Clinical performance of the novel full-genotyping OncoPredict HPV Quantitative Typing assay using the VALGENT framework.

Clinical validation of human papillomavirus (HPV) assays according to international criteria is prerequisite for their implementation in cervical cancer screening. OncoPredict HPV Quantitative Typing (QT) assay (Hiantis Srl, Milan, Italy) is a novel full-genotyping multiplex real-time PCR quantitative assay targeting E6/E7 genes, allowing individual viral load determination of 12 high-risk (HR) HPV types. Quality controls for sample adequacy, efficiency of nucleic acid extraction and PCR inhibition are included in the assay. Clinical performance of OncoPredict HPV QT test was assessed as part of the "Validation of HPV Genotyping Tests" (VALGENT-2) framework, consisting of 1300 cervical liquid-based cytology (LBC) samples of women aged between 20 and 60 years who had originally attended for routine cervical screening in Scotland. The clinical accuracy of the OncoPredict HPV QT (index test) for the detection of CIN2+ was assessed relative to the GP5+/6+ Enzyme ImmunoAssay (GP5+/6+ EIA) (comparator test), using noninferiority criteria. Intra- and interlaboratory reproducibility of the assay was assessed on a subpopulation, comprising 526 samples. The relative sensitivity and specificity for OncoPredict HPV QT vs GP5+/6+-PCR-EIA were 1.01 (95% CI: 0.99-1.03) and 1.03 (95% CI: 1.0-1.06) respectively. The P-values for noninferiority were ≤0.001. The intra- and inter-laboratory reproducibility demonstrated a high concordance (>98.7%) with kappas for individual types ranging from 0.66 to 1.00. OncoPredict HPV QT fulfills the international validation criteria for the use of HPV tests in cervical cancer screening.

FAM19A4/miR124-2 Methylation Testing and Human Papillomavirus (HPV) 16/18 Genotyping in HPV-Positive Women Under the Age of 30 Years.

BACKGROUND: High-grade squamous intraepithelial lesions (HSIL) or cervical intraepithelial neoplasia (CIN) grade 2/3 lesions in human papillomavirus (HPV)-positive women <30 years of age have high spontaneous regression rates. To reduce overtreatment, biomarkers are needed to delineate advanced CIN lesions that require treatment. We analyzed the FAM19A4/miR124-2 methylation test and HPV16/18 genotyping in HPV-positive women aged <30 years, aiming to identify CIN2/3 lesions in need of treatment. METHODS: A European multicenter retrospective study was designed evaluating the FAM19A4/miR124-2 methylation test and HPV16/18 genotyping in cervical scrapes of 1061 HPV-positive women aged 15-29 years (690 ≤CIN1, 166 CIN2, and 205 CIN3+). A subset of 62 CIN2 and 103 CIN3 were immunohistochemically characterized by HPV E4 expression, a marker for a productive HPV infection, and p16ink4a and Ki-67, markers indicative for a transforming infection. CIN2/3 lesions with low HPV E4 expression and high p16ink4a/Ki-67 expression were considered as nonproductive, transforming CIN, compatible with advanced CIN2/3 lesions in need of treatment. RESULTS: FAM19A4/miR124-2 methylation positivity increased significantly with CIN grade and age groups (<25, 25-29, and ≥30 years), while HPV16/18 positivity was comparable across age groups. FAM19A4/miR124-2 methylation positivity was HPV type independent. Methylation-positive CIN2/3 lesions had higher p16ink4a/Ki-67-immunoscores (P = .003) and expressed less HPV E4 (P = .033) compared with methylation-negative CIN2/3 lesions. These differences in HPV E4 and p16ink4a/Ki-67 expression were not found between HPV16/18-positive and non-16/18 HPV-positive lesions. CONCLUSIONS: Compared with HPV16/18 genotyping, the FAM19A4/miR124-2 methylation test detects nonproductive, transforming CIN2/3 lesions with high specificity in women aged <30 years, providing clinicians supportive information about the need for treatment of CIN2/3 in young HPV-positive women.

Evaluation of the clinical performance of OncoPredict HPV® SCR assay within the VALGENT-2 framework.

