extractable nuclear antigens (ENA)

Last reviewed 01/2018

  • some patients are antinuclear antibody (ANA) positive but have antibodies which recognise different sets of nuclear proteins, termed extractable nuclear antigens (ENA)
    • commonest is anti-Ro which is usually clinically associated with photosensitivity
    • ENA antibodies
      • RNP may occur in SLE, scleroderma and 'overlap' connective tissue disease
      • Sm may occur in SLE (associated with risk of renal disease)
      • Ro, La may occur in SLE and Sjögren's (associated with photosensitivity and neonatal heartblock)
      • centromere may occur in limited cutaneous systemic sclerosis (SS)
      • Scl-70 may occur in diffuse cutaneous SS
      • Cardiolipin may occur in SLE and antiphospholipid syndrome (arterial and venous thromboses, mid-trimester foetal loss)


  1. ARC. Connective tissue disease in primary care. Hands On 2006; 9:1-5.