Synonyms: Anti-native DNA, anti-dsDNA antibodies
Clinical significance
Anti-dsDNA antibodies are directed against double-stranded DNA, particularly against the antigenic determinants along the deoxyribose-phosphate backbone of DNA. These antibodies are highly specific for SLE (systemic lupus erythematosus) and appear to be involved in causing the disease. With a prevalence of about 40-80% in affected people, the test has been included among the eleven diagnostic criteria for SLE. Finding anti-dsDNA in people without symptoms suggests subclinical SLE. Anti-dsDNA can be found in other autoimmune diseases (rheumatoid arthritis, Sjögren’s syndrome, mixed connective tissue disease, primary antiphospholipid syndrome).
Clinical indications
SLE. Autoimmune diseases.
Sample type
The patient must have a blood sample taken.
Preparation
You must fast for at least 8 hours; a small amount of water is allowed. You must have been standing or sitting upright for at least 30 minutes.
Notes
High antibody titres strongly suggest a diagnosis of SLE; their presence is related to disease activity, so they are useful for monitoring its course.