Childhood-onset lupus (cSLE) affects a quarter million people worldwide. Lupus registries, which contain patient information and samples, are a powerful way of studying how lupus affects children, predict disease severity, and identify the most effective treatment strategies. CARRA has a North American registry, the UK has a national registry, and nine other European countries use a third cSLE registry, each of which has a slightly different approach to collecting patient reported outcomes, clinical data, and blood/urine samples. The goal of this proposal is to see where the registries are aligned and where they can be better aligned to facilitate research across all three registries. Such research will be much more powerful than research in any single registry. In addition, this project will bring together international lupus researchers and patients/parents from Europe and North America to lay a strong foundation for cSLE research projects worldwide.