INFO - Defination of ANA

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Definition of ANA

ANA: Antinuclear antibody, an unusual antibody directed against structures

within the nucleus of the cell. ANAs are found in patients whose immune

system is predisposed to cause inflammation against their own body tissues.

Antibodies that are directed against one's own tissues are referred to as

autoantibodies. The propensity for the immune system to work against its own

body is referred to as autoimmunity. ANAs indicate the possible presence of

autoimmunity.

The fluorescent antinuclear antibody test (FANA) was designed by

Friou, M.D. in 1957. It is done on a blood sample. The antibodies in the

serum of the blood are exposed in the laboratory to cells and then one

determines whether or not antibodies are present that react with various

parts of the nucleus of the cell. It is a sensitive screening test used to

detect autoimmune diseases.

Autoimmune diseases are conditions characterized by a disorder of the immune

system featured by the abnormal production of antibodies (autoantibodies)

directed against the tissues of the body. Autoimmune diseases are typically

feature inflammation of various tissues of the body. ANAs are found in

patients with a number of autoimmune diseases, such as systemic lupus

erythematosus, Sjogren syndrome, rheumatoid arthritis, polymyositis,

scleroderma, Hashimoto thyroiditis, juvenile diabetes mellitus,

disease, vitiligo, pernicious anemia, glomerulonephritis, and pulmonary

fibrosis. ANAs can also be found in patients with chronic infections and

cancer. Many medications including procainamide (PROCAN SR), hydralazine,

and dilantin can stimulate the production of ANAs.

ANAs present different patterns depending on the staining of the cell

nucleus in the laboratory: homogeneous, or diffuse; speckled; nucleolar; and

peripheral or rim. While these patterns are not specific for any one

illness, certain illnesses can more frequently be associated with one

pattern or another. For example, the nucleolar pattern is more commonly seen

in the disease scleroderma. The speckled pattern is seen in many conditions

and in persons who do not have any autoimmune disease.

ANAs are present in approximately 5% of the normal population, usually in

low titers (low levels). These persons have no disease. Titers of lower than

1:80 are less likely to be significant. Even higher titers are insignificant

with aging over age 60 years. Ultimately, the ANA result must be interpreted

in the specific context of the symptoms and other test results for the

patient. It may or may not be significant in an individual.

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