Human papillomavirus infection is one of the sexually transmitted diseases associated with human papillomavirus (HPV).
HPV is considered a predisposing factor to cervical cancer, as well as a provocateur of other types of cancer: penis, oropharynx, rectum. The annual worldwide incidence of about 1, 5 million.
The overall prevalence of human papillomavirus in the general population is 10% in women and 20% in men.
HPV infection is more common in sexually active young women and men between the ages of 16 and 25.
About 50% of gay men who practice anal sex are at risk of developing squamous cell carcinoma preceded by anorectal warts.
In heterosexual men and women, this risk is 20%.
The most important predictor of HPV infection in men or women is the number of sexual partners.
Approximately 189 HPV genotypes are classified according to their biological niche and their oncogenic potential. About 40 of these can affect the genitourinary tract.
|Risk category||HPV types|
|High risk||16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, 82|
|Low risk||6, 11, 40, 42, 43, 44, 54, 61, 70, 72, 81, 83, 89|
|Uncertain risk||26, 53, 66|
Women with invasive cervical cancer are more likely to be diagnosed with types of HPV
16, 18, 33, 45, 31 and 58, but the clinical outcome may be different.
Lately, vaccination against HPV infection has become more popular, but according to experts, vaccination does not exempt from regular visits to the doctor. There is some evidence that it wears off after 15-20 years, as well as the role of other unexplored genotypes of the virus on which the vaccine has no effect.
Methods of diagnosing HPV infection
Note that the diagnosis can be made by a visual examination, which will determine the location of lesions and clinical manifestations of infection with the human papillomavirus.
There are many ways to diagnose HPV:
- cytological method (PAP test);
- liquid cytology;
- extended colposcopy;
- PCR (polymerase chain reaction, confirms the presence of human papillomavirus DNA);
- Determination of the viral load (HPV Digene test), real-time PCR - methods for detecting the number of copies of DNA oncogenic viruses;
- morphological research;
- Tumor markers with the determination of the oncoproteins p16, ki67, mcm2, mcm7 etc.
PCR diagnosis of HPV
The PCR diagnosis can be carried out qualitatively and quantitatively (real-time PCR, HPV Digene test).
Currently, cervical cancer early detection and infection detection are considered to be the most effective cervical cancer control measures.
Previously used screenings for women are cytology and histology, however, due to the low specificity, a re-examination is required after a short time. A PCR diagnosis with a negative result can reduce the frequency of examinations by the gynecologist (once / 5-6 years).
It should be noted that the qualitative definition of HPV is not very informative as it only allows for confirmation of the infection. To solve the question of the need for therapy in both men and women with clinical manifestations, it is better to conduct the HPV-Digene test, which will reveal the concentration of the virus.
When carrying out the polymerase chain reaction, type and species-specific primers are used that quantify the risk of malignancy (malignancy). Determining viral load is the primary purpose of these tests.
When HPV DNA levels are higher than 5000 genomes and the likelihood of developing cancer is high, therapy aimed at suppressing the activity of HPV is indicated. Less than 3000 genomes - low risk.
PCR diagnostics can detect all types of oncogenic viruses in men and women.
In addition to HPV testing, diagnosis of sexually transmitted diseases and HIV is mandatory; these diseases are considered to be cofactors of a human papillomavirus infection.
Since the link between HPV and cervical, penile and rectal cancer has been established, molecular methods for detecting HPV DNA in biomaterial are warranted. Use the following:
- vaginal discharge and exudate of the cervix in women;
- Urethral scratching in men;
- Anal discharge;
- Pharynx mucus;
Italian scientists conducted a study that showed that PCR diagnostics (88-100%) is more effective than cytology (34-86%) in preventing invasive cervical cancer.
The specificity of the HPV test (82-97%) is considered to be higher than the specificity of cytology (78-99%).
In most people, the human papillomavirus infection heals on its own without the use of medication. However, in women over 30 years of age, HPV is rarely eliminated spontaneously, therefore, as part of cancer monitoring, a regular examination is recommended, which in the Russian Federation is carried out once a year according to current regulations.
In some countries, if the result of the PCR analysis for papillomavirus and cytology when examining a woman is negative, the interval to pass the examination is 1 time in 3 years, with negative cytology, but positive results of the polymerase chain reaction with highly oncogenicHPV types, an annual examination with colposcopy is done.
Men are examined annually by a urologist, in the case of formations suspicious of papillomavirus infections, a consultation with a dermatovenerologist is justified.
A biopsy is possible depending on the indication, especially if it is suspected to have degenerated into a malignant tumor.
Colposcopy in women
Colposcopy is the most easily accessible diagnostic method for women, the results of which allow conclusions to be drawn about the need for follow-up examinations.
Studies have shown that 99-100% of cervical cancers are associated with highly oncogenic types of the human papillomavirus.
During an extended colposcopy, the cervix is treated with a solution or acetic acid, with the interaction of which the following occurs:
- Lightening of the epithelium;
- atypical transformation zone.
After staining with a solution, against the background of HPV, the modified area takes the form of "semolina".
In a cytological study, the leading signs of infection are the presence of cells with koilocytosis and dyskeratosis, suggesting a CIN.
Cytological diagnosis of HPV
The material is picked up with a special brush. In women - from a suspicious area of the cervix, in men - from the urethra, determine the type, number and change of mucosal cells.
Pap smear, Pap test and liquid cytology
Pap smear - a non-invasive study used in gynecological practice, makes it possible to diagnose early-stage cervical and endometrial cancer before clinical manifestations develop. The aim is to identify atypical cells that are suspicious of a tumor process. In the standard Pap test, the material obtained with the cytobrush is stained and examined under the microscope.
A screening study to detect cancer was developed by G. Papanikolaou in 1940 and checks exfoliated cells that are suspected of cancer or precancerous lesions.
Fluid cytology analysis is a type of Pap test, a more modern and effective way to diagnose HPV. When conducting a study, the biomaterial is not placed on a slide, but in a special liquid preservative.
A targeted biopsy of the cervix and curettage of the mucous membrane of the cervical canal with subsequent histological examination are carried out if:
- Detection of atypical cells based on the results of the cytology,
- in highly oncogenic HPV types with changes identified by colposcopy,
- with obvious signs of pathology without taking into account the results of HPV tests.
A biopsy can be performed in men if HPV is suspected. If warts are deep in the urethra, biopsy material is taken during urethroscopy.
Histology for HPV is a diagnostic procedure in which specially treated papilloma tissue is examined under a microscope. The study is 100% informative to confirm malignancy.
- exophytic flat warts with dyskeratosis and acanthosis,
- Changes in the cytoplasm of squamous epithelium,
- Cervical cancer,
- Penile cancer
- anorectal cancer.
Several options have been proposed to control human papillomavirus infection. In the first case, a cytological examination is carried out, in the second, PCR diagnostics are used to determine whether HPV is transient. For this purpose, a PCR analysis is prescribed again after 6 months.
Who needs to be on HPV. be tested?
Qualitative tests are used more often in mass examinations for prevention, quantitative tests are prescribed when a clinical picture suggests an HPV infection.
In addition, the indications for the HPV test are as follows:
- unprotected "casual" sexual intercourse;
- Monitoring the effectiveness of therapy;
- Detection of STIs;
- burdened gynecological history;
- HIV infection;
- planned pregnancy;
- have more than one sexual partner.
Women of childbearing potential are recommended to get tested for HPV every 3-5 years.
What kind of diagnostics is needed - the doctor will tell you.
Examination of men for HPV is justified only in the case of clinical manifestations, sometimes the diagnosis is carried out with a burdened obstetric and gynecological anamnesis of the partner.