COMPARATIVE QUANTIFICATION OF HUMAN CYTOMEGALOVIRUS DNA IN BLOOD OF IMMUNOCOMPROMISED PATIENTS BY PCR AND MUREX HYBRID CAPTURE(TM) SYSTEM

Background: Monitoring of human cytomegalovirus (HCMV) load by quantif ication of antigenemia, viremia and DNAemia is helpful in the manageme nt of HCMV infections in immunocompromised patients. In fact, threshol d values of these viral parameters are associated with the emergence o f clinical symptoms. In addition, the response to antiviral treatment is revealed by a decrease in viral load or virus disappearance from bl ood. Objectives: Aim of this study was to compare HCMV DNA quantificat ion in blood of immunocompromised patients by an 'in house' developed quantitative PCR (Q-PCR) assay and the commercially available Murex Hy brid Capture(TM) System (HCS). Study design: HCMV DNA was quantified i n 95 blood samples from 12 heart and heart-lung transplant recipients and 27 AIDS patients using both techniques. For HCS analysis 3.5 ml wh ole blood were utilized, whereas Q-PCR was performed using 1 x 10(5) p eripheral blood leukocytes (PBL). HCMV DNA levels obtained by HCS and Q-PCR were expressed as number of genome equivalents (GE)/ml whole blo od or 1 x 10(5) PBL, respectively. Results from HCS and Q-PCR were com pared and submitted to statistical analysis. In addition, HCMV DNA val ues were compared to levels of antigenemia and viremia. Results and Co nclusions: Sensitivity of HCS, antigenemia and viremia with respect to Q-PCR were 37.2, 79.5 and 33.3%, respectively. Specificity was 100% f or all techniques. On average, samples positive by Q-PCR only, contain ed low amounts of HCMV DNA. In particular, 45 (91.8%) out of 49 sample s negative by HCS and positive by Q-PCR showed < 500 GE/1 x 10(5) PBL. A significant correlation was found between quantitative DNA levels i n samples positive by both HCS and Q-PCR (n = 29, R = 0.693, P < 0.01) . HCS positivity was associated to significantly higher DNA values as determined by Q-PCR as well as to significantly higher antigenemia and viremia levels, A decrease in DNAemia levels was observed using both HCS and Q-PCR after antiviral treatment. Given that the great majority of blood samples missed by HCS contain low levels of HCMV DNA which a re not clinically significant, HCS seems very promising as an alternat ive to HCMV DNA quantification by PCR in solid organ transplant recipi ents and AIDS patients. (C) 1997 Elsevier Science B.V.