Boom René, Sol Cees J A, Schuurman Tim, Van Breda Alex, Weel Jan F L, Beld Marcel, Ten Berge Ineke J M, Wertheim-Van Dillen Pauline M E, De Jong Menno D
Section of Clinical Virology, Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
J Clin Microbiol. 2002 Nov;40(11):4105-13. doi: 10.1128/JCM.40.11.4105-4113.2002.
Quantitation of cytomegalovirus (CMV) DNA in plasma and serum by PCR is increasingly used to identify patients at risk for developing CMV disease and to monitor the efficacy of antiviral therapy. Although CMV DNA levels are generally interpreted as viral loads, the exact nature of the viral DNA in these specimens is unknown. We studied the state of CMV DNA in plasma and serum specimens obtained from three renal transplant recipients at peak viral DNA levels during primary CMV infection. For this purpose, DNA isolated from these specimens was fractionated by size, and CMV DNA levels in the resulting DNA fractions were measured by quantitative PCR targeted at large (578-bp) and small (134-bp) amplicons. These experiments showed that the molecular sizes of DNA fragments from which CMV DNA is amplified were small (<2,000 bp), indicating that CMV DNA in plasma and serum is highly fragmented. Furthermore, CMV DNA levels were consistently higher when targeted at the smaller amplicon, providing additional evidence for the fragmentation of viral DNA. In conclusion, the first results with three patients have shown that CMV DNA in plasma and serum is highly fragmented and does not necessarily reflect the amount of infectious virus. These observations have potential consequences for understanding CMV pathogenesis and interpreting CMV DNA levels in individual patient management.
通过聚合酶链反应（PCR）对血浆和血清中的巨细胞病毒（CMV）DNA进行定量分析，越来越多地用于识别有发生CMV疾病风险的患者，并监测抗病毒治疗的疗效。尽管CMV DNA水平通常被解释为病毒载量，但这些样本中病毒DNA的确切性质尚不清楚。我们研究了在原发性CMV感染期间，从三名肾移植受者获得的血浆和血清样本中，处于病毒DNA水平峰值时CMV DNA的状态。为此，从这些样本中分离出的DNA按大小进行分级，通过针对大（578 bp）和小（134 bp）扩增子的定量PCR测量所得DNA级分中的CMV DNA水平。这些实验表明，扩增出CMV DNA的DNA片段分子大小较小（<2000 bp），表明血浆和血清中的CMV DNA高度碎片化。此外，当针对较小的扩增子时，CMV DNA水平始终较高，这为病毒DNA的碎片化提供了额外证据。总之，对三名患者的初步结果表明，血浆和血清中的CMV DNA高度碎片化，不一定反映感染性病毒的数量。这些观察结果对于理解CMV发病机制以及在个体患者管理中解释CMV DNA水平具有潜在影响。
