How do you interpret an RPR titer?

If the screening assay is positive, the sample is reflexed to a RPR assay, which, if positive, is reported with a titer and is indicative of active or recent syphilis infection. If the RPR is negative, the sample is reflexed to a second treponemal assay, such as the T pallidum particle agglutination (TP-PA) assay.

What does a positive Rapid Plasma Reagin mean?

A positive test result may mean that you have syphilis. If the screening test is positive, the next step is to confirm the diagnosis with a more specific test for syphilis, such as FTA-ABS. The FTA-ABS test will help distinguish between syphilis and other infections or conditions.

What is considered a positive RPR titer?

A positive RPR test should be followed by another type of test to diagnose syphilis. If you have been treated for syphilis in the past, an RPR test that shows a titer increase of fourfold means you likely have a new syphilis infection if you were not fully treated in the past.

When is RPR positive?

A positive titer with a VDRL or RPR indicates active syphilis and follow-up serologic testing is performed to monitor treatment response. With this new testing algorithm that uses the treponemal test first, some patients may test positive for a treponemal test but test negative with a nontreponemal test.

What does RPR negative mean?

Rapid plasma reagin is commonly abbreviated RPR. A negative (“nonreactive”) RPR test result is compatible with a person not having syphilis. However, a person may have a negative RPR test and still have syphilis since, in the early stages of the disease, the RPR often gives negative results.

Is RPR always positive?

Among people who are in the secondary (middle) stage of infection, the RPR test result is nearly always positive. The RPR test also can produce false-positive results, suggesting you have syphilis when you actually don’t.

What does a 1/16 titer mean?

A patient might be reported to have an “indirect Coombs titer” of 16. This means that the patient’s serum gives a positive indirect Coombs test at any dilution down to 1/16 (1 part serum to 15 parts diluent). At greater dilutions the indirect Coombs test is negative.

Does a reactive RPR mean I have syphilis?

A reactive or positive test result does not always mean that you have syphilis. Other conditions can cause positive test results. These include injecting illegal drugs, recent vaccinations, endocarditis, and autoimmune diseases. The accuracy of testing often depends on the stage of syphilis.