Detection of HPV in Norwegian cervical biopsy specimens with type-specific PCR and reverse line blot assays

Background: Although the association of HPV16 and HPV18 DNA with cervical cancers has been well studied, the prevalence of these types in high-grade cervical intraepithelial neoplasias (CIN2/3) may differ from the prevalence found in cervical cancer specimens. Objective: To determine the prevalence of specific HPV types found in high-grade CIN2/3 biopsy samples. Study design: One thousand eight hundred and forty-eight cervical biopsy specimens were obtained from Norwegian women. HPV16 and HPV18 type and gene-specific PCR assays were performed amplifying a portion of the E6, E7 and LI genes. In addition, the reverse line blot assay was performed on a subset of specimens, in which a portion of L1 was amplified and hybridized to strips coated with complimentary HPV sequences. Results: The prevalences of HPV16 and HPV18 in the 1848 biopsy cohort were 32.3% and 6.0%, respectively. HPV16 was detected in 47.5% and HPV18 in 5.9% bf diagnosed CIN2/3 specimens. Approximately 12% of the CIN2/3 specimens contained two HPV types and 2.5% contained three HPV types. Conclusions: The prevalence of HPV16 increases from grades CIN 1 to CIN2 to CIN3. The prevalence of HPV 18 did not change significantly with increasing CIN grade. The majority of infections diagnosed as CIN2/3 contained a single HPV type. The type-specific PCR assay had increased detection sensitivity over the reverse line blot assay.