Evaluating Companion Diagnostics to the anal Pap test to improve prediction of AIN2+ in HIV-infected MSM

摘要 人类乳头瘤病毒(HPV)感染在男性和女性中非常普遍。高危(HR)HPV 16型 -18(HPV16/18)导致了约90%的肛门癌，其发病率在过去两年上升了96%- 30年，主要是因为艾滋病毒/艾滋病的流行。事实上，与男性发生性行为的感染艾滋病毒的男性 (HIV+MSM)是肛门癌风险最高的人群，发病率为137/100,000 相比之下，未感染艾滋病毒的男性中每10万人中就有2人感染。目前的肛门癌筛查始于肛门 Papanicolaou(巴氏)检测以寻找异常细胞学，在一些诊所包括HR-HPV DNA检测，其中 检测感染。如果意义未知或更高的非典型鳞状细胞的细胞学异常是 在肛门活检上发现，患者被转诊为高分辨率肛门镜(HRA)，这是一种侵入性手术，以 将异常组织可视化并移除以进行组织学检查。不幸的是，肛门巴氏筛查低估了 与组织学相比，异型增生的分级。此外，HR-HPV DNA筛查在 HIV+MSM人群因为肛门HPV感染率很高(~80%)。对个人进行筛查 HR-HPV DNA虽然对检测感染很敏感，但对预测肛门发育不良的风险并不特异。一个 迫切需要更具体的同伴诊断，以帮助确定何时应该转介某人 不管是不是为了HRA。为此，我们将首先评估HPV基因的以下综合测量 肛门标本的表达：a)长控制区(LCR)内所有15个CpG位点的甲基化状态 E6/E7癌基因上游，b)上皮内HR-HPV E6/E7 mRNA水平，以及c)HPV16/18 E6蛋白 表情。我们假设，将这些生物标记物中的一个或多个与肛门巴氏试验相结合，而不是 HR-HPV DNA检测可提高预测AIN2+的特异性。为了评估这一点，我们将进行一项 一组不同人群的HIV+MSM患者的横断面研究 HRA在哥伦比亚特区的诊所进行，哥伦比亚特区是美国艾滋病毒感染率最高的城市 在HRA程序中，将收集3个肛门拭子：将从其中一个提取DNA并用于评估CpG HPV16/18 LCR中的甲基化模式，一个表观遗传生物标记物，而第二个将被置于液基 HPVDNA基因分型、HR-HPVE6/E7mRNA表达和HPV16/18E6癌蛋白的细胞学检测 检测，第3次将直接分析HPV16/18E6癌蛋白。这些测试的结果将是 独立比较它们从HRA引导的活检中预测AIN2+的能力。人乳头瘤病毒DNA基因分型 数据将使我们能够描述在华盛顿特区的HIV+MSM中发现的肛门生殖器HPV类型的分布。 找出更具特异性的生物标记物将提高预测高危患者肛门发育不良的准确性。 如果HRA呈阳性，则通过提供更有力的证据来证明其合理性，或者在以下情况下降低不必要的HRA的发生率 不是。在HPV疫苗时代，发现更好的伴随诊断仍然很重要，因为 许多HIV+MSM从未接种过疫苗，疫苗接种率继续低于目标目标。

ABSTRACT Human papillomavirus (HPV) infections are highly prevalent in men and women. High-risk (HR) HPV types 16 & 18 (HPV16/18) are responsible for ~90% of all anal cancers, whose incidence has risen by 96% in the last 2- 3 decades primarily because of the HIV/AIDS epidemic. Indeed, HIV-infected men who have sex with men (HIV+MSM) are the population at highest risk of anal cancer with an incidence rate of 137 per 100,000 compared with 2 per 100,000 among HIV-uninfected men. Current anal cancer screening begins with an anal Papanicolaou (Pap) test to look for abnormal cytology, and in some clinics include HR-HPV DNA testing, which detects infection. If cytologic abnormalities of atypical squamous cells of unknown significance or higher are found on the anal Pap, patients are referred for high-resolution anoscopy (HRA), an invasive procedure to visualize and remove abnormal tissue for histology. Unfortunately, anal Pap screening under-estimates the grade of dysplasia compared to histology. Furthermore, HR-HPV DNA screening has limited utility among the HIV+MSM population because prevalence of anal HPV infection is so high (~80%). Screening individuals for HR-HPV DNA, although sensitive for detecting infection, is not specific for predicting risk of anal dysplasia. A more specific companion diagnostic is urgently needed to help determine when someone should be referred for HRA or not. To that end, we will be the first to assess the following combined measures of HPV gene expression from anal specimens: a) methylation status of all 15 CpG sites within the long control region (LCR) upstream of E6/E7 oncogenes, b) intra-epithelial levels of HR-HPV E6/E7 mRNA, and c) HPV 16/18 E6 protein expression. We hypothesize that combining 1 or more of these biomarkers with the anal Pap test, rather than the HR-HPV DNA test, would improve specificity for predicting AIN2+. To evaluate this, we will conduct a cross-sectional study of a diverse population of HIV+MSM with abnormal anal Pap results, who are undergoing HRA at clinics here in the District of Columbia, the city with the highest HIV prevalence rate in the U.S. Prior to the HRA procedure, 3 anal swabs will be collected: DNA will be extracted from one and used to assess CpG methylation patterns, an epigenetic biomarker, in HPV16/18 LCR, while the 2nd will be placed into liquid-based cytology media for HPV DNA genotyping, HR-HPV E6/E7 mRNA expression, and HPV16/18 E6 oncoprotein detection, and the 3rd will be analyzed directly for HPV16/18 E6 oncoproteins. Results of these tests will be compared independently for their ability to predict AIN2+ from HRA guided biopsies. HPV DNA genotyping data will permit us to characterize distribution of anogenital HPV types found in HIV+MSM here in DC. Identifying a more specific biomarker will improve the accuracy of predicting anal dysplasia in this high-risk group by providing stronger evidence to justify HRA if positive, or reduce the rate of unnecessary HRA if negative. Discovering a better companion diagnostics remains important in the HPV vaccine era because many HIV+MSM were never vaccinated and vaccine uptake continues to be lower than the target goals.