A comparison of ThinPrep against four non-volatile transport media for HPV testing at or near the point of care

Comparison of the Clinical Accuracy of Xpert HPV Assay on Vaginal Self-Samples and Cervical Clinician-Taken Samples within the VALHUDES Framework

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. Colposcopy and histology outcomes were considered as the reference standard. The Xpert HPV assay had similar accuracy for cervical intraepithelial neoplasia ≥2 on self-collected versus clinician-collected samples [relative sensitivity, 0.96 (95% CI, 0.91-1.02); and relative specificity, 0.96 (95% CI, 0.89-1.04)]. The relative accuracy slightly differed by vaginal collection device [sensitivity ratios of 0.98 (95% CI, 0.90-1.06) and 0.94 (95% CI, 0.87-1.02) for Evalyn and Qvintip, respectively; specificity ratios of 1.06 (95% CI, 0.95-1.19) and 0.88 (95% CI, 0.80-0.98) for Evalyn and Qvintip, respectively]. No difference in cycle threshold values was observed between vaginal and cervical samples. In conclusion, the sensitivity of Xpert HPV assay for cervical intraepithelial neoplasia ≥2 on vaginal self-samples was similar to that of cervical specimens. The clinical specificity was lower than on clinician-collected samples when self-samples were taken with Qvintip.

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.

Development of loop-mediated isothermal amplification (LAMP) assay for rapid and direct screening of yellowfin tuna (Thunnus albacares) in commercial fish products

Tuna is one of the most widely consumed fish on the European market, being available in various consumable options. Among them, Thunnus albacares, also called yellowfin tuna, is a delicacy and is consumed by millions of people around the world. Due to its comparatively high cost and demand, it is more vulnerable to fraud, where low-cost tuna or other fish varieties might be replaced for economic gain. In this study, a loop-mediated isothermal amplification (LAMP) assay was developed and validated for targeting the mitochondrial cytochrome b gene for fast and direct detection of Thunnus albacares, which is a valuable tuna species. The analytical specificity was confirmed using 18 target samples (Thunnus albacares) and 18 samples of non-target fish species. The analytical sensitivity of the LAMP assay was 540 fg DNA per reaction. In addition, a simple and direct swab method without time-consuming nucleic acid extraction procedures and the necessity for cost-intensive laboratory equipment was performed that allowed LAMP detection of Thunnus albacares samples within 13 minutes. Due to its high specificity and sensitivity, the LAMP assay can be used as a rapid and on-site screening method for identifying Thunnus albacares, potentially providing a valuable monitoring tool for food authenticity control by the authorities.

Human papillomavirus (HPV) detection in vaginal self-samples: evaluation of eNat® as an alternative suspension medium to ThinPrep®PreservCyt® for vaginal swabs

Human Papillomavirus (HPV) testing on self-collected samples allows for improved coverage rates of cervical cancer (CC) screening programs. ThinPrep®PreservCyt® (HOLOGIC®, USA) medium is widely used for the suspension of cervical and vaginal self-samples. However, this medium is costly, toxic, and flammable, involving special handling procedures which make its use difficult in screening programs, particularly in low- and middle-income countries. This pilot study aimed to evaluate the analytical performance of eNat ® (Copan SpA), an alternative non-alcohol-based suspension medium, compared to ThinPrep®PreservCyt® (HOLOGIC®) for high-risk HPV (hrHPV) detection in vaginal self-collected swabs using three different real-time polymerase chain reaction (RT-PCR) HPV assays: Anyplex™II HPV28 (Seegene, Korea), Papilloplex® High Risk HPV (GeneFirst, UK), and HPV OncoPredict (Hiantis, Italy). 30 women, referred to colposcopy, were enrolled in this observational, prospective pilot study and asked to collect two vaginal self-taken samples, which were suspended in 5 mL of ThinPrep®PreservCyt® or eNat®. Nucleic acids were extracted from 200 μL using Microlab Nimbus platform (Seegene, Korea) and tested with the three different RT-PCR full-genotyping high-risk HPV assays. The HPV results of vaginal samples resuspended in the two different media were compared to those obtained from the reference clinician-collected cervical sample from the same woman. hrHPV detection in vaginal self-samples suspended in both media demonstrated a substantial agreement with cervical samples with the three assays under-investigation (0.667 Collapse

Key Words

• HPV-testing
• Human Papillomavirus (HPV)
• ThinPrep®PreservCyt
• eNat®
• vaginal self-collection

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Affiliation(s)

Chiara Giubbi Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
Marianna Martinelli Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
Ivan Vallini Hiantis S.r.l., Milano, Italy
Silvia Paganoni Hiantis S.r.l., Milano, Italy
Tarig Dafa'alla GeneFirst Ltd., Abingdon, OX14 3DB, UK
Federica Perdoni Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
Rosario Musumeci Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
Winnie Wu GeneFirst Ltd., Abingdon, OX14 3DB, UK
Santina Castriciano Copan Italia SpA, Brescia, Italy
Paolo Romano Hiantis S.r.l., Milano, Italy
Clementina E. Cocuzza Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy

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