HUMAN PAPILLOMAVIRUS INFECTION IN PROGRESSIVE AND NONPROGRESSIVE CERVICAL INTRAEPITHELIAL NEOPLASIA

Human papillomavirus (HPV) infection is common in cervical intraepithe lial neoplasia (CIN) and is widely held to be responsible for its prog ression to grade 3. This thesis is examined here. Comparison of the le vel of HPV changes in 133 lesions that had not progressed to that in t hose from 197 women with histologically proven CIN 3 failed to reveal significant differences in their level of HPV infection on cytology, h istology or in situ hybridization. However, in both these groups, some of the cases that did not show HPV positivity on in situ hybridizatio n with probes reacting with the common HPV types did show evidence of HPV DNA using a general primer-mediated polymerase chain reaction. Thi s may indicate low-copy number infections or non-productive infections . Such reactions were more frequent in the women with progressive lesi ons, and it is probable that they may also have been at greater risk o f cervical infection in general. The present findings suggest that a f urther factor, a co-carcinogen, may be involved in progression to CIN 3: HPV being a common forerunner, providing a proliferative environmen t and thus favoring such an event.