Double-stranded DNA IgG antibodies, quantitative & qualitative (dsDNA, CLIFT)
| Category | Immunology |
|---|---|
| Test background |
Antibodies directed at double stranded DNA (dsDNA) are found in SLE and are seen in around 50% of patients. They have also been reported in anti-TNF therapy induced lupus and been found in non-SLE patients with new onset rheumatic disease. In SLE the presence of anti-dsDNA Abs tends to correlate with lupus nephritis, and the anti-dsDNA antibody level often correlates with disease activity. These antibodies (together with Sm and ACL antibodies) are included in the 2019 ACR/EULAR SLE classification criteria. Low titres can be present in healthy individuals, and in patients with infection, Sjögren's syndrome, rheumatoid arthritis and other connective tissue and autoimmune disorders. On ANA immunofluorescence anti-dsDNA antibodies will show a homogenous (ICAP AC-1) pattern. The laboratory uses a magnetic bead based immunoassay for quantitative dsDNA IgG measurement. New positive dsDNA antibody patients are confirmed by crithidia luciliae indirect immunofluorescence test (CLIFT) which is a qualitative assay with higher specificity. |
| Clinical Indications |
Diagnosis and monitoring of SLE |
| Reference range | <10 IU/mL (range derived by manufacturer and verified in house) |
| Sample & container required | Serum (RST rust top) |
| Sample volume | 5-10 mL blood (1 mL serum) |
| Turnaround time | 14 days |
| Notes | This test is currently unaccredited due to a relocation of the analyser (no changes to assay used) |