CMV load quantitation by the automated VERSANT k-PCR Molecular System in plasma of transplanted patients

Background: Promptness of results, sensibility and multi-specimen processing represent a significant challenge for the molecular routine in a clinical virology laboratory; this is especially important for viral load in transplanted patients where a rapid diagnosis is essential to start a proper therapy. This study has been initially planned to establish the performance of the Automated VERSANT kPCR Molecular System for herpesviruses and adenovirus viral load quantification in plasma specimens from transplanted patients. Methods: So far, 100 plasma samples randomly collected from patients serially admitted to Sapienza University Hospital “Policlinico Umberto I” were examined. The VERSANT kPCR Molecular System with new VERSANT MiPLX Software Solution (Siemens Healthcare Diagnostics, Tarrytown, NY, USA) was used to extract DNA from samples. CMV amplification, detection and quantification were performed automatically on the AD module of the VERSANT kPCR Molecular System, adding quantitative standards in each run. Data obtained were compared with those from a currently used semi-automated system including EasyMAG (Biomerieux, Italia S.p.A.) extraction and Elite-MGB (ELITech Group S.p.A. Molecular Diagnostics, Italy) Real time PCR Amplification. Results: The VERSANT kPCR Molecular System with new VERSANT MiPLX Software Solution allowed to simultaneously process more than 90 plasma clinical samples in less than 3 hours. Detectable levels of CMV DNA were found in 22 out of 100 samples and a good correlation was observed by data obtained from the two assays used (r = 0.96 p < 0.0001). Sixty-two samples showed undetectable levels of CMV DNA using both methods; 16 specimens showed viremia values detectable but <250 copies/ml using ELITech System; 7 of these were quantified using VERSANT kPCR. The study is still in progress to increase the number of samples and to extend the analysis to other viruses clinically significant in transplanted patients. Conclusion: At the moment the analysis of the data indicates that: in plasma samples, a good correlation was observed when data are compared to those obtained by ELITech system; the new VERSANT MiPLX Software Solution proved to be flexible in his ability to combine extraction and amplification.