Rapid Plasma Reagin (RPR), Serum
Medical Test

Diseases (27)
Screening/Initial Testing (7)
Syphilis, congenital
10
Note:

Should be performed on both maternal and infant samples

Dementia
7
Note:

If syphilis is suspected by history

Pelvic inflammatory disease
6
Note:

Rule out syphilis.

Diagnostic Testing (14)
Alopecia
8
Note:

Rule out syphilis in patients with patchy alopecia

Sexual abuse and assault
7
Note:

If T. pallidum serology is positive.

Herpes simplex infection
5
Note:

Rule out syphilis.

Drug-induced systemic lupus erythematosus
4
Note:

Should be ordered with VDRL as VDRL is usually positive and RPR negative.

Disease Management Testing (6)

Overview

Treponema pallidum, the etiological agent of syphilis, induces the production of at least two types of antibodies in human infection: anti-treponemal antibodies that can be detected by fluorescence treponemal antigen assay (FTA-ABS), and anti-nontreponemal antibodies (reagin) that can be detected by RPR antigen. RPR is a latex flocculation based test that uses a cardiolipin-lecithin-cholesterol carbon-containing antigen reagent. If antibodies are present, black carbon clumps are produced by flocculation indicating a positive test for RPR. It is a rapid test used as a screening test and in suspected primary and secondary syphilis. It is not specific for syphilis and false positives can occur with disorders such as malaria, systemic lupus erythematosus, infectious mononucleosis, viral pneumonia as well as the status of being pregnant.  Positive results must be confirmed by IFA antibody testing or by PCR. The test is also used for treatment monitoring and disease management. After treatment with antibiotics, the levels of syphilis antibodies should fall. These levels can be monitored with the RPR titer.  Successful therapy is indicated by a 4 fold decrease in titer within 6 months after initiation of therapy for primary and secondary stages.  Unchanged or rising levels can mean a persistent infection.

Syphilis is a sexually transmitted infection (STI) caused by the bacterial spirochete Treponema pallidum. Syphilis can be divided into three infectious stages: primary, secondary, and early latent, and two non-infectious disease stages: late latent and tertiary. Untreated syphilis during pregnancy can lead to miscarriage, premature or stillbirth, and birth defects. Testing of the mother is very important during the early stages of pregnancy so that treatment can be administered and the fetus can remain unaffected. It is estimated that approximately 12 million new cases of venereal syphilis occur each year.

Clinical Utility
  • Diagnosis of syphilis
  • Screening test for syphilis
  • Therapy monitoring

Interpretation

Increased in:

  • Syphilis: primary in about 80%
  • Secondary >95%
  • Symptomatic late syphilis in about 75%

False positives:

  • Leprosy
  • Malaria
  • Intravenous Drug Abuse
  • Infectious Mononucleosis
  • HIV infection (15%)
  • Autoimmune Diseases such as SLE and Rheumatoid Arthritis
  • Occasional false positives in elderly and pregnancy

Reference Ranges

Negative (Non-reactive)


 

 

Methodology

Macroscopic agglutination.

Specimen Collection

Serum (Red top) preferred, Serum gel (SST) acceptable

Stability:

  • Ambient: 4 days
  • Refrigerated: 7 days
  • Frozen: 30 days

Additional Testing

Treponemal antibody by IFA or ELISA, T. pallidum by PCR testing, MHA-TP.

