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Interpretive Handbook

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Test 8178 :
DNA Double-Stranded (dsDNA) Antibodies, IgG, Serum

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Double-stranded (ds, native) DNA (dsDNA) antibodies of the IgG class are an accepted criterion (American College of Rheumatology) for the diagnosis of systemic lupus erythematosus (SLE).(1-3) dsDNA antibodies are detectable in approximately 85% of patients with untreated SLE, and are rarely detectable in other connective tissue diseases. Weakly-positive results caused by low-avidity antibodies to dsDNA are not specific for SLE and can occur in a variety of diseases.

 

Testing for IgG antibodies to dsDNA is indicated in patients who have a positive test for antinuclear antibodies (ANA) along with signs and symptoms that are compatible with the diagnosis of SLE.(2) If the ANA test is negative, there is no reason to test for antibodies to dsDNA.(2)

 

The levels of IgG antibodies to dsDNA in serum are known to fluctuate with disease activity in lupus erythematosus, often increasing prior to an increase in inflammation and decreasing in response to therapy.(1,2)

 

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

Useful For Suggests clinical disorders or settings where the test may be helpful

Evaluating patients with signs and symptoms consistent with lupus erythematosus (LE)

 

Monitoring patients with documented LE for flares in disease activity

Interpretation Provides information to assist in interpretation of the test results

A positive test result for double-stranded DNA (dsDNA) antibodies is consistent with the diagnosis of systemic lupus erythematosus.

 

A reference range study conducted at the Mayo Clinic demonstrated that, within a cohort of healthy adults (n=120), no individuals between the ages of 18 and 60 (n=78) had detectable anti-dsDNA antibodies. Above the age of 60 (n=42), 11.9% of individuals (n=5) had a borderline result for dsDNA antibodies and 4.8% of individuals (n=2) had a positive result.

 

Increases of at least 25% in the level of IgG antibodies to dsDNA may indicate an exacerbation of disease.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Measurements of IgG antibodies to dsDNA are semiquantitative. Slight changes in the levels of these antibodies should not be relied upon to predict changes in the clinical course of patients with lupus erythematosus (LE). Clinical flares of disease in patients with LE may not be accompanied by changes in the levels of dsDNA antibodies.

 

Positive results may occur in patients with diseases other than LE.

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.

<30.0 IU/mL (negative)

30.0-75.0 IU/mL (borderline)

>75.0 IU/mL (positive)

Negative is considered normal.

Reference values apply to all ages.

Clinical References Provides recommendations for further in-depth reading of a clinical nature

1. Tran T, Pisetsky D: Chapter 115. Detection of anti-DNA antibodies. In Manual of Molecular and Clinical Laboratory Immunology. Seventh edition. Edited by B Detrick, R Hamilton, JD Folds. Washington, DC, ASM Press, 2006, pp 1027-1032

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

3. Tan EM, Cohen AS, Fries JF, et al: The 1982 revised criteria for the classification of systemic lupus erythematosus. Arthritis Rheum 1982;25:1271-1277


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