Detection of human papillomavirus by in situ polymerase chain reaction in paraffin-embedded cervical biopsies.

The efficiency of the in situ polymerase chain reaction (PCR) for the detection of human papillomavirus (HPV) DNA sequences in 20 cervical biopsies fixed with buffered formalin, paraffin-embedded and revealed negatively by conventional in situ hybridization (ISH) has been investigated. The biopsies were classified histologically into condylomata acuminata without dysplasia, cervical intraepithelial neoplasia and carcinoma in situ. Amplified HPV DNA was performed after an optimal proteolytic digestion using one pair of consensus oligonucleotide primers located in the L1 ORF of HPV 6 and ISH was carried out after the PCR assay with a cocktail of biotinylated HPV probes. Viral DNA was detected in 100% of high grade squamous intraepithelial lesions (SIL) and in 50 to 60% of low grade SIL. The high sensitivity of the in situ PCR applicable to paraffin-embedded archival biopsies facilitated the detection of cells poorly reactive by conventional ISH. In situ PCR appeared clearly an efficient tool to investigate HPV infection in tissue sections.