1. Celiac Disease Center; Department of Medicine; Columbia University College of Physicians and Surgeons; New York NY USA
2. Clinical Epidemiology Unit; Department of Medicine; Karolinska University Hospital and Karolinska Institutet; Stockholm Sweden
3. Division of Gastroenterology and Hepatology; Department of Medicine; Mayo Clinic College of Medicine; Rochester MN USA
4. Department of Pediatrics; Örebro University Hospital; Örebro Sweden