1. Department of Internal Medicine, Gachon University Gil Hospital, Gachon University of Medicine and Science Graduate School of Medicine, Incheon, Korea.
2. Department of Internal Medicine, Chonbuk National University Hospital, Chonbuk National University Medical School, Jeonju, Korea.
3. Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
4. Department of Internal Medicine, Daegu Catholic University Hospital, Daegu Catholic University College of Medicine, Daegu, Korea.
5. Department of Internal Medicine, Sanggye-Paik Hospital, Inje University College of Medicine, Seoul, Korea.
6. Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
7. Department of Internal Medicine, Kyung Hee University Medical Center, Kyung Hee University College of Medicine, Seoul, Korea.
8. Department of Internal Medicine, Chungbuk National University Hospital, Chungbuk National University School of Medicine, Cheongju, Korea.
9. Department of Laboratory Medicine, Seoul Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.