Anti-nuclear antibody

From IDWiki

Background

  • Refers to antibodies that react to nuclear proteins
  • General screen, sometimes followed by assessing for specific antibodies
    • Antigens that are insoluble in saline: double-stranded DNA, deoxyribonucleoprotein (DNP), histones
    • Antigens that are soluble in saline (or extracted; ENA): anti-Smith, anti-RNP, anti-Ro/La, anti-Scl-70
  • May be measured by indirect immunofluorescence assay (IIF) (the gold standard), enzyme-linked immunosorbent assay (EIA), or other technologies

Disease Associations

  • Healthy people can have a 1:40 titre (25 to 45% of health people), 1:80 titre (10 to 15%), or even 1:160 titre (5%)
    • Increases with age
  • Systemic lupus erythematosus
    • ANA assay was essentially developed as a screening tool for SLE
    • It is 90 to 95% sensitive
Disease % Positive Titre Common Patterns
SLE (active) 95 high homogeneous > speckled > rim
SLE (in remission) 90 moderate-high homogeneous > speckled
MCTD 93 high speckled > nucleolar
Systemic sclerosis or CREST 85 high speckled > centromere > nucleolar
Sjögren syndrome 48 moderate-high speckled > homogeneous
Dermatomyositis/Polymyositis 61 low-moderate speckled > nucleolar
Rheumatoid arthritis 41 low-moderate speckled
Drug-induced lupus 95 low-moderate homogeneous > speckled
Pauciarticular JIA 71 low-moderate speckled
Graves disease 50 low-moderate speckled
Hashimoto thyroiditis 46 low-moderate speckled
Autoimmune hepatitis 63–91 low-moderate speckled
Primary biliary cirrhosis 10–40 low-moderate speckled

Further Reading