Publications by authors named "Irene Kraus Christiansen"

Article Synopsis
  • High-grade cervical lesions and cancers (HSIL+) can sometimes test negative for HPV, leading to variability in HPV detection rates among labs.
  • A study re-analyzed 116 HPV-negative cervical specimens, discovering that over 61% actually contained HPV upon further testing.
  • The findings suggest that improving quality assurance measures and re-analysis protocols for HPV-negative HSIL+ cases can enhance the reliability of HPV testing services.
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Background: Previously developed TaME-seq method for deep sequencing of HPV, allowed simultaneous identification of the human papillomavirus (HPV) DNA consensus sequence, low-frequency variable sites, and chromosomal integration events. The method has been successfully validated and applied to the study of five carcinogenic high-risk (HR) HPV types (HPV16, 18, 31, 33, and 45). Here, we present TaME-seq2 with an updated laboratory workflow and bioinformatics pipeline.

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Persistent infection with Human Papillomavirus (HPV) is responsible for almost all cases of cervical cancers, and HPV16 and HPV18 associated with the majority of these. These types differ in the proportion of viral minor nucleotide variants (MNVs) caused by APOBEC3 mutagenesis as well as integration frequencies. Whether these traits extend to other types remains uncertain.

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Background: Cervical cancer screening participation is suboptimal in most settings. We assessed whether human papillomavirus (HPV) self-sampling may increase screening participation among long-term non-attenders in Norway.

Methods: A pragmatic randomised controlled trial with participation as the primary outcome was initiated in the national cervical screening programme in March 2019.

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Background: Cervical cancer screening programs are facing a programmatic shift where screening protocol based on human papillomavirus testing (HPV-Screening protocol) is replacing the liquid-based cytology (LBC-Screening protocol). For safe technology transfer within the nationwide screening programme in Norway, HPV-Screening protocol was implemented randomized to compare the real-world effectiveness of HPV-Screening protocol and LBC-Screening protocol at the first screening round.

Methods: Among 302,295 women ages 34 to 69 years scheduled to attend screening from February 2015 to June 2017, 157,447 attended.

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Human papillomavirus (HPV) 16 and 18 are the most predominant types in cervical cancer. Only a small fraction of HPV infections progress to cancer, indicating that additional factors and genomic events contribute to the carcinogenesis, such as minor nucleotide variation caused by APOBEC3 and chromosomal integration. We analysed intra-host minor nucleotide variants (MNVs) and integration in HPV16 and HPV18 positive cervical samples with different morphology.

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Background & Aim: Women with HIV/HPV coinfection and cervical lesions are at increased risk of developing HPV related anal cancer. Self-collection of anal swabs may facilitate HPV molecular testing in anal cancer screening, especially in high-risk groups, and yet it is not adequately studied. We evaluated level of agreement between self-collected anal swabs (SCAS) and clinician-collected anal swabs (CCAS) when used for HPV genotyping.

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Aim: The VALidation of HPV GENotyping Tests (VALGENT) is a framework for comparison and validation of HPV tests with genotyping capabilities. In this study, the clinical performance of a single tube HPV test -HarmoniaHPV- was assessed in SurePath™ samples and compared to a clinically validated reference test, the GP5+/6+ Enzyme ImmunoAssay (GP5+/6 + EIA).

Methods: HarmoniaHPV test is a real-time, PCR based, limited genotyping HPV test which detects 14 high-risk HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68 with HPV16, and HPV 18 reported individually.

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Background: The VALidation of HPV Genotyping Tests (VALGENT) framework is an international cooperation designed for comparison and clinical validation of HPV assays with genotyping capabilities.

Objectives: Here we addressed the accuracy of the Roche cobas 4800 HPV test using SurePath samples from the Danish cervical cancer screening program under the VALGENT framework.

Material And Methods: The VALGENT4 panel comprises 998 consecutive SurePath cervical samples from routine screening and 297 SurePath samples enriched for disease (100 ASC-US, 100 LSIL, 97 HSIL).

