Nonisotopic human papillomavirus DNA typing of cervical smears obtained at the initial colposcopic examination

Detection of human papillomavirus by nonradioactive hybridization

The presence of the human papillomavirus (HPV) DNA sequence in cervical smears of women with cervical intraepithelial neoplasia (CIN) was investigated through dot blot using a nonradioactive method based on the principle of enhanced chemiluminiscence. From 154 samples examined, 59 (38.3%) had HPV-related sequences determined by dot-blot hybridization; among these, 18 samples (11.68%) reacted either to HPV 6/11 or to HPV 16/18 probes, 20 (12.98%) reacted to only HPV 16/18, and 21 (13.63%) reacted exclusively to HPV 6/11. The relative sensitivity of the method was controlled comparing the results of both tests with those obtained by Southern blot in 32 samples. The risk of HPV positivity was increased in women who first had intercourse at an early age and in patients with CIN II or III. Both associations were significant at the 95% confidence interval (CI). An increased risk of HPV positivity was also associated with patient's age at diagnosis, education levels, number of sexual partners, and use of oral contraceptives, but none of these factors were significant at 95% CI. Other risk factors for cervical cancer, such as the number of pregnancies or cigarette smoking, were not found to be associated with HPV infection and indicate that the association of these factors with cervical cancer probably is independent of HPV infection. Even if HPV is the major risk factor for CIN, this also supports a multifactorial model of cervical cancer etiology with an increased risk of HPV infection.

Detection and typing of human papillomavirus infection affecting the cervix, vagina and vulva. Comparison of DNA hybridization with cytological, colposcopic and histological examinations

The sensitivity of human papillomavirus (HPV) detection was compared by colposcopy, histology and DNA hybridization among 304 women with abnormal Papanicolaou (Pap) smear. Colposcopically directed biopsies revealed HPV infection in 71% of cases, DNA hybridization in 35%, and both together in 78%. DNA hybridization detected HPV in 24% of the 84 benign cases with no histological signs of HPV, in 32% of the 133 condylomas verified by biopsies and in 51% of the 85 cases with intraepithelial neoplasia, 95% of which presented histological signs of HPV. The pattern of occurrence of different HPV-types resembled findings in earlier reports. HPV infection is common with abnormal Pap smears and it can be identified relatively reliably by means of cytology, colposcopy and histology. DNA hybridization serves as a complementary technique which may reveal the oncological potential of the virus.

A comparison of cervical scrapes for HPV typing by dot-blot hybridization obtained by wood and plastic spatulas

A cross-over study was designed to determine whether the type of spatula used to collect cervical cells influences the ability of dot-blot hybridization to detect HPV DNA. Fifty-nine patients had a cervical scrape with a wood spatula first and a plastic spatula second: 60 were scraped in the inverse order. The order of sampling did not affect the HPV DNA positivity rate, which was nearly similar for both wood and plastic spatulas (30 and 32%, respectively). Wood spatulas collected more cells and greater than 1 x 10(5) cells more often than plastic spatulas (P = 0.001 and 0.06, respectively). Non-purple (negative) dots were more frequent in samples obtained by wood than by plastic spatulas (P = 0.001). The study showed that cervical cell collection by wood spatulas is preferred as they harvest more cells, thus optimizing the sensitivity of the hybridization method, and the spatulas are also more economical. Although they yielded more non-purple dots, a reduction in these dots by using plastic spatulas did not result in a significantly increased HPV positivity rate.