Human papillomavirus (HPV) assays used in cervical cancer screening should be clinically validated according to international criteria. OncoPredict HPV® Screening (SCR) is a partial genotyping multiplex real-time PCR assay targeting E6/E7 genes of 13 high-risk (hr) HPVs. OncoPredict HPV® SCR (index assay) identifies HPV-16 and HPV-18 separately, 11 other hrHPV in aggregate and includes quality controls for sample adequacy, DNA extraction efficiency and PCR inhibition. 1300 VALGENT-2 study samples (from women aged 20-60 attending the Scottish cervical cancer screening program) were tested with the index assay and the GP5+/6+ PCR enzyme immunoassay (standard comparator assay). Non-inferior accuracy detecting cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) of the index versus comparator was verified. Intra- and interlaboratory reproducibility of the index was evaluated by overall concordance and Cohen's kappa, using a sub-population (n = 526). Relative sensitivity and specificity for CIN2+ of the index versus comparator were 1.01 (95% confidence interval [CI]: 0.99-1.03) and 1.02 (95% CI: 1.0-1.04), respectively. Noninferiority p values were all ≤0.05, except for CIN3+ in patients ≥30 years. Excellent intra- and interlaboratory reproducibility was shown with concordance >98% and kappas >0.95. OncoPredict HPV® SCR fulfills the three international validation criteria for hrHPV DNA tests in cervical cancer screening.

Clinical validation of full genotyping CLART® HPV4S assay on SurePath and ThinPrep collected screening samples according to the international guidelines for human papillomavirus test requirements for cervical screening.

BACKGROUND: To ensure the highest quality of human papillomavirus (HPV) testing in primary cervical cancer screening, novel HPV assays must be evaluated in accordance with the international guidelines. Furthermore, HPV assay with genotyping capabilities are becoming increasingly important in triage of HPV positive women in primary HPV screening. Here we evaluate a full genotyping HPV assay intended for primary screening. METHODS: The CLART® HPV4S (CLART4S) assay is a newly developed full-genotyping assay detecting 14 oncogenic (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68) and two non-oncogenic HPV genotypes (6, 11). It was evaluated using SurePath and ThinPrep screening samples collected from the Danish and Swedish cervical cancer screening programs, respectively. For calculation of sensitivity, 81 SurePath and 80 ThinPrep samples with confirmed ≥CIN2 were assessed. For clinical specificity analysis, 1184 SurePath and 1169 ThinPrep samples from women with

Use of HPV testing for cervical screening in vaccinated women--Insights from the SHEVa (Scottish HPV Prevalence in Vaccinated Women) study.

The management of cervical disease is changing worldwide as a result of HPV vaccination and the increasing use of HPV testing for cervical screening. However, the impact of vaccination on the performance of HPV based screening strategies is unknown. The SHEVa (Scottish HPV Prevalence in Vaccinated women) projects are designed to gain insight into the impact of vaccination on the performance of clinically validated HPV assays. Samples collated from women attending for first cervical smear who had been vaccinated as part of a national "catch-up" programme were tested with three clinically validated HPV assays (2 DNA and 1 RNA). Overall HR-HPV and type specific positivity was assessed in total population and according to underlying cytology and compared to a demographically equivalent group of unvaccinated women. HPV prevalence was significantly lower in vaccinated women and was influenced by assay-type, reducing by 23-25% for the DNA based assays and 32% for the RNA assay (p = 0.0008). All assays showed over 75% reduction of HPV16 and/or 18 (p < 0.0001) whereas the prevalence of non 16/18 HR-HPV was not significantly different in vaccinated vs unvaccinated women. In women with low grade abnormalities, the proportion associated with non 16/18 HR-HPV was significantly higher in vaccinated women (p < 0.0001). Clinically validated HPV assays are affected differentially when applied to vaccinated women, dependent on assay chemistry. The increased proportion of non HPV16/18 infections may have implications for clinical performance, consequently, longitudinal studies linking HPV status to disease outcomes in vaccinated women are warranted.

Metaproteomic analysis from cervical biopsies and cytologies identifies proteinaceous biomarkers representing both human and microbial species.

