(Deltaretrovirus), causing in humans such malignant neoplasms of lymphoid and hematopoietic tissues as T-cell leukemia and T-cell lymphoma.

Adult T-lymphotropic virus is a strain of the virus that primarily affects adults. Closely related is the bovine leukemia virus. It is likely that this virus is involved in the pathogenesis of some demyelinating diseases, for example, tropical spastic paraparesis.

Classification

HTLV I

Human T-lymphotropic virus type 1(HTLV-I), also known as adult T-cell lymphoma virus(HTLV-1), causes diseases such as HTLV-I associated myelopathy, roundworm hyperinfection Strongyloides stercoralis, as well as viral leukemia. According to some reports, 4-5% of those infected will develop malignant tumors as a result of the activity of these viruses.

HTLV-II

Human T-lymphotropic virus type 2(HTLV-2, HTLV-II) is closely related to human T-lymphotropic virus type 1, HTLV-II has a genome homology of about 70% compared to HTLV-I.

HTLV-III and IV

The terms HTLV-III and HTLV-IV are used to refer to viruses that have been described relatively recently.

These viruses were discovered in 2005 in rural Cameroon, and were likely transmitted from monkeys to hunters through bites and scratches.

HTLV-III is similar to Simian T-lymphotropic virus 3, STLV-III. Numerous strains have been identified.

For these types of T-lymphotropic viruses, transmission between people has not been shown and their pathogenicity in relation to humans has not been proven. The name HTLV-III was previously used to refer to HIV, and HTLV-IV to refer to HIV-2, but these names have now fallen out of use.

Notes

1. Taxonomy of viruses (English) on the website of the International Committee on Taxonomy of Viruses (ICTV).
2. According to Primate T-lymphotropic virus 1(English) on the website of the National Center for Biotechnology Information (NCBI).
3. Mahieux R., Gessain A. (2005). "New human retroviruses: HTLV-3 and HTLV-4". Med Trop (Mars) 65 (6): 525-528.

> Testing for antibodies to human T-lymphotropic virus types 1 and 2

This information cannot be used for self-medication!
Consultation with a specialist is required!

T-lymphotropic viruses are the causative agents of two main diseases: adult T-cell lymphoma and tropical spastic paraparesis. In this case, the main causative agent is type 1 T-lymphotropic virus. The second type of virus is not directly associated with any disease, but there is evidence that it can cause certain neurological disorders and hematological changes.

These viruses, classified as retroviruses, also have a shorter name - HTLV types 1 and 2. They are found mainly in the Caribbean (Cuba, Mexico), South America, and Japan, but also in northern countries there is a risk of contracting this infection.

These viruses are transmitted mainly through blood: through transfusion of blood components, through the use of unsterile medical instruments (including between drug addicts through syringes and needles), from mother to child with milk.

Testing for antibodies to HTLV allows you to identify infected people and include them in the risk group. The presence of viruses and antibodies to them in the body does not necessarily lead to the development of clinical symptoms, so it is important to identify the infection as early as possible in order to prevent its further spread.

Who prescribes a test for antibodies to HTLV?

A general practitioner, therapist, or pediatrician can refer a patient for analysis. However, due to the fact that in our climate zone this is a fairly rare infection, most often a referral is given by infectious disease doctors or epidemiologists.

Where to donate blood for antibodies to HTLV, how to prepare for the examination?

You can donate blood for this test at an immunological laboratory or at an AIDS center. For the analysis, you need 5–7 ml of venous blood, which is taken no earlier than 4 hours after the last meal. The patient does not need to prepare specially for blood sampling.

Indications for research

The method is used to screen patients for the presence of HTLV I/II associated diseases. People from risk groups – drug addicts, residents of endemic areas – must undergo it. If you have promiscuous sex (especially when traveling to the Pacific and Caribbean countries), you should definitely get tested.

People with this infection do not have any specific complaints. But if, after a trip abroad or after unprotected sex with an unknown partner, a person begins to be bothered by weakness in the legs and arms, and signs of muscular dystrophy appear, he should definitely undergo an examination.

Myopathy (muscle disease), manifested by increasing muscle weakness, and myelopathy (spinal cord damage) of unknown origin are also grounds for prescribing this test.

Normal results and their interpretation

Normally, antibodies to human T-lymphotropic viruses are not detected at all. A positive test indicates a potential HTLV I/II infection or asymptomatic virus carriage. In patients with cancer, in some cases (approximately 3%), a false positive result is possible.

