PurposeCytomegalovirus (CMV) infection can cause severe disease and mortality in recipients of allogeneic bone marrow transplants (alloBMT) when either the donor or recipient is CMV seropositive (high-risk alloBMT). We investigated the efficacy of preemptive therapy guided by detection of CMV antigenemia.MethodsIn 11 high-risk alloBMT recipients, high-dose ganciclovir (GCV) treatment was initiated at first positive antigenemia and was continued until antigenemia became negative.ResultsThe treatment strategy prevented CMV disease during the follow-up period of the study in 7 alloBMT recipients with positive CMV antigenemia. Three other patients who were shown to be CMV antigenemia negative but positive for CMV DNA in blood by the polymerase chain reaction (PCR) were not treated and did not develop CMV disease. The eleventh patient was negative for CMV by all tests for the duration of the study and did not develop CMV disease.ConclusionsWe have found antigenemia-guided preemptive GCV therapy to be an effective strategy for the prevention of CMV disease in high-risk alloBMT recipients.