1. Department of Internal Medicine, Soonchunhyang University Hospital Cheonan, Korea.
2. Department of Internal Medicine and Pathology, Soonchunhyang University Hospital Cheonan, Korea.
3. Department of Internal Medicine, Soonchunhyang University Hospital Bucheon, Soonchunhyang University College of Medicine, Korea.
4. Department of Internal Medicine, Hospital Seoul, Soonchunhyang University College of Medicine, Korea.