Clinical utility of cytomegalovirus viral load in solid organ transplant recipients

Quantitative nucleic acid testing (QNAT) to measure viral load has become a mainstay in the management of cytomegalovirus (CMV) infection and disease in solid organ transplant recipients. In this article, we review the clinical applications of CMV QNAT in the management of solid organ transplant recipients.Because several platforms were available for CMV QNAT, there was a wide inter-assay variability in the viral load reporting, and this limited the generation of widely applicable viral load thresholds that can be used for various clinical applications. With the recent availability of international standard and certified reference materials, there is now opportunity to standardize viral load reporting, with the goal of deriving viral load thresholds for various clinical applications, such as rapid diagnosis of CMV infection and disease, predicting the risk of disease and assessing the severity of illness, monitoring efficacy of antiviral therapies and assessing the risk of viral relapse and drug resistance.Recent advances in the field such as CMV QNAT standardization, as discussed in this review, are anticipated to optimize the management of CMV infection and disease in solid organ transplant recipients.