The Venereal Disease Research Laboratory test (VDRL) is a blood test for

syphilis Syphilis () is a sexually transmitted infection caused by the bacterium ''Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms depend on the stage it presents: primary, secondary, latent syphilis, latent or tertiary. The prim ...

and related non-venereal treponematoses that was developed by the eponymous US laboratory. The VDRL test is used to screen for syphilis (it has high sensitivity), whereas other, more

specific Specific may refer to: * Specificity (disambiguation) * Specific, a cure or therapy for a specific illness Law * Specific deterrence, focussed on an individual * Specific finding, intermediate verdict used by a jury in determining the final ...

tests are used to diagnose the disease.

History

The VDRL type test was invented before

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

, with its first iteration being that developed by August Paul von Wasserman with the aid of Albert Neisser in 1906. The VDRL test, as it is largely still done today, was developed in 1946 by Harris, Rosenberg, and Riedel. The lab was renamed to the Treponemal Pathogenesis and Immunology Branch of the

United States Public Health Service The United States Public Health Service (USPHS or PHS) is a collection of agencies of the Department of Health and Human Services which manages public health, containing nine out of the department's twelve operating divisions. The assistant s ...

Mechanism

The VDRL is a nontreponemal serological screening for

that is also used to assess response to therapy, to detect

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

involvement, and as an aid in the diagnosis of congenital syphilis. The basis of the test is that an antibody produced by a patient with syphilis reacts with an extract of ox heart (diphosphatidyl glycerol). It therefore detects

anti-cardiolipin antibodies Anti-cardiolipin antibodies (ACA) are antibodies often directed against cardiolipin and found in several diseases, including syphilis, antiphospholipid syndrome, livedoid vasculitis, vertebrobasilar insufficiency, Behçet's syndrome, idiopathi ...

(IgG, IgM or IgA), visualized through foaming of the test tube fluid, or "flocculation". The

rapid plasma reagin The rapid plasma reagin test (RPR test or RPR titer) is a type of rapid diagnostic test that looks for non-specific antibodies in the blood of the patient that may indicate an infection by syphilis or related non-venereal treponematoses. It is ...

(RPR) test uses the same antigen as the VDRL, but in that test, it has been bound to several other molecules, including a carbon particle to allow visualization of the flocculation reaction without the need of a microscope. Many other medical conditions can produce false positive results, including some viruses (mononucleosis, hepatitis), drugs, pregnancy, rheumatic fever, rheumatoid arthritis, lupus, and leprosy. The syphilis anti-cardiolipin antibodies are beta-2 glycoprotein independent, whereas those that occur in

antiphospholipid syndrome Antiphospholipid syndrome, or antiphospholipid antibody syndrome (APS or APLS), is an autoimmune, hypercoagulable state caused by antiphospholipid antibodies. APS can lead to blood clots (thrombosis) in both arteries and veins, pregnancy-relate ...

(associated to lupus for example) are beta-2 glycoprotein dependent, and this can be used to tell them apart in an

ELISA The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay is a solid-phase type of enzyme immunoassay (EIA) to detect the presence of ...

assay. This test is very useful as the trend of titres are correlated to disease activity (i.e. falling titres indicate successful treatment). It has a very good sensitivity for syphilis, except in late tertiary form.

Other tests

There are a number of treponemal-specific tests such as the fluorescent treponemal antibody-absorption ( FTA-ABS) test, ''T. pallidum'' hemagglutination assays ( TPHA), and the microhemagglutination assay ( MHA-TP). The MHA-TP is used to confirm a syphilis infection after another method tests positive for the syphilis bacteria. The MHA-TP test detects antibodies to the bacteria that cause syphilis and can be used to detect syphilis in all stages, except during the first 3 to 4 weeks. This test is not done on spinal fluid. The MHA-TP test is rarely used any more. Treponema pallidum particle agglutination assay ( TP-PA) and the Toluidine red unheated serum test (TRUST), which may be used to confirm a positive VDRL result, are more

for syphilis than non-treponemal tests and in the presence of a positive test, more likely indicate active infection. Unfortunately, other treponemal infections such as

yaws Yaws is a tropical infection of the skin, bones, and joints caused by the spirochete bacterium ''Treponema pallidum pertenue''. The disease begins with a round, hard swelling of the skin, in diameter. The center may break open and form an ulc ...

, bejel, and pinta and possibly nonpathogenic commensal treponemes can result in a positive. Not all these disease are venereal; it has been recommended that a careful explanation of this fact be included with test results.

References

{{DEFAULTSORT:Venereal Disease Research Laboratory Test Infectious disease blood tests Syphilis