Levels > or = 7 IU/mL are considered positive for anti-dsDNA
0 - 7 IU/mL = within normal limits
7 - 8 IU/mL = may be seen in Sjogrens Syndrome and other connective tissue diseases
>8 IU/mL = high titres largely confined to cases of SLE
Uncertainty of Measurement: 20%
Test performed once a week.
Elevated anti-dsDNA levels are not found in all SLE patients, due to possible saturation of binding sites by circulating DNA.
Positive results higher than the upper limit obtained for healthy adults (4.2 IU/ml)may occur in patients with other rheumatic disorders ,chronic active hepatitis ,infectious mononucleosis, biliary cirrhosis, and may be drug induced (procainamide or hydralazine).
Levels may remain elevated after apparent remission of a disease flare.
Antibodies to native or double-stranded DNA are found primarily in systemic lupus erythematosis (SLE). They are thought to be involved in the pathogenesis of the most severe forms of SLE when deposited as immune complexes. High levels of native DNA occur almost exclusively in SLE and correlate with active disease. Therefore their detection is important in the diagnosis and management of SLE patients.
References
1. Trinity Biotech product insert. This insert has references supporting the use of RIA-based determinations for dsDNA antibodies, and the clinical value of determining anti-dsDNA levels in SLE patients.
For further information contact the laboratory, (09) 307 4949 ext 22103 or:
Associate Professor Rohan Ameratunga
, Immunopathologist: Locator
93-5724,