Performance of the new SLICC classification criteria in childhood systemic lupus erythematosus: a multicentre study.

OBJECTIVES: The Systemic Lupus International Collaborating Clinics (SLICC) group has recently proposed a new set of criteria for the classification of systemic lupus erythematosus (SLE). We aimed to compare the sensitivity and specificity of the new SLICC criteria with those of the American College of Rheumatology (ACR) criteria in our childhood-onset SLE patients. METHODS: Three main paediatric lupus centres from Europe participated in this study. Of these centres, one was predominantly a paediatric nephrology centre (Great Ormond Street Hospital, London, UK), one was predominantly a paediatric rheumatology centre (Istituto Giannina Gaslini, Genoa, Italy), and one was a combined centre taking care of both group of patients (Hacettepe University, Ankara, Turkey). The features present at disease onset in patients with childhood-onset SLE, younger than 18 years of age, seen between January 2000 and December 2012 were retrospectively reviewed. For the evaluation of specificity, patients admitted to each centre between May and December 2012 for conditions other than SLE, in whom ANA was deemed necessary within the diagnostic work-up were included as controls. PASW 18.0 for Windows was used for statistical analyses. RESULTS: Both sets of classification criteria were analysed in 154 childhood SLE patients with a mean age at disease onset of 12.7 years and in 123 controls with a mean age of 8.9 years. The sensitivity and specificity of the ACR criteria were 76.6% and 93.4%, respectively, whereas those of the SLICC criteria were 98.7% and 85.3%, respectively. Four patients out of 5 with haemolytic uraemic syndrome (HUS) and 4 patients out of 8 with juvenile dermatomyositis (JDM) met four of the SLICC criteria, whereas 22 lupus nephritis patients failed to meet four of the ACR criteria. CONCLUSIONS: In our paediatric series, the SLICC criteria showed better sensitivity (p<0.001) and led to fewer misclassifications, but were less specific (p<0.001) than the ACR criteria.