Publications by authors named "Severien Van Keer"

Primary Human Papillomavirus (HPV) screening on samples collected by women themselves has proven to be an effective strategy for cervical cancer screening (CCS) and may increase participation rates in women who do not partake (regularly) in screening. The aim of this study is to investigate reasons for non-participation and perceptions of CCS using self-sampling methods among under-screened women in Flanders. Individual interviews with 15 underscreened women aged 30-64 years were conducted.

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Recent studies demonstrated that human papillomavirus (HPV) specific immunoglobulins (IgG) are present and detectable in non-invasively collected first-void urine (FVU) samples. As IgG levels in urine are low, we evaluated the potential of a highly sensitive HPV16-specific assay based on time-resolved fluorescence, DELFIA, and compared it with three immunoassays, GST-L1-MIA, M4ELISA, and M9ELISA. A total of 225 paired serum and FVU samples from two cohorts of healthy female volunteers were analyzed.

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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.

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The VALHUDES protocol was established to evaluate clinical accuracy of human papillomavirus (HPV) assays to detect cervical precancer on first-void urine (FVU) and vaginal self-samples versus matched clinician-collected cervical samples (CCSs). Here we evaluated clinical performance of Alinity m HR HPV assay in a colposcopy referral population. Home-collected FVU (Colli-Pee FV 5020) 1 day before colposcopy (n = 492), at-clinic collected dry vaginal self-samples [multi-Collect Swab (mC; n = 493), followed by Evalyn Brush (EB; n = 233) or Qvintip (QT; n = 260)] and matched CCSs, were available for the study.

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Assessment of humoral immune responses following human papillomavirus (HPV) vaccination currently relies on invasive blood sampling. This longitudinal cohort study explores the usability of first-void urine as a noninvasive alternative sample for antibody detection. In this study, 58 women receiving three doses of the 9vHPV vaccine within a Gardasil9 (9vHPV) Phase III randomized controlled trial were included.

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The accuracy of high-risk human papillomavirus testing with the Xpert HPV assay on vaginal self-samples was compared with clinician-taken samples within the VALidation of HUman papillomavirus assays and collection DEvices for Self-samples and urine samples (VALHUDES) framework. Five-hundred and twenty-three women were recruited in five Belgian colposcopy clinics, of whom 483 (median age, 40 years; interquartile range, 31 to 49 years) were included in the main analysis (226 collected with Evalyn Brush and 257 collected with Qvintip). Cervical samples were collected with Cervex-Brush.

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Background: In this study, we evaluated accuracy of HPV testing on self-samples versus clinician-taken samples through the VALHUDES protocol. VALHUDES was designed as a diagnostic test accuracy study, where women referred to colposcopy collected self-samples followed by clinician-taken cervical samples.

Methods: Four hundred eighty-five women recruited in five colposcopy clinics (median age = 40 years; IQR, 31-49) with valid results for all specimens were included in the main analysis: 230 vaginal self-samples were collected with Evalyn Brush and 255 with Qvintip.

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Background: Urine collection is a non-invasive self-sampling method offering the prospect of reaching women un(der)-screened for cervical cancer. The VALHUDES research framework was designed to address the lack of clinical accuracy data for high-risk (hr)HPV testing using urine samples.

Objectives: Here, we report on the analytical and clinical accuracy of hrHPV testing on first-void urine, collected at home, using an extended HPV genotyping assay.

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The VALHUDES framework (NCT03064087) was established to evaluate the clinical accuracy of HPV testing on self-samples compared with HPV testing on matched clinician-taken cervical samples. Women referred to colposcopy due to previous cervical abnormalities were recruited at five Belgian colposcopy centers. A total of 486 pairs of matched cervical samples and vaginal self-samples were included in the analysis (228 collected with Evalyn Brush and 258 with Qvintip).

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Background: Interventions to reach women who do not participate regularly in screening may reduce the risk of cervical cancer. Self-collection of a vaginal specimen has been shown to increase participation. The relative clinical accuracy of human papillomavirus (HPV) testing on first-void urine (with Colli-Pee) and on vaginal self-samples versus on cervical clinician-collected samples is being investigated in the VALHUDES trial.

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Objective: Urine self-sampling has gained increasing interest for cervical cancer screening. In contrast to analytical performance, little information is available regarding the clinical accuracy for high-risk Human Papillomavirus (hrHPV) testing on urine.

Methods: VALHUDES is a diagnostic test accuracy study comparing clinical accuracy to detect high-grade cervical precancer (CIN2+) of HPV testing on self-collected compared to clinician-collected samples (NCT03064087).

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The potential of first-void (FV) urine as a non-invasive liquid biopsy for detection of human papillomavirus (HPV) DNA and other biomarkers has been increasingly recognized over the past decade. In this study, we investigated whether the volume of this initial urine stream has an impact on the analytical performance of biomarkers. In parallel, we evaluated different DNA extraction protocols and introduced an internal control in the urine preservative.

