Difference Between VDLR and RPR

VDLR vs RPR

Syphilis is one of the well-known sexually transmitted infections. It is a highly curable disease when proper tests are done for its diagnosis. This disease is caused by the bacteria Treponema pallidum. Syphilis can be transmitted through sexual contact with an infected individual or by mother-to-baby during childbirth or pregnancy. Syphilis can be detected by different tests. These tests are divided into two parts; the nontreponemal tests and the treponemal tests. These two tests are very important in the detection of syphilis. The nontreponemal tests are able to detect non-specific treponemal antibodies. There are two common tests under the nontreponemal test. They include VDLR (Venereal Disease Research Laboratory) and RPR (Rapid Plasma Reagin). These two tests are performed in the same way. However, they have a number of differences.

VDLR was a test developed by the Venereal Disease Research Laboratory during World War I. This test is still done today to detect syphilis. On the other hand, RPR was developed as a more advanced VDRL. RPR is just the VDRL antigen, but it contains carbon or delicately divided charcoal particles. With these charcoal particles, it allows the visualization of the reaction or flocculation between the specimen and the antigen without the use of a microscope. RPR tests can be done without the use of a microscope; the result can be seen by our naked eye. In contrast, a VDLR test requires a microscope to know the results of the test. Rapid Plasma Reagin, or RPR, is the most preferred syphilis test by many for it is easy to use and can be readily purchased in a kit form in contrast to the VDLR.

Both the RPR and VLDR tests use blood as the specimen to detect syphilis. However, in the late stages of syphilis, it involves the central nervous system or what is termed as neurosyphilis. A VDLR is the only test that can be performed using CSF or cerebrospinal fluid. During the testing for syphilis, the specimen that will be used for a VDLR requires it to be heated before it can be tested. VDLR tests also require that the specimen must be freshly collected. However, in an RPR test, the specimen does not need to be heated or unheated before it can be tested for syphilis.

According to research, the RPR test is the more effective nontreponemal test than the VDLR. It can detect syphilis more effectively than a VDLR. VDLR tests and RPR tests can be used in quantitative evaluations. They can measure the antibodies produced as a reaction from the body to Treponema pallidum. However, an RPR test measures nonspecific antibodies produced in response to the Treponema pallidum. In the late stages of the disease, these two tests are found to be less effective in detecting syphilis and yield non-reactive results.

Both nontreponemal tests, Rapid Plasma Reagin test (RPR) and Venereal Disease Laboratory test (VDRL), are not definitive tests for syphilis and may have a false positive result due to other medical conditions such as viral infections (measles, hepatitis), pregnancy, and some autoimmune diseases. A positive result in both of these two tests, RPR and VDLR, requires a further test, and that is the treponemal test. This test is done in order to confirm the diagnosis of syphilis so that prompt treatment can be done.

Summary:

1. RPR is the developed or the more advanced VDRL.

2. RPR is just the VDRL antigen, but it contains carbon or delicately divided charcoal particles.

3. RPR tests can be done without the use of a microscope; the result can be seen by our naked eye. I
In contrast, a VDLR test requires a microscope to know the result of the test.

4. Rapid Plasma Reagin, or RPR, is the most preferred syphilis test by many for it is easy to use and can
be readily purchased in kit form in contrast to a VDLR test.

5. A VDLR test is the only test that can be performed using CSF or cerebrospinal fluid.

6. The specimen that will be used for a VDLR test requires it to be heated before it can be tested unlike
for an RPR specimen.

7. An RPR test is the more effective nontreponemal test than a VDLR. It can detect syphilis more
effectively than a VDLR test.

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