Clinical significance of the examination

Testing for antibodies to human T-lymphotropic viruses allows us to identify infected people, even if they do not have any clinical picture of the disease. These people should never be blood or organ donors.

The significance of the test is to prevent the spread of this infection. A negative result in patients with myelopathy and myopathy allows us to exclude HTLV I/II infection and narrow the scope of the diagnostic search.

The discovery of the virus that causes AIDS began in 1981, when a group of scientists at the National Cancer Institute in the USA, led by immunologist and virologist Robert Gallo, discovered the causative agent of one of the types of human cancer - T-cell leukemia. This disease was first reported in the late 1970s in the Caribbean and Southern Japan. In severe form, leukemia progressed very quickly: patients died within 3-4 months. The causative agent of acute T-cell leukemia in humans was a virus called human T-cell leukemia virus (HTLV-I). According to the existing classification, it was classified as a retrovirus. HTLV-1 was the first human retrovirus discovered and was classified as a subclass of oncoviruses, i.e. viruses that cause cancer. Some varieties of HTLV-I, especially those isolated from vervet monkeys and chimpanzees, had many similarities with it. On this basis, it was assumed that the newly discovered virus originated initially in Africa, where primates and then humans were infected with it, and this retrovirus entered the American continent thanks to the slave trade.

Although most attempts to isolate retroviruses from human tumor cells have been unsuccessful, at least one species of retrovirus has been shown to cause human malignancy. This is a human T-lymphotropic virus type 1 - the causative agent of T-cell leukemia - adult lymphoma, a disease common mainly in Japan and the Caribbean.

Unlike oncogenic animal retroviruses, human T-lymphotropic virus type 1 does not contain oncogenes, and its transforming properties are associated with the Tax protein.

Human T-lymphotropic virus type 1 is transmitted from mother to child (especially through milk), through sexual contact (usually from man to woman), as well as through the transfusion of infected blood and the use of contaminated needles. Most often, infection occurs in the perinatal period. Unlike HIV, which can be transmitted by cell-free material, human T-lymphotropic virus type 1 is less infectious and usually requires cell-to-cell contact for transmission.

Foci of infection have also been found in other Eastern countries (for example, Taiwan), in the Caribbean, including the northeastern part of South America, in Central Africa, Italy, Israel, in the Arctic, and in the southeastern part of the United States.

Although early epidemiological studies revealed an increasing number of carriers of antibodies to human T-lymphotropic virus type 1 among injection drug users, the use of more specific serodiagnostic methods has shown that the vast majority of infections in injection drug users are due to.

Rarely occurs in persons infected through transfusion of blood components; at the same time, about 20% of patients with tropical spastic paraparesis become infected through the blood.

The development of progressive spastic or ataxic myelopathy in carriers of antibodies to human T-lymphotropic virus type 1 is likely due to the direct effect of the virus on the nervous system; a similar disease may be caused by HIV or human T-lymphotropic virus type 2. Rarely, in patients with tropical spastic paraparesis, antibodies to the virus are absent in the serum, but are detected in the CSF.

Carriers of human T-lymphotropic virus type 1 have a 2-5% chance of developing adult T-cell leukemia-lymphoma during their lifetime, and the same risk of developing . These diseases occur only where human T-lymphotropic virus type 1 is common, and 95% of patients have antibodies to this virus in their serum.

Adult T-cell leukemia-lymphoma develops 20-30 years after infection. In half of the cases of tropical spastic paraparesis, the duration of the latent period is about 3 years; this period may be shorter (in one case, the disease developed 4 months after transfusion of infected blood), but can reach 20-30 years.

The discovery of the virus that causes AIDS began in 1981, when a group of scientists at the National Cancer Institute in the USA, led by immunologist and virologist Robert Gallo, discovered the causative agent of one of the types of human cancer - T-cell leukemia. This disease was first reported in the late 1970s in the Caribbean and Southern Japan. In severe form, leukemia progressed very quickly: patients died within 3-4 months. The causative agent of acute T-cell leukemia in humans was a virus called human T-cell leukemia virus (HTLV-I). According to the existing classification, it was classified as a retrovirus. HTLV-1 was the first human retrovirus discovered and was classified as a subclass of oncoviruses, i.e. viruses that cause cancer. Some varieties of HTLV-I, especially those isolated from vervet monkeys and chimpanzees, had many similarities with it. On this basis, it was assumed that the newly discovered virus originated initially in Africa, where primates and then humans were infected with it, and this retrovirus entered the American continent thanks to the slave trade.

