High-throughput genotyping of high-risk HPV by the digene HPV Genotyping LQ Test using GP5+/6+-PCR and xMAP technology

BACKGROUND: Epidemiologic studies have classified 18 genotypes of the human papillomavirus (HPV) as (probably) high-risk (HR) based on their association with cervical cancer, i.e., HPV 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73, and 82. Given the fact that certain HR HPV types confer an increased risk of cervical (pre)cancer, type-specific identification might aid clinical management of women tested positive for HR HPV. Therefore, the development of robust, high-throughput genotyping assays is important.

OBJECTIVES: An analytical comparison of the digene HPV Genotyping LQ Test (digene LQ Test), capable of identifying 18 HR types using bead-based xMAP suspension array technology, with the established Reverse Line Blot (RLB) genotyping assay was carried out on amplimers generated with the clinically validated GP5+/6+-PCR method.

STUDY DESIGN: GP5+/6+ amplimers, generated from 434 digene High Risk HPV HC2 DNA Test (HC2)-positive and 95 HC2-negative cervical smears, were genotyped by both the digene LQ Test and the RLB genotyping assay.

RESULTS: The genotyping assays revealed high agreement for overall HR HPV detection (ú = 0.884) and type-specific identification of the 18 HR HPV types (overall ú = 0.958, individual ú range 0.795 to 1.000). The digene LQ Test demonstrated a very good inter-laboratory reproducibility (ú = 0.987). Among the HC2-positive women, the digene LQ Test revealed positivity for one or more HR HPV type(s) in 85.9%, and negativity was observed in 97.9% of the HC2-negative women.

CONCLUSIONS: The digene LQ Test demonstrated a high genotyping agreement with the established RLB genotyping assay on GP5+/6+ amplimers. This novel assay allows for high-throughput genotyping following HR HPV testing by HC2.