Immunosuppressive Effects of Mycophenolate Mofetil and Valganciclovir in Kidney Transplant Recipients

Valganciclovir (VGCV) has recently been approved by the Food and Drug Administration (FDA) for the treatment and prevention of cytomegalovirus (CMV) retinitis in HIV patients. It is under review for the prevention of CMV disease following organ transplantation. Mycophenolate mofetil (MMF), the morpholinoethyl ester of mycophenolic acid (MPA) is currently the most widespread used immunosuppressant in kidney transplantation. These drugs exerts their effects by blocking the production of DNA primarily in lymphocytes. Recent studies have suggested that combining both MMF and GCV in vitro may have a beneficial effect on the treatment of CMV infections. However, the effect of these two drugs in combination on the effects of the immune system both in vitro and in vivo have not been studied. Preliminary studies in our lab show that a combination of these two drugs have an additive effect on the level of immunosuppression of both the growth and differentiation of progenitor bone marrow cells as well as lymphocyte proliferation. This study is designed to test patients degree of immune reactivity both on and off VGCV when used in combination with MMF. Patients will have blood drawn as several time points and an immune assay will be performed to show if VGCV when used in combination with MMF exerts immunosuppressive effects.