The detection of HPV infection and microbial colonization in cervical lesions is currently done through PCR-based viral or bacterial DNA amplification. Our objective was to develop a methodology to expand the metaproteomic landscape of cervical disease and determine if protein biomarkers from both human and microbes could be detected in distinct cervical samples. This would lead to the development of multi-species proteomics, which includes protein-based lateral flow diagnostics that can define patterns of microbes and/or human proteins relevant to disease status. In this study, we collected both non-frozen tissue biopsy and exfoliative non-fixed cytology samples to assess the consistency of detecting human proteomic signatures between the cytology and biopsy samples. Our results show that proteomics using biopsies or cytologies can detect both human and microbial organisms. Across patients, Lumican and Galectin-1 were most highly expressed human proteins in the tissue biopsy, whilst IL-36 and IL-1RA were most highly expressed human proteins in the cytology. We also used mass spectrometry to assess microbial proteomes known to reside based on prior 16S rRNA gene signatures. Lactobacillus spp. was the most highly expressed proteome in patient samples and specific abundant Lactobacillus proteins were identified. These methodological approaches can be used in future metaproteomic clinical studies to interrogate the vaginal human and microbiome structure and metabolic diversity in cytologies or biopsies from the same patients who have pre-invasive cervical intraepithelial neoplasia, invasive cervical cancer, as well as in healthy controls to assess how human and pathogenic proteins may correlate with disease presence and severity.

Agreement between L1 and E6/E7-based assays for detection of high-risk HPV in cervical, oropharyngeal and penile cancers.

AIMS: Human papillomavirus (HPV) molecular testing targets either the late gene L1 or early genes E6 and/or E7. Loss of L1 during integration is suggested to compromise sensitivity in samples associated with cancer, however, clear evidence for this is lacking. Our aim is to address this by performing a head-to-head comparison between assays targeting L1 vs E6/E7, using a series of high-grade and invasive disease samples within different biological matrices and anatomical sites. METHODS: We obtained 298 samples comprising of liquid-based cytology and biopsies of cervical cancer and cervical intraepithelial neoplasia grade 3, in addition to biopsies of penile and oropharyngeal cancers. Two commercially available HPV primary screening assays and two assays with extended genotyping were applied to the sample set targeting L1 (Abbott RealTime HR HPV Assay and Optiplex HPV Genotyping Test) and E6/E7 genes (Xpert HPV Test and EuroArray HPV Test). RESULTS: Agreement for high-risk HPV (hrHPV) for all samples types between the screening assays is over 88% and over 96% for the two genotyping assays. For HPV 16 agreement is over 90% for both screening and genotyping assays. Kappa statistics show good to very good agreement between the screening and genotyping assays for hrHPV and HPV 16. CONCLUSIONS: Analysis of the valid results from our data indicates that L1 and E6/E7 targeting assays show similar performance for detection of hrHPV in high grade cervical lesions and cancers of cervix, penis and oropharynx.

Influence of resuspension volume on dry sampling devices taken for human papillomavirus testing: implications for self-sampling.

Optimization of technical parameters that influence the performance of human papillomavirus (HPV) testing on self-taken samples is important. Here, the authors assessed the impact of resuspension volume on the detection of HPV using four validated HPV assays. Two self-sampling devices, FLOQSwabs® and Evalyn® Brushes, were inoculated with dilutions of HPV-16-positive cell line, then resuspended in various volumes of ThinPrep. The influence of vortexing during resuspension was also assessed. At target concentrations around the assay cutoff, larger volumes led to decreased HPV detection. Interestingly, the effect(s) of vortexing differed by the self-sampling device. Resuspension in 5 ml or less may maximize the detection of HPV sequences. Using a proxy of clinical material, the current observations underline the importance of optimizing preanalytical laboratory processes to support high-quality HPV testing of self-samples.

The role of circulating viral and tumour DNA in the diagnosis and management of HPV associated anogenital cancers, a systematic review and meta-analysis.

