Lupus is a chronic disease that is more severe and debilitating in children, with over half of lupus patients diagnosed with lupus nephritis. Proteins and cells in patient blood do not function properly and can interact with each other to cause inflammation. We propose to look at these proteins and cells to understand how inflammation develops in lupus nephritis. I will collect blood and kidney biopsy samples from children with untreated lupus nephritis and children without lupus. Kidney samples will be stained with markers that label cells and proteins, to visualize their locations and function. I will determine differences in the proteins and cells from kidneys and blood of children with and without lupus nephritis, to identify mechanisms that drive lupus nephritis. Our hope is that by understanding the cause of inflammation in lupus, we can create new medicines for treatment.