What is Anti-dsDNA?
The Anti-double stranded DNA antibody belongs to group of autoantibodies called antinuclear antibodies (ANA). Autoantibodies are the ones which are produced when body’s own immune system doesn’t distinguish between “self & non-self”. And mistakenly start attacking body’s own healthy cells leading to tissue & organ damage. They are named “anti-dsDNA” because they specifically target DNA found in nucleus of cell.
What is Anti-dsDNA lab test?
The anti-dsDNA antibody test identifies the presence of these autoantibodies in blood. This DNA blood test is utilized in diagnosing lupus or more suitably SLE (systemic lupus erythematosus). Lupus & SLE are chronic inflammatory autoimmune disorder which affect various tissues & organs of body like joints, kidney, blood vessels, lungs, skin & brain. This test may utilize enzyme linked immunosorbent assay (ELISA) technique, Crithidia luciliae immunofluorescence test, and radioimmunoassay test for detecting anti-dsDNA antibodies in blood.
Why is Anti-dsDNA lab test done?
This test is used in:
- In case when ANA test comes positive, & patient suggests signs & symptoms of lupus, then performing this test to diagnose lupus is important
- Presence of anti-ds DNA levels in blood helps concluding disease called lupus
- It will help in differentiating lupus from other autoimmune diseases that a person may have.
- Also helps patients detected with lupus & lupus nephritis in measuring the severity of disease
- In lupus nephritis (severe lupus which leads to inflammation & kidney issues), DNA antibody testing becomes important
- What is the meaning of high DNA ds antibody?
Anti-double stranded DNA in high levels means nearly specific lupus condition. The antibody is named due to its ability to bind with normal DNA in patient’s cell.
- What is meant by positive antinuclear antibody test?
If result comes positive for ANA test, then it means that antinuclear antibodies were present which indicate that you have SLE (lupus)
- Which are the first signs of lupus?
Its first signs include fever, joint pain, fatigue & weight changes. While some individuals have period of SLE symptoms called flares.
- Which conditions lead to positive ANA?
Diseases being related to immune dysfunction like autoimmune hepatitis, primary biliary cirrhosis, autoimmune cholangitis), or hepatitis C infection can make ANA positive result.
- Is it possible to have false-positive result of anti-dsDNA?
Mostly problem occurs with ELISA technique due to binding of immune complexes to pre-coat intermediates.
INTERPRETATION OF THE RESULTS:
These test results are considered with a person’s medical history, signs & symptoms & results of other antibody tests:
- High levels of anti-dsDNA: considered positive; strongly indicate lupus & significantly increased during or just prior to flare-up. In lupus nephritis if high level of anti-dsDNA, then it shows ongoing inflammation & damage to the kidneys.
- Very low levels of anti-dsDNA: considered negative; but doesn’t fully exclude the chance of lupus as only about 65% to 85% with lupus have anti-dsDNA in blood.
- Low to moderate levels of anti-dsDNA: indicate other autoimmune disorders like Sjogren syndrome & mixed connective tissue disease (MCTD).
Ranges include:
- <30.0 IU/mL is negativee. normal
- 0 to 75.0 IU/mL is borderline
- >75.0 IU/mL is positive
The reason is you get diagnosis for lupus (SLE) & for monitoring of lupus.