1. Gastroenterology Service, Department of Medicine; Walter Reed National Military Medical Center; Bethesda Maryland
2. Pediatric Gastroenterology, Hepatology & Nutrition Division; University of Texas Southwestern Medical Center; Dallas Texas
3. Division of Gastroenterology and Hepatology; Centre Hospitalier Universitaire; Vaudois/CHUV Lausanne Switzerland
4. Department of Laboratory Medicine; St. Michael's Hospital; Hamilton Ontario Canada
5. Department of Pathology; University of Iowa Hospitals and Clinics, University of Iowa Carver College of Medicine; Iowa City Iowa
6. Institute of Pathology; University of Bern; Bern Switzerland
7. Ontario Dynacare Laboratories; Ontario Canada
8. Department of Pathology and Laboratory Medicine; Cedars-Sinai Medical Center; Los Angeles California
9. Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, and Department of Pathophysiology and Transplantation; Università degli Studi; Milan Italy
10. Institute of Social and Preventive Medicine; University of Bern; Bern Switzerland
11. Department of Pediatrics and Medicine, Mount Sinai Center for Eosinophilic Disorders; Icahn School of Medicine at Mount Sinai; New York New York