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.