specificity

specificity

 [spes″ĭ-fis´ĭ-te]

1. the quality of having a certain action, as of affecting only certain organisms or tissues, or reacting only with certain substances, as antibodies with certain antigens (antigen specificity).

2. diagnostic specificity; the probability that a person not having a disease will be correctly identified by a clinical test, i.e., the number of true negative results divided by the total number of all those without the disease (which is the sum of the number of true negative plus false positive results). See also sensitivity.

host specificity the natural adaptability of a particular parasite to a certain species or group of hosts.

spec·i·fic·i·ty

(spes'i-fis'i-tē), Do not confuse this word with sensitivity.

1. The condition or state of being specific, of having a fixed relation to a single cause or to a definite result; manifested in the relation of a disease to its pathogenic microorganism, of a reaction to a certain chemical union, or of an antibody to its antigen, or the reverse.

2. In clinical pathology and medical screening, the proportion of those tested with negative test results for the disease that the test is intended to reveal, that is, true negative results as a proportion of the total of true-negative and false-positive results. Compare: sensitivity (2).

specificity

Epidemiology The proportion of persons without disease who are correctly identified by a screening test or case definition as not having disease Immunology The avidity of an antibody for an antigen Physiology The degree of a ligand's affinity for a receptor

spec·i·fic·i·ty

(spes'i-fis'i-tē)

1. The condition or state of being specific, of having a fixed relation to a single cause or to a definite result; manifested in the relation of a disease to its pathogenic microorganism, of a reaction to a certain chemical union, or of an antibody to its antigen or the reverse.

2. clinical pathology The proportion of those who do not have a disease or condition and in whom a test intended to identify that disease or condition yields negative results.
Compare: sensitivity (2)

specificity

The characteristic of a binding site or receptor to be activated only by a single molecule or class of molecules.

specificity

the selective reactivity of an ANTIGEN and its corresponding ANTIBODY.

Specificity

A test's ability to detect only the disease in question.

Mentioned in: Tumor Markers

specificity 

The extent to which a test gives results that are free from false positives (i.e. people found to have the defect when they are actually free of it). The fewer the number of false positives, the greater is the specificity of the test. It is usually presented as the percentage of people truly identified as not defectives, or normal, referred to as true negatives, D (or correct reject), divided by the total number of not defectives or normal people tested. The total number includes all the true negatives, D, plus the false positives, B (or false alarm). Hence

See sensitivity.

spec·i·fic·i·ty

(spes'i-fis'i-tē) Do not confuse this word with sensitivity.

1. Condition or state of being specific, of having a fixed relation to a single cause or definite result; manifested in relation of disease to its pathogenic microorganism, of reaction to a chemical union, or an antibody to its antigen, or the reverse.

2. In clinical pathology and medical screening, proportion of those tested with negative test results for the disease the test is intended to reveal, i.e., true-negative results as a proportion of the total of true-negative and false-positive results.

Patient discussion about specificity

Q. What Causes Specific Abdominal Pain? Everytime I go see a doctor when I have abdominal pains he tells me I probably have gastroenteritis. How does he know that it's not something else for instance, appendicitis, just by examining my abdomen?

A. whats the symptoms of ovarian cyst?

Q. Is Vitiligo caused due to any specific diet? Some people say that vitiligo is caused when we eat fish/chicken and curd together is it true??

A. No it is not write. Although the real causes of vitilgo are not fully understood by anyone. But Many dermatologist say that auto-immunity and second one is inheritance may involve in vitiligo (http://www.antivitiligo.com/).
Also some diet containing specific nutrients may be useful for handling vitiligo.

Q. HIV - does it infect specific Blood Types? A friend of mine joined the army and they took him to an experiment and infected him with HIV. But he was not infected- he said because he has a certain blood type. Is this true?

A. HIV, as all other viruses need specific cells,s surface proteins which called receptors,in case of HIV these receptors are found in certain WBCs that known as T-helper cells which named as T4 cells. All humans have these T4 cells but some people lack the receptor that necessary for virus attachment and pentration of the cell which leeds to the inablity of the virus to cause infection and become a target for the immune system. But they c can infect other suseptable people.