Rapid Plasma Reagin (RPR) titer

TEST DESCRIPTION

Macroscopic nontreponemal flocculation card test that determines the titer (concentration) of reagin (antilipid antibodies) in the serum or plasma of persons with syphilis. This test is reflexed following a positive qualitative RPR test. An RPR titer is useful for monitoring treatment efficacy and disease reoccurrence.

Treponema pallidum, the causative agent of syphilis, induces the production of at least two types of antibodies in human infection: anti-treponemal antibodies that can be detected by the TP-PA test and non-treponemal antibodies (reagin) that can be detected by the RPR test.

Methodology

Quantitative immunoassay

Reference range

Non-reactive

TEST FREQUENCY & RESULT AVAILABILITY

Performed twice weekly. Results are typically available within three business days after specimen receipt.

ACCEPTABLE SPECIMEN TYPES AND COLLECTION

Serum: Collect ≥2 ml of venous blood in a serum separator tube (SST).
Plasma: Collect ≥2 ml of venous blood in an EDTA (lavender-top), lithium heparin (green-top), or citrate (light blue-top) tube.
Note: Centrifugation should be performed 30 minutes to 2 hours after collection.

SPECIMEN STORAGE

Spun (centrifuged) serum or plasma: store refrigerated (2–8 °C/36–46 °F) for up to 5 days.

Unspun (not centrifuged) serum or plasma: store at room temperature (15–25°C/59–77°F) for up to 2 hours.

SPECIMEN TRANSPORT

Shipping conditions should follow the temperature and time requirements outlined above. Refrigerated specimens should be transported on wet ice.

REJECTION CRITERIA

Spun tubes: holding time greater than 24 hours at room temperature or 5 days refrigerated
Non-spun tubes: holding time greater than 2 hours at room temperature
Specimen container not labeled
Specimen container not sealed properly
Grossly contaminated, hemolyzed, lipemic, or icteric specimens should not be used

CODES

CPT: 86593
LOINC: 31147-2
Test code: 5040

TEST FEE

Refer to the current fee schedule.