Management of cytomegalovirus infection after hematopoietic stem cell transplantation

In a highly immunodeficient state following allogeneic hematopoietic stem cell transplantation (HSCT), the reactivation of cytomegalovirus (CMV) is occasionally uncontrollable, which leads to various clinical symptoms, such as pneumonia, enteritis, and hepatitis and finally to lethal outcomes. Although preemptive anti-CMV therapy based on monitoring of CMV infection by quantitative polymerase chain reaction and CMV antigenemia assays has reduced lethal CMV disease, CMV infection is associated with increased non-relapse mortality and reduced survival. A new antiviral drug, letermovir, which exhibited high tolerability and preventive effect on CMV infection, was approved as a prophylactic agent for CMV infection. In the future, it is expected that survival after allogeneic HSCT will be improved by preventing CMV infection. However, further investigations are warranted to solve problems, such as the establishment of the appropriate prophylaxis for CMV infection and the management of late-onset and drug-resistant CMV infection.