The Anti-dsDNA (anti–double-stranded DNA antibody) test is a specialized blood test used to detect autoantibodies against double-stranded DNA (dsDNA). This test is particularly important in the diagnosis and monitoring of systemic lupus erythematosus (SLE) and is considered one of the diagnostic criteria for the disease.
The presence of Anti-dsDNA antibodies in the blood of lupus patients is often associated with disease activity, especially kidney involvement (lupus nephritis) and other severe complications. Methods for performing this test include ELISA (enzyme-linked immunosorbent assay), immunofluorescence using Crithidia luciliae (a highly specific technique), and radioimmunoassay techniques.
A positive result, especially when combined with clinical features such as the characteristic butterfly rash on the face, joint inflammation, photosensitivity, and signs of kidney involvement, strongly indicates lupus. However, Anti-dsDNA positivity can also rarely be seen in other autoimmune conditions (such as Sjögren’s syndrome or autoimmune hepatitis) or with the use of certain medications.
The level of these antibodies may rise with disease flare-ups and decrease during remission, making the test useful for monitoring treatment response. Interpretation of results should be done alongside clinical evaluation, additional laboratory tests (such as ANA and complement levels C3/C4), and sometimes tissue biopsy.
Due to its high specificity for lupus, Anti-dsDNA is considered a key tool in distinguishing this disease from other autoimmune disorders.
