The Pediatric Translational Research Branch is focused on understanding the etiology and pathogenesis of early onset arthritis, including axial disease in juvenile spondyloarthritis. Patients are studied under a natural history protocol (#11-AR-0223; Studies on the Natural History and Pathogenesis of Spondyloarthritis) to find better clinical, laboratory, and imaging modalities to define axial involvement and disease outcome. We are particularly interested in genetic contributions to early onset axial disease. The laboratory also utilizes animal models to understand the role of risk genes and how they interact, and dissect molecular mechanisms that drive arthritis and spondyloarthritis pathogenesis. Current studies are focused on defining novel effects of ERAP1 on HLA-B27, the role of endoplasmic reticulum quality control pathways in HLA-B27 misfolding, and how misfolding impacts immune function. We also have studies addressing the role of gut microbiota in experimental spondyloarthritis.