Inflammation and damage in an individual joint predict further damage in that joint in patients with early rheumatoid arthritis

Objective. Several factors predict joint damage in early rheumatoid arthrit is (RA). In the context of a trial in early RA, we studied the relationship between clinical signs in individual joints and their propensity to develo p progressive damage. Methods. The COBRA (Combinatietherapie Bij Reumatoide Artritis) multicenter trial compared the efficacy of prednisolone, methotrexate, and sulfasalazi nc against sulfasalazine alone in 155 patients with early RA. Two blinded o bservers interpreted radiographs in sequence (using the Sharp/Van der Heijd e scoring system); in each center, one blinded observer performed clinical assessments every 3 months. The current analysis is based on clinical and r adiologic data of the individual metacarpophalangeal (MCP) and proximal int erphalangeal (PIP) joints of 135 patients. Conditional stepwise logistic re gression analyzed the relationship between damage (progression) and clinica l signs at baseline and followup for each of these joints individually in e ach patient. Results. Combination therapy strongly retarded the progression of damage. P rogression was stronger in patients with rheumatoid factor, HLA-DR4, and hi gh levels of disease activity at baseline. At baseline, 6% of the MCP and P IP joints showed damage; after 1 year, disease had progressed in 10% of the se joints. Baseline damage, swelling, or pain in a joint independently and strongly predicted the progression of damage in that joint (P < 0.001). Eac h additional point in the swelling score (range 0-2) tripled the risk for s ubsequent progression. Each additional point on the Sharp scale (range 0-8 per joint) and each additional point on the pain scale (range 0-3) doubled the risk. The mean pain and swelling scores over the year were even stronge r predictors of damage. Conclusion. Local expression of early RA disease activity, both at baseline and at 1-year followup, is strongly related to progression of damage in th e individual joint.