Sample collection: the fasting venous blood (2 ml) was collected in the morning and added to the ET tube. Flow cytometry was performed to detect the differentiation antigens on immune cells with BECKMANCOULTER EPICS XL-II flow cytometer. In 56 patients, the CD3 + , CD4 + , CD8 + , and CD19 were detected, and the NK cell marker CD16 + +56 + was detected in 50 patients.