Researchers have developed an autoantibody reference reagent that they say will help align autoantibody analyses, optimising diagnosis and treatment for SLE patients irrespective of where they live.
Lead author Bernard Fox, senior scientist and study director at the National Institute for Biological Standards and Control (NIBSC) and colleagues noted that in 1985 the WHO endorsed an anti-dsDNA reference reagent which was used to align anti-dsDNA analyses in different laboratories as well as commercial anti-dsDNA antibody tests provided by different companies. However, this reference reagent was exhausted more than 10 years ago.
In a bid to find a new reference reagent the research team identified a large plasma sample (2.4 litres) from a patient with SLE which was evaluated in 42 European laboratories. The plasma was then transferred to 4300 ampoules, and lyophilized to allow for long-term storage.
The preparation, called 15/174, was then evaluated in an international study including 36 laboratories from 17 countries worldwide.
Results showed that the plasma mainly contained anti-dsDNA, other anti-chromatin antibodies and anti-Ku. However, because no statistically meaningful overall potency or assay parallelism and commutability could be shown 15/174 could not be considered equivalent to the first IS for anti-dsDNA (Wo/80).
“This international evaluation showed that although the performance of 15/174 was not perfect, the current situation with large differences between different anti-dsDNA assays would be improved by use of 15/174 as a reference reagent,” the study authors said.
15/174 was endorsed as a WHO reference reagent for anti-dsDNA autoantibodies in November 2017.
“Our intention is that the WHO reference reagent 15/174 will be used to align different test methods for anti-dsDNA antibodies and thus improve the diagnostics and care of patients with SLE,” said Mr Fox.
The new WHO reference reagent 15/174 is available from NIBSC for all companies developing anti-dsDNA assays and for clinical immunology laboratories worldwide.
The study was published in the Annals of the Rheumatic Diseases.