Cytomegalovirus (CMV) virus load kinetics to predict recurrent disease in solid-organ transplant patients with CMV disease

Despite standard therapy, cytomegalovirus (CMV) disease recurs in a significant proportion of organ transplant recipients. The kinetics of CMV load in response to therapy may allow early prediction of recurrence. CMV loads were obtained at regular intervals after starting ganciclovir therapy in 52 transplant recipients with CMV disease. Virus load kinetics were analyzed using decay curves to assess viral dynamics, including half-life and time to viral clearance. Recurrent CMV disease occurred in 12 (23%) of 50 patients. The time period to viral clearance was longer among patients with recurrence of CMV disease (P = .002), and lack of clearance was also associated among patients with disease recurrence (P <.001). Viral kinetics followed a logarithmic decay curve expressed by the equation y = yoe ax. Virus load half-life was 8.8 days among patients with recurrence versus 3.17 days among patients without recurrence (P =.001). This was not explainable by detectable ganciclovir resistance. CMV load kinetics are useful for identifying, at a very early stage, patients who are more likely to have recurrence.