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Test ID: ANA2 Antinuclear Antibodies (ANA), Serum

Reporting Name

Antinuclear Ab, S

Useful For

Evaluating patients suspected of having a systemic rheumatic disease

Clinical Information

Measurement of antinuclear antibodies (ANA) in serum is the most commonly performed screening test for patients suspected of having a systemic rheumatic disease, also referred to as connective tissue disease.(1) ANA occur in patients with a variety of autoimmune diseases, both systemic and organ-specific. They are particularly common in the systemic rheumatic diseases, which include lupus erythematosus (LE), discoid LE, drug-induced LE, mixed connective tissue disease, Sjogren syndrome, scleroderma (systemic sclerosis), CREST (calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia) syndrome, polymyositis/dermatomyositis, and rheumatoid arthritis.(1)


The diagnosis of a systemic rheumatic disease is based primarily on the presence of compatible clinical signs and symptoms. The results of tests for autoantibodies including ANA and specific autoantibodies are ancillary. Additional diagnostic criteria include consistent histopathology or specific radiographic findings. Although individual systemic rheumatic diseases are relatively uncommon, a great many patients present with clinical findings that are compatible with a systemic rheumatic disease and large numbers of tests for ANA are ordered to eliminate the possibility of a systemic rheumatic disease.


See Connective Tissue Disease Cascade (CTDC) in Special Instructions.


A large number of healthy individuals have weakly-positive antinuclear antibody (ANA) results, many of which are likely to be clinical false-positives; therefore, second-order testing of all positive ANA yields a very low percentage of positive results to the specific nuclear antigens.


A positive ANA result at any level is consistent with the diagnosis of systemic rheumatic disease, but a result greater than or equal to 3.0 U is more strongly associated with systemic rheumatic disease than a weakly-positive result.


Positive ANA results greater than 3.0 U are associated with the presence of detectable autoantibodies to specific nuclear antigens. The nuclear antigens are associated with specific diseases (eg, anti-Scl 70 is associated with scleroderma) and can be detected with second-order testing.

Testing Algorithm

See Connective Tissue Disease Cascade (CTDC) in Special Instructions.

Report Available

1 day

Day(s) Performed

Monday through Saturday

Clinical Reference

1. Kavanaugh A, Tomar R, Reveille J, et al: Guidelines for use of the antinuclear antibody test and tests for specific autoantibodies to nuclear antigens. Pathol Lab Med 2000;124:71-81

2. Homburger HA, Cahen YD, Griffiths J, Jacob GL: Detection of antinuclear antibodies: comparative evaluation of enzyme immunoassay and indirect immunofluorescence methods. Arch Pathol Lab Med 1998;122:993-999

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Specimen Type


Ordering Guidance

If suspicious of connective tissue disorder, see CTDC / Connective Tissue Disease Cascade, Serum.


If suspicious of autoimmune liver disease, see ALDG / Autoimmune Liver Disease Panel, Serum.

Specimen Required


Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL

Specimen Minimum Volume

0.4 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 21 days
  Frozen  21 days

Reference Values

≤1.0 U (negative)

1.1-2.9 U (weakly positive)

3.0-5.9 U (positive)

≥6.0 U (strongly positive)

Reference values apply to all ages.

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
ANA2 Antinuclear Ab, S 94875-2


Result ID Test Result Name Result LOINC Value
ANA2 Antinuclear Ab, S 94875-2


If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Gastroenterology and Hepatology Client Test Request (T728)

-Renal Diagnostics Test Request (T830)

Mayo Clinic Laboratories | Neurology Catalog Additional Information:

mml-Behavioral, mml-Epilepsy, mml-Headache, mml-Movement-Disorders, mml-Demyelinating-Diseases, mml-Neuroimmunology, mml-Neuromuscular, mml-Pediatric, mml-Neuro-ophthalmology