Viability of Self-Taken Vaginal Swab Samples for RNA-Based Biomarker Analysis in Cervical Disease

High risk human papillomaviruses (hrHPVs) cause most cervical cancers. Cervical screening programmes aim to identify precancerous disease using detection of hrHPV nucleic acid using clinician-taken liquid-based cytology (LBC) samples, or increasingly, self-taken samples (STSs). However, STSs are incompatible with traditional cytology triage. Therefore, development of novel triage tests is essential. Quantification of cellular and viral mRNA biomarkers is one option, but little is known about mRNA quality in STSs. We extracted RNA from two sets of STSs (reflecting separate sampling devices) from the Scottish HPV Archive (SHA) and the Swedish Cervical Cytology Biobank (SCCB). We investigated whether the ACTB, GAPDH and p16 RNAs could be amplified by reverse transcription quantitative PCR (RT-qPCR). RNA was degraded in both sets of samples, but samples from the Scottish HPV Archive were generally suitable for RT-qPCR analysis, while samples from the SCCB were mostly unsuitable. Genomic DNA contamination was detected in 11.6% of samples. The quantity and quality of RNA derived from STSs was unaffected by storage of the original sample at -70°C for a period of 1 year. These data suggest that feasibility of utilising STSs for mRNA expression work is device-dependent and that optimisation of collection and storage systems is warranted.