1 Department of Medicine, Columbia University Medical Center, New York, New York, USA.
2 Celiac Disease Center, Columbia University Medical Center, New York, New York, USA.
3 Institute of Human Nutrition, Columbia University Medical Center, New York, New York, USA.
4 Departments of Medical and Surgical Sciences and Digestive System, Centro di Ricerca Biomedica Applicata (C.R.B.A.), University of Bologna, St. Orsola-Malpighi Hospital, Bologna, Italy.
5 Bateman Horne Center, Salt Lake City, Utah, USA.