1. Department of Immunology and Rheumatology, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences , Nagasaki, Japan
2. Kyushu Multicenter Rheumatoid Arthritis Ultrasound Prospective Observational Cohort Study Group , Kyushu, Japan
3. Center for Collaborative Medical Education and Development, Nagasaki University Institute of Biomedical Sciences , Nagasaki, Japan