The Swedish Cervical Screening Cohort.

The Cervical Screening Cohort enrols women screened for human papillomavirus (HPV) and cervical abnormalities within the capital region of Sweden from the organised screening program and the non-organised testing of cervical samples. The cohort started in 2011 and has enrolled more than 670,000 women, contributing with more than 1.2 million biobanked samples. The cohort is systematically updated with individual-level data from the Swedish National Cervical Screening Registry (NKCx). Key variables include birthdate, sampling date, cytological, histopathological and HPV analysis results, and invitation history. Each sampling and subsequent clinical follow-up is sequentially registered, allowing for longitudinal analyses of screening results and associated results of the clinical workup. The cohort is ideal for longitudinal, long-term follow-up studies due to its validated documentation and registry-derived information. From the data, it is possible to penetrate important human health mechanisms. The data are available as open-data and GDPR-compliant. Samples are available after getting the required permissions. Results will help researchers understand factors that increase cancer risk and other diseases.

Mapping HPV 16 Sub-Lineages in Anal Cancer and Implications for Disease Outcomes.

The incidence of anal cancer is rising worldwide. As identified in cervical cancer management, an improvement in the early detection and management of anal pre-cancer is essential. In other cancers associated with human papillomavirus (HPV), HPV 16 sub-lineages have been shown to be associated with disease status and prognosis. However, in anal cancer, they have been under-explored. A total of 119 HPV 16-positive anal cancer lesions diagnosed between 2009 and 2018 in Scotland and 134 HPV 16-positive residual rectal swabs from asymptomatic men collected in 2016/7 were whole genome sequenced. The association of HPV 16 sub-lineages with underlying disease status (cancer vs. asymptomatic) and overall survival in anal cancer samples was assessed (comparing A1 vs non-A1 sub-lineages). A1 was the dominant sub-lineage present in the anal cancer (76.5%) and the asymptomatic (76.1%) cohorts. A2 was the second most dominant sub-lineage in both groups (16.8% and 17.2%, respectively). We did not observe significant associations of sub-lineage with demographics, clinical variables or survival (A1 vs. non-A1 sub-lineages (HR 0.83, 0.28-2.46 p = 0.743)). HPV 16 sub-lineages do to not appear to cluster with disease vs asymptomatic carriage or be independently associated with outcomes in anal cancer patients. Further international studies on anal HPV sub-lineage mapping will help to determine whether this is a consistent observation.

Audit of laboratory sensitivity of human papillomavirus and cytology testing in a cervical screening program.

The globally recommended public health policy for cervical screening is primary human papillomavirus (HPV) screening with cytology triaging of positives. To ensure optimal quality of laboratory services we have conducted regular audits of cervical smears taken before cervical cancer or cancer in situ (CIN3+) within an HPV-based screening program. The central cervical screening laboratory of Stockholm, Sweden, identified cases of CIN3+ who had had a previous cervical screening test up to 3 years before and randomly selected 300 cervical liquid-based cytology (LBC) samples for auditing. HPV testing with Roche Cobas was performed either at screening or with biobanked samples. HPV negative samples and subsequent biopsies were retrieved and tested with modified general primer HPV PCR and, if still HPV-negative, the LBCs and biopsies were whole genome sequenced. The Cobas 4800 detected HPV in 1020/1052 (97.0%) LBC samples taken before CIN3+. Further analyses found HPV in 28 samples, with nine of those containing HPV types not targeted by the Cobas 4800 test. There were 4 specimens (4/1052, 0.4%) where no HPV was detected. By comparison, the proportion of CIN3+ cases that were positive in a previous cytology were 91.6%. We find that the routine HPV screening test had a sensitivity in the real-life screening program of 97.0%. Regular laboratory audits of cervical samples taken before CIN3+ can be readily performed within a real-life screening program and provide assurance that the laboratory of the real-life program has the expected performance.

Human Papillomavirus Detection by Whole-Genome Next-Generation Sequencing: Importance of Validation and Quality Assurance Procedures.

Next-generation sequencing (NGS) yields powerful opportunities for studying human papillomavirus (HPV) genomics for applications in epidemiology, public health, and clinical diagnostics. HPV genotypes, variants, and point mutations can be investigated in clinical materials and described in previously unprecedented detail. However, both the NGS laboratory analysis and bioinformatical approach require numerous steps and checks to ensure robust interpretation of results. Here, we provide a step-by-step review of recommendations for validation and quality assurance procedures of each step in the typical NGS workflow, with a focus on whole-genome sequencing approaches. The use of directed pilots and protocols to ensure optimization of sequencing data yield, followed by curated bioinformatical procedures, is particularly emphasized. Finally, the storage and sharing of data sets are discussed. The development of international standards for quality assurance should be a goal for the HPV NGS community, similar to what has been developed for other areas of sequencing efforts including microbiology and molecular pathology. We thus propose that it is time for NGS to be included in the global efforts on quality assurance and improvement of HPV-based testing and diagnostics.

The 2019 HPV Labnet international proficiency study: Need of global Human Papillomavirus Proficiency Testing.

