Anti-dsDNA antibody samples received by the laboratories must now be accompanied by relevant clinical details, and prior testing history, to be processed.
Background
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.
However international recommendations advise testing for anti-dsDNA antibodies only after detecting a positive antinuclear antibody (ANA) in patients with symptoms consistent with systemic lupus erythematosus. In patients who are ANA negative, anti-dsDNA should only be ordered in clinical situations where the pre-test probability of SLE is high.
Current Service
Currently in Canterbury, anti-dsDNA antibody testing is unrestricted and available to all requestors.
New Service
As of 20 July 2020 the service will be rationalised following the argument above, such that anti-dsDNA antibody requests without relevant clinical details, as per below, will not be processed.
Requesting clinicians will need to ensure that the indication is clearly recorded under the clinical details section of the request form to ensure that the test is processed.
- Previous positive Anti Nuclear Antibody test (ANA) (except if definite dense fine speckled pattern which does not correlate with disease)
- Known Systemic lupus erythematosus (SLE)
- High clinical suspicion of SLE