Concordance of HPV load and HPV mRNA for 16 carcinogenic/possibly carcinogenic HPV types in paired smear/tissue cervical cancer specimens.

ABSTRACT

HPV types with high viral load are associated with cervical abnormalities. However, viral load measurements and concordance of HPV loads and viral mRNA have not been demonstrated for all high-risk/possibly high-risk (HR-/pHR-)HPV types in cervical cancer (CxCa). Especially, the biological role of co-infecting HR-/pHR-HPV types with low viral load has not been thoroughly investigated. Using BSGP5+/6+-PCR/MPG genotyping, we analyzed viral loads for all currently defined 51 mucosal HPV types in 74 cervical smears from patients with CxCa and compared this data with HPV DNA and mRNA status in these patients' corresponding CxCa tissues. All cervical smear/tissue pairs were HPV DNA+. Overall HPV type agreement within pairs was 99% (complete agreement in 50%, partial agreement in 49%, and complete disagreement in 1% of cases). The proportion of multiple HPV types was significantly higher in smears compared to tissues (p<0.0001). High load HPV infections (>1 copy/cell) were found in 88% of HPV DNA+ smears, and were significantly associated with the presence of respective HPV DNA (kappa=0.685, CI 0.567-0.803), and HPV mRNA (kappa=0.693, CI 0.566-0.820) in CxCa tissues. In total, 93% (67/72) of high load HR-/pHR-HPV infections identified in smears were also present in corresponding CxCa tissues, and 93% (62/67) of these were HPV mRNA+. On the other hand, 78% (42/54) of low load HR-/pHR-HPV infections identified in smears were not detectable in tissues, including 11 out of 15 low load HPV16 infections. This data demonstrates that the presence of high HPV loads in CxCa smears predicts biologically active HR-/pHR-HPV types in tumor tissues.