Diseases of the immune system began to be studied relatively recently, as this science is one of the youngest in medicine. However, thanks to the rapid development, today there are already many discoveries in this industry. Diseases of the body's defense system are called immunodeficiency states, which are divided into primary and secondary lesions. An example of such pathologies is the DiGeorge syndrome, in which there is a congenital deficiency of T-lymphocytes. In addition to the insufficiency of protective mechanisms, this disease is manifested by multiple anomalies in the development of organs and systems, noticeable already in the neonatal period, and in some cases during intrauterine development.
Mechanism of disease progression
DiGeorge syndrome is characterized by complete or partial underdevelopment of the thymus gland (thymus). This organ is located in the chest cavity in children and is necessary for the formation of a cellular immune response. During puberty, the thymus begins to decrease in size and transform into adipose tissue. This process is normal and notrefers to pathology. With DiGeorge syndrome, we are talking about the congenital absence of this organ or its insufficient development (hypoplasia). As a result, immune cells remain defective and do not perform their functions. In addition, with this disease, the absence of parathyroid glands, which are responsible for the exchange of calcium and phosphorus in the body, is often observed. The mechanism of development of anomalies of various systems is associated with intrauterine fetal development disorders that occur in early pregnancy.
DiGeorge Syndrome: causes of pathology
At the moment there is no exact explanation of why thymus aplasia occurs. In most cases, with this pathology, a genetic defect occurs in the 22nd chromosome, which consists in the loss of one of its sections. It is believed that such a violation is associated with heredity, however, this theory has not been proven. In addition, a defect in the 22nd chromosome is not observed in all patients, but only in 80% of cases. The causes of DiGeorge syndrome are also associated with embryonic fetal disorders resulting from pathologies in the mother. These include infectious diseases transferred during pregnancy (rubella, measles, herpes), diabetes mellitus, brain injuries, etc. Other causes of DiGeorge syndrome are the abuse of psychoactive substances (alcohol, drugs) and exposure to chemicals during the prenatal period. development.
Clinical manifestations of thymus aplasia
The disease becomes noticeablealready in the first days of the baby's life, since in addition to the insufficiency of the immune system, it is manifested by multiple malformations. The most severe are heart pathologies, since some of them are incompatible with life (Fallot's tetrad). Developmental anomalies can affect any organs and systems, but most often DiGeorge syndrome is manifested by the following symptoms:
- Facial disorders: reduction of the bones of the skull and jaw, wide-set eyes, underdevelopment of the auricles, gothic palate, cleft lip, etc.
- Abnormal airways and esophagus.
- Malformations of the nervous system - atrophy of the cerebral cortex or cerebellum. As a result of these disorders, there is a violation of gait, paresis and paralysis, changes in sensitivity. The main manifestation of CNS anomalies is mental retardation, which becomes noticeable in the first years of a child's life.
- Defects of the digestive tract: stenosis and atresia.
- Pathological bone fractures, increase in the number of fingers or toes.
- Anomalies of the visual organ: strabismus, retinal vascular disorders.
- Defects of the urinary system.
Disorders can appear singly or in combination. In some cases, there are no developmental anomalies, and DiGeorge's syndrome consists only in the insufficiency of immune mechanisms. Deficiency of T-lymphocytes is manifested by a tendency to viral and bacterial infections, tumor processes. At the same time, diseasesarising from immunodeficiency, are poorly amenable to antibacterial and anti-inflammatory therapy. Aplasia of the parathyroid glands is manifested by convulsive conditions.
Diagnostic criteria for disease
Diagnosis is made with a combination of the following symptoms: high susceptibility to infectious diseases, developmental anomalies and convulsions. In laboratory tests, you can notice a decrease in the number of lymphocytes and a decrease in calcium levels. In order to confirm the diagnosis, it is necessary to conduct studies of the immune status. In this case, the following changes are observed: lack of response to vaccination and negative tests for hypersensitivity and lymphoblastic transformation. The number of B-lymphocytes is not changed. In the study of the structures of cellular immunity, their decrease and decrease in activity are noted. An ultrasound of the chest cavity reveals the absence or reduction of the thymus and parathyroid glands. The study of the DNA structure allows you to learn about the changes in the 22nd chromosome.
DiGeorge Syndrome: treatment of pathology
Treatment of pathology depends on the degree of violations. In the complete absence of the thymus, organ transplantation is indicated. Surgical treatment is necessary for severe malformations of organs and systems. With an uncomplicated course of the disease and the absence of serious anomalies, maintenance therapy is prescribed. The main drugs are immunostimulants. Throughout life, it is necessary to compensate for calcium deficiency in the body. AtInfectious diseases are symptomatic therapy: antibiotics, antiviral drugs. In addition to taking medications, it is necessary to avoid hypothermia, stressful situations and other adverse factors.
Consequences of thymus aplasia
DiGeorge Syndrome is dangerous because it entails many complications. Patients with this pathology are prone to tumor processes, severe infectious processes. A frequent consequence of the syndrome is the development of autoimmune disorders. This is due to the fact that the patient's body perceives its own cells as foreign agents and begins to fight against them. As a result, diseases such as systemic lupus erythematosus, dermatomyositis, and rheumatoid arthritis occur. With severe developmental anomalies, the following complications can be observed: mental retardation, paralysis of the limbs, blindness. With a convulsive syndrome, respiratory failure may develop due to asphyxia.
Prognosis for DiGeorge Syndrome
With a combination of immune deficiency and visible malformations of the facial skull, a diagnosis is made: DiGeorge syndrome. Photos of people suffering from this disease can be seen in the special medical literature. With this combination of these symptoms, the prognosis for life is usually unfavorable, since developmental anomalies indicate a severe form of pathology. Usually, children suffering from DiGeorge syndrome do not live up to 10 years of age due to severe infectious or oncological diseases. Whena milder course, the absence of malformations and adequate replacement therapy, the prognosis may be favorable.
Prevention of DiGeorge Syndrome
There is no specific prevention of this disease. In order to prevent violations of the embryonic development of the fetus, the expectant mother needs to limit stress factors, give up bad habits, and also prevent infection with bacterial and viral diseases. Developmental anomalies can be detected on a planned ultrasound, which is carried out in each trimester of pregnancy.
