Molecular diagnosis of Cytomegalovirus infection: clinical performance of Transcription Mediated Amplification (TMA) towards conventional qPCR chemistry on whole blood samples

Human Cytomegalovirus (HCMV) infection represents a life-threating pathogen for immunocompromised patients. Molecular quantitative testing on whole blood or plasma represents the gold standard for diagnosis of invasive HCMV infection and for monitoring antiviral treatment in individuals at risk of CMV disease. For these reasons, accurate standardization towards the 1st WHO International standard between different centres and diagnostic kits represent an effort for a better clinical management of CMV-positive patients. Herein, we evaluate for the first time the performance of a new TMA (Transcription Mediated Amplification) kit towards qPCR chemistry, used as routine method, on whole blood samples. 755 clinical whole blood specimens were collected and simultaneously tested with TMA and qPCR assays. Data showed 99.27% agreement for positive quantified samples and 89.39% agreement for those not detected between two tested methods. Evaluation of viraemia in positive samples highlighted a good correlation for TMA and qPCR chemistries in terms of International Units (ΔLog10 IU/ml: − 0.29 ± 0.40). TMA assay showed a significant correlation with qPCR also in monitored patients until three months, thus allowing accurate evaluation of viraemia in transplanted patients. Moreover, preliminary data about analytical sensitivity of TMA chemistry onto DBS samples showed 86.54% correlation with whole blood specimens. Thus, TMA chemistry showed a good agreement with qPCR assay, used as current diagnostic routine, and offers important advantages: FDA and IVD approval on plasma and whole blood, automated workflow with minimal hands-on time, random access loading, thus enabling a rapid and reliable diagnostics in HCMV-infected patients. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was conducted in accordance with the Declaration of Helsinki, and approved by the Intercompany ethics committee of University Hospital Citta' della Salute e della Scienza di Torino, A.O. Ordine Mauriziano di Torino, A.S.L. Citta' di Torino (protocol code 0041695 of 15/04/2021). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors