Cellular immunity and herpesvirus infections in cardiac transplant patients

We observed severe infections with herpes simplex virus in cardiac-transplant patients despite their high serum antibody levels to this virus. Therefore, we sought to correlate clinical susceptibility to 2 herpes virus (simplex and zoster) infections with specific cellular immunity, assessed by the transformation and interferon responses of peripheral blood mononuclear cells to heat-inactivated antigens. Transformation and interferon response to herpes simplex virus was maximally depressed immediately after transplantation, the time when severe and prolonged infection with herpes simplex virus occurred. 6 months to 6 years after transplantation, both clinical susceptibility and cellular immunity to herpes simplex virus were normal. Herpes zoster virus infections were more frequent than normal at all times after cardiac transplantation; depressed or absent cellular responses to the varicella zoster virus paralleled that susceptibility. In these patients the risk of severe herpes virus infections correlated with depressed cellular immune responses to the specific viral agent involved.