Cytomegalovirus prophylaxis in renal transplantation

Abstract

With the tremendous growth of solid organ transplantation over the past 30 years, a great deal has been learned about the significance of cytomegalovirus. Much knowledge regarding the epidemiology, pathogenesis, and diagnosis of cytomegalovirus infection has come from experience with renal transplants, which account for the largest number of solid organ transplantation procedures performed. Cytomegalovirus disease is clearly one of the most important infectious causes of morbidity and mortality in this population. The devastating effects of established cytomegalovirus disease have been ameliorated by effective antiviral treatment with ganciclovir therapy. The continued high incidence of cytomegalovirus infection, combined with the cost of treating cytomegalovirus disease, both in terms of patient well-being and financial issues, has stimulated great interest in the development of effective prophylactic and preemptive regimens. Philosophy regarding the best means of prevention varies. Prophylactic strategies provide therapy for all patients who are designated to be at risk for cytomegalovirus disease. These patients are usually stratified according to cytomegalovirus serologic status. Preemptive strategies provide preventative therapy selectively. Preemptive therapy is administered only when there is evidence for asymptomatic infection by established surveillance criteria (ie, positive cytomegalovirus cultures, positive antigenemia assays, or recent seroconversion). Unfortunately, the terms prophylaxis and preemptive are used loosely, which can lead to confusion when reviewing the literature. This overview focuses on pertinent issues regarding cytomegalovirus in renal transplantation and the various strategies for prophylaxis and preemptive therapy. The approach to cytomegalovirus prophylaxis among renal transplant centers varies widely. Often a specific approach within a given center is inconsistent, poorly documented, and based on anecdotal experience. Although the literature is replete with studies using single-agent or combination therapy, they are usually single-center studies of a relatively small number of patients. Large randomized prospective studies are unfortunately few in number. Hopefully, after reviewing the available data, it will be possible to propose an ideal strategy that is both cost-effective and maximally therapeutic.