Rapid Plasma Reagin (RPR) with Reflex to Treponema pallidum Particle Agglutination, Serum

Casandra

Casandra Test Code MC33552Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID RPRT3CPT Codes 86592, 86593, 86780

Rapid Plasma Reagin (RPR) with Reflex to Treponema pallidum Particle Agglutination, Serum

Clinical Use

Use

The Rapid Plasma Reagin (RPR) test with reflex to Treponema pallidum Particle Agglutination (TP-PA) is primarily used for diagnosing syphilis. Syphilis, caused by the spirochete Treponema pallidum subspecies pallidum, is a systemic infection with periods of latency. Due to its systemic nature, serologic techniques are crucial for diagnosis and follow-up. This test is part of the reverse syphilis screening algorithm. If the initial treponemal antibody assay is positive, it reflexes to RPR testing. Positive RPR results suggest active or recent infection, while negative results reflex to the TP-PA test for confirmation.

Special Instructions

This test is recommended following a reactive initial treponemal antibody assay as part of the reverse syphilis testing algorithm. Detailed instructions for specimen collection and handling are necessary to prevent false-positive results due to biological substances such as pregnancy or autoimmune diseases. A fillable Infectious Disease Serology Test Request form should be submitted if not ordering electronically.

Limitations

Biological false-positive reactions can occur with cardiolipin-type antigens, which are seen in certain diseases like infectious mononucleosis, leprosy, malaria, lupus erythematosus, and others. Pregnancy, certain autoimmune diseases, or narcotic addictions might cause false-positive results. Other treponemal diseases can also lead to false positives. These limitations highlight the need for confirmatory testing in the case of positive results.

Test Details

FDA Approved