Randomized Clinical Trial, Open, Multicenter Parallel, no Suspension Inferiority Prophylactic Treatment With Valganciclovir in Kidney Transplant CMV-seropositive Cellular Immunity to Develop CD8 + CMV-specific Treatment After Induction Thymoglobulin.

Primary endpoint: incidence of CMV disease at 12 months after transplantation. Study the predictive value of the assay of CD8 + T cell immunity specific for defined CMV-patients in which they can stop prophylaxis. The definition of CMV disease was based on those recommended by the American Society of Trasnplantation for use in clinical trials (Humar A. Am J Transplant 2006; 6:262-74) criteria.

Secondary end points: percentage of patients developing T cell immunity in CMV-specific transplantation after receiving timoglubulina induction and valganciclovir prophylaxis. T cell development inmnunidad CD8 + CMV-specific is defined as production of γ\> 0.2 interferon by CD8 + T cells stimulated by CMV-specific CMV antigens (QF reagent).