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Host cell DNA methylation analysis in urine provides promising triage markers for women diagnosed with a high-risk (HR) human papillomavirus (HPV) infection. In this study, we have investigated a panel of six host cell methylation markers (GHSR, SST, ZIC1, ASCL1, LHX8, ST6GALNAC5) in cervicovaginal secretions collected within the first part of the urine void (FVU) from a referral population. Cytology, histology, and HPV DNA genotyping results on paired FVU and cervical samples were available.

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The potential of first-void (FV) urine as a non-invasive method to monitor human papillomavirus (HPV) vaccination has been reported, mainly focusing on urine as a sample to assess HPV DNA. Besides HPV DNA, vaccine-induced HPV antibodies originating from cervicovaginal secretions were recently shown to be detectable in FV urine as well. This presents a novel opportunity for non-invasive sampling to monitor HPV antibody status in women participating in large epidemiological studies and HPV vaccine trials.

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Vaccine-induced human papillomavirus (HPV) antibodies originating from cervicovaginal secretions were recently shown to be detectable in first-void (FV) urine. This presents a novel opportunity for noninvasive sampling to monitor HPV antibody status in women participating in large epidemiological studies and HPV vaccine trials. With a view towards method optimization, this study compared the measurement of HPV antibodies in FV urine using a multiplex L1/L2 virus-like particles (VLP)-based ELISA (M4ELISA) with previously reported results using a glutathione S-transferase (GST)-L1-based immunoassay (GST-L1-MIA).

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Background: Human papillomavirus (HPV) infects and propagates in the cervical mucosal epithelium. Hence, in addition to assessing systemic immunity, the accurate measurement of cervical immunity is important to evaluate local immune responses to HPV infection and vaccination. This review discusses studies that investigated the presence of infection and vaccine-induced HPV-specific antibodies in cervicovaginal secretions (CVS).

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Background: Monitoring HPV antibodies non-invasively would be a major advantage for large epidemiological studies and follow-up of vaccinees.

Objectives: This study investigated the presence of HPV-specific antibody transudates from systemic circulation in first-void urine of (un)vaccinated subjects and the agreement with paired sera.

Study Design: In this case-control study, 55 paired first-void urine and serum samples were included from 19- to 26-year-old women, unvaccinated (n = 19) or vaccinated (n = 36) with the bi- or quadrivalent HPV vaccine during adolescence (NCT02714114).

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Background: Tsetse flies (Glossina sp.) refractory to trypanosome infection are currently being explored as potential tools to contribute in the control of human and animal African trypanosomiasis. One approach to disrupt trypanosome transmission by the tsetse fly vector involves the use of paratransgenesis, a technique that aims to reduce vector competence of disease vectors via genetic modification of their microbiota.

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Great interest has been directed towards the use of first-void (FV) urine as a liquid biopsy for high-risk HPV DNA testing. The aim of this study was to investigate the potential effect of a first generation FV urine collection device on the detection of HPV DNA and to assess if the concentration of HPV DNA varies between FV urine collected in the morning and those collected later during the day. In this prospective cohort study, 33 self-reported HPV-positive women participated.

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The performance and acceptability of first-void urine as specimen for the detection of HPV DNA in a Belgian referral population was evaluated using an optimized sample collection and processing protocol. One hundred ten first-void urine and cervical samples were collected from 25- to 64-year-old women who were referred for colposcopy (January-November 2016). Paired samples were analyzed by the Riatol qPCR HPV genotyping assay.

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Great interest has been directed towards the use of first-void urine as a liquid biopsy for high-risk human papillomavirus DNA testing. Despite the high correlations established between urinary and cervical infections, human papillomavirus testing is unable to distinguish between productive and transforming high-risk infections that have the tendency to progress to cervical cancer. Thus far, investigations have been primarily confined to the identification of biomarkers for triage of high-risk human papillomavirus-positive women in cervicovaginal specimens and tissue biopsies.

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Urine sampling for HPV DNA detection has been proposed as an effective method for monitoring the impact of HPV vaccination programs; however, conflicting results have been reported. The goal of this study was to evaluate the performance of optimized urine HPV DNA testing in women aged 19 to 25 years. Optimization process included the use of first void urine, immediate mixing of urine with DNA preservative, and the concentration of all HPV DNA, including cell-free DNA fragments.

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The link between infection with high-risk human papillomavirus (hrHPV) and cervical cancer has been clearly demonstrated. Virological end-points showing the absence of persistent HPV infection are now accepted as a way of monitoring the impact of prophylactic vaccination programs and therapeutic vaccine trials. This study investigated the use of urine samples, which can be collected by self-sampling at home, instead of cervical samples for follow-up of an HPV intervention trial.

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Prevention and treatment of human papillomavirus related cervical cancer through vaccination is a relative new field with many scientific, technological and implementational challenges requiring numerous new clinical trials. The initial prophylactic HPV vaccine trials allowed to set new end-points based on persistent infection in order to determine vaccine efficacy for prevention of cervical cancer. Major progress has been made regarding detection of HPV DNA in urine and high correlations between urinary HPV DNA and cervical infections have been established.

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