Cytomegalovirus Infection in Bone Marrow Transplantation

Abstract

Cytomegalovirus (CMV) infection occurs in approximately 50% of all marrow transplant recipients, but is more common in CMV-seropositive patients than CMV-seronegative patients. Sources of infection include reactivation of latent endogenous virus, blood products from CMV-seropositive blood donors, and bone marrow from a CMV-seropositive donor. The most common and severe clinical syndrome associated with CMV infection is interstitial pneumonia, which occurs in about 15% of all allotransplants but is less frequent in syngeneic and autologous transplants. Risk factors for CMV pneumonia include CMV-seropositivity before transplant, older age, conditioning with total-body irradiation, and severe graft-versus-host disease (GVHD). The rapid diagnosis of CMV pneumonia has been facilitated by using CMV monoclonal antibodies in either immunochemical stains or centrifugation cell cultures of bronchoalveolar lavage fluid. Treatment of CMV pneumonia remains problematic, but therapy with a combination of intravenous immune globulin (IVIG) plus ganciclovir has resulted in the best survival rates. In CMV-seronegative patients, CMV infection and pneumonia can be prevented or modified by the use of CMV-seronegative blood products and IVIG. IVIG also reduces other infections and GVHD. For CMV-seropositive patients, effective prophylaxis for CMV reactivation and pneumonia has not yet been established, but trials of prophylactic ganciclovir are being conducted.