Search results
Results from the WOW.Com Content Network
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 one of several nontreponemal tests for syphilis (along with the Wassermann test and the VDRL test).
Replacement tests such as the VDRL test and the RPR test, initially based on flocculation techniques (Hinton), have been shown to produce far fewer false positive results. [citation needed] Indeed, the "biologic false positives" of modern tests usually indicate a serious alternate condition, often an autoimmune disease.
Serological assays may give a false positive result, causing the individual to appear to have seroconverted when the individual has not. False positives can occur due to the test reacting to, or detecting, an antibody that happens to be sufficiently similar in structure to the target antibody.
This reaction is the foundation of “nontreponemal” assays such as the VDRL (Venereal Disease Research Laboratory) test and Rapid Plasma Reagin (RPR) test. Both these test are flocculation type tests that use an antigen-antibody interaction. The complexes remain suspended in solution and therefore visible due to the lipid based antigens.
The rapid plasma reagin (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 ...
Since the antibodies do not bridge between antigens, no agglutination occurs. Because no agglutination occurs, the test is interpreted as negative. In this case, the result is a false negative. The range of relatively high antibody concentrations within which no reaction occurs is called the prozone. [5]
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Cross-reactivity, in a general sense, is the reactivity of an observed agent which initiates reactions outside the main reaction expected.This has implications for any kind of test or assay, including diagnostic tests in medicine, and can be a cause of false positives.