[1] Univ Tampere, Sch Med, FIN-33014 Tampere, Finland
[2] Tampere Univ Hosp, Dept Gastroenterol & Alimentary Tract Surg, Tampere, Finland
[3] Tampere Univ Hosp, Dept Paediat, Tampere, Finland
[4] Finnish Red Cross Blood Serv, Dept Tissue Typing, Helsinki, Finland
[5] UKK Inst Hlth Promot Res, Tampere, Finland