1. Department of Rheumatology, Ohta-Nishinouchi Hospital, 2-5-20, Nishinouchi, Koriyama City, Fukushima 963-8558, Japan
2. Department of Hematology, Ohta-Nishinouchi Hospital, 2-5-20, Nishinouchi, Koriyama City, Fukushima 963-8558, Japan
3. Department of Rheumatology, Fukushima Medical University School of Medicine, 1, Hikarigaoka, Fukushima City, Fukushima 960-1295, Japan