1. From the Department of Pediatrics, Division of Rheumatology (JMB), Nephrology (BJF and MBL), Gastroenterology and Nutrition (ES, BSZ, and VAS), The Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA, and the Department of Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia, PA (JMB, JS, BJF, and MBL)