Evaluation of two commercially available in situ hybridization kits for detection of human papillomavirus DNA in cervical biopsies: comparison to Southern blot hybridization.

In order to determine the distribution of human papillomavirus (HPV) types and to compare in situ hybridization (ISH) with Southern blot hybridization (SBH), paired colposcopically directed cervical biopsies and cervical-vaginal lavages were obtained from 92 women referred for abnormal Pap smears. The lavages and one of the biopsies were snap-frozen and subsequently tested by SBH for HPV DNA. The other biopsy was formalin-fixed and paraffin-embedded for conventional light microscopy and for ISH using two commercially available kits from Digene Diagnostics Inc.: ViraType In Situ containing probe mixtures to HPVs 6 and 11, 16 and 18, and 31, 33, and 35; and Omniprobe containing a single probe mixture to 14 different anogenital HPVs. In addition to the aforementioned types Omniprobe contains probes for types 42, 43, 44, 45, 51, 52, and 56. HPV DNA was detected by SBH in 27% of specimens showing no specific pathological change and in 92% of cases of cervical intraepithelial neoplasia (CIN). The HPVs by SBH in CIN were type 16 in 25%, types 31 or 35 in 23%, types 52 or 56 in 17%, uncharacterized types in 13%, mixed types in 8%, and type 18 in 6%. None of the specimens was positive for the low-risk HPV types 6, 11, 42, 43, or 44. The proportion of cases of CIN containing HPV 16 increased as the grade of CIN increased. Otherwise there were no striking differences detected in the HPV types in the different grades of CIN. ISH using ViraType In Situ was positive in only 50% of cases of CIN that were HPV positive by SBH.(ABSTRACT TRUNCATED AT 250 WORDS)