Wassermann test

The Wassermann test is a complement-fixation (Complement system) antibody test for syphilis, named after the bacteriologist August von Wassermann.

A sample of blood or cerebrospinal fluid is taken and introduced to the antigen - a bovine muscle or heart extract containing cardiolipin. Syphilis-specific antibodies (reagines) react with the lipid - the Wassermann reaction of antiphospholipid antibodies (APAs). The intensity of the reaction (1, 2, 3, or 4) indicates the severity of the condition.

The reaction is not actually specific to syphilis and will produce a positive reaction to other diseases, including malaria, tuberculosis, and numerous other diseases. It is possible for an infected individual to produce no reaction and for a successfully treated individual to continue to produce a reaction (called Wassermann fast or fixed).

The antibody test was developed by Wassermann and Albert Neisser at the Robert Koch Institute for Infectious Diseases in 1906. The test was a growth from the work of Bordet and Gengou on complementing-fixation reaction, published in 1901, and the positive reaction is sometimes called the Bordet-Gengou-Wassermann reaction or Bordet-Wassermann reaction.

The Wassermann test has been refined - Kahn test, Kolmer test - and it is rarely used today. Replacement tests (VDRL test, RPR test), initially based on flocculation techniques (Hilton), having been shown to produce far fewer false positive results. Indeed the "biologic false positives" of modern tests usually indicate a serious alternate condition, often an autoimmune disease.