Newer Autoantibodies and Laboratory Assessments in Myositis

Abstract

Purpose of review: We aim to describe the immunoassays that have been used for myositis autoantibody discovery with a focus on newer methods. We describe recently identified myositis autoantibodies that do not yet form part of routine clinical testing, highlighting what is known about their associated clinical phenotype and potential clues as to their presence.

Recent findings: Novel approaches to autoantibody detection have been employed in recent years including chemiluminescent immunoassay, phage immunoprecipitation-sequencing and modifications to the more traditional immunoprecipitation technique. This has led to the discovery of novel autoantibodies, including novel anti-aminoacyl-tRNA synthetase autoantibodies and autoantibodies which modify cancer risk for patients with anti-TIF1ɣ associated dermatomyositis. New approaches to novel autoantibody detection have facilitated autoantibody discovery and will enable the identification of autoantibodies to a broader range of autoantigens. Challenges remain in translating this knowledge into accessible testing particularly given the rarity of most recently discovered autoantibodies.

Keywords: Autoantibody; Biomarker; Detection; Idiopathic inflammatory myopathy; Immunoassay; Myositis.

Fig. 1

A range of different myositis specific and associated autoantibodies have now been described. Very rare autoantibodies and those discovered within the last 5–10 years are typically not included in standard testing panels. When patients test ‘negative’ for myositis autoantibodies clinicians should consider whether extended testing for CTD overlap autoantibodies e.g. U1RNP could be of benefit in addition to extended spectrum autoantibody testing for rare/novel autoantibodies, where facilities to do so are available