Validity and predictive ability of the juvenile arthritis disease activity score based on CRP versus ESR in a Nordic population-based setting.

OBJECTIVE: To compare the juvenile arthritis disease activity score (JADAS) based on C reactive protein (CRP) (JADAS-CRP) with JADAS based on erythrocyte sedimentation rate (ESR) (JADAS-ESR) and to validate JADAS in a population-based setting. METHODS: The CRP and ESR values and the corresponding JADAS scores (JADAS10/27/71) were compared in a longitudinal cohort study of 389 children newly diagnosed with juvenile idiopathic arthritis (JIA) in the Nordic JIA study. The construct validity and the discriminative and predictive ability of JADAS were assessed during a median disease course of 8 years by comparing JADAS with other measures of disease activity and outcome. RESULTS: At the first study visit the correlation between JADAS27-CRP and JADAS27-ESR was r=0.99 whereas the correlation between CRP and ESR was r=0.57. Children with higher JADAS scores had an increased risk of concomitant pain, physical disability and use of disease-modifying antirheumatic drugs (DMARDs). A higher JADAS score at the first study visit also significantly predicted physical disability, damage and no remission off medication at the final study visit, and also use of DMARDs during the disease course. Sensitivity to change, demonstrated as change in JADAS score compared with the American College of Rheumatology paediatric measures of improvement criteria, mostly showed excellent classification ability. CONCLUSION: The JADAS-CRP and JADAS-ESR correlate closely, show similar test characteristics and are feasible and valid tools for assessing disease activity in JIA.

Chorea in juvenile primary antiphospholipid syndrome. Reversible decreased circulation in the basal ganglia visualised by single photon emission computed tomography.

Chorea was observed in a 12-year-old girl with primary antiphospholipid syndrome (APS). She developed severe chorea in a few weeks. On immunosuppressive treatment, including high doses of glucocorticoids and cyclophosphamide, she had a rapid clinical recovery. Single photon emission computed tomography (SPECT) of the brain showed decreased circulation in the basal ganglia and in the medial parts of both temporal lobes. One month after treatment, SPECT was completely normalised. APS in children has a variety of clinical manifestations, and should be suspected in cases of unexplained thromboembolic disease or obscure neurological symptoms.