Joint Involvement and Relationships with Systemic Inflammation in the EULAR Scleroderma Trial and Research Group (EUSTAR) Databa
Posted Mar 16 2010 12:00am
Articular structures may be involved in systemic sclerosis (SSc), causing functional disability. The precise prevalence of clinical articular manifestations has not been accurately defined in a large population of SSc patients.
To determine the prevalence of, and independent factors associated with joint involvement in a large population of patients with SSc.
We queried the EUSTAR database to extract data regarding global evaluation of SSc patients and presence or not of any clinical articular involvement: synovitis (defined by inflammation of the synovial membrane leading to pain and swelling), joint contractures (resulting from joint destruction turning into ankylosis and fibrotic changes in the skin) and tendon friction rubs (defined by tendonitis characterised by fibrosis of the tendon sheaths). Overall joint involvement was defined by the occurrence of synovitis and/or joint contracture and/or tendon friction rubs. We recruited 7286 SSc patients (86% of whom were women); the mean ± SD age was 56±14 years old, the mean ±SD disease duration was 10±29 years and 4210 (58%) had a limited cutaneous subtype.
The point prevalence of joint involvement was 58%: the frequencies of synovitis, joint contractures and tendon friction rubs were 16%, 31% and 11%, respectively. In multivariate stepwise regression, overall joint involvement was associated with the following items, provided in table 1.
Focusing on systemic inflammation, when elevated acute phase reactants were considered as the dependent variable, they were found highly associated with joint symptoms (OR: 2.21, 95% CI 1.77-2.77).
Our results highlight the striking level of articular involvement in SSc, as evaluated by systematic examination in the largest worldwide available cohort of patients. In addition, our data also show that synovitis, joint contracture and tendon friction rubs are associated with a more active and severe disease phenotype. Joint involvement also appeared to strikingly contributes to systemic inflammation. The prospective follow-up of this cohort is ongoing; it will allow to confirm the above associations and to assess articular involvement as a marker and a predictor of disease severity.