DNA methylation as a triage tool for cervical cancer screening - A meeting report.

Introduction: DNA methylation is proposed as a novel biomarker able to monitor molecular events in human papillomavirus (HPV) infection pathophysiology, enabling the distinction between HPV-induced lesions with regression potential from those that may progress to HPV-related cancer. Methods: This meeting report summarises the presentations and expert discussions during the HPV Prevention and Control Board-focused topic technical meeting on DNA methylation validation in clinician-collected and self-collected samples, novel DNA methylation markers discovery, implementation in cervical cancer screening programs, and their potential in women living with human immunodeficiency virus (HIV). Results: Data presented in the meeting showed that HPV-positive, baseline methylation-negative women have a lower cumulative cervical cancer incidence than baseline cytology-negative women, making DNA methylation an attractive triage strategy. However, additional standardised data in different settings (low- versus high-income settings), samples (clinician-collected and self-collected), study designs (prospective, modelling, impact) and populations (immunocompetent women, women living with HIV) are needed. Conclusion: Establishing international validation guidelines were identified as the way forward towards accurate validation and subsequent implementation in current screening programs.

Concentration strategies for spiked and naturally present biomarkers in non-invasively collected first-void urine.

BACKGROUND: First-void urine (FVU) provides a non-invasive method for collecting a wide range of biomarkers found in genital tract secretions. To optimize biomarker collection in FVU, this study investigated the impact of naturally present and supplemented precipitating agents: uromodulin (UMOD) and polyethylene glycol (PEG), on the concentration of human papillomavirus (HPV) pseudovirions (PsV), cell-free DNA (cfDNA), and cellular genomic DNA (gDNA) through centrifugation. METHODS: FVU samples from ten healthy female volunteers, along with a control sample, were spiked with seal herpesvirus 1 (PhHV-1) DNA, HPV16 plasmid DNA, and HPV16 PsV with an enhanced green fluorescent protein (EGFP) reporter. The samples were subjected to various concentration protocols involving PEG precipitation, low-speed centrifugation (5 min at 1000×g), and medium-speed centrifugation (1 h at 3000×g). Subsequently, quantitative PCR (qPCR) was used to assess cellular and cell-free glyceraldehyde-3-phosphate dehydrogenase (GAPDH) DNA, cell-free PhHV-1 and HPV16 DNA, and PsV (EGFP) DNA. In addition, UMOD levels were measured. RESULTS: The findings revealed that PEG significantly increased the concentration of cfDNA and gDNA in the pellet after centrifugation, with the most pronounced effect observed for cfDNA. Moreover, low-speed centrifugation without PEG effectively depleted cellular gDNA while preserving cfDNA in the supernatants. Pseudovirions were consistently pelleted, even with low-speed centrifugation, and a positive but not significant effect of PEG on PsV (EGFP) DNA yield in the pellet was observed. Additionally, a significant correlation was observed between UMOD and GAPDH, HPV16, and PsV (EGFP) DNA quantities in the pellet. Furthermore, large variations among the FVU samples were observed. CONCLUSIONS: With this study, we provide novel insights into how various biomarker precipitation protocols, including both the properties of FVU and the use of PEG as a precipitating agent, influence the concentration of cfDNA, cellular gDNA, and pseudovirions.

An update on one-dose HPV vaccine studies, immunobridging and humoral immune responses - A meeting report.

The 12th HPV Prevention and Control meeting was held on June 2-3, 2022, in Antwerp, Belgium. This technical meeting focused on several topics. This report summarises the discussions and lessons learned on two topics: an update on one-dose HPV vaccination studies and humoral immune responses upon HPV vaccination. Long-term follow-up studies from Costa Rica (eleven years) and India (ten years) report stable levels of antibodies after a single HPV vaccination. High vaccine effectiveness against incident persistent HPV 16/18 infection was seen in India (95.4%, 85.0-99.9) ten years postvaccination and in Kenya (97.5%, 81.7-99.7) eighteen months postvaccination, an important observation in a setting with a higher HPV prevalence. The potential impact of HPV vaccination using a one-dose schedule in India was modelled and showed that implementation of one-dose schedule can contribute towards achieving WHO Cervical Cancer elimination goals. These data support the WHO SAGE recommendations for adopting a one-dose schedule for females aged 9-20 years. Immunobridging studies were discussed during the meeting. General agreement was reached that when thoughtfully applied, they can support and accelerate the expanded use of HPV vaccine with new vaccine schedules, age cohorts, or vaccine formulations. Internationally standardised measurements of HPV immune responses important for the progress of HPV vaccinology field. Humoral immune responses upon HPV vaccination plateau at 24 months regardless of number of doses, therefore, data should be analysed after at least 24 months of follow-up to bridge studies accurately.