CMV infection, diagnosis and antiviral strategies after liver transplantation.

Cytomegalovirus (CMV) is a significant pathogen complicating the post-transplant course of organ recipients. In liver transplant patients, the febrile clinical illness caused by CMV may be associated with end-organ disease, such as hepatitis or infection of the gastrointestinal tract. In addition to direct effects, CMV may have indirect effects including the risk of other infections or graft rejection. Recently, major advances in the management of CMV infection have been achieved through the development of new diagnostic techniques and antiviral strategies to prevent CMV disease. Quantitative nucleic acid testing to monitor viral load is now commonly used to diagnose and guide the treatment of CMV infections. The standardization of the testing, however, needs to be improved. There are two main strategies to prevent CMV disease after liver transplantation: prophylaxis and pre-emptive therapy. Both strategies are effective, but also have disadvantages. The disadvantages of prophylaxis include prolonged drug exposure, the development of resistance and, most of all, the development of delayed and late-onset CMV disease. On the other hand, the pre-emptive strategy is based on frequent laboratory monitoring of viral loads, and some patients may develop symptomatic infection before the diagnosis of CMV. This overview summarizes the current status of CMV in liver transplantation.