VDRL Venereal Disease Research Laboratory:
VDRL Venereal Disease Since very long time Venereal Disease Research Laboratory (VDRL) test is performed solely by physicians to screen patients for syphilis, yet VDRL is still the most commonly used test all over the world for screening and it still remains unchallenged. Most interesting fact is that it is a test most commonly performed by patients themselves, even in the absence of a medical advice and the result obtained thereof is remembered and reminded to consulting physicians every time they visit them for rest of their life. This holds true when a patient suffers from a disease pertaining to genital system. However, most horrifying fact is that a positive test penetrates so deep into patients’ psyche that patient is self-stigmatized and hurt affecting him mentally and physically, affecting his daily activities and performance. Clinically in immunocompetent persons, a negative result is strong evidence against presence of the disease. In human immunodeficiency virus (HIV)-infected persons, the serological response is unusual as in many other diseases, so while interpreting a serological test result, great care should be given. The aim of this article is to convey the right massage to physicians and patients about the facts and miss facts surrounding this test and importance of proper interpretation of its results.
Why doctors perform a VDRL test
Your doctor will most likely order a VDRL test if there’s a chance you have syphilis. Early symptoms that may prompt your doctor to order this test include:
- one small, painless sore
- swelling in lymph nodes near the sore
- a skin rash that doesn’t itch
In other cases, your doctor may screen for syphilis even if you don’t have any symptoms or reasons to think you have the disease. For example, your doctor will screen for syphilis as a routine part of your care if you’re pregnant. This is a standard procedure, and it doesn’t mean your doctor thinks you have syphilis.
How the Test is Performed
The test is most often done using a blood sample. It can also be done using a sample of spinal fluid. This article discusses the blood test.
A blood sample is needed.
A blood draw involves a healthcare provider inserting a hollow needle into a vein in the elbow or on the back of the hand.
The blood flows into an airtight collection tube attached to the other end of the needle.
A healthcare provider may tie a rubber band, or tourniquet, above the injection site before inserting the needle to make the veins easier to locate.
Healthcare providers collect samples of CSF through a procedure known as a lumbar puncture or spinal tap.
During the procedure, a person will lie on their side and pull their knees towards their chest.
The healthcare provider will disinfect and numb the injection site with a local anesthetic.
Then they will insert a spinal needle into the lower spine, which they use to extract a small quantity of CSF.
Understanding the results of your VDRL test
If your test comes back negative for syphilis antibodies, the result suggests that you don’t have syphilis.
If your test comes back positive for syphilis antibodies, you probably (but not definitely) have syphilis. If this occurs, your doctor will order a more specific test to confirm the results. A treponemal test is often used to confirm the positive test. Treponemal tests check whether your immune system has produced specific antibodies in direct response to the syphilis-causing Treponema pallidum
Potential for false positives and negatives
The VDRL test isn’t always accurate. For example, you may have false-negative results if you’ve had syphilis for less than three months, as it could take this long for your body to make antibodies. The test is also unreliable in late-stage syphilis.
On the other hand, the following can cause false-positive results:
- Lyme disease
- pneumonia (certain types only)
- systemic lupus erythematosus
- IV drug use
In some cases, your body may not produce antibodies even if you have been infected with syphilis. This means the VDRL test will be inaccurate.
The antibodies produced as a result of a syphilis infection can stay in your body even after your syphilis has been treated. This means you might always have positive results on this test.
A negative test is normal. It means that no antibodies to syphilis have been seen in your blood sample.
The screening test is most likely to be positive in the secondary and latent stages of syphilis. This test may give a false-negative result during early- and late-stage syphilis. This test must be confirmed with another blood test to make the diagnosis of syphilis.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test Result.
What Abnormal Results Mean
A positive test result means you may have syphilis. If the test is positive, the next step is to confirm the results with an FTA-ABS test, which is a more specific syphilis test.
The VDRL test’s ability to detect syphilis depends on the stage of the disease. The test’s sensitivity to detect syphilis nears 100% during the middle stages; it is less sensitive during the earlier and later stages.
Some conditions may cause a false-positive test, including:
- Lyme disease
- Certain types of pneumonia
- Systemic lupus erythematosus
The body does not always produce antibodies specifically in response to the syphilis bacteria, so this test is not always accurate.
The VDRL test offers a safe and convenient way to screen for syphilis infections. The test itself does not carry any significant risks.
However, there may be some slight complications associated with the process of drawing blood and lumbar punctures.
Blood draws may cause:
- tenderness or pain near the injection site
- bruising or bleeding immediately after the procedure
Although rare, a lumbar puncture can cause the following complications:
- a mild to severe headache
- numbness or tingling in the lower back or legs
- lower back or leg pain
- infections at the injection site
Symptoms of syphilis vary according to the stage of the disease.
A chancre appears during the primary stage of syphilis. It will appear where the infection entered a person’s body.
If a person does not receive treatment, syphilis will develop into the secondary stage.
This is when skin rashes and lesions appear. They may occur in the vagina, the anus, or the mouth.
The rashes are not typically itchy.
A person may also develop a fever, muscle aches, swollen lymph glands, sore throat, and hair loss.
No symptoms of syphilis appear in this stage.
This stage can be fatal and typically occurs between 10-30 years after the initial infection.
It can affect the brain, eyes, heart, blood vessels, joints, and bones.
The symptoms may vary depending on which organ the syphilis is affecting.