WESTPORT, CT (Reuters Health) – Radiographic evidence of damage from early rheumatoid arthritis can be predicted on the basis of just four factors, according to the results of a multiparameter prospective study. The most important are initial x-ray findings and the presence of rheumatoid factor.
Dr. B. Combe, of the Fיdיration de Rhumatologie in Montpellier, France, and colleagues obtained radiographs after 3 years for 172 patients whose disease duration had been shorter than 1 year at presentation. The investigators evaluated most of the clinical, biologic, immunologic, and genetic factors thought to be pertinent to rheumatoid arthritis outcome.
The patients were treated primarily with sulfasalazine, methotrexate, or both. The authors found that "radiologic scores [determined by Sharp's method, modified by van der Heijde] at baseline and both IgM and IgA rheumatoid factor positivity were the most important factors determining severity and progression of structural damage," as they report in Arthritis and Rheumatism for August.
The French researchers developed an equation based on radiographic score, presence of IgM rheumatoid factor, presence of DRB1*04 rheumatoid arthritis-associated genes, and either erythrocyte sedimentation rate or pain score. They conclude that the resulting score gave "a maximal accuracy higher than ever reported to predict radiologic damage and individual radiographic progression."