HPV infection is the known cause of cervical cancer and in Sweden, the recommendation for primary HPV testing in cervical cancer screening was initiated in 2016. In the Örebro region, the Aptima (Hologic) HPV assay is used for primary HPV testing, detecting mRNA from 14 hrHPV genotypes, however without distinction between types and also without a human control gene for verification of sample adequacy. The Aptima assay is an in vitro amplification test for qualitative detection of E6/E7 viral messenger RNA (mRNA) but the expression level in a sample might not always correlate with the magnitude of a positive assay signal, especially for samples near the assays detection limit. Using the sensitive digital droplet PCR method we aim to compare mRNA and DNA levels in clinical samples as well as establishing laboratory cut-off levels that can be used as internal controls.
This ongoing study includes hrHPV positive samples from the primary HPV screening in Örebro, Sweden. Analyzed Aptima sample tubes are collected and 200 µl of residual sample extracted for sample DNA. Genotyping using extracted DNA is performed with Anyplex II HPV28 (Seegene). For HPV16, -18, 33 and 45 positive samples, corresponding liquid based ThinPrep cytology (LBC) vials are retrieved and used for both RNA and DNA extraction. Digital droplet PCR is performed in parallel for both DNA and mRNA amplicons using primer and probesets for E6/E7 of genotypes 16, 18, 33 and 45, also including the human controlgene HBB.
Results will be presented at congress.
Results will be presented at congress.