[Flow cytometry and acute renal rejection confirmed by histopathologic analysis]

Transplantation of solid organs, tissues or hematopoietic cells is now standard in the treatment of patients with terminal stage disease in order to cure and improve the recipients' quality of life. The study included 54 patients having undergone single or multiple organ transplantation. All patients received a combination of immunosuppressant therapy consisting of corticosteroids, calcineurin inhibitor (cyclosporine; tacrolimus), anti-CD25 (daclizumab) and mycophenolate-mofetil. In 24 patients, acute rejection was stratified by histopathologic analysis of renal biopsy. Fifteen highly sensitized patients were administered antithymocyte globulin (ATG) therapy. Absolute count and percentage of B/T lymphocyte subsets, NK cells and CD25+ or CD69+ activated T cells were measured on a flow cytometer (EPICS XL, Coulter) using single platform standardized protocol. Upon ATG therapy, rapid decline to a very low level of T and NK cell lymphocyte count was observed, as well of B lymphocytes, resulting in redistribution of lymphocyte compartment. Between consecutive measurements, kinetic changes of lymphocyte subset numbers (absolute count or percentage) did not differ in a large spectrum of immune parameters between the groups with and without rejection episode and having received quadruple immunosuppressive induction and maintenance therapy. Immunologic monitoring must be initiated prior to transplantation and continued consistently and frequently post-transplantation. Such a program is expensive and time-consuming and stressful for the patient, therefore, prospective studies should identify whether treatment decisions can be based reliably on these immune parameters. Serial measurement of immune cell counts is necessary for maintenance of ATG therapy and could be useful for monitoring patient recovery.