1. Department of Rheumatology and Clinical Immunology, The First Hospital of Xiamen University, Xiamen 361003, China
2. Department of Biological Sciences, University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968, USA
3. Microbiology, College of Medicine University of Nebraska Medical Center, Omaha, NE 68198-7660, USA
4. Department of Rheumatology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China