1 Department of Rheumatology, Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.
2 Department of Rheumatology and Immunology, The First Affiliated Hospital and College of Clinical Medicine, Henan University of Science and Technology, Luoyang, Henan 471003, China.
3 Division of Arthritis and Rheumatic Diseases, Oregon Health & Science University and VA Portland Health Care System, Portland, Oregon, United States.