Macrophage activation syndrome in juvenile systemic lupus erythematosus: an under-recognized complication?

Macrophage activation syndrome (MAS) is a life-threatening complication of rheumatic diseases that is thought to be caused by the activation and uncontrolled proliferation of T lymphocytes and macrophages, leading to widespread haemophagocytosis and cytokine overproduction. It is seen most commonly in systemic juvenile idiopathic arthritis, but is increasingly recognized also in juvenile systemic lupus erythematosus (J-SLE). Recognition of MAS in patients with J-SLE is often challenging because it may mimic the clinical features of the underlying disease or be confused with an infectious complication. This review summarizes the characteristics of patients with J-SLE-associated MAS reported in the literature or seen by the authors and analyses the distinctive clinical, diagnostic and therapeutic issues that the occurrence of MAS may raise in patients with J-SLE.

Design and validation of a new scale to assess the functional ability in children with juvenile idiopathic arthritis (JIA).

OBJECTIVE: The assessment of the functional ability is one of the items of the core set to define improvements in patients with JIA, CHAQ being the most used scale already validated in 32 countries. The aim of this study was to design and validate a new scale named CAPFUN (capacidad funcional = functional ability) to assess functional ability in children with JIA. METHODS: This scale includes 20 items, 8 of upper limbs, 8 of lower limbs, 3 combined, and 1 of cervical spine, developed in two steps according with OMERACT. Each item is scored: 0 when it is impossible to be performed, 1 when it is performed incompletely or with difficulties, and 2 when it is well performed. Seventy three patients with JIA according to ILAR criteria were assessed: 25 boys (34.2%) and 48 girls (65.8%) whose aver-age age was 12.8 years (95% CI 11.8 - 13.8) and the time from disease onset was 5.02 years (95% CI 3.9 - 6.1). For validation purposes, it was applied to 91 healthy children and adolescents. In every patient, correlation with active joints count and functional class according to Steinbrocker was assessed and with CHAQ in 31 patients in this series. RESULTS: The CAPFUN index obtained in all healthy children was 2. Patients' media CAPFUN index was 1.54 (95%CI 1.38 - 1.68). The CAPFUN index for Steinbrocker's class I was 1.84 +/- 1.8; for class II 1.60 +/- 1.5 and for class III 0.91 +/- 1 (F 24.1 p < 0.001). CAPFUN showed significant correlation with CHAQ (Spearman coefficient -0.79 p < 0.001), with active joints count (Spearman coefficient -0.72 p < 0.001) and with Steinbrocker functional classes (Spearman coefficient -0.69 p < 0.001). This scale showed a good internal reliability (alpha coefficient equal to 0.94), its construct validity is demonstrated by its good correlation with Steinbrocker's scale and with CHAQ. CONCLUSION: CAPFUN is a new instrument in order to assess functional ability in children with JIA. This scale showed a good internal reliability. Construct validity is demonstrated by its high correlation with Steinbrocker's scale and with CHAQ. This study demonstrates the usefulness of CAPFUN for the assessment of functional ability in children with JIA.