Cytomegalovirus (CMV) DNA load in plasma for the diagnosis of CMV disease before engraftment in hematopoietic stem-cell transplant recipients

Among hematopoietic stem-cell transplant (HSCT) recipients, cytomegalovirus (CMV) disease before engraftment is rare but often fatal, and cell-based d iagnostic tests have low sensitivity in this clinical setting. We used the quantitative real-time polymerase chain reaction (PCR) assay to test for CM V DNA in plasma samples from 15 HSCT recipients who developed CMV disease b efore engraftment and from 33 matched control patients. CMV DNA was detecte d in plasma in 14 (93.3%) of the 15 patients who had CMV disease before eng raftment, compared with 5 (15.2%) of 33 control patients (P < .001). CMV DN A was detected a median of 13 days before the onset of CMV disease (range, 0-35 days). The maximum CMV virus load in plasma was >1 log(10) higher amon g case patients than among control patients (median, 1700 [range, 50 to 5.5 X 10(7)] vs. <50 [range, <50- 350] CMV DNA copies/mL plasma, respectively; P < .001). Quantitative PCR for CMV DNA in plasma appears to be useful for the identification of HSCT recipients at risk for CMV disease before engra ftment.