Article Text

other Versions

PDF
Extended report
PUF60: a prominent new target of the autoimmune response in dermatomyositis and Sjögren's syndrome
  1. David F Fiorentino1,
  2. Matthew Presby2,
  3. Alan N Baer2,
  4. Michelle Petri2,
  5. Kerri E Rieger3,
  6. Mark Soloski2,
  7. Antony Rosen2,
  8. Andrew L Mammen4,5,
  9. Lisa Christopher-Stine2,
  10. Livia Casciola-Rosen2
  1. 1Department of Dermatology, Stanford University School of Medicine, Redwood City, California, USA
  2. 2Division of Rheumatology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
  3. 3Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
  4. 4Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
  5. 5Muscle Disease Unit, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland, USA
  1. Correspondence to Dr Livia Casciola-Rosen, Johns Hopkins Bayview, Division of Rheumatology, Department of Medicine, Mason F. Lord Building, Center Tower, Suite 5300, 5200 Eastern Ave, Baltimore, MD 21224, USA; lcr{at}jhmi.edu

Abstract

Objectives Autoantibodies are used clinically to phenotype and subset patients with autoimmune rheumatic diseases. We detected a novel 60 kDa autoantibody specificity by immunoblotting using a dermatomyositis (DM) patient's serum. Our objective was to identify the targeted autoantigen and to evaluate disease specificity and clinical significance of this new autoantibody.

Methods A new 60 kDa specificity was detected by immunoblotting HeLa cell lysates. The targeted autoantigen was identified as poly(U)-binding-splicing factor 60 kDa (PUF60) using (i) a human protein array and (ii) two-dimensional gel electrophoresis and liquid chromatography tandem mass spectrometry peptide sequencing. Anti-PUF60 antibodies were assayed by ELISA using sera from patients with primary Sjögren's syndrome (SS; n=84), systemic lupus erythematosus (SLE; n=71), DM (n=267), polymyositis (n=45), inclusion body myositis (n=45) and healthy controls (n=38).

Results PUF60 was identified as a new autoantigen. Anti-PUF60 antibodies were present in 25/84 (30%) patients with SS, 6/71 (8.5%) patients with SLE and 2/38 (5.0%) control subjects (SS vs controls, p=0.002; SLE vs controls, p=0.711). Anti-PUF60 antibodies were present in 48/267 (18.0%) patients with DM versus 4/45 (8.9%) and 5/45 (11.1%) patients with inclusion body myositis and polymyositis, respectively. The antibody was significantly associated with anti-Ro52 antibodies, rheumatoid factor and hyperglobulinemia in the patients with primary SS. In patients with DM, the antibody was associated with anti-transcription intermediary factor 1 gamma seropositivity and Caucasian race.

Conclusions PUF60 represents a novel autoantigen in patients with SS and DM. PUF60 antibodies are associated with distinct clinical features and different immune responses in different diseases.

  • Dermatomyositis
  • Autoantibodies
  • Sjøgren's Syndrome
  • Systemic Lupus Erythematosus

Statistics from Altmetric.com

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.