Evaluation of the Quality and Suitability of Self-Collected Vaginal and Urine Samples for Human Papillomavirus Testing: A Prospective Matched Study.

Abstract

To evaluate the analytical suitability of different storage and laboratory processes of self-samples for an HPV assay. Prospective matched study. Royal London Hospital Colposcopy Clinic. One hundred seventy seven patients aged 25-65 years referred to colposcopy due to their screening results (abnormal cytology or recurrent HPV infection). Each participant provided a first void urine sample (10 mL/20 mL, Collipee), two vaginal self-samples (Copan FLOQSwabs transported 'dry' and 'wet'), and a clinician-collected cervical sample. Samples were processed immediately or after 1 or 2 weeks stored at room temperature. HPV testing used BD Onclarity. Genomic DNA Quality Score (GQS), detection of HPV, and HPV cycle threshold (Ct) values. DNA quality of dry samples was not significantly lower than wet samples when resuspended within 2 weeks (median GQS dry vs. wet: 3.35 vs. 3.41, immediately; 3.00 vs. 3.14, 1 week; 3.45 vs. 2.78, 2 weeks; all p [one-sided] > 0.05). Urine samples had lower HPV positivity compared to other sample types and had higher HPV Ct values (median 30 vs. 27 for dry/wet/clinician samples). Dry self-samples from a Copan FLOQSwab taken in clinic are likely to have sufficient DNA quality and accuracy for HPV testing compared with wet self-samples and clinician-collected samples if resuspension takes place up to 2 weeks, with storage at room temperature, and using the BD Onclarity assay. Urine samples using the Colli-pee device are likely to be less sensitive for HPV detected from clinician-collected samples.