Expansion
Each autoimmune disease has a characteristic antibody profile
Mnemonic
Pair each antibody with its disease, grouped by system:
- Anti-dsDNA and anti-Smith - lupus. dsDNA tracks renal activity
- Anti-histone - drug induced lupus
- Anti-centromere - limited systemic sclerosis (CREST)
- Anti-Scl-70 - diffuse systemic sclerosis
- Anti-Ro and anti-La - Sjogren’s, and congenital heart block
- Anti-CCP - rheumatoid arthritis, specific and predicts erosions
- cANCA / PR3 - granulomatosis with polyangiitis
- pANCA / MPO - microscopic polyangiitis
- Anti-mitochondrial - primary biliary cholangitis
- Anti-smooth muscle - autoimmune hepatitis
- Anti-tTG - coeliac disease
- Anti-GBM - Goodpasture’s
- Anti-acetylcholine receptor - myasthenia gravis
- Anti-TPO - Hashimoto’s; TSH receptor - Graves’
“cANCA is C for granulomatosis with Cavities and the C-shaped upper airway; pANCA is P for the Poorer defined microscopic polyangiitis.”
A positive ANA is common in healthy people, especially at low titre and with age, so it must never be used as a screening test without clinical features.
Expansion
| Antibody | Disease |
|---|---|
| ANA | Lupus (sensitive, not specific), many connective tissue diseases |
| Anti-dsDNA | Lupus, specific; correlates with nephritis and activity |
| Anti-Smith | Lupus, highly specific |
| Anti-histone | Drug-induced lupus |
| Anti-Ro and anti-La | Sjogren, and neonatal lupus with congenital heart block |
| Anti-centromere | Limited systemic sclerosis (CREST) |
| Anti-Scl-70 | Diffuse systemic sclerosis |
| Anti-Jo-1 | Polymyositis and dermatomyositis |
| Rheumatoid factor | Rheumatoid arthritis (also Sjogren, infection, healthy elderly) |
| Anti-CCP | Rheumatoid arthritis, more specific than rheumatoid factor |
| cANCA (anti-PR3) | Granulomatosis with polyangiitis |
| pANCA (anti-MPO) | Microscopic polyangiitis, eosinophilic granulomatosis |
| Anti-mitochondrial | Primary biliary cholangitis |
| Anti-smooth muscle | Autoimmune hepatitis type 1 |
| Anti-TTG and anti-endomysial | Coeliac disease |
| Anti-GBM | Goodpasture disease |
| Anti-acetylcholine receptor | Myasthenia gravis |
The general principle is that sensitive tests such as ANA are used to screen and specific ones such as anti-dsDNA to confirm, and that a positive antibody without compatible clinical features rarely establishes a diagnosis.