Human Papillomavirus 31 integration events and cervical disease progression post-vaccination


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Rachel Houghton1, Gavin Wilkinson1, Amanda Tristram1, Sam Hibbitts1
1Cardiff University, Cardiff, UK

Background

Human papillomavirus (HPV) is a small DNA virus that is responsible for 99% of cervical cancers. The introduction of the prophylactic HPV vaccine will help reduce the prevalence of cervical cancer in the vaccinated population; however the vaccine only provides full protection against HPV types 16 and 18 with some degree of cross-protection against other types. Novel screening methods are essential to further reduce the prevalence of cervical cancer. As viral integration is seen in the majority of cervical cancers integration is one possible biomarker for disease progression.
The primary aim of this work is to investigate if viral integration is a suitable biomarker for disease progression in the vaccinated cohort. This will be done by correlating disease progression to viral integration status at baseline and investigating hotspots for integration.

Method

Integration is detected using two assays: Detection of Integrated Papillomavirus Sequences (DIPS) PCR assay and E2 PCR assay. Both of these assays use novel primers that are specific to HPV type 31. These assays are currently being applied to HPV31 positive liquid based cytology (LBC) samples from a cohort of women aged 20-22 who attended their first cervical smear prior to the introduction of the vaccine. Primers will be used to confirm the host-viral junction and results will be evaluated alongside clinical data.

Results

Both HPV 31 assays have been shown to be sensitive and reproducible using control plasmid material. Work is ongoing to apply these assays to LBC samples and updated results will be presented.

Conclusion

With the vaccine introduction it is important to consider if HPV 31 represents a significant risk to the vaccinated population. This research will address the prevalence of HPV 31 viral integration and if these assays are able to function as a potential biomarker of high-grade disease progression.