ANA

Category:

ANA

Known as: Antinuclear Antibody test, Fluorescent Antinuclear Antibody, FANA, Extractable Nuclear Antigen Antibodies, ENA

Purpose:

The ANA test identifies the presence of antinuclear antibodies (ANA) in the blood. ANA is a group of special antibodies produced by a patient’s immune system when it fails to adequately distinguish between “self” and “nonself." These autoantibodies attack the body’s own cells, causing signs and symptoms such as tissue and organ inflammation, joint and muscle pain, and fatigue. The presence of ANA is a marker of an autoimmune process and is associated with several autoimmune disorders but is most commonly seen in the autoimmune disorder systemic lupus erythematosus (SLE).

How is the sample collected for testing?

A blood sample is taken by needle from a vein in the arm.

How is it used?

The ANA test is ordered to help screen for autoimmune disorders and is most often used as one of the tests to diagnose systemic lupus erythematosus (SLE). Depending on the patient’s symptoms and the suspected diagnosis, ANA may be ordered along with one or more other autoantibody tests. Other laboratory tests associated with presence of inflammation, such as erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) may also be ordered. ANA may be followed by additional tests that are considered subsets of the general ANA test and that are used in conjunction with the patient’s clinical history to help rule out a diagnosis of other autoimmune disorders.