Prognostic indicators of joint destruction in systemic-onset juvenile rheumatoid arthritis

We retrospectively reviewed the charts and radiographs of 38 patients with systemic-onset juvenile rheumatoid arthritis, attempting to identify early in the disease course the clinical and laboratory observations most predictive of the later development of destructive arthritis. In 12 of the patients, destructive arthritis developed within 2 years of disease onset. When first examined, these patients could not readily be differentiated from those in whom joint destruction did not develop, but they more commonly had hepatosplenomegaly (p less than 0.04), serositis (p less than 0.01), and a lower mean serum albumin concentration (26.7 vs 31.3 gm/L; p less than 0.02). However, by 6 months after onset, patients with destructive arthritis more frequently had persistent systemic symptoms (92% vs 12%; p less than 0.0001), polyarthritis (67% vs 19%; p less than 0.0005), a lower mean hemoglobin level (95 vs 114 gm/L; p less than 0.001), a higher mean leukocyte count (21.2 vs 10 x 10(9)/L; p less than 0.0003), a higher mean platelet count (794 vs 400 x 10(9)/L; p less than 0.0001), and a higher mean erythrocyte sedimentation rate (43 vs 24 mm/hr; p less than 0.05). Multivariate analysis of the results at 6 months revealed that persistent systemic symptoms and a platelet count greater than or equal to 600 x 10(9)/L were the variables most highly predictive of the later development of joint destruction. We conclude that patients at high risk for the development of destructive arthritis may be identified within 6 months of disease onset, thereby indicating the need for more aggressive early therapy.