Bryant Dean, Hibbitts Samantha, Almonte Maribel, Tristram Amanda, Fiander Alison, Powell Ned
School of Medicine, Heath Park, Cardiff University, CF64 3RL, UK.
Prevention and Implementation Group, IARC, Lyon CEDEX 08, France.
J Clin Virol. 2015 May;66:66-71. doi: 10.1016/j.jcv.2015.03.001. Epub 2015 Mar 5.
Persistent infection with human papillomavirus (HPV) type 16 causes the majority of cervical cancers. Genital HPV infection is very common, but neoplastic progression is uncommon. There is an urgent need for biomarkers associated with cervical neoplasia, to enable triage of women who test positive for HPV.
To assess the ability of quantitative measurement of HPV16 DNA methylation to separate samples of different cytological and histological grades from young women, among whom rates of HPV infection are high.
DNA methylation was quantified by pyrosequencing of bisulphite converted DNA from liquid based cytology samples from 234 women (mean age 20.6 years) who tested positive for HPV16 and showed varying degrees of neoplasia. Methylation was assessed at CpGs in the HPV E2 and L1/L2 regions.
The performance of methylation-based classifiers was assessed by ROC curve analyses. The best combination of CpGs (5600 and 5609) achieved AUCs of 0.656 (95% CI=0.520-0.792) for separation of cytologically normal and severely dyskaryotic samples, and 0.639 (95% CI=0.547-0.731) for separation of samples with or without high-grade neoplasia (CIN2+/-).
The data are consistent with HPV L1/L2 methylation being a marker of the duration of infection in a specific host. Assessment of HPV DNA methylation is hence a promising biomarker to triage HPV-positive cytology samples, but may have limited utility in young women. Future studies assessing the likely utility of HPV DNA methylation as a potential triage biomarker must take account of women's age.
16型人乳头瘤病毒（HPV）的持续感染导致了大多数宫颈癌。生殖器HPV感染非常常见，但肿瘤进展并不常见。迫切需要与宫颈肿瘤形成相关的生物标志物，以便对HPV检测呈阳性的女性进行分流。
评估定量检测HPV16 DNA甲基化以区分年轻女性中不同细胞学和组织学分级样本的能力，这些年轻女性HPV感染率较高。
通过焦磷酸测序对234名HPV16检测呈阳性且显示不同程度肿瘤形成的女性（平均年龄20.6岁）的液基细胞学样本经亚硫酸氢盐转化后的DNA进行甲基化定量。在HPV E2和L1/L2区域的CpG位点评估甲基化情况。
通过ROC曲线分析评估基于甲基化的分类器的性能。最佳的CpG组合（5600和5609）在区分细胞学正常和严重核异质样本时的曲线下面积（AUC）为0.656（95%可信区间=0.520-0.792），在区分有或无高级别肿瘤形成（CIN2+/-）的样本时的AUC为0.639（95%可信区间=0.547-0.731）。
数据表明HPV L1/L2甲基化是特定宿主中感染持续时间的一个标志物。因此，评估HPV DNA甲基化是一种有前景的用于分流HPV阳性细胞学样本的生物标志物，但在年轻女性中的效用可能有限。未来评估HPV DNA甲基化作为潜在分流生物标志物可能效用的研究必须考虑女性的年龄。
