When the symptoms have already appeared and the patient consults a doctor about them or in connection with another problem, a gynecologist or urologist during the physical examination will necessarily pay attention to the appearance of outgrowths in such unusual places as the genitals and anus. If such neoplasms appear in the mouth (larynx and vocal cords), their occurrence may be of interest to both the therapist or the ENT.
When examining women, the suspicion of a papilloma virus can decrease if there is erosion of the cervix (especially if there is a long absence of its treatment), hyperplastic processes at the entrance to the cervical canal, cystic formations that actively increase in size. In men, the urologist or andrologist will pay attention to the appearance of spots and plaques in the region of the head and body of the penis of the patient.
Physical examination of the lesion site allows to suspect (with sufficient accuracy) the papillomavirus infection. But the doctor can not determine by eye what strain of the virus caused the appearance of specific external symptoms. Usually, with HPV type 18 or 16, flat warts appear on the mucosa, but in most cases, several strains of the virus are found in one patient at a time, which means that pointed cannillomas (single or multiple) and anogenital warts can appear on mucous membranes.
In such circumstances, it is very difficult to determine which types of virus the individual patient has. But this must be done, because besides safe low-cancerous strains, types with medium or high oncogeneity can be detected, which can turn an innocuous tumor into a cancer tumor.
Diagnosis of HPV is not only an external examination. To identify the virus in the body and determine its type, practice:
- Study of mucosal tissues of internal genital organs by means of a special microscope (colposcopy). This method allows you to carefully consider lesions and identify not only genital warts (they are usually seen with the naked eye), but also flat. By colposcopy, doctors can carefully examine the tissues with dysplastic processes and their reaction to special reagents (Schiller test): Lugol's solution or vinegar (3% aqueous solution). If there are malignant cells, the affected area acquires a whitish shade.
- Smear microscopy (a cytological study of a biomaterial taken from the surface of the vaginal mucosa, cervical canal or urethra). Cytology in the case of papillomavirus infection does not play a decisive role in the diagnosis of the disease. Nevertheless, it allows us to identify the modified cells (koylocytes and diskuratsity) and by their number to judge the degree of development of the malignant process.
- Histological examination is also a microscopy of tissues, but the biomaterial is already served not by mucus, but by a small piece of affected epidermis and deeper tissues taken during a gynecological or urological examination (biopsy). Such an analysis is carried out if the cytology shows a dubious or positive result. This is the most accurate method for detecting cancer.
- Blood test for antibodies. This study is indicative even in the event that there are no external manifestations of the viral infection yet, but the virus has already entered the human body and can circulate by hematogenous way (by blood). The study allows you to identify the human papilloma virus, but it can not determine the degree of infection (quantitative indicators of virions) and the type of the virus itself with absolute accuracy.
- PAP test. This study is relevant not only for women with suspected cervical cancer, but also for the detection of HPV 18 in men. Like lesions of dysplasia, neoplasms on the penis are lubricated with 3% r-rum acetic acid. A positive test with HPV 18 will show the correct vascular reticulum in the reagent application area.
- HPV Digene test or hybrid capture method. An innovative technique that allows to differentiate high-coagulated strains of the papilloma virus from low-ionogenic ones. There are 2 tests. One (395) identifies types of HPV with low oncogeneity, and the other (394) - with high oncogeneity, including HPV 18 and 16.
Usually this research is carried out in conjunction with a cytological analysis of the smear.
- The PCR analysis (polymerase chain reaction, PCR test) is no longer a new, widely tested method for detecting highly ionogenic types of human papillomavirus: HPV 18, 16, 31, 33, 56, etc., which allows us to identify dangerous diseases already on early stages. As a biomaterial use a smear with mucous, less often blood or urine.
To date, PCR testing is the most popular and accurate analysis that allows isolating the DNA of a virus. It determines not only the type and type of the virus, but also its quantity.
The structure of the PCR test distinguishes:
- PCR of HPV 16 and 18 qualitative (definition of highly-oncogenic strains of the virus)
- PCR of HPV with genotyping (determination of the genotype of the virus, which is necessary for effective treatment taking into account the resistance of the detected strain to medicinal products),
- PCR of HPV 18 is quantitative (determining the degree of infection or number of virions) and some other variants of the study, including combined ones.
The qualitative type of research allows us to determine only the presence of a specific strain of the virus in the body. Decoding results for HPV 18 or another type of virus will contain one of the words: "positive" or "negative". For example, HPV 16 18 positive (+) if the DNA fragments of the virus were detected in the biomaterial, or HPV 16 18 negative (-), if none were found.
To find out how serious the situation is in the detection of highly co-genic strains of the virus, additional quantitative analysis is needed. Here, everything will depend on the human immunity (both general and local). The weaker the immune system, the more virions in the biomaterial will be detected.
The PCR test analyzer allows detecting more than 0.3 copies of HPV DNA per ml, which is considered the norm for HPV 18, since fewer copies are no longer clinically important and can not cause serious pathology.
In itself, the detection of a minimum number of DNA from the papilloma virus indicates good immunity. But we can not exclude the fact that the infection could have occurred quite recently (in this case, the result of PCR will be declared doubtful), therefore, after a time, on the recommendation of a doctor, it is necessary to pass a second analysis.
When it comes to cervical cancer, 16 and 18 types of papillomavirus infection most often appear in the research results. What is the difference between HPV 16 and HPV 18, because both types of virus are considered highly coenotic and are accused of developing uterine cancer? It must be said that the degree of oncogenicity in these strains of the virus is not the same. According to some Internet sources, HPV 16 is the most dangerous, not accounting for 50% of oncology detection cases, while HPV 18 becomes the culprit of this dangerous disease in only 10% of cases.
However, foreign scientists, after conducting a series of studies, came to the conclusion that the cause of the development of invasive adenocarcinomas (this type of cervical cancer is detected by doctors in most patients) is in most cases still HPV-18, and in cases when both strains are detected virus, the 18th type contributes to the rapid progression of the disease. In the case of non-invasive species of glandular cancer, affecting not only the reproductive system, but also other organs, the leading role belongs to HPV-16.
The emergence of early dysplastic processes in the uterus during studies in some cases was observed even before the introduction of the genome of HPV 16 into the cell, and it says that the integration of this type of virus into the cells of a living organism is not a necessary condition for the development of the disease. The pathological process begins even before its first signs appear.
But the development of severe grade 3 dysplasia of the cervix, often turning into an invasive adenocarcinoma, in most cases implied the integration of HPV 18 and other types of papillomavirus infection that cause pathological processes in the uterus (highly oncogenic HPV 31, 33, 52b, 58 and low-oncogenic HPV 6 and 11 ), inside the cell. This is necessary to transfer her genetic information, the information that will later change its properties and turn into a cancerous tumor.
But even the introduction of highly ionogenic virus into the cell does not always cause cancer. Only 1 in 100 women with dysplasia subsequently diagnosed with cervical cancer. It all depends on the length of the virus's stay in the body and its ability to express carcinogenic genes E6 and E7 (inserting them into the genome of the host cell and transmitting information causing mutations), activating the mechanisms of converting the female sex hormone estradiol to 16α OH steron, the presence or absence of multiple mutational damage to the chromosomes of a living cell. Thus, oncological diseases against the background of papillomavirus infection develop only when several factors interact simultaneously, creating fertile soil for the initiation of malignant cell degeneration.