[Risk factors for cytomegalovirus in solid organ transplant recipients]

Cytomegalovirus (CMV) is the most important opportunistic pathogen in patients undergoing solid organ transplantation and increases mortality due to both direct and indirect effects. The most important risk factor for the development of CMV disease is discordant donor-recipient CMV serology (positive donor and negative recipient), which confers more than 50% risk of developing CMV disease if no prophylaxis is given. The use of highly potent antiviral agents for CMV prophylaxis in high-risk patients has changed the characteristics of CMV disease in this population. Other classical risk factors for CMV disease include acute graft rejection, the type of organ transplanted, coinfection with other herpesviruses and the type of immunosuppressive agents employed. New risk factors for this complication have recently been described, including variations in the CMV genotype between donor and recipient and genetic alterations in the recipient's innate immunity. The present review discusses classical risk factors and the latest findings reported on the development of CMV in organ transplant recipients.