Baldanti F, Zavattoni M, Sarasini A, Gatti M, Chezzi L, Gerna G
Viral Diagnostic Service, IRCCS Policlinico S. Matteo, Pavia, Italy.
Clin Diagn Virol. 1997 Aug;8(2):159-65. doi: 10.1016/s0928-0197(97)00016-0.
Monitoring of human cytomegalovirus (HCMV) load by quantification of antigenemia, viremia and DNAemia is helpful in the management of HCMV infections in immunocompromised patients. In fact, threshold values of these viral parameters are associated with the emergence of clinical symptoms. In addition, the response to antiviral treatment is revealed by a decrease in viral load or virus disappearance from blood.
Aim of this study was to compare HCMV DNA quantification in blood of immunocompromised patients by an 'in house' developed quantitative PCR (Q-PCR) assay and the commercially available Murex Hybrid Capture System (HCS).
HCMV DNA was quantified in 95 blood samples from 12 heart and heart-lung transplant recipients and 27 AIDS patients using both techniques. For HCS analysis 3.5 ml whole blood were utilized, whereas Q-PCR was performed using 1 x 10(5) peripheral blood leukocytes (PBL). HCMV DNA levels obtained by HCS and Q-PCR were expressed as number of genome equivalents (GE)/ml whole blood or 1 x 10(5) PBL, respectively. Results from HCS and Q-PCR were compared and submitted to statistical analysis. In addition, HCMV DNA values were compared to levels of antigenemia and viremia.
Sensitivity of HCS, antigenemia and viremia with respect to Q-PCR were 37.2, 79.5 and 33.3%, respectively. Specificity was 100% for all techniques. On average, samples positive by Q-PCR only, contained low amounts of HCMV DNA. In particular, 45 (91.8%) out of 49 samples 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 in 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 are not clinically significant, HCS seems very promising as an alternative to HCMV DNA quantification by PCR in solid organ transplant recipients and AIDS patients.
通过定量检测抗原血症、病毒血症和DNA血症来监测人巨细胞病毒（HCMV）载量，有助于免疫功能低下患者的HCMV感染管理。事实上，这些病毒参数的阈值与临床症状的出现有关。此外，抗病毒治疗的反应可通过病毒载量的降低或血液中病毒的消失来体现。
本研究的目的是比较用自行研发的定量聚合酶链反应（Q-PCR）检测法和市售的Murex杂交捕获系统（HCS）对免疫功能低下患者血液中的HCMV DNA进行定量检测的结果。
使用这两种技术对12例心脏和心肺移植受者以及27例艾滋病患者的95份血液样本中的HCMV DNA进行定量检测。HCS分析使用3.5 ml全血，而Q-PCR检测则使用1×10⁵外周血白细胞（PBL）。通过HCS和Q-PCR获得的HCMV DNA水平分别表示为每毫升全血或1×10⁵ PBL中的基因组当量（GE）数。对HCS和Q-PCR的结果进行比较并进行统计分析。此外，将HCMV DNA值与抗原血症和病毒血症水平进行比较。
相对于Q-PCR，HCS、抗原血症和病毒血症的敏感性分别为37.2%、79.5%和33.3%。所有技术的特异性均为100%。平均而言，仅通过Q-PCR呈阳性的样本中HCMV DNA含量较低。特别是，49份HCS检测为阴性而Q-PCR检测为阳性的样本中，有45份（91.8%）显示每1×10⁵ PBL中HCMV DNA含量<500 GE。在HCS和Q-PCR均呈阳性的样本中（n = 29，R = 0.693，P < 0.01），定量DNA水平之间存在显著相关性。HCS检测呈阳性与Q-PCR测定的显著更高的DNA值以及显著更高的抗原血症和病毒血症水平相关。抗病毒治疗后，使用HCS和Q-PCR均观察到DNA血症水平下降。鉴于HCS漏检的绝大多数血液样本中HCMV DNA含量较低，临床上无显著意义，因此HCS作为实体器官移植受者和艾滋病患者中替代PCR进行HCMV DNA定量检测的方法似乎非常有前景。
