1. Division of Rheumatology; Department of Medicine; University of Pennsylvania and Philadelphia Veteran Affairs Medical Center; Philadelphia; Pennsylvania; USA
2. Shanxi Medical University; The Second Hospital of Shanxi Medical University; Taiyuan; Shanxi Province; China
3. Third Affiliated Hospital of Sun Yat-sen University; Guangzhou; Guangdong Province
4. China-Japan Friendship Hospital; Beijing
5. Northern Jiangsu People's Hospital; Yangzhou; Jiangsu Province; China
6. Section of Rheumatology 2-8-29; Tokyo Metropolitan Tama Medical Center; Tokyo; Japan