MEASUREMENT OF HUMAN CYTOMEGALOVIVUS-ASSOCIATED DNA-POLYMERASE-ACTIVITY IN PATIENT URINE AS A POTENTIAL DIAGNOSTIC-TOOL

Virus-associated DNA polymerase activity has recently been proposed fo r the detection of human cytomegalovirus (HCMV) in urine, a method tha t should allow rapid and quantitative determination of the viral load. In this report, the virus-associated DNA polymerase activity recovere d from the urine of a group of patients shedding HCMV was measured usi ng a poly(dA) oligo(dT)12-18 synthetic template after polyethylene gly col precipitation of the virions. Detection of virus-associated DNA po lymerase activity was compared to the classical methods most widely us ed to diagnose HCMV shedding in urines, such as virus culture followed by indirect immunofluorescence and pp65 gene-specific polymerase chai n reaction. Although less sensitive than the polymerase chain reaction and cross-reactive with other herpesvirus DNA polymerases, the activi ty measured in the urine samples was correlated with the number of pos itive nuclei found in shell vials (r = 0.89). The diagnostic threshold of the assay could be placed between 50 and 100 fluorescent nuclei pe r shell with a diagnostic sensitivity of 56%. Being simple and quantit ative, the measurement of virus-associated DNA polymerase activity cou ld be of value in some clinical conditions where it is necessary to as sess viral load in urine. This method is proposed as an alternative to more laborious quantitative assays and to support qualitative polymer ase chain reaction.