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HelpTest ID: ANA2 Antinuclear Antibodies (ANA), Serum
Reporting Name
Antinuclear Ab, SUseful For
Evaluating patients at-risk for antinuclear antibodies-associated systemic autoimmune rheumatic disease particularly systemic lupus erythematosus, Sjogren syndrome, and mixed connective tissue disease
Clinical Information
Measurement of antinuclear antibodies (ANA) in serum is the most commonly performed screening test for patients suspected of having a systemic autoimmune rheumatic disease (SARD), also referred to as connective tissue disease.(1) ANA occur in patients with various autoimmune diseases, both systemic and organ specific, but they are particularly common in SARDs, which include systemic lupus erythematosus (SLE), discoid lupus erythematosus, drug-induced lupus erythematosus, mixed connective tissue disease (MCTD), Sjogren's syndrome (SjS), systemic sclerosis, CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia), and idiopathic inflammatory myopathies.
ANA can be detected by different technologies, including indirect immunofluorescence assay (IFA) and solid phase assays such as enzyme immunoassays and multiplex bead immunoassays. In a study performed in the Mayo Clinic Antibody Immunology Laboratory, no significant differences were demonstrated between ANA IFA and ANA enzyme-linked immunosorbent assay (ELISA) for a cohort of patients with connective tissue disease consisting predominantly of patients with SLE, SjS, and MCTD. Weakly positive ANA ELISA results were not a strong indicator of SARD in this laboratory cohort. The likelihood of finding an autoantibody to a specific extractable nuclear antigen including double-stranded DNA on a second-order testing increased directly with the level of ANA: 88% of sera that had detectable autoantibodies on second-order testing had an ANA level greater than 3.0 U.(2)
Overall, an ANA ELISA result of greater than or equal to 3.0 U was demonstrated as the optimal cutoff for CTDC / Connective Tissue Disease Cascade, Serum. This algorithm is intended to evaluate patients with common connective tissue diseases such as SLE, SjS, and MCTD.
For more information see Connective Tissue Disease Cascade.
Interpretation
A large number of healthy individuals have weakly-positive (1.1-2.9 U) antinuclear antibody (ANA) enzyme-linked immunosorbent assay (ELISA) results, many of which are likely to be clinical false-positive results; therefore, second-order testing of all positive ANA yields a very low percentage of positive results to extractable nuclear antigens including double-stranded (ds) DNA.(2)
Positive ANA results greater than 3.0 U are associated with the presence of detectable autoantibodies to specific extractable nuclear antigens (SM, SS-A, SS-B, Sm/RNP or RNP 68 and RNP A, Jo-1, Scl-70) including dsDNA.
Testing Algorithm
For more information see Connective Tissue Disease Cascade.
Report Available
1 dayDay(s) Performed
Monday through Saturday
Clinical Reference
1. Agmon-Levin N, Damoiseaux J, Kallenberg C, et al. International recommendations for the assessment of autoantibodies to cellular antigens referred to as anti-nuclear antibodies. Ann Rheum Dis. 2014 Jan;73(1):17-23. doi: 10.1136/annrheumdis-2013-203863
2. Deng X, Peters B, Ettore MW, et al: Utility of antinuclear antibody screening by various methods in a clinical laboratory patient cohort: J Appl Lab Med. 2016 Jul 1;1(1):36-46. doi: 10.1373/jalm.2016.020172
3. Sparchez M, Delean D, Samasca G, Miu N, Sparchez Z: Antinuclear antibody screening by ELISA and IF techniques: discrepant results in juvenile idiopathic arthritis but consistency in childhood systemic lupus erythematous. Clin Rheumatol. 2014 May;33(5):643-647. doi: 10.1007/s10067-014-2529-y
4. Bossuyt X, De Langhe E, Borghi MO, Meroni PL: Understanding and interpreting antinuclear antibody tests in systemic rheumatic diseases. Nat Rev Rheumatol. 2020 Dec;16(12):715-726. doi: 10.1038/s41584-020-00522-w
5. Bossuyt X, Claessens J, De Langhe E, et al: Antinuclear antibodies by indirect immunofluorescence and solid phase assays. Ann Rheum Dis. 2020 Jun;79(6):e65. doi: 10.1136/annrheumdis-2019-215443
6. Alsaed OS, Alamlih LI, Al-Radideh O, Chandra P, Alemadi S, Al-Allaf AW. Clinical utility of ANA-ELISA vs ANA-immunofluorescence in connective tissue diseases. Sci Rep. 2021 Apr 15;11(1):8229. doi: 10.1038/s41598-021-87366-w
Method Name
Enzyme-Linked Immunosorbent Assay (ELISA)
Specimen Type
SerumOrdering 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
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 21 days | |
| Frozen | 21 days |
Special Instructions
Reference Values
Negative: ≤1.0 U
Weakly positive: 1.1-2.9 U
Positive: 3.0-5.9 U
Strongly positive: ≥6.0 U
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
86038
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 |
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)
-Gastroenterology and Hepatology Test Request (T728)
-Renal Diagnostics Test Request (T830)
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