Expansion
Antinuclear antibody first, then the specific antibodies
Expansion
Connective tissue disease
| Antibody | Association |
|---|---|
| ANA | Sensitive but non-specific screen for lupus and connective tissue disease |
| Anti-dsDNA | Lupus, specific, and correlates with renal activity |
| Anti-Smith | Lupus, highly specific, insensitive |
| Anti-histone | Drug induced lupus |
| Anti-Ro and anti-La | Sjögren’s, subacute cutaneous lupus, congenital heart block |
| Anti-centromere | Limited systemic sclerosis (CREST) |
| Anti-Scl-70 (topoisomerase) | Diffuse systemic sclerosis, lung fibrosis |
| Anti-RNA polymerase III | Systemic sclerosis, renal crisis |
| Anti-Jo-1 | Antisynthetase syndrome, myositis with lung disease |
| Anti-U1-RNP | Mixed connective tissue disease |
Rheumatoid: rheumatoid factor is sensitive but non-specific, raised in Sjögren’s, endocarditis, hepatitis C and in healthy older people; anti-CCP is far more specific and predicts erosive disease.
Vasculitis
- cANCA / anti-PR3: granulomatosis with polyangiitis
- pANCA / anti-MPO: microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis
Organ specific
- Anti-TPO and anti-thyroglobulin: Hashimoto’s; TSH receptor antibody: Graves'
- Anti-mitochondrial: primary biliary cholangitis
- Anti-smooth muscle and anti-LKM: autoimmune hepatitis
- Anti-tissue transglutaminase with total IgA: coeliac disease
- Anti-GBM: Goodpasture’s
- Anti-acetylcholine receptor and anti-MuSK: myasthenia gravis
- Anti-intrinsic factor and anti-parietal cell: pernicious anaemia
Antiphospholipid antibodies (lupus anticoagulant, anticardiolipin, anti-beta-2 glycoprotein I) must be positive on two occasions 12 weeks apart to be meaningful, since transient positivity is common with infection.