Novel autoantibodies against 7SL RNA in patients with polymyositis/dermatomyositis

J Rheumatol. 2005 Sep;32(9):1727-33.

Abstract

Objective: Autoantibodies against signal recognition particle (SRP) are detected in patients with polymyositis/dermatomyositis (PM/DM). The SRP consists of 7SL RNA and 6 protein components. We examined autoantibodies against deproteinized 7SL RNA in PM/DM patients with anti-SRP antibodies and evaluated the association of anti-7SL RNA antibodies with PM/DM clinically and serologically.

Methods: Sera from 10 Japanese and 22 North American PM/DM patients with anti-SRP antibodies were tested for the presence of anti-7SL RNA antibodies, using the sera to immunoprecipitate deproteinized RNA extracts derived from HeLa cells.

Results: The immunoprecipitation analysis indicated that 5 Japanese (50%) and one North American (5%) patient with anti-SRP antibodies had novel autoantibodies against deproteinized 7SL RNA. The frequency of anti-7SL RNA antibodies was significantly higher in Japanese than North American patients (p = 0.006). The presence of anti-7SL RNA antibodies appeared to be associated with DM (2 patients) and finger swelling (2 PM patients). The seasonal onset of the disease was different (p = 0.008) for Japanese PM/DM patients with anti-7SL RNA antibodies, who developed the disease between October and January (mean month November; p = 0.01) from that of patients without these antibodies, who developed it between June and August (mean month July; p = 0.01).

Conclusion: Novel autoantibodies against 7SL RNA were identified in patients with PM/DM, and the presence of these antibodies was correlated to ethnic background, clinical features, and season of disease onset. These findings indicated that autoantibodies against 7SL RNA are a novel serological marker for a subset of PM/DM cases.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asians*
  • Autoantibodies / analysis
  • Autoantibodies / immunology*
  • Biomarkers
  • Cohort Studies
  • Dermatomyositis / blood
  • Dermatomyositis / ethnology
  • Dermatomyositis / immunology
  • Female
  • Follow-Up Studies
  • Humans
  • Immunoprecipitation
  • Male
  • Middle Aged
  • Polymyositis / blood
  • Polymyositis / ethnology*
  • Polymyositis / immunology*
  • Probability
  • RNA, Small Cytoplasmic / analysis
  • RNA, Small Cytoplasmic / immunology*
  • Risk Assessment
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Signal Recognition Particle / analysis
  • Signal Recognition Particle / immunology*
  • Whites*

Substances

  • 7SL RNA
  • Autoantibodies
  • Biomarkers
  • RNA, Small Cytoplasmic
  • Signal Recognition Particle