Study flow chart. We enrolled patients undergoing testing for CMV replication as part of the preemptive management strategy. CMV-PCR testing was performed together with the measurement of CMV-specific T-cell responses. According to the initial CMV PCR results, the patients were divided into the 2 groups of CMV replication positive and negative. Further viral testing was done and patients were then newly assigned to a CMV PCR positive or negative. The corresponding numbers of D(+)R(-) and R(+) are shown.