Laboratoire de santé publique du Québec, Institut national de santé publique, 20045, Chemin Sainte-Marie, Sainte-Anne-de-Bellevue, Québec, H9X 3R5, Canada.
Ludwig Institute for Cancer Research, R. João Julião, 245, 01323-903 São Paulo, SP, Brazil.
J Gen Virol. 2013 Aug;94(Pt 8):1850-1857. doi: 10.1099/vir.0.051722-0. Epub 2013 May 15.
Viral load measurements may predict whether human papillomavirus (HPV) type 16 infections may become persistent and eventually lead to cervical lesions. Today, multiple PCR methods exist to estimate viral load. We tested three protocols to investigate viral load as a predictor of HPV clearance. We measured viral load in 418 HPV16-positive cervical smears from 224 women participating in the Ludwig-McGill Cohort Study by low-stringency PCR (LS-PCR) using consensus L1 primers targeting over 40 known HPV types, and quantitative real-time PCR (qRT-PCR) targeting the HPV16 E6 and L1 genes. HPV16 clearance was determined by MY09/11 and PGMY PCR testing on repeated smears collected over 5 years. Correlation between viral load measurements by qRT-PCR (E6 versus L1) was excellent (Spearman's rank correlation, ρ = 0.88), but decreased for L1 qRT-PCR versus LS-PCR (ρ = 0.61). Viral load by LS-PCR was higher for HPV16 and related types independently of other concurrent HPV infections. Median duration of infection was longer for smears with high copy number by all three PCR protocols (log rank P<0.05). Viral load is inversely related to HPV16 clearance independently of concurrent HPV infections and PCR protocol.
病毒载量测量值可能预测人乳头瘤病毒 (HPV) 16 型感染是否会持续存在，并最终导致宫颈病变。目前，存在多种聚合酶链反应 (PCR) 方法来估计病毒载量。我们测试了三种方案，以研究病毒载量作为 HPV 清除的预测因子。我们通过低严格性聚合酶链反应 (LS-PCR) ，使用针对 40 多种已知 HPV 类型的共识 L1 引物，对来自 224 名参与 Ludwig-McGill 队列研究的女性的 418 份 HPV16 阳性宫颈涂片进行了病毒载量测量，还通过针对 HPV16 E6 和 L1 基因的实时定量 PCR (qRT-PCR) 进行了测量。通过 MY09/11 和 PGMY PCR 在 5 年内对重复采集的宫颈涂片进行检测，以确定 HPV16 的清除情况。qRT-PCR (E6 与 L1) 的病毒载量测量之间具有极好的相关性 (Spearman 等级相关，ρ = 0.88)，但 L1 qRT-PCR 与 LS-PCR 之间的相关性降低 (ρ = 0.61)。LS-PCR 检测到的 HPV16 及其相关类型的病毒载量独立于其他同时存在的 HPV 感染而升高。所有三种 PCR 方案的高拷贝数涂片的感染中位持续时间较长 (对数秩检验，P<0.05)。病毒载量与 HPV16 清除呈负相关，与同时存在的 HPV 感染和 PCR 方案无关。
