Prophylaxis and treatment of cytomegalovirus infection after solid organ transplantation

Cytomegalovirus (CMV) infection occurs in the majority of patients following solid organ transplantation. The mainstay of treatment for symptomatic CMV infection in this patient population is intravenous ganciclovir and, to a lesser extent, foscarnet. Methods of preventing CMV infection include: (i) protective matching; (ii) use of CMV-seronegative, filtered or leucocyte-poor blood products; (iii) active immunisation with a vaccine; (iv) passive immunisation with immunoglobulins; (v) prophylaxis with antiviral agents such as interferons, aciclovir (acyclovir), ganciclovir or foscarnet; and (vi) pre-emptive therapy. Protective matching is not feasible due to the scarcity of donor organs. CMV-seronegative, filtered or leucocyte-poor blood products should be used, at least in seronegative recipients. A live attenuated CMV vaccine has been shown to be of limited efficacy in preventing CMV disease in renal transplantation recipients; however, a subunit vaccine is in development. Prophylaxis with immunoglobulins has been shown to be effective in some solid organ transplantation populations; however, the cost of such an approach is considerable. Of the antiviral agents, intravenous ganciclovir is the only agent that has been shown to have some degree of prophylactic efficacy in the majority of solid organ transplantation recipients. However, the cost and need for intravenous access make intravenous ganciclovir a suboptimal prophylactic agent. Several newer drugs, including oral agents, are currently being studied in this mode. Pre-emptive therapy, based either on the early detection of CMV or the targeting of patients with risk factors for CMV, appears to be a promising new approach.