CPT
86592$4.27
86593$4.4

ICD10
ICD CODE AND DESCRIPTIONLCD CODENCD CODE
A50 - Congenital syphilis——
A50.1 - Early congenital syphilis, latent——
A50.4 - Late congenital neurosyphilis [juvenile neurosyphilis]——
A50.40 - Late congenital neurosyphilis, unspecified——
A50.49 - Other late congenital neurosyphilis——
A50.6 - Late congenital syphilis, latent——
A50.7 - Late congenital syphilis, unspecified——
A50.9 - Congenital syphilis, unspecified——
A51 - Early syphilis——
A51.0 - Primary genital syphilis——
A51.3 - Secondary syphilis of skin and mucous membranes——
A51.32 - Syphilitic alopecia——
A51.39 - Other secondary syphilis of skin——
A51.4 - Other secondary syphilis——
A51.41 - Secondary syphilitic meningitis——
A51.42 - Secondary syphilitic female pelvic disease——
A51.49 - Other secondary syphilitic conditions——
A51.5 - Early syphilis, latent——
A52 - Late syphilis——
A52.1 - Symptomatic neurosyphilis——
A52.10 - Symptomatic neurosyphilis, unspecified——
A52.19 - Other symptomatic neurosyphilis——
A52.3 - Neurosyphilis, unspecified——
A52.7 - Other symptomatic late syphilis——
A52.79 - Other symptomatic late syphilis——
A52.8 - Late syphilis, latent——
A53 - Other and unspecified syphilis——
A53.0 - Latent syphilis, unspecified as early or late——
A53.9 - Syphilis, unspecified——
A54 - Gonococcal infection——
A56 - Other sexually transmitted chlamydial diseases——
A56.11 - Chlamydial female pelvic inflammatory disease——
A56.8 - Sexually transmitted chlamydial infection of other sites——
A60 - Anogenital herpesviral [herpes simplex] infections——
A60.0 - Herpesviral infection of genitalia and urogenital tract——
A60.00 - Herpesviral infection of urogenital system, unspecified——
A60.01 - Herpesviral infection of penis——
A60.02 - Herpesviral infection of other male genital organs——
A60.03 - Herpesviral cervicitis——
A60.04 - Herpesviral vulvovaginitis——
A60.09 - Herpesviral infection of other urogenital tract——
A60.1 - Herpesviral infection of perianal skin and rectum——
A60.9 - Anogenital herpesviral infection, unspecified——
B00 - Herpesviral [herpes simplex] infections——
B00.0 - Eczema herpeticum——
B00.1 - Herpesviral vesicular dermatitis——
B00.2 - Herpesviral gingivostomatitis and pharyngotonsillitis——
B00.3 - Herpesviral meningitis——
B00.4 - Herpesviral encephalitis——
B00.5 - Herpesviral ocular disease——

Additional ICD10
ICD CODE AND DESCRIPTIONLCD CODENCD CODE
A38.1 - Scarlet fever with myocarditis——
A39.52 - Meningococcal myocarditis——
A50.0 - Early congenital syphilis, symptomatic——
A50.01 - Early congenital syphilitic oculopathy——
A50.02 - Early congenital syphilitic osteochondropathy——
A50.03 - Early congenital syphilitic pharyngitis——
A50.04 - Early congenital syphilitic pneumonia——
A50.05 - Early congenital syphilitic rhinitis——
A50.06 - Early cutaneous congenital syphilis——
A50.07 - Early mucocutaneous congenital syphilis——
A50.08 - Early visceral congenital syphilis——
A50.09 - Other early congenital syphilis, symptomatic——
A50.1 - Early congenital syphilis, latent——
A50.2 - Early congenital syphilis, unspecified——
A50.3 - Late congenital syphilitic oculopathy——
A50.30 - Late congenital syphilitic oculopathy, unspecified——
A50.31 - Late congenital syphilitic interstitial keratitis——
A50.32 - Late congenital syphilitic chorioretinitis——
A50.39 - Other late congenital syphilitic oculopathy——
A50.4 - Late congenital neurosyphilis [juvenile neurosyphilis]——
A50.40 - Late congenital neurosyphilis, unspecified——
A50.41 - Late congenital syphilitic meningitis——
A50.42 - Late congenital syphilitic encephalitis——
A50.43 - Late congenital syphilitic polyneuropathy——
A50.44 - Late congenital syphilitic optic nerve atrophy——
A50.45 - Juvenile general paresis——
A50.49 - Other late congenital neurosyphilis——
A50.5 - Other late congenital syphilis, symptomatic——
A50.51 - Clutton's joints——
A50.52 - Hutchinson's teeth——
A50.53 - Hutchinson's triad——
A50.54 - Late congenital cardiovascular syphilis——
A50.55 - Late congenital syphilitic arthropathy——
A50.56 - Late congenital syphilitic osteochondropathy——
A50.57 - Syphilitic saddle nose——
A50.59 - Other late congenital syphilis, symptomatic——
A50.6 - Late congenital syphilis, latent——
A50.7 - Late congenital syphilis, unspecified——
A50.9 - Congenital syphilis, unspecified——
A51.0 - Primary genital syphilis——
A51.1 - Primary anal syphilis——
A51.2 - Primary syphilis of other sites——
A51.3 - Secondary syphilis of skin and mucous membranes——
A51.31 - Condyloma latum——
A51.32 - Syphilitic alopecia——
A51.39 - Other secondary syphilis of skin——
A51.4 - Other secondary syphilis——
A51.41 - Secondary syphilitic meningitis——
A51.42 - Secondary syphilitic female pelvic disease——
A51.43 - Secondary syphilitic oculopathy——

References
  • Sex Transm Dis. 1998;25:569. [PMID:9858355]
  • Int J STD AIDS. 1995 Jul-Aug;6(4):241-8. [PMID:7548285]
  • J Emerg Med. 2000;18:361. [PMID:10729677]
  • Dermatol Clin .2006;24:497. [PMID:17010778]
  • Stevens CD. Clinical Immunology & Serology: A Laboratory Perspective 3rd edition. Philadelphia: F.A. Davis Company (2010).