1. Gastroenterology and Hepatology Unit, Division of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Songkhla 90110, Thailand
2. Department of Internal Medicine, Phaholponpayuhasena Hospital, Kanchanaburi 71000, Thailand
3. Department of Pathology, Faculty of Medicine, Prince of Songkla University, Songkhla 90110, Thailand
4. Department of Medicine, Panyananthaphikkhu Chonprathan Medical Center, Srinakharinwirot University, Nonthaburi 11120, Thailand