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HPV-DNA integration results in dysregulation of viral oncogene expression. Because viral-cellular fusion transcripts inherently lack the viral AU-rich elements of the 3'UTR, they are considered to be more stable than episome-derived transcripts. The aim of this study is to provide formal proof for this assumption by comparing the stability of viral early transcripts derived from episomal and integrated HPV16 DNA, respectively.

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Background: Many countries have initiated school-based human papillomavirus (HPV) vaccination programs. The real-life effectiveness of HPV vaccines has become increasingly evident, especially among girls vaccinated before HPV exposure in countries with high vaccine uptake. In 2009, Norway initiated a school-based HPV vaccination program for 12-year-old girls using the quadrivalent HPV vaccine (Gardasil®), which targets HPV6, 11, 16, and 18.

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Background: Chronic infections by one of the oncogenic human papillomaviruses (HPVs) are responsible for near 5% of the global cancer burden and HPV16 is the type most often found in cancers. HPV genomes display unexpected levels of variation when deep-sequenced. Minor nucleotide variations (MNVs) may reveal HPV genomic instability and HPV-related carcinogenic transformation of host cells.

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HPV genomic variability and chromosomal integration are important in the HPV-induced carcinogenic process. To uncover these genomic events in an HPV infection, we have developed an innovative and cost-effective sequencing approach named TaME-seq (tagmentation-assisted multiplex PCR enrichment sequencing). TaME-seq combines tagmentation and multiplex PCR enrichment for simultaneous analysis of HPV variation and chromosomal integration, and it can also be adapted to other viruses.

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Background: The VALidation of HPV GENoyping Tests (VALGENT) is an international initiative designed to validate HPV assays with genotyping capability. The VALGENT4 protocol differs from previous VALGENT installments as the sample collection medium is SurePath, and exclusively includes samples from women ≥30 years of age which is concordant with the majority of HPV primary screening guidelines. Here we present the protocol for the fourth installment of the VALGENT framework.

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Background: In 2009, quadrivalent human papillomavirus (HPV) vaccine was introduced in a school-based single-cohort program targeting 12-year-old girls in Norway. We estimated the impact of the Norwegian HPV immunization program.

Methods: Three birth cohorts of 17-year-old girls, 2 nonvaccine-eligible cohorts (born 1994 or 1996) and 1 vaccine-eligible cohort (born 1997) were invited to deliver urine samples.

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Human papillomaviruses (HPVs) co-evolve slowly with the human host and each HPV genotype displays epithelial tropisms. We assessed the evolution of intra HPV genotype variants within samples, and their association to anogenital site, cervical cytology and HIV status. Variability in the L1 gene of 35 HPV genotypes was characterized phylogenetically using maximum likelihood, and portrayed by phenotype.

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Sensitive and specific genotyping of human papillomaviruses (HPVs) is important for population-based surveillance of carcinogenic HPV types and for monitoring vaccine effectiveness. Here we compare HPV genotyping by Next Generation Sequencing (NGS) to an established DNA hybridization method. In DNA isolated from urine, the overall analytical sensitivity of NGS was found to be 22% higher than that of hybridization.

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Background: Human papillomavirus (HPV) testing as primary screening for cervical cancer is currently being implemented in Norway in a randomized controlled fashion, involving three laboratories. As part of the quality assurance programme of the implementation, an evaluation of the inter-laboratory reproducibility of the HPV test was initiated, to ensure satisfactory HPV test reliability in all three laboratories.

Methods: The HPV test used is the cobas 4800 HPV Test, detecting 14 high-risk types with individual HPV genotype results for HPV16 and HPV18.

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Integration of human papillomavirus (HPV) into the host genome is regarded as a determining event in cervical carcinogenesis. However, the exact mechanism for integration, and the role of integration in stimulating cancer progression, is not fully characterized. Although integration sites are reported to appear randomly distributed over all chromosomes, fragile sites, translocation break points and transcriptionally active regions have all been suggested as being preferred sites for integration.

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