OBJECTIVES: The diagnosis of inclusion body myositis (IBM) can be challenging as it can be difficult to clinically distinguish from other forms of myositis, particularly polymyositis (PM). Recent studies have shown frequent presence of autoantibodies directed against cytosolic 5'-nucleotidase 1A (cN-1A) in patients with IBM. We therefore, examined the autoantigenicity and disease specificity of major epitopes of cN-1A in patients with sporadic IBM compared with healthy and disease controls. METHODS: Serum samples obtained from patients with IBM (n=238), PM and dermatomyositis (DM) (n=185), other autoimmune diseases (n=246), other neuromuscular diseases (n=93) and healthy controls (n=35) were analysed for the presence of autoantibodies using immunodominant cN-1A peptide ELISAs. RESULTS: Autoantibodies directed against major epitopes of cN-1A were frequent in patients with IBM (37%) but not in PM, DM or non-autoimmune neuromuscular diseases (<5%). Anti-cN-1A reactivity was also observed in some other autoimmune diseases, particularly Sjögren's syndrome (SjS; 36%) and systemic lupus erythematosus (SLE; 20%). CONCLUSIONS: In summary, we found frequent anti-cN-1A autoantibodies in sera from patients with IBM. Heterogeneity in reactivity with the three immunodominant epitopes indicates that serological assays should not be limited to a distinct epitope region. The similar reactivities observed for SjS and SLE demonstrate the need to further investigate whether distinct IBM-specific epitopes exist.

• Klíčová slova
• Autoantibodies, Autoimmune Diseases, Dermatomyositis, Polymyositis,
• MeSH
• 5'-nukleotidasa imunologie   MeSH
• autoimunitní nemoci imunologie   MeSH
• autoprotilátky imunologie   MeSH
• dermatomyozitida diagnóza   imunologie   MeSH
• diabetes mellitus 1. typu imunologie   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• myozitida s inkluzními tělísky diagnóza   imunologie   MeSH
• neuromuskulární nemoci imunologie   MeSH
• polymyozitida diagnóza   imunologie   MeSH
• revmatoidní artritida imunologie   MeSH
• ROC křivka MeSH
• roztroušená skleróza imunologie   MeSH
• senioři MeSH
• senzitivita a specificita MeSH
• Sjögrenův syndrom imunologie   MeSH
• studie případů a kontrol MeSH
• systémová sklerodermie imunologie   MeSH
• systémový lupus erythematodes imunologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• 5'-nukleotidasa MeSH
• autoprotilátky MeSH
• NT5C1A protein, human MeSH Prohlížeč