From the Guidelines
VDRL (Venereal Disease Research Laboratory) is a blood test used to screen for syphilis, a sexually transmitted infection caused by the bacterium Treponema pallidum, by detecting non-specific antibodies called reagins in the blood of infected individuals. The test is considered a non-treponemal test and is often used as an initial screening tool due to its relatively low cost and quick results. According to a study published in 2020 1, the sensitivity of VDRL ranged from 82.1-100% for early latent syphilis, and 100% for secondary syphilis. However, VDRL can produce false-positive results in certain conditions like pregnancy, autoimmune diseases, or other infections, so positive results typically require confirmation with more specific treponemal tests such as FTA-ABS or TP-PA. The test is particularly useful for monitoring treatment response in syphilis patients, as antibody levels (measured as titers) should decrease following successful treatment. VDRL results are typically reported as reactive (positive) or non-reactive (negative), along with the titer if reactive.
Some key points to consider when interpreting VDRL results include:
- The test is not specific for syphilis and can produce false-positive results in certain conditions
- Positive results require confirmation with more specific treponemal tests
- The test is useful for monitoring treatment response in syphilis patients
- Antibody levels (measured as titers) should decrease following successful treatment
- VDRL results are typically reported as reactive (positive) or non-reactive (negative), along with the titer if reactive
It's also important to note that the performance characteristics of VDRL can vary depending on the population being tested and the stage of the disease. For example, a study published in 2020 1 found that the sensitivity of VDRL was higher for secondary syphilis (100%) than for early latent syphilis (82.1-100%).
In clinical practice, the use of VDRL as a screening test for syphilis is recommended, followed by confirmation with a treponemal test if the result is positive. This approach can help to reduce the risk of false-positive results and ensure that patients receive accurate diagnoses and appropriate treatment.
From the Research
What is VDRL
- VDRL stands for Venereal Disease Research Laboratory test, which is a nontreponemal test used for screening of syphilis 2.
- The VDRL test is used to detect the presence of antibodies against the syphilis bacteria in the blood or cerebrospinal fluid (CSF) 3, 4, 2.
What does VDRL test for
- The VDRL test is used to diagnose syphilis, a sexually transmitted disease caused by the bacterium Treponema pallidum 3, 5, 4, 2.
- The test can also be used to monitor the treatment of syphilis, as the levels of antibodies in the blood or CSF can decrease after treatment 3, 2.
- The VDRL test can be used to diagnose neurosyphilis, which is a complication of syphilis that affects the central nervous system 4, 2.
Characteristics of VDRL test
- The VDRL test is simple, sensitive, and low-cost, making it a widely used screening test for syphilis 2.
- The test has some shortcomings, including the prozone phenomenon and biological false positive (BFP) reaction 2.
- Quantitative estimation of VDRL is essential in treatment evaluation, and CSF VDRL test is very specific for neurosyphilis, although its sensitivity is low 2.
- The interpretation of VDRL in HIV infection is incompletely understood 2.