1. Department of Rheumatology, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima 960-1295, Fukushima, Japan
2. Department of Rheumatology, Jananese Red Cross Fukushima Hospital, Yashima 7-7, Fukushima 963-8558, Fukushima, Japan
3. Department of Rheumatology, Ohta-Nishinouchi Hospital, 2-5-20 Nishinouchi, Koriyama 963-8558, Fukushima, Japan