A total of 311 smears from the lower genital tract were examined by the filter in situ hybridization method to identify human papillomavirus (HPV) DNA.
Of these 311 smears, 229 came from clinically and cytologically negative patients and served as a control group. In this group HPV-DNA was detected in 5 cases (2.2%).
Of 82 cytologically positive cases (25 confirmed by histology) 56 (68%) contained HPV-DNA. A high prevalence of HPV 6/11 and absence of HPV 16/18 was found in cases with cytological signs of permissive HPV infection. In mild and moderate dysplasia all viruses occurred at almost the same frequency. In severe dysplasia/carcinoma in situ HPV 16/18 was found 5 times more frequently than HPV 6/11. HPV 16/18 was identified in all 4 invasive cancer cases.
Cervical irrigation of colposcopically suspect areas was performed in 15 cytologically and HPV-DNA positive cases using the hydrodynamic filtration method. In 12 cases only the cells obtained from the colposcopically positive areas contained HPV-DNA.
The sensitivity and reproducibility of the filter in situ hybridization was shown by: (1) comparing the results obtained by HPV-DNA hybridization using Southern blot analysis of tumor biopsies; (2) analysing the correlation of cytologic diagnosis and presence of HPV-DNA in follow-up examinations, and (3) diagnosing presence or absence of HPV-DNA in parallel filters from the same patients.