Detection of antibody against extractable nuclear antigen by an enzyme-linked immuno-sorbent assay. Results from patients with rheumatic and internal medical diseases

Allergy. 1985 Aug;40(6):442-6. doi: 10.1111/j.1398-9995.1985.tb02683.x.


Anti-ENA antibody determination by ELISA technique may offer a valuable diagnostic help in the discrimination of patients with mixed connective tissue disease (MCTD) from those with other chronic inflammatory connective tissue diseases. Determination of this antibody was performed in a prospective designed investigation among 101 blood donors, 154 patients with various non-rheumatic internal medical diseases, and 229 patients with chronic inflammatory connective tissue diseases, including five patients with MCTD. A positive titre of anti-ENA antibody was found in approximately 10% of blood donors and patients with various internal medical disorders. A highly positive anti-ribonucleoprotein (RNP) titre was found in the patients with MCTD, but was also observed in patients with other chronic inflammatory connective tissue diseases, giving a predictive value of 56% for MCTD. We conclude that highly positive anti-RNP antibody values do not automatically indicate the diagnosis MCTD. Other diagnostic possibilities should still be considered.

MeSH terms

  • Adult
  • Aged
  • Antibodies, Antinuclear / analysis*
  • Cell Nucleus / immunology*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Male
  • Middle Aged
  • Mixed Connective Tissue Disease / diagnosis
  • Mixed Connective Tissue Disease / immunology*
  • Rheumatic Diseases / diagnosis
  • Rheumatic Diseases / immunology*
  • Solubility


  • Antibodies, Antinuclear