Antinuclear Antibodies (ANA), HEp-2 Substrate, Serum
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Antinuclear antibodies are seen in a number of autoimmune disorders such as systemic lupus erythematosus; mixed connective tissue disease; rheumatoid arthritis; Sjogren syndrome; progressive systemic sclerosis; and calcinosis, Raynaud phenomenon, esophageal dysmotility, syndactyly, and telangiectasia (CREST) syndrome.
Diagnosis of autoimmune diseases
Anticentromere antibody (ACA) pattern:
-A positive test for ACA is strongly associated with calcinosis, Raynaud phenomenon, esophageal dysmotility, syndactyly, and telangiectasia (CREST) syndrome; in various reported clinical studies ACA occurs in 50% to 96% of patients with CREST syndrome.
-The presence of detectable levels of ACA may antedate the appearance of diagnostic clinical features of CREST syndrome, in some cases by several years.
The incidence of low-titer antinuclear antibodies (ANA) positives increases with age in normal individuals.
For positive ANA titers of > or =1:160, and for all ANA titers whenever there is a strong clinical suspicion of rheumatic disease, we recommend follow up using the assays ADNA/200043 DNA Double-Stranded (dsDNA) Antibodies, IgG, Serum and ENAE/200047 Antibody to Extractable Nuclear Antigen Evaluation, Serum.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is a laboratory diagnostic aid and by itself is not diagnostic. Positive results of this test may occur in apparently healthy people. Therefore, the results of this test must be interpreted by a medical authority in the context of the patient's total clinical condition.
Sera from systemic lupus erythematosus patients undergoing steroid therapy may give negative test results.
No definitive association between the pattern of nuclear fluorescence and any specific disease state is intended with this test.
Many drugs (eg, hydralazine, procainamide) may induce antinuclear antibodies production.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Negative (titer of <1:40)
If positive, pattern will be reported and serum will be titered.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Bradwell AR, Stokes RP, Johnson GD: Atlas of HEp-2 patterns. San Diego, CA. The Binding Site, 1995, pp 9, 10, 19, 38-54
2. Fritzler MJ: Immunofluorescent antinuclear antibody test. In Manual of Clinical Laboratory Immunology. Fourth edition. Edited by NR Rose, EC De Macario. Washington, DC, ASM Press, 1992, pp 724-727
3. McCarty GA, Valencia DW, Fritzler MJ: Antinuclear antibodies. In Contemporary Techniques and Clinical Application to Connective Tissue Diseases. Oxford University Press, Inc, 1984, p 3
4. Stites DP, Terr AI: Basic and Clinical Immunology. Seventh edition. Edited by DP Stites, AI Terr. Norwalk, CT. Appleton & Lange, 1991, p 220