rapid plasma reagin

Abbreviation: RPR
A nonspecific serological test for syphilis. The RPR titer is elevated in most patients with syphilis (and falsely elevated in some patients with other diseases). The titer decreases or returns to normal after successful eradication of the disease. See also: reagin

Syphilis Serology

Synonym/acronym: Automated reagin testing (ART), fluorescent treponemal antibody testing (FTA-ABS), microhemagglutination– Treponema pallidum (MHA-TP), rapid plasma reagin (RPR), treponemal studies, Venereal Disease Research Laboratory (VDRL) testing.

Common use

To indicate past or present syphilis infection.

Specimen

Serum (1 mL) collected in a gold-, red-, or red/gray-top tube. Place separated serum into a standard transport tube within 2 hr of collection.

Normal findings

(Method: Dark-field microscopy, rapid plasma reagin, enzyme-linked immunosorbent assay [ELISA], microhemagglutination, fluorescence) Nonreactive or absence of treponemal organisms.

Description

Syphilis is a sexually transmitted disease with three stages. On average, symptoms start within 3 weeks of infection but can appear as soon as 10 days or as late as 90 days after infection. The primary stage of syphilis is usually marked by the appearance of a single sore, called a chancre, at the site where the organism entered the body. The chancre is small and round in appearance, is firm, and is usually painless. The chancre lasts 3 to 6 weeks and heals with or without treatment. If untreated, the infection progresses to the secondary stage as the chancre is healing or several weeks after the chancre has healed. The secondary stage is characterized by a skin rash and lesions of the mucous membranes. Other symptoms may include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue. As with the primary stage, the signs and symptoms of secondary syphilis will resolve either with or without treatment. If untreated, the infection will progress to the latent or hidden stage in which the infection and ability to transmit infection is present even though the infected person is asymptomatic. The latent stage begins when the primary and secondary symptoms disappear, and it can last for years. About 15% of people in the latent stage, who have not been treated, will develop late-stage syphilis, which can appear 10 to 20 years after infection. Untreated disease at this stage can result in significant damage to the brain, nerves, eyes, heart, blood vessels, liver, bones, and joints—damage serious enough to cause death. Signs and symptoms of the late stage of syphilis include difficulty coordinating muscle movements, numbness, paralysis, blindness, and dementia.

There are numerous methods for detecting Treponema pallidum, the gram-negative spirochete bacterium known to cause syphilis. Syphilis serology is routinely ordered as part of a prenatal work-up and is required for evaluating donated blood units before release for transfusion. Selection of the proper testing method is important. Automated reagin testing (ART), rapid plasma reagin (RPR), and Venereal Disease Research Laboratory (VDRL) testing have traditionally been used for screening purposes. These nontreponemal assays detect antibodies directed against lipoidal antigens from damaged host cells. Nontreponemal assays can produce false-positive results, which are associated with older age or conditions unrelated to syphilis, such as autoimmune disorders or injection drug use, and require confirmation by a treponemal test method. Fluorescent treponemal antibody testing (FTA-ABS), microhemagglutination– Treponema pallidum (MHA-TP), and Treponema pallidum by particle agglutination (TP-PA) are confirmatory methods for samples that screen positive or reactive. Some laboratories have begun using a reverse-screening approach. Highly automated, rapid-testing treponemal enzyme immunoassays (EIA) and chemiluminescent assays (CIA) detect antibodies directed against T. pallidum proteins. These assays detect early primary infections as well as past treated infections. The problem with the EIAs and CIAs is that they are very sensitive but less specific; therefore, positive test results should be confirmed using a nontreponemal assay. If reverse screening is used, the Centers for Disease Control and Prevention recommends (1) positive EIA/CIA be confirmed using the RPR and reactive RPR test results should be reported as the endpoint titer of reactivity; (2) a positive EIA/CIA followed by a nonreactive RPR should be tested by a direct treponemal assay such as the TP-PA or FTA-ABS to ensure a false-positive result is not reported and acted upon. Cerebrospinal fluid should be tested only by the FTA-ABS method. Cord blood should not be submitted for testing by any of the aforementioned methods; instead, the mother’s serum should be tested to establish whether the infant should be treated.

This procedure is contraindicated for

N/A

Indications

Monitor effectiveness of treatment for syphilis
Screen for and confirm the presence of syphilis

Potential diagnosis

Positive findings in:

Syphilis

False-positive or false-reactive findings in screening (RPR, VDRL) tests

Infectious:
- Bacterial endocarditis
- Chancroid
- Chickenpox
- HIV
- Infectious mononucleosis
- Leprosy
- Leptospirosis
- Lymphogranuloma venereum
- Malaria
- Measles
- Mumps
- Mycoplasma pneumoniae
- Pneumococcal pneumonia
- Psittacosis
- Relapsing fever
- Rickettsial disease
- Scarlet fever
- Trypanosomiasis
- Tuberculosis
- Vaccinia (live or attenuated)
- Viral hepatitis
Noninfectious:
- Advanced cancer
- Advancing age
- Chronic liver disease
- Connective tissue diseases
- IV drug use
- Multiple blood transfusions
- Multiple myeloma and other immunological disorders
- Narcotic addiction
- Pregnancy

