Human cytomegalovirus DNA kinetics using a novel HCMV DNA quantitative assay in white blood cells of immunocompromised patients under Ganciclovir therapy

The clearance of human cytomegalovirus (HCMV) was evaluated in infected patients under Ganciclovir (GCV) treatment, using a novel HCMV DNA quantitation assay (HCMV DNA hybrid capture system, Murex Diagnostics). Peripheral white blood cells (WBC) from whole blood specimens of seven AIDS patients, three kidney and two allogeneic bone marrow transplant (BMT) recipients suffering from HCMV disease, were assessed by this method. HCMV DNA 50 and 90% mean clearances were observed at 2.11 +/- 1.97 and 6.22 +/- 4.31 days, respectively, after initial GCV treatment. The viral DNA kinetics were correlated with positive and negative pp65 antigenaemia and viral blood culture. Two-fold higher clearances and initial DNA levels were observed in the AIDS group compared to the transplant group. Neither clinical nor virological relapses were observed under GCV treatment. HCMV DNA quantitation in WBC appears well adapted for a therapeutic follow up of patients with HCMV disease.

Novel DNA assay for cytomegalovirus detection: comparison with conventional culture and pp65 antigenemia assay

We compared conventional cytomegalovirus (CMV) isolation, rapid viral culture, a CMV pp65 antigenemia assay, and a novel CMV DNA hybrid capture system (HCS). A total of 309 blood samples from individuals in different risk groups were assessed by at least two of the methods mentioned above. Leukocytes were recovered either after centrifugation in Leucosep tubes containing 1.080 Ficoll for pp65 assay or after simple differential lysis steps for DNA detection. HCS was based on DNA hybridization with a CMV RNA probe and its capture by antibodies to DNA-RNA hybrids. The CMV pp65 lower matrix protein was detected by fluorescence with c10-c11 monoclonal antibody in formalin-fixed leukocytes. Concordant results were observed for 92.9, 78.3, and 82.7% of the patients when comparing (i) viral culture and the pp65 antigenemia assay, (ii) viral culture and HCS, and (iii) the pp65 antigenemia assay and HCS, respectively. Discordant results were observed between a positive HCS result and negative culture and/or pp65 results. These results were associated with relatively low DNA levels (< 20 pg/10(6) cells) and positive viruria. In conclusion, the pp65 antigenemia assay is a rapid and reliable method of detecting CMV and is preferable to culture, but the Murex HCS appears to be more sensitive for CMV detection.