[Prevention and treatment of cytomegalovirus infections after graft of allogenic bone marrow]

Abstract

Cytomegalovirus (CMV) infection is the most frequent cause of lethal infection after bone marrow transplantation. Viremia occurs in 50% of patients seropositive for CMV before transplantation. Interstitial pneumonitis due to CMV occurs in 10% to 20% of patients with 85% mortality. It is known that CMV infection is due to host reactivation of latent CMV infection or to the transmission of the virus by the marrow donor or by blood transfusions. Treatment of CMV infection has been disappointing in the past. All attempts to treat CMV pneumonia with available agents have failed. Recent studies have indicated the usefulness of prophylactic measures and the early treatment of CMV infections. The use of hyperimmune gammaglobulins has given contradictory results. The selection of seronegative marrow donors or blood donors is useful only if the recipient is seronegative. New antiviral drugs have been used recently in preliminary clinical trials. In preliminary studies a guanosine analogue similar to Acyclovir (DHPG Synthex or BWB 759 U Wellcome) has given reasonable hope of disease cure if it is used early before the occurrence of pneumonia. Phosphonoformate (Foscarnet) has also been shown to be active against CMV infection. Both drugs have good antiviral and clinical action in immunosuppressed patients but the results have been disappointing in cases of pneumonia. Relapse occurs frequently after cessation of the treatment and attempts are being made to use maintenance therapy.