Calculated withdrawal of low-dose immunosuppression based on a detailed immunological monitoring after kidney transplantation between monocygotic twins.

Background: Pretransplant screening in living donor kidney transplantation includes human leukocyte antigen matching, and panel reactive antibody analysis, whereas T cell mediated anti-donor reactivity is not assessed routinely. We investigated T cell reactivity after living related kidney transplantation between two monocygotic twins and in consequence correlated the withdrawal of individual immunosuppressive medication with immunological findings.

Methods: Immunosuppression consisted of mycophenolate mofetil, glucocorticoid single shot, and induction therapy with antithymocyte immunoglobulin.

Results: FACS analysis of recipient peripheral blood cells revealed a normal haemogram after transplantation, showing non-activated CD4 and CD8 cells. Mixed lymphocyte reaction did not reveal donor-specific T cell activity. IFN-gamma and IL-10 ELISA of supernatants of recipient cells cocultivated with donor cells support the lack of Th1 and Th2 cell differentiation.

Conclusion: Based on immunological findings on days 5 and 20 MMF-therapy was reduced and stopped. Immunological monitoring on day 90 confirmed the absence of immune reactions directed against donor tissue.