[1] Foothills Med Ctr, Dept Med, Div Hematol, Calgary, AB T2N 2T9, Canada
[2] Univ Calgary, Div Gastroenterol, Calgary, AB, Canada
[3] Univ Calgary, Dept Med, Calgary, AB, Canada
[4] Univ Calgary, Dept Biol Sci, Calgary, AB, Canada
[5] Univ Alberta, Dept Med, Edmonton, AB, Canada