1 Department of Rheumatology, Beijing Children's Hospital, Capital Medical University, National Centre for Children's Health, No. 56 Nan Li Shi Lu, Beijing, 100045, China.
2 Department of Rheumatology, Beijing Children's Hospital, Capital Medical University, National Centre for Children's Health, No. 56 Nan Li Shi Lu, Beijing, 100045, China. licaifeng@bch.com.cn.
3 Department of Rheumatology and Immunology, Clinical Immunology Center, Peking University People's Hospital, No. 11 Xizhimen South Street, Beijing, 100044, China.