Intratype variations of HPV 31 and 58 in Italian women with abnormal cervical cytology.

Oncogenic human papillomaviruses (HPVs) are the recognized etiological agents of cervical cancer. A number of epidemiological, etiological, and molecular data suggest that variants of the same HPV type are distinct biologically and may confer differential pathogenic risks. Therefore, investigation of genome variants of clinically important HPV types may be important for the identification of pathogenically important variants. In this study, the genomic regions of L1, E6, E7, and long control region (LCR) of HPV 31 and 58, identified in women with abnormal cervical smear, were investigated. Several mutations were identified in the regions examined. Of the mutations found in the L1 region of HPV 31 and 58, the novel mutations described in this study fall within a protein region which may play a critical role in the binding of neutralizing antibodies against different HPV types. No significant association was found between the E6 and E7 mutations of both HPV types and the cytological lesion found. Some mutations found in the LCR of HPV 31 and 58 encompassed known transcription binding sites with possible consequences on the transcription of the oncogenic genes. Intratype genetic characterization of HPV types may help to define the pathogenetic risk of HPV variants.