1. Department of Clinical Laboratory, The Second Hospital of Tianjin Medical University, Tianjin 300211, P.R. China
2. Department of Rheumatology, Featured Medical Center of Chinese People's Armed Police Force, Tianjin 300072, P.R. China
3. Department of Clinical Laboratory, Hebei Yanda Hospital, Langfang, Hebei 065201, P.R. China