Disappearance of anti-MDA-5 autoantibodies in clinically amyopathic DM/interstitial lung disease during disease remission

Rheumatology (Oxford). 2012 May;51(5):800-4. doi: 10.1093/rheumatology/ker408. Epub 2011 Dec 30.


Objective: Autoantibodies against melanoma differentiation-associated gene 5 (MDA-5) are one of the serological markers for DM. Anti-MDA-5 antibodies are especially associated with rapidly progressive interstitial lung disease (ILD) in amyopathic DM (ADM). It is known that the antibody status of anti-ENAs does not generally change significantly with disease course. For anti-MDA-5 antibodies, however, few longitudinal studies have investigated such changes. This study aimed to establish a quantitative assay for anti-MDA-5 antibodies towards assessing the long-term outcome of ADM patients who had anti-MDA-5 antibodies.

Methods: We established ELISA for measuring anti-MDA-5 antibody levels using in vitro transcription and translation recombinant protein. The antibody levels were measured at different time points in 11 clinically ADM patients who tested positive for the anti-MDA-5 antibody on their first visit (range of follow-up 3 months to 16 years).

Results: At the stage of clinical remission, six patients received no medication and the four others received low-dose CS. ELISA showed that anti-MDA-5 antibodies disappeared in nine of the patients and fell to just above the cut-off in one patient; in the patient who died, the antibodies remained.

Conclusion: Our results suggest that anti-MDA-5 antibodies may be useful as a marker for monitoring disease activity in ILD complicated with ADM. Serial monitoring at short intervals is required to evaluate whether anti-MDA-5 antibody levels correlate with ADM disease activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Autoantibodies / immunology*
  • Biomarkers
  • DEAD-box RNA Helicases / immunology*
  • Dermatomyositis / complications
  • Dermatomyositis / immunology*
  • Disease Progression
  • Female
  • Follow-Up Studies
  • Humans
  • Interferon-Induced Helicase, IFIH1
  • Lung Diseases, Interstitial / complications
  • Lung Diseases, Interstitial / immunology*
  • Male
  • Middle Aged
  • Prognosis


  • Autoantibodies
  • Biomarkers
  • IFIH1 protein, human
  • DEAD-box RNA Helicases
  • Interferon-Induced Helicase, IFIH1

Supplementary concepts

  • Amyopathic dermatomyositis