[1] Istanbul Univ, Cerrahpasa Med Fac, Dept Gastroenterol, TR-34098 Istanbul, Turkey
[2] Univ Pittsburgh, Med Ctr, Dept Human Researches, Pittsburgh, PA USA
[3] Istanbul Univ, Cerrahpasa Med Fac, Dept Infect Dis, TR-34098 Istanbul, Turkey
[4] Istanbul Educ & Training Hosp, Dept Internal Med, Istanbul, Turkey
[5] Istanbul Univ, Cerrahpasa Med Fac, Dept Pathol, TR-34098 Istanbul, Turkey