Abstract
Human papillomavirus (HPV) DNA genotyping is an essential test to establish efficacy in HPV vaccine clinical trials and HPV prevalence in natural history studies. A number of HPV DNA genotyping methods have been cited in the literature, but the comparability of the outcomes from the different methods has not been well characterized. Clinically, cytology is used to establish possible HPV infection. We evaluated the sensitivity and specificity of HPV multiplex PCR assays compared to those of the testing scheme of the Hybrid Capture II (HCII) assay followed by an HPV PCR/line hybridization assay (HCII-LiPA v2). SurePath residual samples were split into two aliquots. One aliquot was subjected to HCII testing followed by DNA extraction and LiPA v2 genotyping. The second aliquot was shipped to a second laboratory, where DNA was extracted and HPV multiplex PCR testing was performed. Comparisons were evaluated for 15 HPV types common in both assays. A slightly higher proportion of samples tested positive by the HPV multiplex PCR than by the HCII-LiPA v2 assay. The sensitivities of the multiplex PCR assay relative to those of the HCII-LiPA v2 assay for HPV types 6, 11, 16, and 18, for example, were 0.806, 0.646, 0.920, and 0.860, respectively; the specificities were 0.986, 0.998, 0.960, and 0.986, respectively. The overall comparability of detection of the 15 HPV types was quite high. Analyses of DNA genotype testing compared to cytology results demonstrated a significant discordance between cytology-negative (normal) and HPV DNA-positive results. This demonstrates the challenges of cytological diagnosis and the possibility that a significant number of HPV-infected cells may appear cytologically normal.