Article Text

Download PDFPDF
Comparison of autoantibody specificities tested by a line blot assay and immunoprecipitation-based algorithm in patients with idiopathic inflammatory myopathies
  1. Fabricio Espinosa-Ortega1,
  2. Marie Holmqvist2,
  3. Helene Alexanderson1,3,
  4. Helena Storfors4,
  5. Tsuneyo Mimori5,
  6. Ingrid E Lundberg1,
  7. Johan Rönnelid6
  1. 1 Division of Rheumatology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
  2. 2 Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
  3. 3 Division of Physiotherapy, Department of Neurobiology Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
  4. 4 Department of Clinical Immunology and Transfusion Medicine, Uppsala University Hospital, Uppsala, Sweden
  5. 5 Department of Rheumatology and Clinical Immunology, Kyoto University Graduate school of Medicine, Kyoto, Japan
  6. 6 Department Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
  1. Correspondence to Professor Ingrid E Lundberg, Division of Rheumatology, Department of Medicine, Karolinska University Hospital, SE-171 76 Stockholm, Sweden; ingrid.lundberg{at}

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

More than 15 autoantibodies have been identified in patients with idiopathic inflammatory myopathies (IIM). Most of them are specific to patients with IIM and therefore called myositis-specific autoantibodies (MSA).1 There is no standardised approach of MSA testing to be used in clinical settings. Immunoprecipitation (IP) of RNA and/or proteins in cellular lysates has traditionally been considered the golden standard for most autoantibodies but does not differentiate between antibodies targeting proteins with the same molecular weight and is not routinely available. Line blot assays (LB) represent a faster and semi-quantitative option to detect autoantibodies.2 3 Our aim was to compare a LB version with 16 specificities and an IP-based algorithm, as well as to describe clinical associations to autoantibody specificities in a cohort of patients classified as IIM.

The first available sera collected between 2013 and 2017, from 110 patients classified as having IIM4 followed at the rheumatology clinic at Karolinska University Hospital (Stockholm, Sweden) and sera from 60 healthy controls were included. We used a commercial LB assay (Euroline Myositis …

View Full Text


  • Handling editor Josef S Smolen

  • Contributors Study concept and design: IEL, JR. Acquisition of data: JR, HS, TM, FE. Statistical analysis: FE. Analysis and interpretation of data, drafting manuscript and critical revision of manuscript: all authors.

  • Funding The Swedish Research Council and King Gustav V:th 80-year Foundation.

  • Competing interests IEL has received honoraria from Bristol Myers Squibb and MedImmune and is currentlyreceiving a research grant from Bristol Myers Squibb and from Astra Zeneca; and is a scientificadvisor for Bristol Myers Squibb, aTyr and IDERA.

  • Patient consent for publication Not required.

  • Ethics approval Our study had the permit for antibody analysis from the Ethics Committee in Stockholm, Sweden.

  • Provenance and peer review Not commissioned; externally peer reviewed.