Interpretation

Reactive RPR results may indicate exposure to Treponema pallidum. Reactive RPR results will also be reported with titers. In untreated syphilis, reactive RPR’s are found in the chancre stage, 30% after 1 week, and 90% after 3 weeks. In the secondary stage the RPR should be reactive 100% of the time, decreasing to 80% in the tertiary stage. In the latent stage without treatment and in a month to 2 years after successful treatment, the RPR may become nonreactive. The titer of antibody will vary from patient to patient. There is no direct relationship between the amount of reagin and the severity of disease. A peak titer will usually occur during the secondary stage, then decrease and plateau during later stages prior to falling to undetectable levels. Reactive RPR results may also be found in a variety of non-syphilis conditions. These conditions include various infectious diseases such as malaria, infectious mononucleosis, infecti ous hepatitis, leprosy, atypical pneumonia, and autoimmune conditions such as lupus erythematosus, rheumatoid arthritis, and many other collagen vascular diseases. Additionally, false positives may be caused by old age and chronic illnesses.

RPR titers are reported with every reactive RPR result.

Non-Reactive RPR results may indicate that the patient has not been exposed to Treponema pallidum, or that the patient has been exposed and successfully treated. Non-Reactive RPR results also occur in latent syphilis in the absence of treatment.