BACKGROUND: Human papillomavirus associated anogenital cancers are a significant global burden. The detection of biomarkers (circulating tumour DNA; ctDNA or circulating HPV DNA; cHPV DNA) in blood referred to as "liquid biopsy" may support the early diagnosis and monitoring of affected individuals. METHODS: A systematic review, including meta-analysis of studies available in the literature on the utilization of ctDNA and cHPV DNA as diagnostic, predictive, and monitoring biomarker tests of HPV associated anogenital cancers was performed following the criteria of PRISMA. RESULTS: A total of 31 studies were eligible for systematic review; 20 used cHPV DNA in cervical cancers; 7 used ctDNA in cervical cancer; 5 used cHPV DNA in anal cancer; no eligible studies on vulva, vaginal or penile cancer were available. The meta-analysis identified low sensitivity (0.36) and high specificity (0.96) of cHPV DNA as diagnostic for cervical cancer. Comparatively, there was high sensitivity (0.95) and specificity (1.0) of cHPV DNA for the diagnosis of anal cancer. cHPV DNA and/or ctDNA in cervical cancer were prognostic markers associated with poor clinical outcomes. Additionally, in anal cancer the post treatment detection of cHPV DNA was informative in the prediction of treatment response or progression-free survival. CONCLUSION: ctDNA and cHPV DNA are promising diagnostic and prognostic biomarkers for the detection of anogenital disease. Evolution and refinement of molecular tools is likely to improve performance further. Additionally the comparative absence of studies in the vulval, vaginal and penile context warrants further exploration and research.

Papilloplex HR-HPV test has non-inferior clinical performance for detection of human papillomavirus infection: assessment using the VALGENT framework.

AIM: The Papilloplex high-risk human papillomavirus (hrHPV) test (Genefirst, Oxford, UK) is a single tube real-time HPV test which provides multiplex detection and separate identification of 14 hrHPV types. Here, we present the clinical validation of the test in SurePath samples in comparison to a clinically validated reference test, the GP5+/6+Enzyme ImmunoAssay (GP5+/6+EIA) using the VALGENT (VALidation of HPV GENotyping Tests) framework. METHODS: Clinical performance was assessed using 998 unselected, cervical screening samples enriched with 297 cytologically abnormal specimens (100 atypical squamous cells of unspecified significance, 100 low-grade squamous intraepithelial lesions, 97 high-grade squamous intraepithelial lesions). Cases were defined as women diagnosed with histologically confirmed cervical intraepithelial neoplasia two or more (≥CIN2, N=119) and controls defined as women with two subsequent negative cytology results (N=834). RESULTS: The Papilloplex HR-HPV test has non-inferior sensitivity for detection of cervical precancer (p=0.0001 for ≥CIN2 and p=0.0005 for ≥CIN3) and non-inferior specificity, compared with GP5+/6+EIA (pni=0.0167)). The assay also showed excellent or good agreement for overall hrHPV and nearly all individual HPV types as compared with GP5+/6+EIA/Luminex. CONCLUSION: The Papilloplex HR-HPV applied on cervical specimens stored in SurePath medium fulfils the international clinical accuracy criteria for use in cervical cancer screening.

Diversity of cervicovaginal human papillomavirus (HPV) genotypes and naturally occurring E6/E7 DNA polymorphisms of HPV-16 in Ghana.

Human papillomavirus (HPV) E6 and E7 oncogene expression is essential for cervical carcinogenesis. Evidence exists that E6/E7 variants may have different transforming activities while the risk of HPV-16 variants (A/D) differs by race/ethnicity. We determined the type-specific diversity of HPV infection in women with high grade cervical disease or cervical cancer in Ghana and investigated naturally occurring E6/E7 DNA variants in this population. HPV genotyping was carried out on 207 cervical swab samples collected from women referred to a gynaecology clinic at two teaching hospitals in Ghana. HPV-16, HPV-18 and HPV-45 were detected in 41.9%, 23.3% and 16.3% of cases respectively. HPV-16 E6/E7 DNA sequencing was performed in 36 samples. Thirty samples contained E6/E7 variants of the HPV-16-B/C lineage. 21/36 samples were of the HPV-16C1 sublineage variant and all contained the E7 A647G(N29S) single nucleotide polymorphism (SNP). This study reveals the diversity of E6/E7 DNA and the dominance of HPV16 B/C variants in cervicovaginal HPV infection in Ghana. Type-specific HPV diversity analysis indicates that most Ghanaian cervical disease cases are vaccine preventable. The study provides an important baseline from which for the impact of vaccine and antivirals on clinically relevant HPV infection and associated disease can be measured.

Clinical performance of DNA and RNA based HPV tests for test of cure (TOC) post treatment for cervical intraepithelial neoplasia (CIN) - a retrospective study.

