[1] Hosp Clin Barcelona, Dept Gastroenterol, Barcelona 08036, Spain
[2] Pontificia Univ Catolica Chile, Dept Gastroenterol, Santiago, Chile
[3] Hosp Clin Barcelona, Dept Immunol, Barcelona, Spain
[4] Hosp Clin Barcelona, Dept Haemotherapy & Haemostasias, Barcelona, Spain
[5] Hosp Clin Barcelona, Dept Surg, Barcelona, Spain