Human papillomavirus infection is one of the sexually transmitted diseases associated with the human papillomavirus (HPV).
HPV is considered a predisposing factor for cervical cancer, as well as a provocateur of other types of cancer: penis, oropharynx, rectum. The annual global incidence of about 1. 5 million.
The overall prevalence of human papillomavirus in the general population is 10% among women and 20% among men.
HPV infection is most common in sexually active young women and men between the ages of 16 and 25.
About 50% of gay men who engage in anal sex are at risk of developing squamous cell carcinoma, which was preceded by anorectal warts.
For 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. Of these, about 40 can affect the urogenital 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 HPV types
16, 18, 33, 45, 31, and 58, but the clinical outcome may differ.
Recently, vaccination against HPV infection has been gaining popularity, but according to experts, vaccination does not exempt you from regular visits to the doctor. There is evidence that the effect weakens after 15-20 years, in addition, it is worth considering the role of other unexplored genotypes of the virus, on which there is no effect of the vaccine.
Methods to diagnose HPV infection
Note that the diagnosis can be suspected by visual examination, during which the location of lesions and clinical manifestations of human papillomavirus infection are determined.
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 viral load (HPV-Digene test), real-time PCR - methods for detecting the number of copies of oncogenic DNA viruses;
- morphological research;
- tumor markers with determination of oncoproteins p16, ki67, mcm2, mcm7, etc.
HPV PCR diagnosis
PCR diagnostics can be qualitative and quantitative (real-time PCR, HPV-Digene test).
Currently, cervical cancer screening and early detection of infections are recognized as the most effective measures for cervical cancer control.
Previously used screening tests for women are cytology and histology, but due to their low specificity, a repeat test is necessary after a short period of time. Negative PCR diagnoses can reduce the frequency of gynecologist examinations (1 time / 5-6 years).
It should be noted that the qualitative definition of HPV is not very informative, since it only allows to confirm the infection, therefore, to resolve the issue of the need for therapy in both men and women with clinical manifestations, it is better to perform the HPV test -Digene, which will reveal the concentration of the virus.
When performing the polymerase chain reaction, type and species specific primers are used, which quantify the risk of malignancy (malignancy). Determination of viral load is the main objective of these tests.
If the level of HPV DNA is greater than 5000 genomes (the probability of developing cancer is high, therapy aimed at suppressing the activity of HPV is indicated). Less than 3, 000 genomes: low risk.
PCR diagnostics can detect all types of oncogenic viruses in men and women.
In addition to HPV tests, it is mandatory to carry out diagnoses of STDs, HIV, these diseases are considered cofactors of human papillomavirus infection.
Since the relationship between HPV and cancer of the cervix, penis and rectum has been demonstrated, molecular methods for the detection of HPV DNA in biomaterials are justified. Use the following:
- vaginal discharge and discharge from the cervix in women;
- urethral scraping in men;
- anal discharge;
- pharyngeal mucus;
Italian scientists conducted a study that showed that PCR diagnosis (88-100%) is more effective than cytology (34-86%) for the prevention of invasive cervical cancer.
The specificity of the HPV test (82-97%) is considered higher than the specificity of cytology (78-99%).
In most people, the human papillomavirus infection resolves on its own without the use of medication. But in women over the age of 30, HPV is rarely eliminated spontaneously, therefore, in the framework of cancer surveillance, a regular examination is recommended, which in the Russian Federation, according to current orders, a Once a year.
In some foreign countries, if the result of the PCR analysis for papillomavirus and cytology when examining a woman is negative, the interval to pass the exam is 1 time in 3 years, in the case of negative cytology, but positive results of the polymerase chain reaction for HPV of highly oncogenic types, an annual examination with colposcopy is performed.
Men are examined annually by a urologist, with formations suspicious of papillomavirus infection, a consultation with a dermatovenerologist is warranted.
Depending on the indications, especially if there is a suspicion of degeneration into a malignant tumor, a biopsy may be performed.
Colposcopy in women
Colposcopy is the most accessible diagnostic method for women, the results of which allow conclusions to be drawn about the need for further examinations.
Studies have shown that 99-100% of cervical cancers are associated with highly oncogenic types of human papillomavirus.
During an extended colposcopy, the cervix is treated with a solution or acetic acid, interacting with which the following appear:
- whitening of the epithelium;
- atypical transformation zone.
After staining with a solution, the modified area in the context of HPV takes the form of "semolina".
In a cytological study, the main signs of infection are the presence of cells with koilocytosis and dyskeratosis, which is evidence in favor of CIN.
Cytological diagnosis of HPV
The material is taken with a special brush. In women, scraping from a suspicious area of the cervix, in men - from the urethra, determine the type, number and change of mucosal cells.
Pap Smear, Pap Smear, and Liquid Cytology
Pap smear - a non-invasive study used in gynecological practice, it allows you to diagnose cervical and endometrial cancer in the early stages, before the development of clinical manifestations. The objective is to detect atypical cells suspected of a tumor process. In the standard Pap smear, the material obtained with the cytobrush is stained and examined under a microscope.
G. Papanikolaou developed a cancer screening study in 1940 and checks for exfoliated cells suspected of cancer or precancer.
The liquid cytology test is a type of Pap test, a more modern and efficient method of diagnosing HPV. When conducting a study, the biomaterial is not placed on a glass 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 performed when:
- atypical cell detection based on cytology results,
- with highly oncogenic HPV types with changes identified by colposcopy,
- with obvious signs of pathology regardless of HPV test results.
In men, a biopsy may be done for tumors that are suspicious for HPV. If the warts are located deep in the urethra, biopsy material is taken during urethroscopy.
HPV histology is a diagnostic method 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 the squamous epithelium,
- cervical cancer,
- penile cancer
- anorectal cancer.
Several options have been proposed to control human papillomavirus infection. In the first case, a cytological study is used, in the second, using PCR diagnostics, it is determined whether HPV is transient. For this, a PCR analysis is again prescribed after 6 months.
Who Needs to Get Tested for HPV
Qualitative tests are most often used for mass screening for prevention purposes, while quantitative tests are prescribed when a clinical picture appears suspicious for HPV infection.
In addition, the indications for HPV testing are as follows:
- unprotected "casual" sex;
- monitor the effectiveness of therapy;
- detection of STIs;
- overwhelmed gynecological history;
- HIV infection;
- planned pregnancy;
- have more than one sexual partner.
It is recommended that women of reproductive age get tested for HPV once every 3-5 years.
What kind of diagnosis is required, the doctor will tell you.
Examination of men for HPV is justified only in case of clinical manifestations, sometimes diagnoses are carried out with a burdened obstetric and gynecological history of the partner.