Severe Combined Immunodeficiency (SCID) is a condition known as Bubble Boy Syndrome because affected individuals are highly vulnerable to infectious diseases and must be kept in a sterile environment. This disease is the result of severe damage to the immune system, so the latter is considered practically absent.
This is a disease that belongs to the category of primary immunodeficiencies and is caused by multiple molecular defects that lead to the fact that the functions of T-cells and B-cells are impaired. Sometimes the functions of killer cells are disrupted. In most cases, the diagnosis of the disease is made before the age of 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 illness
Every two years, experts from the World He alth Organization very carefully review the classification of this disease and is consistent with modern methods of control regarding disorders of the immune system and immunodeficiency states. Over the past few decades, they have identified eight classifications of the disease.
Severe combined immunodeficiency is quite well studied in the world, and yet the survival rate of sick children is not very high. An accurate and specific diagnosis is important here, which will take into account the heterogeneity of the pathogenesis of immune disorders. However, it is often carried out either incompletely or untimely, with a great delay.
Typical infections and skin diseases are the most common signs of severe combined immunodeficiency. We will consider the reasons below. It is they who help in making a diagnosis in children.
With advances in gene therapy and the possibility of bone marrow transplantation in recent years, SCID patients have a good opportunity to develop a he althy immune system and, as a result, hope for survival. But still, if a serious infection develops rapidly, the prognosis is often unfavorable.
Causes of disease
The main cause of severe combined immunodeficiency is mutations at the genetic level, as well as naked lymphocyte syndrome, deficiency of tyrosine kinase molecules.
These causes include infections such as hepatitis, pneumonia,parainfluenza, cytomegalovirus, respiratory syncytial virus, rotavirus, enterovirus, adenovirus, herpes simplex virus, chickenpox, Staphylococcus aureus, enterococci and streptococci, Pseudomonas aeruginosa. Fungal infections also cause predisposition: biliary and renal candidiasis, Candida Albicans, legionella, moraxella, listeria.
Many of these pathogenic factors are also present in the body of an absolutely he althy person, but when adverse conditions are formed, a situation may occur when the protective properties of the body decrease, which, in turn, will provoke the development of immunodeficiency states.
Aggravating factors
What can trigger severe combined immunodeficiency? The presence of maternal T-cells in sick children. This circumstance can cause reddening of the skin with T-cell infiltration, an increase in the amount of liver enzyme. Inadequately, the body can also respond to an inappropriate bone marrow transplant, blood transfusion, which differs in parameters. Signs of rejection include: destruction of the biliary epithelium, necrotic erythroderma on the intestinal mucosa.
In past years, newborn babies were vaccinated with vaccinia. In this regard, children with severe immunodeficiency were dying. To date, the BCG vaccine, which contains the Calmette-Guerin bacillus, is used all over the world, but it is often the cause of death in children with this disease. Therefore veryit is important to remember that live vaccines (BCG, varicella) are strictly prohibited for SCID patients.
Basic shapes
Severe combined immunodeficiency in children is a disease characterized by an imbalance of T and B cells, resulting in reticular dysgenesis.
This is a rather 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 red blood cells and megakaryocytes. This disease is characterized by underdevelopment of secondary lymphoid organs and is also a very severe form of SCID.
The cause of this dysgenesis is the inability of granulocyte precursors to form he althy stem cells. Therefore, the functions of hematopoiesis and bone marrow are distorted, blood cells do not cope with their function, respectively, the immune system cannot protect the body from infections.
Other shapes
Other forms of SCID include:
- Alpha-1 antitrypsin deficiency. Lack of T-cells, and, as a result, lack of activity in B-cells.
- Adenosine deaminase deficiency. A lack of this enzyme can lead to excessive accumulation of toxic metabolic products inside lymphocytes, which causes cell death.
- Deficiency of T-cell receptor gamma chains. It is caused by a mutation of a gene on the X chromosome.
- Janus kinase-3 deficiency,CD45 deficiency, CD3-chain deficiencies (combined immunodeficiency, in which mutations occur in genes).
There is an opinion among doctors that there is a certain group of unrecognized immunodeficiency conditions.
The causes and symptoms of severe combined immunodeficiency are often interrelated.
However, there are 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 helped by bone marrow transplantation from both relatives and outside donors.
Manifestations of illness
These states are characterized by the following manifestations:
- Severe infections (meningitis, pneumonia, sepsis). However, for a child with he althy immunity, they may not pose a serious threat, while for a child with severe combined ID (SCID) they are a mortal danger.
- Manifestations of inflammation of the mucous membranes, swollen lymph nodes, respiratory symptoms, cough, wheezing.
- Impaired kidney and liver function, skin lesions (redness, rash, ulcers).
- Thrush (fungal infections of the genitals and mouth); manifestations of allergic reactions; enzyme disorders; vomiting, diarrhea; poor blood test results.
Diagnosing severe immunodeficiency is now becoming more and more difficult, since the use of antibiotics is very widespread, which in turn tend to change the nature of the course of diseases as a side effect.
Treatment for severe combined immunodeficiency is shown below.
Therapy Methods
Since the method of treatment of such severe immunodeficiencies is based on bone marrow transplantation, other methods of treatment are practically ineffective. Here it is necessary to take into account the age of patients (from the moment of birth to two years). Children must be given attention, show love, affection and care for them, create comfort and a positive psychological climate.
Family members and all relatives should not only support such a child, but also maintain friendly, sincere and warm relations within the family. Isolation of sick children is unacceptable. They should stay at home, within the family, while receiving the necessary supportive care.
Hospitalization
Hospitalization is required if there are severe infections or if the child's condition is unstable. At the same time, it is imperative to exclude contact with relatives who have recently had chickenpox or any other viral diseases.
It is also necessary to strictly observe the rules of personal hygiene of all family members who are next to the child.
Stem cells for transplantation are obtained mainly from bone marrow, but in some cases, cord blood and even peripheral blood from related donors may be suitable for this purpose.
The ideal option is a brother or sister of a sick child. But transplants can be successful andfrom "related" donors, i.e. mother or father.
What do the statistics say?
According to statistics (over the past 30 years), the overall survival rate of patients after surgery is 60-70. Greater chance of success if the transplant is performed early in the course of the disease.
Surgeries of this kind should be carried out in specialized medical institutions.
So, the article examined severe combined immunodeficiency in a child.