Although most attempts to isolate retroviruses from human tumor cells have been unsuccessful, at least one species of retrovirus has been shown to cause human malignancy. This is a human T-lymphotropic virus type 1 - the causative agent of T-cell leukemia - adult lymphoma, a disease common mainly in Japan and the Caribbean.

Unlike oncogenic animal retroviruses, human T-lymphotropic virus type 1 does not contain oncogenes, and its transforming properties are associated with the Tax protein.

Human T-lymphotropic virus type 1 is transmitted from mother to child (especially through milk), through sexual contact (usually from man to woman), as well as through the transfusion of infected blood and the use of contaminated needles. Most often, infection occurs in the perinatal period. Unlike HIV, which can be transmitted by cell-free material, human T-lymphotropic virus type 1 is less infectious and usually requires cell-to-cell contact for transmission.

Foci of infection have also been found in other Eastern countries (for example, Taiwan), in the Caribbean, including the northeastern part of South America, in Central Africa, Italy, Israel, in the Arctic, and in the southeastern part of the United States.

Although early epidemiological studies identified an increasing number of human T-lymphotropic virus type 1 antibody carriers among injection drug users, the use of more specific serodiagnostic methods has shown that the vast majority of infections in injection drug users are due to human T-lymphotropic virus type 2.

Adult T-cell leukemia-lymphoma rarely occurs in individuals infected through blood transfusions; at the same time, about 20% of patients with tropical spastic paraparesis become infected through the blood.

The development of progressive spastic or ataxic myelopathy in carriers of antibodies to human T-lymphotropic virus type 1 is probably due to the direct effect of the virus on the nervous system; a similar disease may be caused by HIV or the latent period is about 3 years; this period may be shorter (in one case, the disease developed 4 months after transfusion of infected blood), but can reach 20-30 years.

A retrovirus is a family of viruses in which the genetic material consists of RNA. Microorganisms contain reverse transcriptase.

Retroviruses are microscopic organisms that can cause certain types of cancer and various viral infections. Moreover, pathologies can occur not only in people, but also in animals. In humans, retroviruses cause

Features of the virus

Retroviruses are unique organisms. They are able to reproduce by being transcribed into DNA. They enter the bloodstream and the process of transcription begins. After its completion, the viral genome gains full access to the DNA of the host cell and begins to reproduce all the processes occurring with it. In daughter cells, the viral DNA creates RNA copies. This process can continue for a long time, but eventually the copies leave the daughter cells and become coated with a protein coat. As a result, retroviruses cause a change in the normal replication process that occurs in cells, which involves RNA. This process is reversed. The infected cells themselves remain in the body for a long time. In some cases, the cells that change are destroyed, as happens with HIV infection, and sometimes turn into cancer.

Retroviruses include the Retroviridae family of viruses. They are prone to mutations, which is why they quickly become resistant to antiviral drugs. Because of this feature, it is difficult to fight retroviral infection.

Some people believe that a retrovirus is a simple flu-like virus, but this is not true. This species is dangerous and almost impossible to fight. To counteract this, it is necessary to develop special treatment regimens using antiviral drugs. To avoid contracting a retroviral infection, it is easier to carry out preventive measures in the form of routine vaccinations.

Despite the fact that retroviruses can cause life-threatening diseases, they can be easily combated with ordinary soap and water: to decontaminate, simply wash your hands with soap. To prevent the spread, barrier prevention measures are used, including rubber gloves, face masks, and certain brands of condoms.

Classification of retroviruses

The first examples of a retrovirus and its effect on a living organism were described more than a hundred years ago. Since then, interest in the microorganism has grown greatly. Retroviruses are now divided into the following types:

1. Family of oncogenic viruses. This variety contributes to the development of sarcomas and leukemia in humans and animals. One of the most important representatives of this type of disease is the human T-lymphotropic virus.
2. Lentivirus family. A prominent representative of the group is HIV.
3. Spumavirus family. This species is not associated with any pathologies, but is capable of causing changes at the cellular level.

