Autoantibody testing is a key step in the diagnosis of many autoimmune diseases, including myositis. Against this backdrop, an international consortium of laboratories responsible for these tests has compared its practices and issued recommendations:
- 15 laboratories (in Europe, North America, Australia and Japan) took part in this comparative study and tested 24 reference sera from quality control,
- assay techniques may have been developed by the laboratory itself or may have used commercial kits,
- there is considerable variability in results, even among laboratories using the same diagnostic kits,
- discrepancies between laboratories exist for both myositis-specific antibodies (MSA) and myositis-associated antibodies (MAA).
The authors emphasise the urgent and pressing need to achieve the harmonisation sought by all stakeholders (clinicians, manufacturers of diagnostic kits and diagnostic laboratories).
