1. Department of Internal Medicine, Division of Hematology, Rheumatology and Respiratory Medicine, Faculty of Medicine, Kagawa University, Miki, Kagawa 761-0793, Japan
2. Department of Laboratory Medicine, Kawasaki Medical School, Kurashiki, Okayama 701-0192, Japan
3. Department of Community Medicine, Faculty of Medicine, Kagawa University, Miki, Kagawa 761-0793, Japan
4. Department of Laboratory Medicine, Faculty of Medicine, Kagawa University, Miki, Kagawa 761-0793, Japan