CMV Prophylaxis, preemption or “wait and watch”

Wadhawan et al advocate a “wait and watch” strategy for management of CMV infection in liver transplant recipients[1]. Before the proposed strategy can be widely accepted as a new standard for CMV seropositive recipients, its efficacy relative to more established prevention strategies needs to be proven. Their data indicates that CMV disease developed in the majority of patients (6/10) that had asymptomatic CMV viremia > 500 copies/mL. It is likely that CMV disease in those patients would have been prevented with a prophylaxis or preemptive strategy. Given the substantial morbidities, including prolonged hospitalizations and even irreversible organ damage that can occur with symptomatic CMV disease, we have an obligation to do our utmost to prevent this from happening. Neither CMV prophylaxis nor preemptive therapies are completely satisfactory, but both strategies are clearly advantageous over doing nothing [2]. More insidious are the indirect effects induced by CMV including allograft injury, vascular thrombosis, accelerated HCV infection, opportunistic infections and EBV associated post transplant lymphoproliferative disorder[3, 4]. Unfortunately, adequate data regarding rates of such non-lethal complications were not reported in this paper.

Until proven otherwise, the standard for CMV disease prevention in seropositive recipients should continue to be either prophylaxis or preemptive therapy, rather than “wait and watch”. This may be especially so for patients with CMV viremia that exceeds 500 copies/mL.