HPV testing as a "test of cure" (TOC) of women treated for cervical high-grade lesions can support and inform appropriate clinical management pathways. However, there is a lack of studies that report the discrete performance of different HPV assays in this context, including HPV mRNA based assays. To address this, we performed an analysis of the clinical performance of two hrHPV assays in the (TOC) setting; the recently launched DNA based Alinity m HR HPV (Abbott Molecular) and RNA based Aptima HPV assay (Hologic). Using a retrospective case-control design, two panels of archived cervical liquid based cytology samples, originally taken as per routine TOC protocols in Scotland were assessed. Each panel contained 63 cases, where cervical intraepithelial neoplasia 2 or worse (CIN2+) was detected and 160 controls (women with no CIN2+ and two subsequent cytology negative results (minimum) 3 years apart or women who had histologically confirmed ≤CIN1). All samples were previously tested using the RealTime High Risk HPV assay (Abbott Molecular) as per national TOC protocol. Panel A and Panel B were tested using Alinity and Aptima assay respectively. Both assays showed similar performance to the original RealTime assay. Aptima had sensitivity for CIN2+ of 96.8% (95% CI: 89.0- 99.6) compared to RealTime (93.7% (95% CI: 84.5 - 98.2)). Alinity had sensitivity for CIN2+ of 92.1% (95% CI: 82.4- 97.4) compared to RealTime (98.4% (95% CI: 91.5- 99.95)). Both mRNA based and DNA based HPV tests show robust performance for the monitoring of residual disease post-treatment.

Development and Validation of a Raman Spectroscopic Classification Model for Cervical Intraepithelial Neoplasia (CIN).

The mortality associated with cervical cancer can be reduced if detected at the precancer stage, but current methods are limited in terms of subjectivity, cost and time. Optical spectroscopic methods such as Raman spectroscopy can provide a rapid, label-free and nondestructive measurement of the biochemical fingerprint of a cell, tissue or biofluid. Previous studies have shown the potential of Raman spectroscopy for cervical cancer diagnosis, but most were pilot studies with small sample sizes. The aim of this study is to show the clinical utility of Raman spectroscopy for identifying cervical precancer in a large sample set with validation in an independent test set. Liquid-based cervical cytology samples (n = 662) (326 negative, 200 cervical intraepithelial neoplasia (CIN)1 and 136 CIN2+) were obtained as a training set. Raman spectra were recorded from single-cell nuclei and subjected to a partial least squares discriminant analysis (PLSDA). In addition, the PLSDA classification model was validated using a blinded independent test set (n = 69). A classification accuracy of 91.3% was achieved with only six of the blinded samples misclassified. This study showed the potential clinical utility of Raman spectroscopy with a good classification of negative, CIN1 and CIN2+ achieved in an independent test set.

Direct bisulphite conversion of cervical samples for DNA methylation analysis.

Sodium bisulphite conversion of DNA to separate methylated from unmethylated cytosines is a standard for methylation analysis. This study evaluated a direct cell conversion protocol on cervical samples as alternative to isolated genomic DNA as input.Clinician-collected cervical samples (n = 120) were subjected to a direct conversion protocol, or genomic DNA was isolated with a fixed amount used for subsequent bisulphite conversion. Converted samples were compared for ACTB control gene and methylation of FAM19A4 and miR124-2 genes using quantitative methylation-specific PCR (QIAsure Methylation Test).Direct conversion resulted in a high success rate, i.e., 119/120 (99.2%) samples reported a valid test result. ΔΔCq values of FAM19A4 and miR124-2 were significantly correlated between both protocols (Spearman Rho 0.708 and 0.763, respectively, all p-values = 0.000). Agreement between both the bisulphite protocols was demonstrated by Bland-Altman plots.A direct cell conversion protocol shows good technical and analytical performance and offers a streamlined workflow for methylation analysis.

The challenges of defining sample adequacy in an era of HPV based cervical screening.

