Abstract: Objective： To investigate the difference of CD15S antigen expression on peripheral lymphocytes and its clinical significance in patients before and after acute rejection and of those with a stable graft function after renal transplantation. Methods： Flow cytometry was used to detect the expression of CD15S antigen on peripheral lymphocytes in 70 patients( 95 specimens). These subjects were divided into 3 groups: patients with a stable graft function (group 1), patients with acute rejection (group 2) and patients recovered after an anti-rejection therapy (group 3). There were respectively 45, 25 and 25 subjects in each group. The percent of CD15S positive lymphocytes of each subject was detected. CD15S expression of every group was compared with a Student t test. Result： The data of group 2 were significantly higher than those of the other 2 groups, and there were no significant differences between group 1 and 3. Conclusions： CD15S expression of group 3 is equal to that of group 1. Monitoring of CD15S antigen expression on peripheral lymphocytes after renal transplantation may contribute to the diagnosis of acute rejection and may predict the effect of an anti-rejection therapy.

Key words: Renal transplantation, Flow cytometry, Cell adhesion molecules, Rejection