1. Department of Rheumatology, Sasebo City General Medical Center, Sasebo, Japan;
2. Rheumatic and Collagen Disease Center, Sasebo Chuo Hospital, Sasebo, Japan;
3. Department of Clinical Studies, Radiation Effects Research Foundation, Nagasaki, Japan;
4. Department of Hematology, Sasebo City General Medical Center, Sasebo, Japan;
5. Department of Rheumatology and Immunology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan