To evaluate the clinical significance of using real-time quantitative polymerase chain reaction (RQ-PCR) in monitoring cytomegalovirus infection in allogenic hemopoietic stem-cell transplant (allo-HSCT) recipients.
A total of 318 patients who received allo-HSCT in the past 2 years were analyzed retrospectively. RQ-PCR was performed to monitor CMV viremia twice a week after transplantation.
CMV-DNA was detected in the plasma of 136 patients. The median time for the occurrence of CMV-DNA was 42 days after HSCT. The highest CMV-DNA load was 1.5 x 10(4) copies/ml while the CMV-DNA load at onset of reactivation was 4.5 x 10(3) copies/ml. CMV pneumonia or CMV enteritis occurred in 23 patients and the incidence of these CMV diseases is 7.2%. The CMV-DNA was detectable before CMV disease among 14 patients and after the clinical manifestation of CMV disease in 4 patients, while 5 patients were diagnosed with CMV disease having no plasma CMV-DNA positive at all. The highest CMV-DNA load was higher in the CMV patients than those with no CMV disease (4.3 x 10(4) copies/ml and 1.3 x 10(4) copies/ml, P = 0.009) although the initial load had no difference (3.7 x 10(3) copies/m vs 4.7 x 10(3) copies/ml, P = 0.63). The highest CMV-DNA load also rose with the occurring frequency of CMV infection occurred from 1 to 4 times. The median values of CMV-DNA were 82.6 x 10(2), 261.3 x 10(2), 440.8 x 10(2) and 10,659.0 x 10(2) copies/ml (P < 0.01) respectively. Meanwhile, the incidence of CMV disease also increased markedly from 2.7% (5/182) to 50% (2/4) (P = 0.001).
Detection of CMV-DNA in plasma by RQ-PCR appears to be an effective prognostic predictor of CMV diseases. High CMV-DNA load and repeated viremia indicate a high incidence of CMV diseases.