Identifying human papillomavirus subtypes in cervical biopsies with in situ DNA hybridization with biotinylated probes

To test the utility of biotinylated DNA probes against various subtypes of human papillomavirus (HPV), we performed in situ DNA hybridization on routinely processed archival material from 30 patients with serial cervical biopsies including conization (group I) and a prospective group of 35 patients whose cervical biopsies showed various degrees of koilocytotic atypia and/or dysplasia (group II). Commercially available biotinylated probe cocktails against HPV types 6 and 11, 16 and 18, and 31, 35 and 51 were detected via the avidin-biotin horseradish peroxidase technique. Virus was found in 87% (26/30) of group I and 57% (20/35) of group II. Almost exclusively, viral types 16, 18, 31, 35 and 51 were detected in group I; 54% (19/35) of group II stained for types 16, 18 or 31, 35 and 51; 2.9% (1/35) stained for types 6 and 11. Nine percent of group II (3/35) showed coinfection with types 16, 18 and 31, 35 and 51. Three of six vulvar condylomata (50%) stained for types 6 and 11. In general, weaker staining was associated with greater dysplasia. In situ hybridization using biotinylated DNA probes is useful in identifying patients infected with dysplasia/carcinoma-associated HPV subtypes and can be performed easily on routine surgical specimens.