1. Department of Hematology, Daqing Oilfield General Hospital, Daqing, Heilongjiang 163001, P.R. China
2. Department of Hematology, Heze Municipal Hospital, Heze, Shandong 274000, P.R. China
3. Department of Central Laboratory, Daqing Oilfield General Hospital, Daqing, Heilongjiang 163001, P.R. China