As the morphology of the virus was studied, a variety of types of organisms were identified, which were divided into several groups:

1. Non-enveloped organisms.
2. Enveloped species with acentric arrangement of nucleocapsids.
3. Enveloped species in which the nucleocapsid is located centrally.
4. Viruses are large in size with a minimum number of spines.

The RNA of the virus has several information reading frames; accordingly, it will encode only certain groups of structural proteins: the Gag, CA, MA and NC groups.

Pathologies caused by RNA viruses

There are a number of pathologies that are caused by RNA viruses. These include:

1. Flu.
2. Rubella.
3. Measles.
4. Viral enteritis.
5. Mumps.
6. Enteroviral infections.
7. Human T-lymphotropic infection type 1.
8. Human T-lymphotropic infection type 2.

RNA viruses can trigger the development of sarcomas and leukemias.

Acute retroviral syndrome in HIV

Among all existing pathologies caused by RNA-containing microorganisms, the most common is acute retroviral syndrome. This is a primary infection that lasts up to six months after infection.

After becoming infected with HIV, it usually takes several weeks to several months. At this time there are no clinical manifestations of infection. This asymptomatic period is called incubation. In some cases it can last up to a year.

Symptoms of the retrovirus appear gradually, starting with damage to the upper respiratory tract, as with the flu, although much more often in patients the onset of pathology occurs as mononucleosis:

• stomatitis, pharyngitis with damage to the lymph nodes appears;
• body temperature rises;
• appetite decreases, the patient begins to lose weight;
• nausea, bowel dysfunction;
• the size of the spleen and liver increases;
• a rash appears on the skin;
• Aseptic meningitis develops, the patient’s mental state is disturbed, and neuritis appears.

Diagnosis of the syndrome

The acute phase of the pathology lasts about ten days. To establish that a patient has a viral pathology, it is necessary to take a blood test: HIV RNA is detected in the plasma. Then the acute phase of the retroviral syndrome is confirmed. To do this, take a repeat analysis. If after three weeks antibodies to HIV are detected in the blood, and leukopenia and lymphopenia are detected in the general analysis, then an acute phase can be assumed.

If the disease is not detected during this phase and treatment is not prescribed, the symptoms of the retrovirus may subside for several years. The only clinical manifestation may be enlarged lymph nodes.

If the diagnosis is made on time and the retrovirus treatment is prescribed correctly, then patients can live with the pathology for more than twenty years.

Treatment

There are many different opinions about initial treatment, but they all boil down to the fact that therapy should begin immediately after diagnosis, without waiting for clinical manifestations and complications.

Knowing what causes the retrovirus to die, the doctor can choose the right treatment regimen and prescribe antiviral drugs. Usually two doses are selected, which are carried out under laboratory control of blood serum.

Most often prescribed:

• drugs belonging to the group of reverse transcriptase nucleosides;
• agents from the protease group;
• drugs related to non-nucleoside transcriptase inhibitors.

Therapy of secondary pathologies plays a huge role in the treatment of retroviral infection. For this purpose, the doctor prescribes a full examination, during which they determine what ailments the patient suffers from. After identifying chronic diseases, therapy is selected aimed at getting rid of the disease or achieving stable remission.

As additional treatment, vitamin therapy, physical therapy, immunotherapy, and nutrition correction are mandatory.

After treatment, the patient will have to be observed by a doctor for the rest of his life, lead a healthy lifestyle, and follow strict recommendations. Otherwise, the retrovirus may reactivate.

Human T-lymphotropic viruses

T-lymphotropic pathologies are divided into two types: type 1 and type 2. Each of them is represented by certain ailments caused by RNA viruses.

The first type of T-lymphotropic infection includes T-cell leukemia, lymphoma and spastic paraparesis of the tropical type. In epidemiological areas where there is a high level of infection with the T-lymphotropic virus, dermatitis, pneumonia, and arthritis are diagnosed.

T-lymphotropic infection type 2 causes T-cell lymphoma and in some rare cases the microorganism can lead to the development of hairy cell leukemia.

Finally

It is easier to prevent any infection than to treat it, especially infection with RNA viruses. To be healthy, you should follow the rules of personal hygiene, wash your hands with soap. Good immunity and a healthy lifestyle will help protect against pathology.

To prevent retroviral infections, you should make it a habit to wash your hands every time you enter your home from the street, and before every meal. It is mandatory to use barrier means - condoms, rubber gloves, masks. These simple rules will help minimize the risk of contracting a retroviral infection.