Acquired Immunodeficiency Syndrome (AIDS)

Acquired Immunodeficiency Syndrome (AIDS) is a particularly dangerous viral disease; Characterized by a long incubation period, suppression of cellular immunity, the development of secondary infections (viral, bacterial, protozoal) and tumor lesions, which, as a rule, lead the patients to death. The disease was first described in 1981; By 1989, it was registered in 130 countries with a total number of patients of about 140,000, annually their number is doubled. The risk groups include those who received multiple transfusions of blood and its drugs; drug addicts; Homosexuals; Persons who have numerous casual sex partners.

Etiology, pathogenesis. The causative agent of AIDS is the human T-lymphotropic virus, which belongs to the family of retroviruses. The virus was discovered in 1983, at first it was designated as LAV, and also as HTLV-111. Since 1986, the designation of human immunodeficiency virus (HIV), or the human immunodeficiency virus (HIV), has been introduced. Retroviruses contain an enzyme-reverse transcriptase. Viruses can be cultured in a cell culture. Warming at 56 g. C inactivates viruses. Two types (variants) of the human immunodeficiency virus were identified. Many of their properties have not been studied enough.

The causative agent of AIDS penetrates the human body through microtraumas of the skin (contact with blood) and mucous membranes of the genital tract or rectum. From the moment of infection to the appearance of the first symptoms of infection, a long latent (incubation) period lasts from 1 month to 4-6 years.

The persistence and accumulation of the virus occurs in the lymphoid tissue. However, already in this period, from time to time, the virus enters the bloodstream and can be found in secretions. Such persons without significant symptoms of AIDS can be the source of infection. With the advent of clinical symptoms, viralemia becomes more intense. At the heart of the pathogenesis of AIDS lies the T-lymphotropicity of the virus. Breeding in T4-cells (heppers), AIDS viruses inhibit their proliferation and disrupt the protein structure of the T-helper plasmolemma. The change in the structure of these proteins prevents the recognition of infected T4 cells in their destruction by cytotoxic T8 lymphocytes. Inhibition of proliferation leads to a decrease in the absolute number of T4 cells.

The defectiveness of the mechanisms of recognition of the antigens of the AIDS virus is manifested by the increased synthesis of antibodies of classes A and G, which, however, do not possess the ability to neutralize the causative agent of the disease. Deficiency of immunity leads to the activation of a latent infection or the addition of a so-called opportunistic (accidental) infection caused by opportunistic microorganisms. It is these diseases that usually lead to the death of patients in the next 1-2 years after the appearance of the first clinical symptoms of AIDS. Reduction of cellular immunity can also lead to the appearance of several malignant neoplasms: Kaposi's sarcoma, brain lymphoma, angioblastic lymphadenopathy.

As a layered infection, pneumonia caused by pneumocysts, gastrointestinal and pulmonary forms of cryptosporidosis, generalized toxoplasmosis, most often in the form of encephalitis, generalized manifestations of herpetic and cytomegalovirus infections, mycoses, bacterial infections are most often noted.

Symptoms, course. The incubation period lasts more than 6 months. The onset of the disease is gradual. The initial (prodromal, nonspecific) period is characterized by an increase in body temperature (above 38 ° C) with profuse sweating, symptoms of general intoxication (lethargy, depression, decreased efficiency). Typically, the lesion of the gastrointestinal tract. Sometimes it develops (pain when swallowing, diophagy, ulcers caused more often by candida fungi, and sometimes by a viral infection (herpetic, cytomegalovirus) .The enteritis manifests itself with abdominal pain, diarrhea, with the sigmoidoscopy of the changes is not detected.The enteritis is more often due to protozoa (lamblia, cryptosporids, isospores ) And helminths (strongyloidiasis), rarely cytomegaloviruses.Colit is more often caused by Shegels, Salmonella, Campylobacter, less often by dysentery amoebae and chlamydia.In homosexuals, sometimes the symptoms of proctitis associated with infection by gonococci, syphilis, and, more rarely, cytomegalovirus and herpetic infection, come to the fore.

A characteristic manifestation of the initial period of AIDS is generalized lymphadenopathy. The increase begins more often with cervical, axillary and occipital lymph nodes. AIDS is characterized by lymph node involvement in at least two places and for 3 months or more. Lymph nodes can grow up to 5 cm in diameter and remain painless, there is a tendency to merge them. In 20% of patients with lymphadenopathy, there is an increase in the spleen.

