Cytomegalovirus disease in solid organ transplant recipients: advances lead to new challenges and opportunities

Purpose of review Despite advances in its management, cytomegalovirus remains a significant pathogen that influences the outcome of solid organ transplantation. Herein, the current epidemiology of cytomegalovirus disease and its prevention and treatment are discussed. Recent findings Antiviral prophylaxis is preferred over preemptive therapy in preventing cytomegalovirus disease in cytomegalovirus donor seropositive/recipient seronegative (D+/R-) solid organ transplantation recipients. Antiviral prophylaxis is complicated by delayed-onset cytomegalovirus disease. Risk factors for delayed-onset cytomegalovirus disease include cytomegalovirus D+/R- status, allograft rejection, and severe immunosuppression. The potential roles of innate and adaptive immune responses in cytomegalovirus predisposition are being recognized. Delayed-onset cytomegalovirus disease is associated with allograft loss and mortality, and in some cases, the disease is due to drug-resistant virus. The optimal method for preventing delayed-onset cytomegalovirus disease is not defined. Randomized trials comparing 100 versus 200 days of valganciclovir prophylaxis, and maribavir versus ganciclovir prophylaxis are underway. A recent trial demonstrated comparable efficacy between valganciclovir and intravenous ganciclovir in treating cytomegalovirus disease in solid organ transplantation recipients. Summary The clinical impact of cytomegalovirus on the outcome of solid organ transplantation remains evident in the era of antiviral prophylaxis. The challenges of delayed disease and drug resistance provide opportunities for optimizing the current management of cytomegalovirus disease after solid organ transplantation.