Validation of TypeSeq2, a Next-Generation–Based Sequencing Assay for the Detection of 46 Human Papillomavirus Genotypes, at the US National Cancer Institute and Costa Rica Laboratories
Abstract
Background
Cervical cancer is caused by persistent infection with carcinogenic human papillomavirus (HPV) genotypes. Prophylactic HPV vaccines are highly efficacious in preventing the acquisition of HPV infection. HPV vaccine trials and epidemiologic studies based on virologic endpoints rely on valid and reproducible measurements of HPV. We evaluated the second version of TypeSeq (TS2), a next-generation, sequencing-based assay that detects 46 HPV genotypes, in a historical phase 3 clinical trial.
Methods
We used 1214 stored cervical samples from women enrolled in the Costa Rica HPV Vaccine Trial with available HPV results from Short PCR Fragment 10- Line Probe Assay 25 (SPF10-LiPA25). TS2 was first validated at the National Cancer Institute (NCI) and transferred to the laboratory in Costa Rica, where we conducted a second validation study. We compared TS2 results generated at each laboratory to the SPF10-LiPA25 results.
Results
Overall, each laboratory demonstrated high positive agreement for most carcinogenic and noncarcinogenic genotypes between TS2 and SPF10-LiPA25. Intralaboratory comparisons revealed very high agreement in repeated testing. Interlaboratory comparisons showed high agreement for most carcinogenic and noncarcinogenic types. Overall, there were no statistically significant differences in vaccine efficacy in the according-to-protocol cohort using TS2 (either in NCI or Costa Rica) or SPF10-LiPA25 (McNemar P values >.05). Costa Rica produced similar vaccine efficacy estimates as NCI for HPV16/18, HPV31/33/45, and HPV35/39/51/52/56/58/59 as NCI (P values ≥.36).
Conclusions
Compared to SPF10-LiPA25, a well-established standard for HPV genotyping, TS2 demonstrated high accuracy. Inter- and intralaboratory comparisons demonstrated that TS2 is valid and reproducible. TS2 can accurately classify the presence of HPV, which is essential in HPV vaccine trials evaluating virological endpoints.
Clinical Trials Registration
NCT00128661.
