Baccard-Longere M, Freymuth F, Cointe D, Seigneurin J M, Grangeot-Keros L
Laboratoire de Virologie, Centre Hospitalier Universitaire de Grenoble, BP 217, 38043 Grenoble, France.
Clin Diagn Lab Immunol. 2001 Mar;8(2):429-31. doi: 10.1128/CDLI.8.2.429-431.2001.
An easy, rapid, and reproducible test to distinguish residual cytomegalovirus (CMV) immunoglobulin M (IgM) antibodies from antibodies produced in primary infection could be useful, especially for pregnant women. The CMV avidity of IgG antibodies with the VIDAS automated enzyme-linked fluorescent assay and 6 M urea was evaluated in a multicenter study to differentiate between primary CMV infections and past infections or reactivations. A total of 416 serum specimens were tested: 159 specimens were from follow-up of primary infections, and 257 were from past infections. All of the specimens from primary infections collected within 4 months (17 weeks) after the onset of the infection had an avidity index lower than 0.8. An avidity index higher than 0.8 excludes a recent primary infection of less than 4 months. However, an avidity index higher than 0.8 cannot confirm all past infections, since 48 specimens (18%) from past infections had an avidity index lower than 0.8 (between 0.5 and 0.8). The exclusion capacity could be improved (96.9%) by using a cutoff of 0.7, but this index would decrease the specificity of the technique, since the avidity index was found to be between 0.7 and 0.8 in two patients with recent primary infection. All specimens from primary infections obtained more than 4 months after the onset of infection had an avidity index more than 0.2. In this study, an avidity index less than 0.2 confirms the presence of a recent primary infection of less than 4 months. The VIDAS CMV IgG avidity test is a rapid, reproducible test with very good performance.
一种简便、快速且可重复的检测方法，用于区分残留的巨细胞病毒（CMV）免疫球蛋白M（IgM）抗体与原发性感染产生的抗体，可能会很有用，尤其是对孕妇。在一项多中心研究中，使用VIDAS自动酶联荧光分析法和6M尿素评估了IgG抗体的CMV亲和力，以区分原发性CMV感染与既往感染或再激活。共检测了416份血清标本：159份标本来自原发性感染的随访，257份来自既往感染。感染发作后4个月（17周）内收集的所有原发性感染标本的亲和力指数均低于0.8。亲和力指数高于0.8可排除近期小于4个月的原发性感染。然而，亲和力指数高于0.8不能确认所有既往感染，因为257份既往感染标本中有48份（18%）的亲和力指数低于0.8（在0.5至0.8之间）。通过使用0.7的临界值，排除能力可提高（96.9%），但该指数会降低该技术的特异性，因为在两名近期原发性感染患者中发现亲和力指数在0.7至0.8之间。感染发作后4个月以上获得的所有原发性感染标本的亲和力指数均大于0.2。在本研究中，亲和力指数小于0.2可确认存在近期小于4个月的原发性感染。VIDAS CMV IgG亲和力检测是一种快速、可重复且性能良好的检测方法。
