Increased levels of HPV16 E6*I transcripts in high-grade cervical cytology and histology (CIN II+) detected by rapid real-time RT-PCR amplification.

OBJECTIVE: As cervical dysplasia may regress to normal cytology or progress to cervical carcinoma, it would be valuable to have a diagnostic tool to help decide whether therapeutic conization should be performed.

METHODS: Cervical samples of 301 HPV16 positive women were collected in RNAlater reagent to prevent RNA degradation. Relative levels of HPV16 DNA and HPV16 E6*I mRNA in the samples were determined using real-time polymerase chain reaction. Findings were correlated with histological diagnoses and cytological follow-up.

RESULTS: HPV16 E6*I mRNA levels were significantly higher in women with cytologically diagnosed severe cervical dysplasia (mean normalized ratio = 0.25) than in those with mild-to-moderate dysplasia (mean norm. ratio = 0.12), atypical squamous cells of uncertain origin (mean norm. ratio = 0.071) or normal cytology (mean norm. ratio = 0.034). Viral DNA levels were not significantly different between severe and mild-to-moderate dysplasia (mean norm. ratios, 55.8 and 63.5, respectively). The PPV for a histological diagnosis of severe cervical dysplasia [cervical intraepithelial neoplasia (CIN) II+] increased with the amounts of E6*I mRNA to more than 90% whereas the sensitivity decreased. The absence of HPV16 E6*I transcripts as well as HPV16 DNA considerably increased the negative predictive value and the specificity. However, low concentrations (or complete absence) of E6*I mRNA did not preclude a CIN II+ diagnosis.

CONCLUSIONS: Although the sensitivity is low, high levels of HPV16 E6*I mRNA are indicative of CIN II+ in cytologically diagnosed cervical dysplasia of individual patients. Thus, quantification of HPV16 E6*I mRNA could be helpful in managing follow-up and treatment in a subset of HPV16 positive women.