title: Infection by human papillomavirus types 6, 11, 16, 18, 31, 33 and 35 of the cervix in Japanese women.
abstract: Exfoliated cervical cells from 321 Japanese women were examined for human papillomavirus (HPV) DNA types 6, 11, 16, 18, 31, 33 and 35 using polymerase chain reaction (PCR) and dot-blot hybridization methods. HPV DNA was present in 9.3% of patients with normal cervixes, 72.7% of patients with cervical intraepithelial neoplasia (CIN) and 77.8% of patients with invasive carcinoma. Younger patients (</=29 years) with normal cervixes had a 18.5% incidence of HPV DNA, whilst similar older patients (>/=50 years) had a 1.9% incidence, a significant difference (chi2= 6.478, P < 0.01). In the CIN I and II groups, an incidence of 11.1% of types 16 and 18 was found, while in the CIN III or invasive carcinoma group the incidence was 58.1%, again a significant difference (chi2 = 12.075, P < 0.01). Furthermore, persistence or progression of CIN showed a significant correlation with infections by types 16 and 33 (chi2= 4.904, P < 0.01). However, no significantly different incidence of HPV infection was found between the CIN and the invasive carcinoma groups. It is suggested that (a) younger patients with normal cervixes have a higher incidence of HPV infection than do older patients; (b) HPV types 16, 18 and 33 are important etiologic agents of CIN III and invasive carcinoma, as well as in the persistence and progression of CIN; (c) progression of CIN to invasive carcinoma may depend on factors other than HPV infection in the cervix.
authors.affiliation: Department of Obstetrics and Gynecology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Y.
authors.initials: Y
authors.lastname: Takahashi
authors.forename: I.
authors.initials: I
authors.lastname: Yamade
authors.forename: T.
authors.initials: T
authors.lastname: Nakamura
authors.forename: M.
authors.initials: M
authors.lastname: Akiyama
authors.forename: Y.
authors.initials: Y
authors.lastname: Hayashi
authors.forename: T.
authors.initials: T
authors.lastname: Ishiguro
authors.forename: Y.
authors.initials: Y
authors.lastname: Noda