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
- Antinuclear Antibody Tests. Clin Lab Med. 2019 Dec;39(4):513-524. doi: 10.1016/j.cll.2019.07.001. PMID: 31668266.
