Uniplex E6/E7 PCR method detecting E6 or E7 genes in 39 human papillomavirus types.

We have developed a new human papillomavirus (HPV) assay using the uniplex E6/E7 polymerase chain reaction (PCR) method, which is able to detect E6 and E7 genes in 39 HPV types. We validated the assay for sensitivity and specificity using cloned HPV DNA and clinical samples. A comparative study using Genosearch-31 (GS-31) to determine HPV genotypes in clinical samples was also performed. E6 or E7 genes, measured by uniplex E6/E7 PCR, were detectable in 15 low-risk (HPV-6, -11, -40, -42, -44, -54, -55, -61, -62, -71, -74, -81, -84, -89, -90), 11 intermediate-risk (HPV-26, -30, -34, -53, -66, -67, -69, -70, -73, -82, -85), and 13 high-risk (HR) HPV types. The detection limit of this assay was 100 copies in all 39 HPV types and no cross-reactivity was observed with any type. This assay detected HPV in all 226 cervical cell samples, including 222 high-grade squamous intraepithelial lesions (HSIL) and 4 squamous cell carcinoma (SCC) cases, whereas GS-31 identified HPV in 99.6% (225/226) of the same samples. All SCC and 41.0% (90/222) of HSIL cases were infected with a single HPV type, while the remaining 59% of HSIL cases involved multiple HPV types. It was noted that high-risk and probably high-risk HPV types (HPV-66, -70 and -82) were identified, but no low-risk types were identified as a single-type infection in these HSIL and SCC cases. The uniplex E6/E7 PCR assay has high sensitivity, and can be useful tool in epidemiological studies or clinical follow-ups after surgery.