Clinical utility of monitoring sialyl Lewis (x) (CD15s) antigen on peripheral lymphocytes for the diagnosis and treatment of rejection after renal transplantation

Background. In organ transplantation, the grafts must be carefully monitore d, but it is often difficult to make a quick and accurate diagnosis of unus ual changes. Extensive research has failed to identify a useful marker for rejection. We investigated the clinical utility of sialyl Lewis (X) (CD15s) monitoring in 17 renal transplant patients with acute rejection. Methods. The expression of CD15s on peripheral lymphocytes was examined usi ng flow cytometry in renal transplant recipients with rejection (n=1.7), wi thout rejection (n=23), recipients infected with cytomegalovirus (n=7), rec ipients with other diseases (n=7), and healthy volunteers (n=18), CD15s exp ression was compared with histological findings, and was also examined befo re and after steroid pulse therapy to investigate the effects of steroids o n CD15s antigen expression on the surface of the peripheral lymphocytes, Results. CD15s was strongly expressed in all patients with rejection, but w as not expressed in any of the patients without rejection or in any healthy volunteers, Histologically, cell infiltration into the rejected graft was moderate or severe in all patients with strong expression of CD15s, In cont rast, no or only mild infiltration was observed in patients with weak expre ssion of CD15s, In addition, 14 of 17 patients (14/17, 82%) with strong CD1 5s expression improved upon administration of steroid pulse therapy, althou gh there was no benefit from steroids in any of the patients with weak expr ession of CD15s, Conclusions. The CD15s antigen is expressed strongly on the peripheral lymp hocytes at the time of rejection. It is interesting that the efficacy of st eroid therapy in the patients with elevated creatinine could be predicted b y CD15s expression on the peripheral lymphocytes before graft biopsy. There have been only few reports showing the relationship between CD markers and the efficacy of the treatment in patients with elevated creatinine, We rep ort that the detection of CD15s on the peripheral lymphocytes by flow cytom etry was an easy, helpful, and noninvasive means for the diagnosis and trea tment of patients with elevated creatinine after renal transplantation.