1. Department of Pharmacy, Beijing Friendship Hospital, Capital Medical University, Beijing, China
2. Harvard Celiac Disease Research Program, Division of Gastroenterology, Hepatology & Nutrition, Boston Children’s Hospital, Boston, MA, USA
3. Department of Medicine, Duke University School of Medicine, Durham, NC, USA
4. Department of Epidemiology, University of North Carolina Gillings School of Global Public Health, Chapel Hill, NC, USA
5. Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China
6. Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, 2101 McGavran-Greenberg Hall, Campus Box 7453, 27599 Chapel Hill, NC 27515, USA