We evaluated whether the regulatory function of CD4+CD25high+FoxP3+T-cells from patients on tacrolimus and mycophenolate mofetil (MMF) is affected by preceding steroid and anti-CD25 mAb induction therapy and whether this function is associated with rejection after kidney transplantation. Kidney recipients (N = 15) were randomized to receive either anti-CD25 mAb induction (i.e., daclizumab) or steroids for 4 months. We analyzed the presence and suppressive activity of CD4+CD25high+FoxP3+peripheral T-cells in samples obtained at pre and 4-6 months after transplantation. Anti-CD25 mAb therapy and treatment with steroids did not significantly affect protein expression of FoxP3. However, at the functional level, significant differences were found in the regulatory activities of CD4+CD25high+T-cells from the anti-CD25 group vs those from the steroid group. At 4-6 months after transplantation, the regulatory activities of CD4+CD25high+T-cells were comparable to those before anti-CD25 mAb therapy; 49 ± 13% (mean ± SEM) vs 40 ± 14% at a 1:20 ratio (CD25high+:CD25-/dim), respectively. In contrast, the regulatory capacities of CD+D25bright+T-cells from the steroid patient group became significantly impaired. The percentage inhibition of the anti-donor response decreased from 57 ± 12% before transplantation to 12 ± 7% after transplantation (p < 0.01). Five out of 15 patients experienced a rejection episode. At 4-6 months after transplantation, the CD25high+cells from these rejectors (who all received daclizumab induction therapy) had clear regulatory function, while suppression by CD25high+cells from non-rejectors (N = 10) was significantly lower. The percentage inhibition of the anti-donor response was 48 ± 14% (mean ± SEM) vs 10 ± 7%, respectively, p = 0.02. Anti-CD25 mAb induction therapy does not negatively influence the regulatory function of CD4+CD25high+FoxP3+T-cells from kidney transplant recipients on tacrolimus and MMF. The majority of these patients experienced an acute rejection episode, which suggests that immune activation is required for persistent immunoregulatory function.

Additional Metadata
Keywords +, Anti-CD25 Ab induction therapy, CD25, CD4, Kidney transplantation, Patients, Rejectors, Steroids, high+, regulatory T-cell
Persistent URL dx.doi.org/10.1016/j.trim.2009.04.003, hdl.handle.net/1765/24513
Citation
Hendrikx, T.K, Klepper, M, IJzermans, J.N.M, Weimar, W, & Baan, C.C. (2009). Clinical rejection and persistent immune regulation in kidney transplant patients. Transplant Immunology, 21(3), 129–135. doi:10.1016/j.trim.2009.04.003