Short communicationQuantitative analysis of human papillomavirus type 16 in cervical neoplasm: A study in Chinese population
Introduction
Although cervical screening programmes have dramatically reduced the incidence of cervical cancer, 50% of invasive cervical cancers arise in women screened with existing cytological methodologies due to some inherent limitations (Cuzick et al., 1998). The sensitivity of cytology for high-grade squamous intraepithelial lesion (SIL) was only 40% possibly due to sampling or interpretation errors (Cuzick et al., 1995). On the other hand, over-reading of high-grade SIL leads to unnecessary colposcopic examinations and over-treatment. Various researchers have suggested for additional methods to improve the accuracy of smear, especially in distinction between low-grade and high-grade disease. In late 1970s, the hypothesis that human papillomavirus (HPV) were related to cervical cancers was proposed and throughout 1980s gained rapid support. Those positive for HPV DNA have a risk of developing cervical cancer 15–50 times higher than those without HPV DNA (Lo et al., 2002). Similar correlation is found between HPV and SIL in epidemiological studies (Kulasingam et al., 2002). Therefore, it is possible to use HPV test for the detection of cervical lesions as an adjunct to cervical cytology. The present study was conducted to establish a quantitative real-time polymerase chain reaction (PCR) assay for a precise determination of HPV 16 viral load, and to investigate the role of viral load in the development of cervical precancerous lesions and invasive cancers.
Section snippets
Specimens
Patients with normal and abnormal smears were recruited with informed consents and ethical approval from the local institute. All patients with abnormal smears were examined colposcopically with biopsies when indicated. According to WHO criteria, they were classified as high-grade SILs (HG-L), low-grade SILs (LG-L) and Normal. Smears collected by cervical brush were immersed into phosphate buffered saline and centrifuged. The pellet at the bottom of the tube was homogenized by TRIzol® Reagent
Grading of smears
The study design is summarized in Fig. 1. There were 269 cervical smears collected in colposcopic clinic. After colposcopic examination with biopsies, 148 cases with cervical cancer, CIN 2 or CIN 3 were classified as HG-L; 121 with CIN 1, HPV or inflammation were LG-L. Another 125 smears collected from women with normal cytology at out-patient clinic served as control.
Incidence of HPV 16
All the smears underwent DNA extraction and subsequently screened with PCR for β-actin and HPV 16 specific primers. There were
Discussion
The accumulated molecular and clinical evidences have left no doubt that HPV directly influences the pathogenesis of cervical neoplasia (Alani and Munger, 1998). Several markers have been proposed for the use in prediction of disease severity of SILs. The presence of HPV DNA, the integration state of HPV genome and the viral load were three major areas currently under investigations.
A study showed that 75.4% of patients with abnormal cytology were HPV-positive, a much higher proportion than
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Kinetics of DNA load predict HPV 16 viral clearance
2011, Journal of Clinical VirologyCitation Excerpt :Infection with HPV type 16 is responsible for >50% of cervical cancer cases worldwide.1,2 Additionally, among HPV 16 infected women, elevated DNA viral load measured at a single time-point using either semi- or fully quantitative methods is positively associated with a cross-sectional diagnosis of cervical squamous intraepithelial lesions (SIL) or cervical intraepithelial neoplasia (CIN).3–27 Higher HPV 16 viral load measured has also been shown prospectively to be associated with development of high-grade cervical pre-cancer (CIN 2+),28 carcinoma in situ,29–31 and cervical carcinoma.32
High level of HPV 16 and 18 DNA load in anal swabs from male and female HIV-1 infected patients
2009, Journal of Clinical VirologyCitation Excerpt :The relative risk of invasive anal cancer was 163-fold higher among HIV-positive men younger than 30 years of age than among seronegative men of the same age,5 and in a large cohort of HIV-infected women, anal HPV infection was even more frequent than cervical infection.6 The greater sensitivity of HPV DNA testing compared to cervical cytology for the detection of cervical intraepithelial neoplasia7–9 as well as the relationship between the severity of cervical lesions and HPV 16/18 DNA load10–12 were recently demonstrated. Therefore, HPV DNA testing was implemented in several studies to evaluate women at risk for cervical cancer.12–14
Dynamics of HPV16 DNA load reflect the natural history of cervical HPV-associated lesions
2006, Journal of Clinical Virology