Novel serology testing for sporadic inclusion body myositis: disease-specificity and diagnostic utility

Curr Opin Rheumatol. 2015 Nov;27(6):595-600. doi: 10.1097/BOR.0000000000000216.


Purpose of review: The purpose of this article is to discuss recent advances in serological testing for sporadic inclusion body myositis (sIBM) and to provide a review of their diagnostic utility and disease-specificity of auto-antibodies in sIBM.

Recent findings: The identification, prevalence and diagnostic utility of a new auto-antibody targeting cytosolic 5'-nucleotidase 1A (cN-1A) in the serum of sIBM patients have recently been published. These studies have shown that anti-cN-1A auto-antibodies have diagnostic utility for differentiating sIBM from other forms of myositis and from other neuromuscular diseases. Anti-cN-1A-positive patient sera are directed to multiple epitopes of cN-1A and contain, in addition to IgG, IgA and IgM, anti-cN-1A auto-antibodies. Recent studies have also shown a relatively high prevalence of these auto-antibodies in sera form Sjögren's syndrome and systemic lupus erythematosus patients.

Summary: The recent discovery of auto-antibodies to cN-1A provides a serological tool to aid the differentiation between inflammatory myopathies and supports the idea that apart from degeneration, an adaptive immune response may also play a role in sIBM pathophysiology. Future research will need to focus on standardization of methods to detect these auto-antibodies in order to further explore their specificity and diagnostic utility for sIBM.

Publication types

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

MeSH terms

  • 5'-Nucleotidase / biosynthesis*
  • 5'-Nucleotidase / blood
  • Autoantibodies / blood*
  • Humans
  • Myositis, Inclusion Body / blood
  • Myositis, Inclusion Body / diagnosis*
  • Myositis, Inclusion Body / immunology
  • Sensitivity and Specificity
  • Serologic Tests


  • Autoantibodies
  • 5'-Nucleotidase