Detection of human herpesvirus 6 and human papillomavirus 16 in cervical carcinoma

A subset of human papillomaviruses (HPVs) is associated with the majority of cervical cancers; however, cofactors appear to be required for carcinogenic progression of HPV-induced neoplasia. As human herpesvirus-6 (HHV-6) was recently shown to infect cervical epithelial cells in vitro and activate transcription of HPV-transforming genes, human cervical dysplasia and cancers were analyzed for the presence of HHV-6 by multiple methods, including polymerase chain reaction, slot blot, Southern blot, and in situ hybridization. HHV-6 DNA sequences were detected in 6 of 72 cases of squamous cervical carcinoma and cervical intraepithelial neoplasia. HPV-16 was found in four of the HHV-6-positive cases (two squamous cervical carcinomas and two cervical intraepithelial neoplasias). None of the 30 normal cervices and biopsies of patients with cervicitis was positive for HHV-6 DNA. These results are the first suggestion of an in vivo association between HHV-6 and some cervical neoplasia.