Cytomegalovirus antigenemia assay or PCR can be used to monitor ganciclovir treatment in bone marrow transplant recipients

The antigenemia assay, polymerase chain reaction (PCR) and rapid culture technique on buffy coat cells (DEAFF test) were used to monitor 37 cytomegalovirus (CMV) seropositive bone marrow transplant (BMT) recipients for active CMV infection during the first 3 months after BMT. The antigen assay and PCR demonstrated a comparable sensitivity for the detection of CMV in blood: discordant results were only obtained in the early or late phase of infection when the viral load was low. The antigen assay was more sensitive than the DEAFF test. Only 12 out of 40 antigen-positive samples yielded a positive result with DEAFF test, whereas viremia without antigenemia was never found. The discordance between these two tests increased further during antiviral therapy with ganciclovir. A correlation was observed between the duration of antigenemia during treatment and the recurrence of systemic CMV reactivation. Ten out of 11 patients with antigen-positive leukocytes present for more than 1 week after starting the treatment subsequently exhibited a relapse of active infection, whereas only three out of nine patients who resolved their antigenemia within 1 week did so. In conclusion, the antigen assay and PCR are useful techniques for detection of CMV infection in BMT patients. Test results obtained during therapy give reliable information regarding the viral load and the possibility of recurrence of antigenemia, and can be taken into account when prolonged administration of ganciclovir is considered.