[Detection and quantification of human papillomavirus genital infections: virological, epidemiological, and clinical applications]

Abstract

Human papillomaviruses (HPV) are the main risk factor for cervical cancer. By introducing its DNA into the genome of infected human cells, the virus expresses two oncoproteins (E6 and E7) that induce inactivation of tumour suppressors and telomerase. HPV infection is extremely common. But most of women will clear the infection over an 8-10-month period without developing any cervical lesion. In fact, it is the persistence of infection that truly exposes to the risk of cervical cancer. HPV testing, used for primary screening, has better sensitivity but lower specificity than cervical cytology. A secondary use of cytology would compensate the loss of HPV testing specificity. Thus, cervical cytology would be performed only in HPV positive women and colposcopy finally performed only in women with abnormal cytology. The characteristics of such screening would allow to increase interscreening intervals and therefore to reduce additional costs. The quantification of HPV viral load could be a way to differentiate significant infections from others. Despite proven significant association between high HPV viral load and the risk of CIN 2-3 and cervical cancer, crude variations within disease grades currently limit the clinical utility of viral load measurement. More than a just measure of HPV viral load, its evolution over time is what would really be of clinical relevance.