[1] Univ Pavia, Coeliac Ctr, Dept Internal Med 1, Fdn IRCCS Policlin San Matteo, I-27100 Pavia, Italy
[2] Osped Civile Voghera, Internal Med Unit, Voghera, Italy
[3] Univ Turin, Dept Gastrohepatol, AOU San Giovanni Battista Molinette, I-10126 Turin, Italy
[4] Univ Messina, Reg Ctr Celiac Dis, Messina, Italy
[5] Fdn IRCCS Policlin San Matteo, Serv Biometry & Clin Epidemiol, Pavia, Italy