More than half of the patients develop various skin changes - maculopapular elements, seborrheic dermatitis of eczema, fever resistant to steroid preparations, etc.

Clinical manifestations of the initial period of the disease in laboratory changes are designated as "a symptom complex, related to AIDS". Simultaneous detection of two or more clinical signs included in this complex and two or more laboratory and diagnostic signs allows us to say with very high probability that the patient develops AIDS and that it is necessary to conduct a complex of special studies that will allow us to make a final diagnosis.

Symptomocomplex, related to AIDS.

Clinical signs (for 3 months or more):

1. Unmotivated lymphadenopathy;
2. Unmotivated weight loss (more than 7 kg or 10% of body weight);
3. Unmotivated fever (constant or intermittent);
4. Unmotivated diarrhea;
5. Unmotivated night sweat.

Laboratory and diagnostic features:

1. Decrease in the number of T-helpers;
2. Decrease in the ratio of T-helpers / T-suppressors;
3. Anemia or leukopenia, or thrombocytopenia, or lymphopenia;
4. Increase in the number of immunoglobulins G and A in the blood serum;
5. Decrease in the response of the blast-transformation of lymphocytes to mitogens;
6. Absence of skin reaction of hypersensitivity of delayed type on several antigens;
7. Increase in the level of circulating immune complexes.

The Manifest period of AIDS (the period of the height of the disease) is characterized by the prevalence of clinical manifestations of secondary (opportunistic) infection. Almost half of the patients have lung lesions (pulmonary type of AIDS), caused more often by pneumocystis. Pneumocystis pneumonia flows heavily, 90-100% slowness. There is pain in the chest, increasing with inspiration, coughing, shortness of breath, cyanosis, radiographically reveal multiple infiltrates of lung tissue. Almost the same severe lung damage caused by legionella and other bacterial agents. Lungs can be affected with generalized cytomegalovirus infection. When forming abscesses in their lungs, an infection caused by fungi (more often aspergillosis

In 30% of patients, the central nervous system (cerebral form of AIDS) is at the forefront. The picture of encephalitis, caused by generalized toxoplasmosis infection, is more common, less often cytomegalovirus and herpetic. Signs of encephalitis can be combined with signs of serous meningitis. Primary or secondary lymphoma of the brain can also develop.

In the gastrointestinal form of AIDS, the main manifestations are long-term diarrhea, loss of body weight, a picture of enteritis caused by cryptosporidia and microorganisms. Sometimes in AIDS patients, long-term fever and symptoms of general intoxication come to the fore, fever is more often of the wrong (septic) type, there may be focal manifestations. More often it is a consequence of disseminated mycobacteriosis.

Approximately 30% of patients develop Kaposi's sarcoma. In normal conditions, this is a rare disease of the elderly with a predominant lesion of the skin of the lower extremities. In AIDS patients, it affects many groups of lymph nodes, mucous membranes, skin, proceeds more aggressively. The disease is steadily progressing. Patients with manifest forms of AIDS die within the next 1-2 years.

Diagnostics. The surveyed contingent, as well as the stages and scope of clinical and laboratory studies are regulated by the Decree of the Presidium of the Supreme Soviet of the USSR of August 25, 1987 and the rules of medical examination for the detection of infection by the AIDS virus, established by the Ministry of Health of the USSR in accordance with the provisions of this decree. Studies are conducted in specially designated laboratories.

Treatment. There are no effective etiotropic agents. Antiviral drugs (azidothymidine, virazol) are used. The search for new antiviral drugs is under way. When developing a secondary infection, appropriate atiotropic drugs are prescribed. Immunomodulators (preparations of the thymus gland, lymphocytes, interferon, etc.) are also used. It is possible to achieve only temporary improvement, then the disease recurses usually due to the layering of another infectious agent.

Prevention. General measures of prevention are regulated by the Decree of the Presidium of the Supreme Council of the USSR of August 25, 1987 "On measures to prevent infection with the AIDS virus."

Patients are accommodated in separate boxes, care for them is carried out by specially assigned instructed personnel. The taking of blood and other materials, as well as their processing, is carried out in rubber gloves. When the infectious material hits the skin, it is treated with 70% alcohol or 1% chloramine solution. Labware containing blood and other materials should be specially marked. Work is underway to create a specific vaccine.