Commonly tested antibodies against extractable nuclear antigens (ENA) and their respective sensitivities and specificities (%) for rheumatic diseases.6
| Autoantibody | Disease | Sensitivity | Specificity | Comments |
|---|---|---|---|---|
| Anti-Ro (SS-A) | Sjögren’s syndrome | 87 | 49 | |
| SLE | 29 | 49 | ||
| Anti-La (SS-B) | Sjögren’s syndrome | 83 | 60 | |
| SLE | 23 | 48 | ||
| Anti-Sm | SLE | 36 | 91 | Anti-Sm may indicate less severe form of SLE without renal involvement |
| Anti-Jo-1 | Polymyositis/Dermatomyositis | 51 | 96 | |
| Anti-Mi-2 | Polymyositis/Dermatomyositis | 13 | 99 | |
| Anti-U1 RNP | Mixed CTD | 91 | 64 | |
| SLE | 38 | 60 | ||
| Anti-Scl-70 | Systemic sclerosis | 35 | 93 | Anti-centromere is sometimes performed in parallel to help differentiate between limited and diffuse cutaneous forms of systemic sclerosis |
| SLE | 13 | 10 |
CTD = connective tissue disorder. RNP = ribonucleoprotein. SLE = systemic lupus erythematosus.