DNA- versus RNA-based methods for human papillomavirus detection in cervical neoplasia.

Objective: To compare DNA-based and mRNA-based methods for detection of high-grade cervical neoplasia in Norway.

Methods: HPV prevalence was analyzed in 383 women with positive index cytology, selected from gynecology clinics. All patients were investigated by a new PAP smear, histology, and two commercially available HPV tests: Hybrid Capture II (Digene, Gaithersburg, MD) and the Pre Tect HPV-Proofer (NorChip AS). Cases with positive DNA test and negative mRNA test and cases with high-grade histology and negative HPV tests were retested with PCR and sequencing. We regarded the infection as latent or transient if sequencing revealed an HPV type included in both assays.

Results: High-risk HPV was detected in 99.7% of the histological confirmed high-grade lesions (CIN2+) (290/291). The DNA test was positive in 95% (275/291), and the mRNA test was positive in 77% (225/291) of the histological confirmed high-grade lesions. All invasive carcinomas were mRNA positive. The DNA test was significantly more often positive in benign and low-grade lesions, some of which were found to be false positive due to cross-contamination with unrelated types. High-grade histology was detected in 83% of women with normal cytology and positive mRNA test. Latent or transient infections were detected in 11 low-grade and 12 high-grade preinvasive lesions. Sequencing revealed high-risk HPV types included only in the DNA test in 35 high-grade preinvasive lesions, HPV 52 and 58 were the most prevalent HPV types.

Conclusions: These HPV tests have the potential to improve the detection rate of high-grade cervical neoplasia, with some limitations. The mRNA test seems to be more appropriate for risk-evaluation. Larger scale, population based studies are necessary to evaluate the predictive values of HPV testing in Norway.