RPR, Serum (Syphilis Serology)

Tube Type

Test ID		LAB494
EPIC Order		RPR SERUM
CPT Code(s)		86592, (86593 if positive)
Group/Individual Test		Group
Laboratory		Clinical Immunology
Tube Station		30
Specimen	Routine:	2 ml blood/Gold SST tube
Availability	Routine:	Monday-Friday
	STAT:	Stat requests require phone call to lab: 984-974-1815 (Mon-Sat, 8am-4pm); 984-974-1805 (after hours)
Turnaround Time		1-3 Days (Routine); 1-2 Hours (STAT)
Reference Range	Normal:	Non-Reactive; See Comments.
Comments	The Rapid Plasma Reagin (RPR) test is a nontreponemal test detecting antibodies (reagin) reacting with the cardiolipin-lecithin-cholesterol antigen. The RPR is performed with undiluted serum. Results are reported as non-reactive or reactive. Reactive samples are serially diluted and retested to determine the endpoint titer that is reported with the reactive result. Reactive results are reflexed to TP-PA confirmation if the patient has not been previously confirmed. TP-PA reflex is not conducted on patients that have a documented previously positive treponemal test result. RPR titers can decline with time during late syphilis. Additionally, titers can be used to monitor the response to therapy. The RPR is not to be used for testing CSF. The CSF VDRL test is offered for detection of non-treponemal antibodies in CSF.

Reviewed by J. Carr on November 04, 2025

UNC Hospitals
McLendon Clinical Laboratories
101 Manning Drive
Chapel Hill, NC 27514