Publish date: 17 March 2025
Dear colleagues,
Due to a series of technical issues causing suboptimal turnaround times and underperformance of our double stranded DNA antibody test (anti-dsDNA), we have made the decision to expedite a transition of the test to a new method. Any results that are generated from now on will be from the new method and are not comparable with the previous results. Please interpret results in the clinical context and in conjunction with other lab findings, and not against the previous results for dsDNA antibodies. Individual reports will have a comment on that states that the result is from the new method, as of 06/03/25, and include the advice as given above regarding monitoring.
Performance of the new assay
Reference range: <10 IU/mL Negative>
10 - 15 IU/mL Equivocal
>15 IU/mL Positive
Upper reporting limit: 379 IU/mL
A previous evaluation of this new method (performed in 2022) gave the sensitivity of 96.2% but a low specificity of 19.0%. However in the latest evaluation of the assay, the specificity has significantly improved and has now been calculated as 78.3%, meaning that there should be a reduction in false positive results for patients without clinical signs of lupus.
We will continue to confirm positive results with the Crithidia method.
If you have any questions regarding this change, please contact the Immunology Clinical Scientist, Katy Keymer, either via email (catherine
Best wishes,
LCL Communications