Table 3.
Comparison of the key features of rheumatoid arthritis and systemic lupus erythematosus
| Key features | Rheumatoid arthritis | Systemic lupus erythematosus | |||
|---|---|---|---|---|---|
| Seropositive | Seronegative | Non-deforming non-erosive (NDNE) arthritis | Jaccoud’s arthropathy (JA) | Rhupus syndrome | |
| Predominant feature(s) | Synovitis | Synovitis | Tendinitis, tenosynovitis | Tendinitis, tenosynovitis | Synovitis |
| Secondary feature(s) | Tenosynovitis, bursitis, joint effusion, BME | Tenosynovitis, bursitis, joint effusion, BME. BME may be lower than in seropositive patients | Synovitis and BME (lower prevalence or grade than JA, Rhupus and RA) | Synovitis, BME (higher prevalence than NDNE arthritis but lower than Rhupus and RA) | Tendinitis, tenosynovitis, bursitis, BME, joint effusion |
| Erosions detected by radiographic imaging | Yes, increases as disease progresses | Yes, increases as disease progresses | No | No | Yes. Similar to RA |
| Erosions detected by MSUS or MRI | Yes | Yes, but at a lower level than seropositive patients | Yes, but at a lower number and lower severity than JA, Rhupus and RA | Yes | Yes. Similar to RA |
| Enthesitis | Usually absent | Usually absent | Present | Present | Present |
| Radiographical progression | Progression to erosion and deformity | Progression to erosion and deformity | Usually minimal progression to erosions and no deformity | Progression to deformity only | Progression to erosion and deformity |
| Deformities present in untreated or inadequately treated disease | Yes—irreversible | Yes—irreversible | No | Yes—reversible | Yes—irreversible |
| Autoantibody formation | Yes | No | Yes | Yes | Yes |
The most common features affecting hands and wrists in patients with RA or SLE detected by MRI and MSUS imaging are summarized in this table. RA is categorized by seropositivity or seronegativity and SLE is categorized by NDNE arthritis, Jaccoud’s arthropathy (JA) or ‘Rhupus’ phenotype. A well-defined disease progression, the development of deformities in untreated or inadequately treated disease and the presence of autoantibodies are also noted. Data from [1, 2, 4, 6, 7, 31, 40–42, 49, 50, 54, 57, 59, 61, 67, 68, 71, 73, 76, 78, 80, 105–107]
BME Bone marrow edema, JA Jaccoud’s arthropathy, MRI Magnetic resonance imaging, MSUS Musculoskeletal ultrasound, NDNE Non-deforming non-erosive, RA Rheumatoid arthritis, SLE Systemic lupus erythematosus