Natural Killing of Cytomegalovirus-Infected Targets in Renal Transplant Recipients

The ability of peripheral blood mononuclear cells of renal transplant recipients to lyse cytomegalovirus (CMV) infected fibroblasts was determined in an 18-hr 51Cr release assay. Natural killing (NK) against CMV-infected targets was generally depressed for the first two years after transplantation. In three individuals who developed CMV disease after transplantation, NK activity against CMV-infected and uninfected targets rose to high levels following reductions in immunosuppressive therapy and in temporal association with resolution of disease.