What is the treatment for a patient with a quantitatively reactive Rapid Plasma Reagin (RPR) result?

From the Guidelines

The treatment for a patient with a quantitatively reactive Rapid Plasma Reagin (RPR) result is parenteral penicillin G, with the specific regimen depending on the stage of syphilis. When interpreting RPR results, it's crucial to consider that nontreponemal test antibody titers usually correlate with disease activity, and results should be reported quantitatively 1. The following are key points to consider in the treatment approach:

• For primary, secondary, or early latent syphilis (less than one year duration), a single intramuscular injection of benzathine penicillin G 2.4 million units is recommended.
• For late latent syphilis (more than one year duration) or syphilis of unknown duration, the recommended regimen is benzathine penicillin G 2.4 million units intramuscularly once weekly for three consecutive weeks.
• Neurosyphilis, ocular syphilis, or otosyphilis requires more intensive treatment with aqueous crystalline penicillin G 3-4 million units intravenously every 4 hours for 10-14 days.
• For penicillin-allergic patients, doxycycline 100 mg orally twice daily for 14 days (early syphilis) or 28 days (late syphilis) can be used, though desensitization to penicillin is preferred for pregnant women. Follow-up serologic testing is essential to confirm treatment success, typically at 6 and 12 months after treatment, considering that nontreponemal tests usually become nonreactive with time after treatment, but in some patients, nontreponemal antibodies can persist at a low titer for a long period of time 1.

From the FDA Drug Label

Syphilis (neurosyphilis) 12 to 24 million units/day, as 2 to 4 MU every 4 hours for 10 to 14 days; many experts recommend additional therapy with Benzathine PCN G 2. 4 MU IM weekly for 3 doses after completion of IV therapy

The treatment for a patient with a quantitatively reactive Rapid Plasma Reagin (RPR) result is penicillin G (IM), with a dosage of 12 to 24 million units/day for 10 to 14 days for neurosyphilis. Additional therapy with Benzathine PCN G may be recommended. 2

From the Research

Treatment for Quantitatively Reactive RPR Result

The treatment for a patient with a quantitatively reactive Rapid Plasma Reagin (RPR) result is typically focused on the underlying cause of the reactivity, which is often syphilis.

• The RPR test is a non-treponemal test used for screening for syphilis, and a reactive result indicates the presence of antibodies against the syphilis bacterium 3.
• According to the study by 3, patients with syphilis who were given therapy showed a significant decrease in antibodies, with 56% of patients showing a decrease in RPR reactivity after 1 year of follow-up.
• The treatment for syphilis typically involves the use of antibiotics, such as penicillin, to eliminate the infection 4.
• It's worth noting that a reactive RPR result can also be caused by other conditions, such as biological false-positive results, which can occur in patients with other infections or autoimmune disorders 5.
• In these cases, further testing, such as treponemal tests like the fluorescent treponemal antibody absorption (FTA-ABS) test, may be necessary to confirm the diagnosis of syphilis 6.
• The study by 7 found that automated treponemal immunoassays can be used for syphilis screening, and that signal strength values can be correlated with reactivity of confirmatory treponemal testing.

Diagnostic Approach

• The diagnostic approach for a patient with a quantitatively reactive RPR result typically involves a combination of non-treponemal and treponemal tests.
• Non-treponemal tests, such as the RPR test, are used for initial screening, while treponemal tests, such as the FTA-ABS test, are used to confirm the diagnosis of syphilis 3, 6.
• The study by 5 found that the Serodia Treponema pallidum particle agglutination assay, the Murex Syphilis ICE, and the Enzywell TP tests can be used as substitutes for screening for serodiagnosis of syphilis.
• The choice of diagnostic tests and treatment approach will depend on the individual patient's clinical presentation and medical history.