Pediatric Rheumatology Online Journal → June 2003 → Systemic Onset Arthritis → Abstract #14

GROWTH DELAY IN SYSTEMIC ONSET JRA: INTERPLAY BETWEEN MEDICATION USAGE AND DISEASE SEVERITY

T. C. Lee,¹ K. Biederman,¹ T. Holmes,² D. Bloch,² B. Mellins,¹ C. Sandborg.¹

¹Pediatric Rheumatology, Stanford University, Stanford, CA; ²Health Research Policy Division of Epidemiology, Stanford University, Stanford, CA

Growth delay in children with SOJRA is significant; however, the relative contributions of disease severity versus medication use are not well understood. METHODS: Medical records of children with SOJRA were reviewed. Z scores were calculated and compared against standardized reference values for the US. Changes in Z scores (delta Z) were calculated up to 12 mo after diagnosis. Disease severity was graded on clinical symptoms and laboratory results. Arthritis activity was graded on number of joints swollen or limited and painful. RESULTS: 54 patients were evaluated, with a mean Z score at diagnosis of -0.05 +/-1.1, at 6 mo of -0.37 +/-1.13, and at 12 mo of -0.73 +/-1.12. Patients with moderate and severe systemic symptoms during the first 6 mo grew less (p0.01) compared to patients with mild disease. The median delta Z for patients with mild systemic disease was -0.16 +/-0.32; for moderate,-0.31 +/-0.36; and for severe, -0.58+/-0.51 (p0.01). Patients with severe arthritis activity was also associated with poor growth (p0.01). Increasing corticosteroid (CS) dosage correlated with worsening delta Z. Patients on CS or methotrexate (MTX) in the first 6 mo had significantly worse delta Z scores at 6 and 12 mo compared to patients not on these medications. 25 patients were studied in detail. With CS taper to 0.2 mg/kg/day, only patients with improvement of their systemic symptoms to either no or mild activity showed increased growth (3/25). CONCLUSIONS: Most patients with SOJRA grew more slowly than expected during the first 12 mo. Systemic symptom severity, increasing CS dosage, MTX usage, and severe arthritis (20 joints) were significantly associated with slower growth. Even with no or low dose CS, patients with mild to moderate disease severity were still unable to grow normally. Growth delay in SOJRA in the first year of disease is dependent on disease activity as well as CS use. However, tapering CS to low doses does not result in improved growth unless disease activity is well controlled.