symptoms and other diagnostic tests due to the potential for false positives and the need for confirmatory testing 1.
  • The RPR test's performance characteristics, including sensitivity and specificity, can vary depending on the stage of syphilis and other factors, highlighting the importance of understanding its limitations in different clinical scenarios 1.

From the Research

RPR Test Overview

  • The Rapid Plasma Reagin (RPR) test is a nontreponemal flocculation test used to assess disease activity in syphilis cases 2.
  • It is one of the traditional serological assays used in the laboratory diagnosis of syphilis, along with treponemal serological tests such as T. pallidum IgG chemiluminescence immunoassay (CLIA) and the T. pallidum particle agglutination (TPPA) 2.

Disease Activity Assessment

  • The RPR test is utilized to evaluate the level of disease activity in patients with syphilis, providing valuable information for clinicians to monitor the progression of the disease and the effectiveness of treatment 2.
  • The test results can help identify large foci of infection, particularly in isolated communities with unique sociocultural characteristics, posing challenges to traditional diagnostic and treatment approaches 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

The Laboratory Diagnosis of Syphilis.

Journal of clinical microbiology, 2021

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.