From the Guidelines
RPR, QL W/REFLX/CONFIRM refers to a Rapid Plasma Reagin (RPR) test, which is a blood test used to screen for syphilis infection, with reflex confirmation using a treponemal-specific test, such as the Treponema pallidum particle agglutination (TP-PA) or fluorescent treponemal antibody absorption (FTA-ABS) test, as recommended by the most recent guidelines 1. This is a qualitative (QL) test, meaning it detects the presence or absence of antibodies to cardiolipin, a substance released during syphilis infection, making it a non-treponemal test. The RPR test is sensitive for detecting syphilis, but it can produce false-positive results due to other conditions like autoimmune diseases, pregnancy, or other infections, as reported in several studies 1. The reflex confirmation with a treponemal-specific test is important to verify true syphilis infection, as it can distinguish between true positives and false positives. The RPR test is commonly used in routine STI screening, prenatal care, and for monitoring treatment response in patients with previously diagnosed syphilis, as stated in the guidelines 1. Some key points to consider when interpreting RPR test results include:
- The sensitivity and specificity of the RPR test, which can vary depending on the population being tested and the stage of syphilis infection 1.
- The potential for false-positive results, which can be caused by a range of factors, including autoimmune diseases, pregnancy, and other infections 1.
- The importance of reflex confirmation with a treponemal-specific test to verify true syphilis infection, as recommended by the guidelines 1. Overall, the RPR test with reflex confirmation is a useful tool for detecting syphilis infection, but it should be used in conjunction with clinical evaluation and other diagnostic tests to ensure accurate diagnosis and treatment.
From the Research
Test Identification
- The test referred to as "RPR, QL W/REFLX/CONFIRM" is likely the Rapid Plasma Reagin (RPR) test, which is a non-treponemal test used for the diagnosis of syphilis 2, 3, 4, 5.
Test Description
- The RPR test is used to detect the presence of antibodies against the syphilis bacterium, Treponema pallidum, in the blood 2, 3, 4, 5.
- The test is often used in conjunction with other tests, such as the Treponema pallidum hemagglutination (TPHA) test or the fluorescent treponemal antibody absorption (FTA-ABS) test, to confirm the diagnosis of syphilis 3, 4, 5.
Test Performance
- The sensitivity and specificity of the RPR test have been evaluated in several studies, with varying results 3, 4, 5.
- One study found that the RPR test had a sensitivity of 57.7% and a specificity of 57.1% compared to the FTA-ABS test 3.
- Another study found that the RPR test had a sensitivity of 100% and a specificity of 97.2% in a population of patients with syphilis 4.
Automated RPR Tests
- Automated RPR tests, such as the HiSens Auto Rapid Plasma Reagin (AutoRPR) test, have been developed to improve the efficiency and accuracy of syphilis testing 5.
- These tests have been shown to have high concordance rates with conventional RPR tests and may be suitable for use in treatment monitoring 5.