High risk HPV load estimated by Hybrid Capture II correlates with HPV16 load measured by real-time PCR in cervical smears of HPV16-infected women.

Background: High risk human papillomavirus (HR-HPV) load determined by quantitative methods has already been considered as highly predictive of future development of high grade cervical lesions. Some studies also demonstrated that Hybrid Capture II (HCII) results can be considered as a reflection of HPV DNA load, while others did not. HCI assay, well suited for routine HR-HPV screening, is not especially dedicated for quantitative use. However, we have recently shown that women with high viral loads assessed by HCII were at increased risk of cervical precancer.

Objectives: The aim of the study was to determine if the values given by the HCII assay can be considered as quantitative.

Study Design: We used a real-time PCR allowing precise quantification of both HPV16 genome and albumin gene to normalize the measuring HPV16 load in cervical cells and to compare the data with those obtained by HCIIin a series of 40 HR-HPV positive samples.

Results: Reproducibility of the HPV16 real-time PCR, assessed from nine independent experiments of serial dilutions of SiHa cell DNA, was reflected in coefficients of variation for standard curves of crossing point (Cp) values below 5%. The HPV16 loads with a broad individual variability were significantly related to the cumulative load estimated by HCII and did not depend on the cellularity of samples.

Conclusions: We assume that the HCII values can be used as a quantitative measure of HR-HPV DNA, so long as cervical specimens are collected using standardized protocols.