BACKGROUND: The implementation of Human Papillomavirus based cervical screening continues apace on a global scale. Understanding the basis and burden of inadequate or invalid samples is important to ensure confidence in high quality laboratory results and inform the development of new technologies. Here we present population based data from Scotland and Denmark which detail the extent of invalid samples for HPV detection in both clinician-taken and self-taken samples. As a comparator we report on the rate of inadequate cytology preparations in both countries. METHODS: The proportion of samples with an invalid HPV test result was calculated by retrospective analysis of routine laboratory data associated with cervical screening programmes in the two countries. Two assays were in use for the programmes at the time (the Abbott RealTime High Risk HPV assay and the BD Onclarity); both have internal endogenous controls for human genes. In addition, acellular cytology samples were reported through a prospective audit (Scotland) and National quality reporting (Denmark). RESULTS: In total, 89,418 clinician samples and 14,677 self-taken samples were assessed. We observed low rates of invalid HPV tests in clinician taken samples (0.05-0.10 %), irrespective of sample collection media (ThinPrep or SurePath), HPV test system/endogenous control type or clinical indication for testing (primary screening, triage or test of cure). For self-taken samples, the number of invalid samples was 0.18 %. Complete absence of sample material (acellular) in clinician taken samples were observed at a level of 1 in approximately 16.5 thousand. CONCLUSIONS: Clinician and self-taken samples appear robust specimens for HPV testing and acellular samples are very rare. Efforts to develop endogenous controls for HPV assays that provide greater insight into true sample adequacy for cervical disease detection, beyond measuring the presence of human cells, will be welcome.

Evaluation of HarmoniaHPV test for detection of clinically significant Human Papillomavirus infection using the VALGENT framework.

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. Clinical performance was assessed using 998 unselected, cervical screening samples enriched with 297 cytologically abnormal specimens (100 atypical squamous cells of unspecified significance, 100 low-grade squamous intraepithelial lesions, 97 high-grade squamous intraepithelial lesions). Cases were defined as women diagnosed with histologically confirmed cervical intraepithelial neoplasia 2 or more (≥CIN2, N = 122). RESULTS: Using the manufacturer recommended (un-adjusted) cut-offs, HarmoniaHPV had non-inferior sensitivity for detection of ≥ CIN2 but showed inferior specificity. A cut-off optimisation exercise was therefore carried out and optimised cut-offs for each individual channel rendered a sensitivity and specificity of HarmoniaHPV that was non-inferior to GP5+/6 + EIA. Analytically, the test showed excellent intra- and inter-laboratory reproducibility, which improved further with the use of the optimised cut-offs. CONCLUSION: HarmoniaHPV when operated with optimised cut-offs fulfils the international clinical criteria for use in cervical cancer screening on SurePath samples. The optimised cut-offs warrant additional testing and independent validation.

Sensitivity of RT-PCR testing of upper respiratory tract samples for SARS-CoV-2 in hospitalised patients: a retrospective cohort study.

Background: This study aimed to determine the sensitivity and specificity of reverse transcription PCR (RT-PCR) testing of upper respiratory tract (URT) samples from hospitalised patients with coronavirus disease 2019 (COVID-19), compared to the gold standard of a clinical diagnosis. Methods: All URT RT-PCR testing for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in NHS Lothian, Scotland, United Kingdom between the 7 th of February and 19 th April 2020 (inclusive) was reviewed, and hospitalised patients were identified. All URT RT-PCR tests were analysed for each patient to determine the sequence of negative and positive results. For those who were tested twice or more but never received a positive result, case records were reviewed, and a clinical diagnosis of COVID-19 allocated based on clinical features, discharge diagnosis, and radiology and haematology results. For those who had a negative RT-PCR test but a clinical diagnosis of COVID-19, respiratory samples were retested using a multiplex respiratory panel, a second SARS-CoV-2 RT-PCR assay, and a human RNase P control. Results: Compared to the gold standard of a clinical diagnosis of COVID-19, the sensitivity of a single upper respiratory tract RT-PCR for COVID-19 was 82.2% (95% confidence interval 79.0-85.1%).   The sensitivity of two upper respiratory tract RT-PCR tests increased sensitivity to 90.6% (CI 88.0-92.7%). A further 2.2% and 0.9% of patients who received a clinical diagnosis of COVID-19 were positive on a third and fourth test; this may be an underestimate of the value of further testing as the majority of patients 93.0% (2999/3226) only had one or two URT RT-PCR tests. Conclusions: The sensitivity of a single RT-PCR test of URT samples in hospitalised patients is 82.2%. Sensitivity increases to 90.6% when patients are tested twice.  A proportion of cases with clinically defined COVID-19 never test positive on URT RT-PCR despite repeat testing.

