Severe combined immunodeficiency in children: possible causes, symptoms and ways of treatment
Severe combined immunodeficiency syndrome (SCID)is a pathology that is known as a boy's syndrome in a bladder, as sick people are highly vulnerable to infectious diseases and must remain in a sterile environment. This ailment is the result of severe damage in the immune system, so the latter is considered to be practically absent.
This is a disease that belongs to the categoryprimary immunodeficiencies and is caused by multiple molecular defects that lead to the fact that the functions of T cells and B cells are disrupted. Sometimes the functions of killer cells are violated. In most cases, the diagnosis of the disease is placed at the age of up to 3 months from birth. And without the help of doctors such a child will very rarely be able to live more than two years.
About the disease
Every two years experts of the World Organizationhealth care, the classification of this disease is very carefully reviewed and is consistent with modern methods of control concerning immune system disorders and immunodeficiency states. Over the past few decades, they have been allocated eight classifications of the disease.
Severe combined immunodeficiencyquite well studied in the world, and yet the survival rate of sick children is not very high. Here an accurate and specific diagnosis is important, which will take into account the heterogeneity of the pathogenesis of immune disorders. However, it is often carried out either incomplete, or untimely, with a long delay.
Typical infections and skin diseases are the most common signs of severe combined immunodeficiency. The reasons are discussed below. It is they who help in diagnosing children.
Given that in recent years, achievements ingene therapy and the possibility of bone marrow transplantation have moved far ahead, patients with SCID have a good opportunity to develop a healthy immune system and, as a consequence, a hope for survival. But still, if a serious infection develops rapidly, then the prognosis is often unfavorable.
Causes of the disease
The main cause of severe combined immunodeficiency is mutations at the genetic level, as well as the syndrome of "bare" lymphocytes, deficiency of tyrosine kinase molecules.
These causes include infections such ashepatitis, pneumonia, parainfluenza, cytomegalovirus, respiratory syncytial virus, rotavirus, enterovirus, adenovirus, herpes simplex virus, chickenpox, Staphylococcus aureus, enterococci and streptococci, Pseudomonas aeruginosa. Also predisposition is caused by fungal infections: biliary and renal candidiasis, Candida albicans, legionella, moraxella, listeria.
Many of these pathogenic factors are present andin the body of an absolutely healthy person, but with the formation of unfavorable conditions, a situation may occur when the protective properties of the body decrease, which, in turn, provokes the development of immunodeficiency states.
What can provoke a severe combinedimmunodeficiency? The presence of mother T cells in sick children. This circumstance can cause reddening of the skin with T-cell infiltration, an increase in the amount of the hepatic enzyme. Inadequately, the body can also respond to an inappropriate bone marrow transplant, blood transfusion that is different in parameters. The signs of rejection include: the destruction of the biliary epithelium, necrotic erythroderma on the intestinal mucosa.
In previous years, newborns were vaccinatedthe vaccinia virus. In this regard, children with severe immunodeficiency conditions died. To date, the BCG vaccine, which contains the bacillus of Calmette-Guérin, is used around the world, but it is often the cause of death of children with this disease. Therefore, it is very important to remember that SCID patients are strictly prohibited live vaccines (BCG, chicken pox).
Severe combined immunodeficiency in children is a disease characterized by unbalance of T and B cells, resulting in a reticular dysgenesis.
This is a fairly rare pathology of the bone marrow,which is characterized by a decrease in the number of lymphocytes and a complete absence of granulocytes. It does not affect the production of erythrocytes and megakaryocytes. This disease is characterized by an underdevelopment of secondary lymphoid organs, and is also a very severe form of SCID.
The cause of this dysgenesis is the impossibilitypredecessors of granulocytes to form healthy stem cells. Therefore, the functions of hematopoiesis and bone marrow are distorted, blood cells do not cope with their function, accordingly the immune system can not protect the body from infections.
Other forms of SCID include:
- Deficiency of alpha-1 antitrypsin. Lack of T cells, and, as a consequence, lack of activity in B cells.
- Deficiency of adenosine deaminase. The lack of this enzyme can lead to an excessive accumulation of toxic metabolic products inside lymphocytes, which causes the death of cells.
- Deficiency of gamma chains of the T-cell receptor. It is caused by a mutation of the gene on the X chromosome.
- Deficiency of janus-kinase-3, deficiency of CD45, deficiencies of CD3-chain (combined immunodeficiency, which causes mutations in genes).
Among doctors there is an opinion that there is a certain group of unrecognized immunodeficiency states.
The causes and symptoms of severe combined immunodeficiency are often interrelated.
However, there is still a number of rare genetic diseases of the immune system. These are combined immunodeficiencies. They have less severe clinical manifestations.
Patients with this form of deficiency are assisted by bone marrow transplantation from both relatives and from outside donors.
Manifestations of ailment
These states are characterized by the following manifestations:
- Severe infections (meningitis, pneumonia, sepsis). At the same time, for a child with healthy immunity, they can not pose a serious threat, whereas a child with a severe combined ID (TKID) carries a mortal danger.
- Manifestations of inflammation of the mucous membranes, an increase in lymph nodes, respiratory symptoms, coughing, wheezing.
- Violations of kidney and liver function, skin lesions (redness, rash, ulcers).
- Thrush (fungal infections of genital organs and oral cavity); manifestations of allergic reactions; enzymatic disorders; vomiting, diarrhea; poor blood test results.
To diagnose severe immunodeficiency in the presenttime is becoming more difficult, since the use of antibiotics is very widespread, which in turn have the property of changing the nature of the course of diseases as a side effect.
Treatment of severe combined immunodeficiency is presented below.
Methods of therapy
Since, in the basis of the method of treatment of such heavyimmunodeficiencies are bone marrow transplantation, then other methods of treatment are practically ineffective. Here it is necessary to take into account the age of the patients (from birth to two years). Children need to pay attention, show them love, caress and care, create coziness and a positive psychological climate.
Family members and all relatives should not onlysupport such a child, but also maintain friendly, sincere and warm relations within the family. Isolation of sick children is unacceptable. They should be at home, inside the family, while receiving the necessary supportive treatment.
Hospitalization in hospital is required if availablesevere infections, or if the child's condition is unstable. In this case, it is necessary to exclude contact with relatives who have recently undergone varicella or some other viral diseases.
It is also necessary to comply with the strict rules of personal hygiene of all family members who are close to the child.
Stem cells for transplantation are obtained mainly from bone marrow, but in some cases for this purpose, cord blood and even peripheral blood from related donors can approach.
The ideal option is a brother or sister of a sick child. But transplants can also be successful from "connected" donors, that is, mothers or fathers.
What does statistics say?
According to statistics (over the past 30 years), the total percentagethe survival rate of patients after surgery is 60-70. More chances of success in the event that the transplantation is carried out at the early stages of the development of the disease.
Operations of this kind should be conducted in specialized medical institutions.
So, the article examined the severe combined immunodeficiency in a child.