Human papillomavirus (HPV) is a small, non-enveloped oncogenic virus, has double-stranded, circular-shaped DNA genetic material and is classified in the genus Papillomavirus of the Papovaviridae family. HPV DNA is integrated into the cervical cell genome, promoting oncogene activation and suppressing the host cell's immune response. HPV protein products prevent DNA repair and programmed cell death (apoptosis), events that can lead to cell instability and uncontrolled cell growth.
Human papillomavirus infects the genital epithelium and is transmitted through direct contact with the skin. Some HPV strains cause genital warts, but very often HPV infections show no signs or symptoms. As a result, infected individuals are often unaware that they are carriers and transmit the viruses unknowingly.
The types of HPV viruses are classified into two groups (low-risk or non-oncogenic strains and high-risk or oncogenic strains), based on their oncogenic potential and ability to induce tumorigenesis. Low-risk strains (HPV 6, 11, 42, 43, and 44) are associated with warts (genital warts) and small cervical lesions (mild dysplasia). Lesions caused by low-risk HPV strains have a high risk of recurrence and a low likelihood of malignancy and are considered to be zero or very small. High-risk strains (HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68) are associated with intraepithelial neoplasms and are more likely to develop serious lesions and cervical cancer.
A clear causal link between HPV infection and cervical cancer has been established. HPV is widespread and is found in almost all cases of cervical malignancy. Of the high-risk HPV strains, HPV strains 16 and 18 are the most carcinogenic and most widespread (more than 90% of cervical cancer cases are HPV strains 16 and 18). The HPV 16 strain is the dominant strain in the world. High-grade cervical intraepithelial lesions are mainly associated with HPV 16 and 18 strains, but the same strains are also often found in minor lesions and mild malformations. The latency between the initial exposure to HPV and the development of cervical cancer can be months or years. Women who have normal Pap smear tests and do not have HPV infection are at very low risk (0.2%) for developing cervical cancer.
Molecular testing for HPV is done in women who have a pathological Pap smear. Pap test results, such as "atypical epithelial cells of undetermined significance" or "low-grade intraepithelial lesion" should be investigated with a molecular test for HPV.
Numerous sources indicate that more than 60% of women with abnormal Pap tests are positive for high-risk HPV strains. If the molecular test for HPV is positive, the woman should undergo colposcopy and probe for more serious cervical lesions, such as cancer. HPV infection is more common in younger women and is often spontaneously self-limited, especially in women younger than 30 years. In contrast, persistent infections with high-risk HPV strains are more common in women older than 30 years. Recent guidelines recommend that HPV molecular tests be performed on women older than 30 years or younger women with high grades of intraepithelial lesions.
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. The correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings, and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.