Prevalence of selected autoantibodies in connective tissue diseases (CTDs)
| Antibodies | Disease | Prevalence % | Associations/comment |
| ANA | SLE | >95 | |
| MCTD | 95 | ||
| SSc | 70–90 | ||
| PM/DM | 40–60 | ||
| SS | 50–80 | ||
| RA | 40–50 | ||
| Pattern | |||
| Homogeneous and diffuse | |||
| Anti-histone | SLE | 60–80 | Present in >95% of patients with drug-induced SLE |
| Anti-dsDNA | SLE | 40–60 | Highly specific Severe disease and renal involvement Titres tend to associate with disease activity |
| Speckled | |||
| Anti-Sm | SLE | 25–30 | Highly specific |
| Anti-topoisomerase 1 | SSc | 20–25 | Increased risk of diffuse cutaneous involvement and pulmonary fibrosis |
| Anti-U1 RNP | MCTD | 100 | Present at high titre in all patients with MCTD, often before disease onset At lower titre may be found also in SLE, RA and SSc |
| SLE | 30–40 | ||
| Anti-U3 RNP | SSc | 10–15 | |
| Anti-SS-A/Ro | SS | 60–75 | Extraglandular involvement (e.g. vasculitis, lymphadenopathy and nephritis) Rarely found in healthy individuals |
| SLE | 40–50 | Photosensitivity, cutaneous vasculitis and ILD | |
| Anti-SS-B/La | SS | 40–50 | Rarely present in other CTDs |
| SLE | 15–20 | Rarely present in other CTDs | |
| Centromeric | |||
| Anti-centromere | lcSSc | 30–35 | Increased risk of PH Reduced risk of pulmonary fibrosis Rarely found in patients with other CTDs or in healthy persons |
| Nucleolar | |||
| Anti-RNA polymerase | SSc | 25–30 | Low incidence of pulmonary fibrosis |
| Anti-PM-Scl | SSc | 7–10 | Younger age at disease onset Skeletal muscle involvement Inflammatory arthritis |
| Cytoplasmic staining | |||
| Anti-(t)RNA synthetases | PM/DM | 25 to 40 (mainly anti-Jo-1) | High risk of ILD, Raynaud's phenomenon and mechanic's hands |
| RF | RA | 50–85 | May be negative in early-phase RA High titres strongly predict severe disease (e.g. ILD and vasculitis) May be present also in SLE and SS |
| Anti-CCP | RA | 30–60 | More specific than RF for RA May be present years before disease onset and while RF is negative Increased risk of progressive joint damage May be present also in SLE and SS |
More than one pattern can be present in a patient. ANA: anti-nuclear antibody; ds: double-stranded; Sm: Smith; RNP: ribonucleoprotein; t: transfer; RF: rheumatoid factor; CCP: cyclic citrullinated peptide; SLE: systemic lupus erythematosus; MCTD: mixed connective tissue disease; SSc: systemic sclerosis; PM: polymyositis; DM: dermatomyositis; SS: Sjögren's syndrome; RA: rheumatoid arthritis; lc: limited cutaneous; PH: pulmonary hypertension; ILD: interstitial lung disease. Data from [57–60].