Is Prevention the Best Treatment? CMV After Lung Transplantation

Cytomegalovirus (CMV) is the most prevalent opportunistic infection that occurs in lung-transplant recipients. In addition to its direct morbidity, multiple studies have demonstrated that CMV, in particular CMV pneumonia, is associated with an increased risk for chronic graft dysfunction manifested as bronchiolitis obliterans syndrome (BOS) and worse posttransplant survival. Therefore, prevention of CMV remains an important goal to improve long-term lung-transplant outcomes. Although centers often employed 3 months of prophylaxis in at-risk patients after lung transplantation, a significant proportion of patients still developed infection or disease after the discontinuation of prophylaxis, highlighting the need for more effective approaches to CMV prevention. A number of early single-center reports suggested benefit to extending prophylaxis to longer durations, but concerns regarding cost, late-onset CMV disease, viral resistance and bone marrow toxicity limited enthusiasm for longer durations. However, several recent studies including a multicenter, prospective, randomized, double-blinded clinical trial have demonstrated significant benefits to extending CMV prophylaxis beyond 3 months. Although some areas of controversy remain, the clinical implications of these recent studies suggest that extending prophylaxis with valganciclovir up to 12 months is clearly beneficial for CMV prevention after lung transplantation.