[Detection of human cytomegalovirus infection by FQ-PCR technique and its application in the diagnosis and treatment of HCMV infected children].

Background: To detect quantitatively HCMV DNA in peripheral blood leukocytes to monitor the status of HCMV infection, evaluate the effectiveness of antiviral treatment with ganciclovir (GCV) combined with intravenous immunoglobulin (IVIG) and find out the relationship among the HCMV DNA levels, the state of infection and the clinical outcome.The long-term goal of the study was to establish a molecular diagnostic standard for HCMV infection in children.

Methods: 45 cases of suspected HCMV-infected children were examined by PCR, ELISA and fluorescent quantitative (FQ)-PCR, respectively. Twenty five HCMV hepatitis cases of the 45 were randomly assigned to a treated group or a control group. Both groups were treated with prednisone, glucurone, Luminal and Xiaoyanlidanpian. But the treated group was given with GCV+IVIG in addition. Each infant of the two groups was checked with FQ-PCR at the five time points.

Results: The positive rates of PCR, ELISA and FQ-PCR were 60.00%, 33.33% and 66.67%,their sensitivities were 84.38%, 46.88% and 93.75%, respectively. There was no significant difference in viral DNA copy numbers between the two groups before being treated (P>0.05), but there was significant difference between HCMV hepatitis and normal infants (P<0.001). Although viral load of both groups decreased in both groups, the viral load of the treated group decreased more significantly. The level of HCMV DNA fell to 103 copies/ml at second time point while that of the control group fell to the same level after third time point. The differences between the two groups at each time point were statistically significant (P<0.001). The results of 135 person times testing indicated that 103 copies/ml of FQ-PCR can be taken as a critical value for prediction of active HCMV infection.

Conclusions: FQ-PCR may be one of the effective methods for diagnosis of HCMV disease; it can offer a key index in the diagnosis of HCMV active infection; dynamic detection of HCMV viral load can play a role not only in monitoring antiviral therapy, but also in evaluating the development and prognosis of HCMV disease.