Classification of systemic lupus erythematosus in children and adults

Systemic Lupus Erythematosus (SLE) is an autoimmune multisystem disease with a variable clinical phenotype and no single clinical, laboratory or pathological feature that can be used as a gold standard for disease classification or diagnosis. Classification criteria have been developed in an attempt to define homogenous groups of SLE patients for clinical research. They have been mainly validated in adult cohorts, given the much lower prevalence of SLE before puberty. The three commonly used sets of current classification criteria and their validation studies to date are described in this review. Challenges relating to classification of SLE patients, including important differences across age-groups and ethnicities, are explored along with future directions in the classification of SLE. •EULAR/ACR-2019 exhibit high sensitivity and specificity in adult-onset SLE.•Concerns about their performance in the paediatric age group may be linked to pathophysiology.•EULAR/ACR-2019 criteria allow the definition of homogenous study cohorts.•Classification criteria should not be used for diagnosis.