BACKGROUND: Accurate and internationally comparable human papillomavirus (HPV) testing services are essential for cervical cancer elimination programs. The WHO HPV Laboratory Network started issuing international HPV testing proficiency panels in 2008. OBJECTIVES: We report the results of the 2019 global proficiency study and evaluate the proficiency over time. STUDY DESIGN: The proficiency panel contained 40 coded samples containing mixes of purified HPV types (HPV6/11/16/18/31/33/35/39/45/51/52/56/58/59/68a/68b) and 4 controls. Proficiency required detection of both single and multiple infections of 50 International Units of HPV 16/18, of 500 genome equivalents (10x higher concentration) for other HPV types, and no false positives (stricter requirement compared to previous panels). RESULTS: Seventy-eight laboratories submitted 110 datasets with 38 different assays. Most samples (38/44) were reported with 100% proficiency in most datasets. Mostly commercial assays were used (88/110 datasets). Overall, 47.3% of the datasets were 100% proficient. False positivity was detected in at least one sample in 30.1% of datasets. When analysing all datasets ever since 2008 using exactly the same proficiency criteria, there was a steady improvement up to 2017 (the proportion of datasets being completely proficient increased from 25% to 73%). However, in the 2019 proficiency testing the proportion of fully proficient datasets dropped to 50%. CONCLUSIONS: Although we initially documented a worldwide improvement in comparability and reliability of HPV testing services, the trend now appears to be reversed. In response, the International HPV Reference Center will provide support for improved quality of laboratory services, including issuing of global proficiency panels every year.

Antibodies to SARS-CoV-2 and risk of past or future sick leave.

The extent that antibodies to SARS-CoV-2 may protect against future virus-associated disease is unknown. We invited all employees (n = 15,300) at work at the Karolinska University Hospital, Stockholm, Sweden to participate in a study examining SARS-Cov-2 antibodies in relation to registered sick leave. For consenting 12,928 healthy hospital employees antibodies to SARS-CoV-2 could be determined and compared to participant sick leave records. Subjects with viral serum antibodies were not at excess risk for future sick leave (adjusted odds ratio (OR) controlling for age and sex: 0.85 [95% confidence interval (CI) (0.85 (0.43-1.68)]. By contrast, subjects with antibodies had an excess risk for sick leave in the weeks prior to testing [adjusted OR in multivariate analysis: 3.34 (2.98-3.74)]. Thus, presence of viral antibodies marks past disease and protection against excess risk of future disease. Knowledge of whether exposed subjects have had disease in the past or are at risk for future disease is essential for planning of control measures.Trial registration: First registered on 02/06/20, ClinicalTrials.gov NCT04411576.

Viremia preceding multiple sclerosis: Two nested case-control studies.

Infections have been suggested to be involved in Multiple Sclerosis (MS). We used metagenomic sequencing to detect both known and yet unknown microorganisms in 2 nested case control studies of MS. Two different cohorts were followed for MS using registry linkages. Serum samples taken before diagnosis as well as samples from matched control subjects were selected. In cohort1 with 75 cases and 75 controls, most viral reads were Anelloviridae-related and >95% detected among the cases. Among samples taken up to 2 years before MS diagnosis, Anellovirus species TTMV1, TTMV6 and TTV27 were significantly more common among cases. In cohort2, 93 cases and 93 controls were tested under the pre-specified hypothesis that the same association would be found. Although most viral reads were again related to Anelloviridae, no significant case-control differences were seen. We conclude that the Anelloviridae-MS association may be due to multiple hypothesis testing, but other explanations are possible.

Towards quality and order in human papillomavirus research.

The International Human Papillomavirus (HPV) Reference Center supports quality and order in HPV research and diagnostics. Notably, the center assigns HPV type numbers to novel HPV types, maintains a reference clone repository, and issues international proficiency panels for HPV genotyping. The established HPV types, currently up to HPV225, belong to 5 different genera: alpha (65 types), beta (54 types), gamma (98 types), mu (3 types) and nu (1 type). Since 2014, 23 novel types have been established, 82.6% of which belong to the gamma genus. Reference clones have been provided to 44 different research laboratories and the global proficiency program for HPV genotyping has seen an increasing participation (currently 146 laboratories) and complete proficiency has increased over time (from 26% to 59% of datasets). In summary, an increasing complexity of the HPVs requires international efforts to support a recognized quality and order among HPV types.

Deep sequencing extends the diversity of human papillomaviruses in human skin.

Most viruses in human skin are known to be human papillomaviruses (HPVs). Previous sequencing of skin samples has identified 273 different cutaneous HPV types, including 47 previously unknown types. In the present study, we wished to extend prior studies using deeper sequencing. This deeper sequencing without prior PCR of a pool of 142 whole genome amplified skin lesions identified 23 known HPV types, 3 novel putative HPV types and 4 non-HPV viruses. The complete sequence was obtained for one of the known putative types and almost the complete sequence was obtained for one of the novel putative types. In addition, sequencing of amplimers from HPV consensus PCR of 326 skin lesions detected 385 different HPV types, including 226 previously unknown putative types. In conclusion, metagenomic deep sequencing of human skin samples identified no less than 396 different HPV types in human skin, out of which 229 putative HPV types were previously unknown.

Diversity of human papillomaviruses in skin lesions.

Pools of frozen biopsies from patients with squamous cell carcinoma (SCC) (n=29) actinic keratosis (AK) (n=31), keratoacanthoma (n=91) and swab samples from 84 SCCs and 91 AKs were analysed with an extended HPV general primer PCR and high-throughput sequencing of amplimers. We found 273 different HPV isolates (87 known HPV types, 139 previously known HPV sequences (putative types) and 47 sequences from novel putative HPV types). Among the new sequences, five clustered in genus Betapapillomavirus and 42 in genus Gammapapillomavirus. Resequencing of the three pools between 21 to 70 times resulted in the detection of 283 different known or putative HPV types, with 156 different sequences found in only one of the pools. Type-specific PCRs for 37 putative types from an additional 296 patients found only two of these putative types. In conclusion, skin lesions contain a large diversity of HPV types, but most appeared to be rare infections.