Human papillomaviruses are a group of viruses that infect epithelial tissues, especially often the skin and mucous membranes. Pathogens are transmitted by contact, most often sexually, so both men and women suffer from HPV.
Human papillomaviruses cause the appearance of various neoplasms on the skin and mucous membranes. The “handiwork” of the HPV are:
- vulgar and flat warts;
- plantar warts (tongs);
- genital and flat condylomas;
- Bowenoid papulosis.
In addition, HF leads to the formation of cervical neoplasia.
All these phenomena are unpleasant, but not fatal. Any defects of the skin and mucous membranes are easily treated today by simple removal. But the danger is that some subtypes of HPV are oncogenous – that is, over time, tumors caused by them can become malignant.
Accurate diagnosis is the first stage of a full-fledged treatment, so it is so important to take tests prescribed by a doctor. In this article, we will consider in which situations blood is given for HPV.
Indications for HPV tests
HPV is one of the most common sexually transmitted infections today. The thing is that condoms do not adequately protect against it. Condylomas or papillomas can also be located outside the area that is closed by the condom, and the mucous membranes are very vulnerable to the virus due to the lack of a protective stratum corneum. The oral-genital route of transmission is also frequent.
Often, HPV is successfully suppressed by the immune system and does not cause any clinical manifestations at all. At the same time, the changes that the virus causes are not always visible to the naked eye. It happens that there are no growths on the skin, but the mucous membranes are affected. The following symptoms should cause concern:
- pain during intercourse, spotting blood discharge in women after PA or douching;
- burning and pain in the urethra in men;
- pain in the anus during bowel movements, sensation of a foreign body in the rectum;
- infertility, miscarriage.
With these symptoms or with the appearance of genital warts, papillomas in the perineum, on the genitals, you need to see a doctor. Woman – to the gynecologist, man – to the urologist. HPV tests are also recommended if it is found in a sexual partner, even in the absence of complaints.
What tests do you have for HPV?
Since the human papilloma virus is tropic to the tissues of the epithelium, scraping from the mucous membrane is usually taken to detect it. In men – from the urethra, in women – from the cervical canal. Sometimes – from the oropharynx, with the mucosa of the rectum. The resulting material is sent for research by polymerase chain reaction (PCR). This allows you to accurately detect the genetic material of the virus in the tissues.
To begin with, a high-quality PCR analysis is performed that determines only the presence or absence of a virus with high oncogenicity without specifying the type (group is detected in aggregate). To clarify the analysis, PCR with genotyping is carried out, in this case, you can accurately determine which type of virus is in the body.
The quantitative method (real-time PCR) is used to determine the viral load, that is, the concentration of a certain type of HPV in the tissues of the epithelium. Three options are possible here:
- Lg less than 3 – clinically insignificant load;
- Lg from 3 to 5 – moderate load, there is a risk of tissue degeneration;
- Lg more than 5 – high load and risk of malignancy.
In addition to the polymerase chain reaction technique, a hybrid capture method (digene test) is also used. It is good because it gives both qualitative and quantitative results. Allows you to accurately determine the strain and viral load. The only negative is the high cost of the study. Epithelial cells obtained by scraping are also used for this test.
Another way to detect HPV in women is morphological. For this, a cytological smear (PAP test) is used – the cells deposited on a glass slide are studied in a laboratory. Detection in the diagnostic material of altered cells – coilocytes and diskeratocytes – indicates infection. But for an accurate diagnosis, PCR analysis is always prescribed.
The question arises, is it possible to determine HPV in the blood? Are HPV blood tests taken?
Antibodies to HPV in the blood
Indeed, human papillomavirus infection can also be detected by a blood test, however, the study of this biomaterial is diagnostically less significant. Why? Because the presence of HPV in the body does not necessarily mean the development of infection. Only its detection in epithelial tissues means that the virus actually reached a clinically significant concentration and affected the body.
Papillomavirus in the blood is determined by the results of an enzyme immunoassay. ELISA is a modern laboratory technique for blood testing. It is very sensitive, so it gives fairly accurate results – more than 90%. The principle of the technique is based on the detection in the blood of a person of antibodies to an infectious pathogen – in this case, to the human papilloma virus.
It is clear that HPV in this case is found indirectly – by the “trace” of antibodies that the immune system produces against its invasion. At the same time, it is impossible to find out exactly which strain caused the reaction, therefore ELISA does not allow to identify the oncogenicity of the pathogen. In principle, it only shows the “contact” with the virus that the immune system could have successfully suppressed.
It is difficult even for a specialist to correctly interpret the results of ELISA, since specific antibodies to HPV are detected in the analyzes much longer than with other infections.
Moreover, due to the peculiarities of the life cycle of the virus (it produces a small amount of viral protein and, accordingly, causes a weak reaction of blood cells), the body’s immune system may not include protection against “invasion”, therefore, antibodies will not be produced.
All this makes it difficult to predict the immune response to HPV and the outcome of the disease in a particular person. Therefore, we can say that the enzyme immunoassay perfectly illustrates the course of many infections in the body, but it is in the case of HPV that it is not very informative and is mainly used for making a preliminary diagnosis. For example, if HPV is detected in a woman, her partner may be asked to do a blood test to find out if he should undergo an in-depth examination.
How to prepare for the analysis
Venous blood is taken for analysis, it is given in the morning on an empty stomach. No special preliminary preparation is required, there are only general recommendations:
- do not drink alcohol, overeat, and do not abuse fatty foods the day before;
- take care of yourself by limiting physical and emotional stress;
- stop antiviral treatment in at least two weeks (this issue is resolved with the attending physician).
So, in the diagnosis of HPV, the main thing is to pass a smear, and a blood test can be used as an additional research method.