PROJECT SUMMARY Systemic Lupus Erythematosus is a systemic autoimmune condition which is life long and can be life threatening. Up to 15-20% of all SLE patients are diagnosed in childhood (<18 years of age). Although it is estimated that up to 10,000 children in the United States have pediatric-onset SLE (pSLE), the natural history, treatment and outcomes for this vulnerable population of children have not been well defined. We propose to use the well-established Childhood Arthritis and Rheumatology Research Alliance (CARRA) pSLE registry, which currently includes 870 patients followed longitudinally for up to ten years (goal of enrolling 1300-1400 participants), in order to thoroughly assess the biologic/disease related factors, as well as the non- biologic factors, which can impact short and long-term pSLE outcomes. This proposal will address critical gaps in pSLE knowledge including description of treatments for lupus nephritis and the prevalence and outcomes of neuropsychiatric pSLE, the two primary causes of pSLE short and long-term morbidity. In addition, we will describe important patient reported outcomes including pain, quality of life and disability, and long-term outcomes, including transition to adulthood. Research findings will be disseminated through patient/family partnerships with a goal of developing future interventions to improve the health and well- being of patients with pSLE.