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 onsef. 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<0.04), serositis (p<0.01), and a lower mean serum albumin concentration (26.7 vs 31.3 gm/L; p<0.02). However, by 6 months after onset, patients with destructive arthritis more frequently had persistent systemic symptoms (92% vs 12%; p<0.0001), polyarthritis (67% vs 19%; p<0.0005), a lower mean hemoglobin level (95 vs 114 gm/L; p<0.001), a higher mean leukocyte count (21.2 vs 10×10⁹/L; p<0.0003), a higher mean platelet count (794 vs 400×10⁹/L; p<0.0001), and a higher mean erythrocyte sedimentation rate (43 vs 24 mm/hr; p<0.05). Multivariate analysis of the results at 6 months revealed that persistent systemic symptoms and a platelet count ≥600×10⁹/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.