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

OBJECTIVE

To evaluate the analytical suitability of different storage and laboratory processes of self-samples for an HPV assay.

DESIGN

Prospective matched study.

SETTING

Royal London Hospital Colposcopy Clinic.

POPULATION: One hundred seventy seven patients aged 25-65 years referred to colposcopy due to their screening results (abnormal cytology or recurrent HPV infection).

METHODS

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.

MAIN OUTCOME MEASURES: Genomic DNA Quality Score (GQS), detection of HPV, and HPV cycle threshold (Ct) values.

RESULTS

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).

CONCLUSION

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.