Anti-dsDNA (anti-double stranded DNA)

1. When Should I do the test?

Typically, your doctor will request an anti-dsDNA test if you exhibit signs and symptoms of lupus and have received a positive ANA test. As this test necessitates specialized equipment, your blood sample will be collected in a laboratory equipped to conduct this specific analysis. Alternatively, you can opt to order the test online through a Clinical Laboratory Improvement Amendments (CLIA) approved lab.

2. What should I do before the test?

Typically, no specific preparations are required before undergoing an anti-dsDNA test. However, as with other blood tests, it's advisable to inform your doctor about any prescription or over-the-counter medications you are currently taking. Some laboratories may suggest discontinuing the use of Biotin (also known as vitamin B7, B8, H, or coenzyme R) at least 72 hours before providing your sample.

3. What should I do during the test?

Anti-dsDNA tests can be conducted using various assays, with the anti-dsDNA ELISA test (enzyme-linked immunosorbent assay) being commonly employed by many laboratories, although alternative methods may also be utilized.

During the test, a medical professional will draw a blood sample from a vein in your arm using a needle. The blood is collected in an attached vial, and the procedure usually takes less than five minutes to complete.

While anti-dsDNA is associated with diseases such as chronic hepatitis, primary biliary cirrhosis, and infectious mononucleosis, it can also be found in individuals taking certain medications like procainamide and hydralazine. However, testing or monitoring for anti-dsDNA is not typically done under these medication-related conditions.

Apart from the anti-dsDNA test, there is also an anti-single-stranded DNA (anti-ssDNA) test. This autoantibody is less commonly ordered and is not strongly linked to lupus but may be observed in other autoimmune disorders.

Antinuclear antibodies (ANA) encompass a group of antibodies. If an ANA test yields a negative result, it implies negativity for the entire group. As anti-dsDNA is part of this antibody group, it does not require a separate order when an ANA test is negative.

4. How is the test result interpreted?

The interpretation of anti-dsDNA test results is typically done in conjunction with an individual's medical history, presenting signs and symptoms, and the outcomes of other autoantibody tests.

A substantial elevation in the level of anti-dsDNA in the blood is strongly linked to lupus and is often notably increased during or just before a flare-up. When the anti-dsDNA is positive alongside other clinical indicators associated with lupus, it suggests a likelihood of having lupus. This association is particularly significant if an anti-Sm test also returns a positive result.

In the assessment of individuals with lupus nephritis, a high level (titer) of anti-dsDNA is generally linked to ongoing inflammation and damage to the kidneys.

Conversely, a very low level of anti-dsDNA is considered negative but does not rule out a diagnosis of lupus, as only about 65-85% of individuals with lupus will test positive for anti-dsDNA.

Lower to moderate levels of this autoantibody may be observed in other autoimmune disorders, such as Sjgrens syndrome and mixed connective tissue disease (MCTD).