The oncogenic potential of the high-risk human papillomavirus (HPV) genotypes (types 16,18,31, 33,35,39,45,51,52,56,58,59,66 and 68) depends on the expression of the two viral oncogenes E6 and ET Thus, the detection of HPV E6/E7 oncogene transcripts could serve as a factor in the evaluation of a risk of development of cervical intraepithelial neoplasia (CIN) and its progression to cervical cancer. A nested RT-PCR assay for the detection of E6/E7 oncogene transcripts of all known high-risk HPV genotypes was established. In the study described, 779 high-risk HPV-DNA-positive cervical scrapes exhibiting all grades of CIN, including non-dysplastic cervical mucosa (CIN 0), were examined. Spliced E6/E7 oncogene transcripts of all the high-risk HPVs were detected in numerous samples, with an overall detection rate of 47%. In 227 cases with agreement between the cytologic and histologic findings, the prevalence increased with lesion severity: CIN 0, 18%; CIN 1, 58%; CIN 11, 77%; CIN 111, 84%. Multiple transcriptionally active high-risk HPVs were detected in 12% (33/279) of patients with multiple high-risk HPV infections. This work sets the stage for a prospective follow-up study currently being undertaken to evaluate the prognostic relevance of the detection of high-risk HPV E6/E7 oncogene transcripts for the persistence of a high risk HPV infection, and the possible evolution and further development of a CIN. Future applications of the assay described may include the monitoring of women in studies investigating antiviral treatment or vaccination. (C) 2004 Wiley-Liss, Inc.