HPV infection and pre-term birth: a data-linkage study using Scottish Health Data.

Background: We aimed to investigate whether infection with high-risk (HR) types of human papilloma virus (HPV) or HPV-associated cervical disease were associated with preterm birth (<37 weeks gestation). In a sub-group of younger women who were eligible for the HPV vaccine, we aimed to determine whether prior vaccination against the specific HPV-types, HPV-16 and -18 modified preterm birth risk. Methods: This was a data-linkage study, which linked HPV-associated viral and pathological information (from the Scottish HPV Archive) from women aged 16-45 years to routinely collected NHS maternity- and hospital-admission records from 1999-2015. Pregnancy outcomes from 5,598 women with term live birth (≥37 weeks gestation, n=4,942), preterm birth (<37 weeks gestation, n=386) or early miscarriage (<13 weeks gestation, n=270). Of these, data from HPV vaccine-eligible women (n=3,611, aged 16-25 years) were available, of whom 588 had been vaccinated. HPV-associated disease status was defined as: HR HPV-positive no disease, low-grade abnormalities or high-grade disease. Results: High-grade HPV-associated cervical disease was associated with preterm birth (odds ratio=1.843 [95% confidence interval 1.101-3.083], p=0.020) in adjusted binary logistic regression analysis, in all women, but there were no associations with HR HPV-infection alone or with low-grade abnormalities. No associations between any HPV parameter and preterm birth were seen in vaccine-eligible women, nor was there any effect of prior vaccination. Conclusions: HPV-associated high-grade cervical disease was associated with preterm birth, but there were no associations with HR HPV-infection or low-grade cervical disease. Thus HPV-infection alone (in the absence of cervical disease) does not appear to be an independent risk factor for preterm birth. For women who have undergone treatment for CIN and become pregnant, these results demonstrate the need to monitor for signs of preterm birth.

The potential of biobanked liquid based cytology samples for cervical cancer screening using Raman spectroscopy.

Patient samples are unique and often irreplaceable. This allows biobanks to be a valuable source of material. The aim of this study was to assess the ability of Raman spectroscopy to screen for histologically confirmed cases of Cervical Intraepithelial neoplasia (CIN) using biobanked liquid based cytology (LBC) samples. Two temperatures for long term storage were assessed; 80°C and -25°C. The utility of Raman spectroscopy for the detection of CIN was compared for fresh LBC samples and biobanked LBC samples. Two groups of samples were used for the study with one group associated with disease (CIN 3) and the other associated with no disease (cytology negative). The data indicates that samples stored at -80°C are not suitable for assessment by Raman spectroscopy due to a lack of cellular material and the presence of cellular debris. However, the technology can be applied to fresh LBC samples and those stored at -25°C and is, moreover, effective in the discrimination of negative samples from those where CIN 3 has been confirmed. Pooled fresh and biobanked samples are also amenable to the technology and achieve a similar sensitivity and specificity for CIN 3. This study demonstrates that cervical cytology samples stored within biobanks at temperatures that preclude cell lysis can act as a useful resource for Raman spectroscopy and will facilitate research and translational studies in this area.

Development of an in-house ELISA to detect anti-HPV16-L1 antibodies in serum and dried blood spots.

Measuring anti-HPV antibody levels is important for surveillance of the immunological response to both natural infection and vaccination. Here, an ELISA test for measurement of HPV-16L1 antibodies was developed and validated in sera and dried blood spots. An in-house ELISA was developed for measuring anti-HPV-16L1 IgA and IgG levels. The assay was standardized against WHO international standard serum and validated on serum, dried blood spots and cervical liquid based cytology samples from women attending colposcopy clinics in Scotland. Antibody avidity index was also measured in serum samples. The average HPV 16-L1 specific IgG and IgA levels measured in sera, in women attending a routine colposcopy service were 7.3 units/ml and 8.1 units/ml respectively. Significant correlations between serum and dried blood spot eluates for both IgG and IgA were observed indicating that the latter serve as a credible proxy for antibody levels. Average IgG Avidity Index was 35% (95% CI 25%-45%) suggesting previous, historical challenge with natural infection. This ELISA has potential for use in epidemiological and field studies of antibody prevalence and if coupled with avidity measurement may be of use in individual case monitoring of vaccine responses and failures.