Diagnostic and predictive value of an immune monitoring program for complications after kidney transplantation

We have tested an immune monitoring program consisting of cytofluorometric analysis of lymphocytic and monocytic markers, using a set of different monoclonal antibodies (mAb), in about 500 transplant patients including about 300 long-term renal allograft recipients. The high sensitivity (95%) of these cytofluorometric analyses in the peripheral blood allows to discriminate between acute rejection and other causes of deteriorated kidney transplant function (infection, toxicity, arteriopathy), especially in the late phase (> 1 year) after transplantation. Additionally, the immune monitoring is sufficient to predict success of antirejection therapy as early as a few days after onset of treatment. A life-threatening complication in allograft recipients is septic disease. Proceeding from immune parameters, septic patients were found to fall into two categories: those with decreased expression of HLA-DR on monocytes (< 20%, termed as 'immunoparalysis') and patients with nearly normal HLA-DR+ monocytes. Septic immunoparalysis requires drastic reduction of immunosuppression (mortality after drastic reduction: 8%; after marginal reduction or without reduction: 90%). We have not observed severe rejection as a consequence of reduced immunosuppression in such patients. Our immune monitoring seems to be useful for management of immunosuppression in patients with unclear deterioration in graft function as well as patients with septic complications in order to minimize two risks, i.e. death by sepsis or loss of graft.