External quality assessment for molecular detection of human papillomaviruses

Background: The United Kingdom National External Quality Assessment Service (UK NEQAS) distributes clinically relevant and educational specimens for external quality assessment (EQA). Objectives: The aim of this report was to assess the suitability of using liquid based cytology (LBC) samples for the EQA of molecular methods and to review the methods used by participants to detect the presence of high risk (HR) human papillomavirus (HPV) genotypes. Study design: Three pilot distributions were dispatched between January 2008 and January 2009 with each distribution consisting of four different specimens. Results: Performance was good with over 90% of participants reporting correctly on the presence or absence of high risk genotypes in all but one specimen, specimen 9006 (82.1%). Specimen 9006 was a pooled specimen, negative for HR genotypes but containing low risk (LR) genotypes 61, 70 and 81. The most commonly used assay for the detection of the presence of HR HPV was the Digene Hybrid Capture II assay. The in-house PCR assays were most commonly associated with incorrect results, and the use of these assays decreased during the 13 month pilot study. Conclusions: The UK NEQAS molecular detection of HPV scheme provides a standardised, homogeneous and characterised clinical specimen, however this study has shown that genotyping results reported by participants were still varied. Inclusion of available HPV standards will help to standardise assays. Robust EQA of HPV molecular screening programmes will be essential for monitoring the impact of the HPV vaccine.