Optimal Prevention of Late‐Onset Cytomegalovirus (CMV) Disease and Other Sequelae of CMV Infection in Organ Transplant Recipients

To the Editor—Legendre et al. [1] address an important and topical issue—namely, late-onset cytomegalovirus (CMV) disease in transplant recipients who receive antiviral prophylaxis. A number of points in their report, however, warrant clarification or closer scrutiny. The authors assuage the profound clinical relevance of late-onset CMV disease by noting that this entity—at least in renal transplant recipients—is a mild event [1]. A recent study [2] found that CMV disease developed in 29% of previously CMVnegative recipients of renal transplants from CMV-positive donors receiving long-termantiviral prophylaxis;CMVdisease comprised tissue-invasive disease in 51% of these cases and was clinically attributable to ganciclovir-resistant virus in 16%. Tissue-invasive CMV disease was independently associated with allograft loss and mortality [2]. Late-onsetCMVdisease was also independently predictive of mortality in the first year after liver transplantation [3]. Thus, late-onset CMV disease cannot be considered a benign occurrence. The lynchpin of the authors' viewpoint is that extending the duration of antiviral prophylaxis will improve outcomes in transplant recipients [1]. Supportive data are cited that indicate a 7% prevalence of CMV disease among renal transplant recipients who received antiviral prophylaxis for 24 weeks, compared with a 31% prevalence of CMV disease among those who received a 12-week course [4]. It should, however, be noted that the 7% incidence of CMV disease in the former group is still high, compared with the rates of 2%–6% that are attainable with preemptive therapy in the current era [5, 6].