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.