False-positive or false-reactive findings in confirmatory (FTA-ABS, MHA-TP) tests

Infectious:
- Infectious mononucleosis
- Leprosy
- Leptospirosis
- Lyme disease
- Malaria
- Relapsing fever
Noninfectious:
- Systemic lupus erythematosus

False-positive findings in confirmatory (TP-PA) tests

Infectious:
- Pinta
- Yaws

N/A

Critical findings

N/A

Interfering factors

N/A

Nursing Implications and Procedure

Potential nursing problems

Problem	Signs & Symptoms	Interventions
Knowledge (Related to new condition or diagnosis; lack of familiarity with or understanding of disease and treatment)	Lack of interest or questions; multiple questions; anxiety in relation to disease process and management	Identify sexual orientation; teach the process of disease transmission, heterosexual or homosexual activity; teach the patient that infection risk increases with the number of sexual partners over time; identify the patient’s sexual activity; discuss importance of notifying sexual partners of disease exposure; assess for cultural, literacy, or vision and hearing concerns that would interfere with learning; teach the importance of taking the entire course of prescribed medication to treat the disease; administer prescribed medication; explore with the patient the value of monogamous relationship to support positive health
Infection	Rash on body; rash on the palms of the hands; rash on the soles of the feet; small firm nodules on genitalia, anus, or mouth; lack of coordinated movement; paralysis; gradual blindness; numbness; dementia; internal organ damage (brain, nerves, eyes, heart, liver, bones, joints); death at end stage	Assess for signs and symptoms of syphilis; ensure understanding that the disease is transmitted through direct contact with syphilis sores (located in genitalia, vagina, anus, inside the rectum, in the mouth); ensure understanding that it is a sexually transmitted disease; identify sexual partners who are at risk, notify them; assess for mucocutaneous infections; administer prescribed antibiotic
Body image (Related to the presence of lesions; rash)	Focus on appearance (lesions, rash); states feelings of worthlessness due to physical changes; reports difficulty in coping with syphilis diagnosis; change in social interaction; withdrawal	Assess the patient’s perception of physical changes; note the frequency of negative comments about changed physical state; assist in the identification of positive coping strategies to address changed physical appearance
Sexuality (Related to alterations in sexual role secondary to syphilis infection)	Hesitancy to discuss sexual relationship with significant other	Facilitate a discussion of realistic changes to sexual intimacy associated with syphilis disease; provide a relaxed atmosphere in which to discuss sexuality concerns; provide contact information for a support group

Pretest

Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
Patient Teaching: Inform the patient this test can assist in diagnosing syphilis.
Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
Obtain a history of exposure.
Obtain a history of the patient’s immune and reproductive systems, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
Review the procedure with the patient. Inform the patient that specimen collection takes approximately 5 to 10 min. Address concerns about pain and explain that there may be some discomfort during the venipuncture.
Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
Note that there are no food, fluid, or medication restrictions unless by medical direction.

Intratest

Potential complications: N/A
Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection. Perform a venipuncture.
Remove the needle and apply direct pressure with dry gauze to stop bleeding. Observe/assess venipuncture site for bleeding or hematoma formation and secure gauze with adhesive bandage.
Promptly transport the specimen to the laboratory for processing and analysis.

Post-Test

Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
Recognize anxiety related to test results, and offer support. Counsel the patient, as appropriate, regarding the risk of transmission and proper prophylaxis, and reinforce the importance of strict adherence to the treatment regimen. Inform the patient that positive findings must be reported to local health department officials, who will question him or her regarding sexual partners. Provide teaching and information regarding the clinical implications of the test results, as appropriate. Educate the patient regarding access to counseling services.
Offer support, as appropriate, to patients who may be the victim of rape or sexual assault. Provide a nonjudgmental, nonthreatening atmosphere for a discussion during which risks of sexually transmitted diseases are explained. It is also important to discuss problems the patient may experience (e.g., guilt, depression, anger).
Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.
Patient Education
- Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP.
- Inform the patient that repeat testing may be needed at 3-mo intervals for 1 yr to monitor the effectiveness of treatment.
- Provide information regarding vaccine-preventable diseases where indicated (e.g., sexually transmitted diseases such as hepatitis B and human papillomavirus). Provide contact information, if desired, for the CDC (www.cdc.gov/vaccines/vpd-vac).
- Answer any questions or address any concerns voiced by the patient or family.
- Educate the patient regarding access to counseling services.
Expected Patient Outcomes
- Knowledge
- States understanding of the importance of notifying sexual partners of disease exposure
- States understanding that untreated syphilis can be passed to an unborn child resulting in multiple health problems including the possibility of death if untreated
- Skills
- Describes the importance of a yearly gynecological exam to assess for sexually transmitted disease
- Demonstrates proficiency in the self-administration of antibiotic to treat syphilis infection
- Attitude
- Complies with the request to notify exposed current sexual partners about diagnoses to decrease community risk
- Complies with the request to attend a support group to address specific concerns of self and sexual partner

Related Monographs

Related tests include acid phosphatase, cerebrospinal fluid analysis, Chlamydia group antibody, culture bacterial anal, Gram stain, hepatitis B, hepatitis C, HIV, and β₂-microglobulin.
Refer to the Immune and Reproductive systems tables at the end of the book for related tests by body system.

rapid plasma reagin