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.

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.

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.

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.

Host chemokine signature as a biomarker for the detection of pre-cancerous cervical lesions.

BACKGROUND: The ability to distinguish which hrHPV infections predispose to significant disease is ever more pressing as a result of the increasing move to hrHPV testing for primary cervical screening. A risk-stratifier or "triage" of infection should ideally be objective and suitable for automation given the scale of screening. RESULTS: CCL2, CCL3, CCL4, CXCL1, CXCL8 and CXCL12 emerged as the strongest, candidate biomarkers to detect underlying disease [cervical intraepithelial neoplasia grade 2 or worse (CIN2+)]. For CIN2+, CCL2 had the highest area under the curve (AUC) of 0.722 with a specificity of 82%. A combined biomarker panel of six chemokines CCL2, CCL3, CCL4, CXCL1, CXCL8, and CXCL12 provides a sensitivity of 71% and specificity of 67%. CONCLUSION: The present work demonstrates that the levels of five chemokine-proteins are indicative of underlying disease. We demonstrate technical feasibility and promising clinical performance of a chemokine-based biomarker panel, equivalent to that of other triage options. Further assessment in longitudinal series is now warranted. METHODS: A panel of 31 chemokines were investigated for expression in routinely taken archived and prospective cervical liquid based cytology (LBC) samples using Human Chemokine Proteomic Array kit. Nine chemokines were further validated using Procartaplex assay on the Luminex platform.

Increased cycling cell numbers and stem cell associated proteins as potential biomarkers for high grade human papillomavirus+ve pre-neoplastic cervical disease.

High risk (oncogenic) human papillomavirus (HPV) infection causes cervical cancer. Infections are common but most clear naturally. Persistent infection can progress to cancer. Pre-neoplastic disease (cervical intraepithelial neoplasia/CIN) is classified by histology (CIN1-3) according to severity. Cervical abnormalities are screened for by cytology and/or detection of high risk HPV but both methods are imperfect for prediction of which women need treatment. There is a need to understand the host virus interactions that lead to different disease outcomes and to develop biomarker tests for accurate triage of infected women. As cancer is increasingly presumed to develop from proliferative, tumour initiating, cancer stem cells (CSCs), and as other oncogenic viruses induce stem cell associated gene expression, we evaluated whether presence of mRNA (detected by qRT-PCR) or proteins (detected by flow cytometry and antibody based proteomic microarray) from stem cell associated genes and/or increased cell proliferation (detected by flow cytometry) could be detected in well-characterised, routinely collected cervical samples from high risk HPV+ve women. Both cytology and histology results were available for most samples with moderate to high grade abnormality. We found that stem cell associated proteins including human chorionic gonadotropin, the oncogene TP63 and the transcription factor SOX2 were upregulated in samples from women with CIN3 and that the stem cell related, cell surface, protein podocalyxin was detectable on cells in samples from a subset of women with CIN3. SOX2, TP63 and human gonadotrophin mRNAs were upregulated in high grade disease. Immunohistochemistry showed that SOX2 and TP63 proteins clearly delineated tumour cells in invasive squamous cervical cancer. Samples from women with CIN3 showed increased proliferating cells. We believe that these markers may be of use to develop triage tests for women with high grade cervical abnormality to distinguish those who may progress to cancer from those who may be treated more conservatively.