Treponema pallidum (Syphilis) Screening Cascade

CPT: 86780
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  • Syphilis
  • Trep-Sure™
  • Treponemal

Test Includes

Reflex to qualitative rapid plasma reagin (RPR) on positives

Expected Turnaround Time

1 - 4 days

Related Documents

Specimen Requirements




1 mL

Minimum Volume

0.5 mL (Note: This volume does not allow for repeat testing.)


Red-top tube or gel-barrier tube

Storage Instructions

Room temperature

Stability Requirements



Room temperature

14 days


14 days


14 days

Freeze/thaw cycles

Stable x3

Causes for Rejection

Hemolysis; lipemia; gross bacterial contamination; plasma specimen

Test Details


Serological test for screening for syphilis infection. This panel includes a Treponema-specific test which may be positive in all stages of syphilis. It may be positive with treponemal infections other than syphilis (bejel, pinta, yaws). Like FTA-ABS and TP-PA, once positive, it remains so; it cannot be used to judge the effectiveness of treatment.


The test is not applicable to CSF.


Enzyme immunoassay (EIA) with reflex to charcoal flocculation if reactive

Additional Information

The traditional syphilis screening approach when the first-line test is a nontreponemal assay (like RPR) and if positive, the second-line confirmatory test is a treponemal test (such as TP-PA) was developed many years ago when treponemal tests lacked necessary sensitivity but delivered acceptable specificity. In the early 1990s, the CDC published guidelines that recommended the traditional algorithm for screening. Since that time, a number of new, more sensitive treponemal immunoassays have been introduced. In 2008, the CDC issued a report that describes the new syphilis screening approach in which the treponemal test was used as the first-line test, and if positive, reflexes to the nontreponemal test. This report shows that a number of infected individuals would be missed using the traditional approach. In addition, a number of tested individuals would receive false-positive results.1

The implementation of the new approach−if the highly sensitive and specific treponemal assay is used−allows for an improvement in the early detection of syphilis infection that should lead to more effective treatment while preventing the spread of disease. When the treponemal test is positive, it will reflex to qualitative RPR and, if positive, reflex to RPR titer. If the RPR is negative, it will reflex to another (second) treponemal test for confirmation.


1. Centers for Disease Control and Prevention. Syphilis testing algorithms using treponemal tests for initial screening−Four laboratories. New York City, 2005-2006. MMWR. 2008 Aug 15; 57(32):872-875. 18701877


Association of Public Health Laboratories Laboratory Diagnostic Testing for Treponema pallidum: Expert Consultation Meeting Summary Report. Atlanta, Ga, January 13-15, 2009.
Ballard R. Changing Times in Syphilis Serology. Atlanta, Ga: Centers for Disease Control and Prevention, Association of Public Health Laboratories, Laboratory Learning Links Teleconference Series, 2008.
Centers for Disease Control and Prevention. Sexually Transmitted Disease Surveillance, 2008. Atlanta, Ga: CDC, November 2009.
Cox DL. Letter to Phoenix Biotech, April 21, 2006. Cited with permission.
Dang Q, Feng J, Lu X, et al. Evaluation of specific antibodies for early diagnosis and management of syphilis. Int J Dermatol. 2006 Oct; 45(10):1169-1171.17040431
Knight CS, Crum MA, Hardy RW. Evaluation of the LIAISON chemiluminescence immunoassay for diagnosis of syphilis. Clin Vaccine Immunol. 2007 Jun; 14(6):710-713.17460119
Lehnus & Associates Consulting. K053570-Response 1 for TREP-SURE Treponemal Antibody EIA. [letter] East Stroudsburg, Pa: Lehnus, May 4, 2006.
Miranda APF, Sato NS. Profile of anti-Tp47 antibodies in patients with positive serology for syphilis analyzed by Western blot. Braz J Infect Dis. 2008 Apr; 12(2):139-143.18641851
Sambri V, Marangoni A, Eyer C, et al. Western immunoblotting with five Treponema pallidum recombinant antigens for serologic diagnosis of syphilis. Clin Diagn Lab Immunol. 2001 May; 8(3):534-539.11329453
Singh AE, Wong T, De P. Characteristics of primary and late latent syphilis cases which were initially nonreactive with the rapid plasma reagin as screening test. Int J STD AIDS. 2008 Jul; 19(7)464-468.18574118
Sloma CR, Stier TJ, Majewski DW, et al. Comparative evaluation of Capture®-S and TREP-SURE™ assays for serologic detection of syphilis in blood donors, May 11, 2007, abstract N° 07-AB-407-AABB.
Stanford Hospital and Clinics, Stanford Medical Center. New ELISA screening for syphilis . . . flipping the treponemal paradigm. Lab Letter. 2007 Nov-Dec; 3(4):1-2.
Tramont EC. Treponema pallidum (Syphilis). In: Mandell GL, Douglas RG Jr, Bennett JE, eds. Principles and Practice of Infectious Diseases. 2nd ed. Hoboken, NJ: John Wiley & Sons;1985.
TREP-SURE™, Anti-Treponema EIA Screen. [Package insert] Mississauga, Ontario, Canada: Phoenix Bio-Tech; 2010.
US Preventive Services Task Force. Screening for syphilis infection in pregnancy: US Preventive Services Task Force reaffirmation recommendation statement. Ann Intern Med. 2009 May 19; 150(10)705-709.19451577


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
082345 T pallidum Screening Cascade 47236-5 082356 T pallidum Antibodies 47236-5
Reflex Table for T pallidum Antibodies
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 006099 RPR 006097 RPR 20507-0
Reflex 2 006476 RPR, Quant 006476 RPR, Quant 31147-2
Reflex Table for T pallidum Antibodies
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 006099 RPR 006097 RPR 20507-0
Reflex 2 163038 T pallidum Antibody, EIA 163038 T pallidum Antibody, EIA 34147-9

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