The immune system acts as a shield for humans. It protects it both inside and out so that its own organs and tissues function properly.
But, like any body system, the immune system is subject to pathological processes. One or more links in the immune response chain may be missing or deficient. The result is immunodeficiency states, primary or secondary immunodeficiencies.
Primary immunodeficiencies
These diseases, which are based on a hereditary defect in the structure and functioning of the immune system, are quite common. They are manifested by serious violations of the immune defense. Many syndromes are linked to the X chromosome, so they appear much more often in boys. The other part has an autosomal recessive pattern of inheritance and occurs equally in girls.
In general, this group consists of more than 100 different diseases, the frequency of occurrence from one patientper 1,000,000 people to one in 100,000. They almost always occur in childhood, since a significant proportion of these patients have severe forms of immunodeficiency and do not live past 20 years. In mild forms, immunological defects can be partially compensated with age and do not pose a risk to the life of the carrier, while severe ones, on the contrary, cause death even in infancy.
Classification
Primary immunodeficiencies are subdivided according to the level of damage into:
Cellular immunodeficiencies:
- deficiency of CD4 cells (manifested in early childhood in the form of cryptococcal meningitis and chronic oral candidiasis);
- deficiency of CD7 cells (one clinical case described):
- interleukin deficiency of two or more interleukins;
- deficiency of one or more cytokines;
- DiGeorge's syndrome (in the early stages of pregnancy, the thymus gland of the embryo does not receive T-cell precursors, the parathyroid glands remain underdeveloped - as a result of tetany, convulsions, as well as heart defects, structural disorders of the face in the form of cleft lip and palate, anomalies in the development of the bones of the skeleton, nervous system, kidneys).
2. Humoral immunodeficiencies
- Hyper-IgM-syndrome: T-cells begin to synthesize immunoglobulin of only one type M. In this case, there is a deficiency of other types of Ig. Manifested from an early age by neutropenia, pneumocystis pneumonia, during the first yearslife, frequent purulent sinus-pulmonary infections are observed. If a child survives to puberty, cirrhosis of the liver or B-cell lymphomas often occur.
- IgA deficiency. Since this immunoglobulin provides local immunity to the skin and mucous membranes, bronchitis, conjunctivitis, diarrhea, sinusitis, pneumonia, and furunculosis skin lesions become manifestations of deficiency. Lactose intolerance, multiple allergic manifestations, autoimmune pathologies are also possible.
- IgG deficiency. Manifestations depend on which particular G-subclass suffers. Basically, these are permanent otitis media, sinusitis, bronchitis, conjunctivitis.
- Bruton's disease (X-linked agammaglobulinemia) - manifested by purulent infections of the gastrointestinal tract, ENT organs, musculoskeletal system, abscesses and furunculosis, frequent complications - meningitis and sepsis.
- Deficiency of antibodies with normal levels of immunoglobulins. It is manifested by recurrent sinus-pulmonary infections, as well as atopic diseases (asthma, rhinitis, dermatitis). Rarely seen before the age of two years.
3. Combined immunodeficiencies
- Louis Bar Syndrome (ataxia telangiectasia), many functions are affected: underdeveloped thymus gland, T-cell deficiency, IgG, IgE, IgA, ataxia, vascular lesions, pigmentation disorders, sinusitis, respiratory infections.
- Combined immune deficiency (severe manifestations, numerous lesions, poor prognosis).
- Deficiency of individual enzymes (purine nucleotide phosphorylase, adenosine deaminase). From-for the accumulation of toxic metabolic products in the cells in the first case, T-cells suffer, in the second - T-cells and B-lymphocytes. Clinically, it is developmental delay, neurological disorders - spasms, mental retardation, thyroiditis, systemic lupus erythematosus.
- CD3 deficiency and 8 - differ in the standard manifestations of immunodeficiency conditions.
- Bald lymphocyte syndrome - the number of T-helpers suffers, manifests itself as immune disorders along with mental retardation and constant diarrhea.
- Wiskott-Aldrich syndrome - thrombocytopenia with hemorrhagic syndrome, neoplasms, eczema and combined immunodeficiency.
4. Deficiencies in specific immune factors
- Insufficiency of the complement system. Depending on the component that is affected, the clinical picture is different. Some are vasculitis, lymphomas, sepsis, sinusitis, otitis media, meningitis, while others are pneumonia, skin lesions, autoimmune pathologies.
- Defects in phagocytosis - neutropenia (many variants), frequent lung damage by intracellular pathogens or fungal infections.
Clinic
Clinically, primary and secondary immunodeficiency states are manifested by impaired immune defenses and an infectious syndrome. Reduced resistance to infectious agents, not only pathogenic, but also included in the normal microflora (for example, Candida, Pneumocystis, cytomegalovirus, staphylococcus, enteroviruses, protozoa).
The nature of the manifestations of immune defense disorders is determined by the localization of the lesion inimmune system and/or a combination of affected factors.
- There are chronic lesions of the upper respiratory tract, ear, paranasal sinuses, gastrointestinal tract, skin and mucous membranes. Infections are prone to generalization and septicemia, not amenable to standard therapy.
- Autoimmune diseases - scleroderma, thyroiditis, hepatitis, arthritis etc.
- Anemia, decreased number of leukocytes and lymphocytes, thrombocytopenia.
- Delayed growth and development of the child.
- Often there is a tendency to allergic reactions in the form of immediate hypersensitivity - Quincke's edema, eczema, allergies to drugs and products.
- Digestive disorders, malabsorption, diarrhea syndrome.
- Inadequate reaction of the body to the introduction of sera and vaccines, with the introduction of a live vaccine, sepsis may occur.
- Predisposition to cancer, especially blood cells.
Diagnosis
Both primary and secondary immunodeficiency states have a similar pattern of infectious lesions. A clinical and immunological examination will help to establish a more accurate cause. If the defect is localized, for example, the absence of T or B lymphocytes, or a decrease in the concentration of complement, cytokines, or certain immunoglobulins can be detected.
Treatment
Since the cause of primary immunodeficiencies is a defect in the genome, the etiotropic treatment is gene therapy (if the gene responsible for a particular immunodeficiency is determined). The gene can be identifiedby polymerase chain reaction. Other approaches are replacement therapy (bone marrow transplantation, transfusion of neutrophils and lymphocytes, administration of enzymes and cytokines. And symptomatic treatment - therapy of infectious diseases, immunomodulators, vitamins.
Secondary immunodeficiencies
Acquired secondary immunodeficiencies develop as a result of the action of external or internal factors and are not associated with the genetic apparatus. In fact, these are conditions associated with known diseases or the action of damaging factors.
Secondary immunodeficiency conditions: classification
According to development there are:
- acute (due to trauma, surgery, acute infectious disease);
- chronic (with malignant neoplasms, chronic infections, helminthiases, autoimmune processes).
Severity:
- compensated (light, with incomplete loss of immunity link);
- subcompensated (moderately severe condition, some link of immunity is completely affected);
- decompensated (often systemic, severe condition).
According to the level of the pathological process: primary and secondary immunodeficiency states. Their pathophysiology is very similar:
- violation of T-cell immunity;
- violation of B-cell immunity;
- pathology of the phagocytosis system;
- pathology of the complement system.
Secondaryimmunodeficiency state, ICD 10:
D50-D89. Diseases of the blood, hematopoietic organs and certain disorders involving the immune mechanism.
D80-D89. Selected disorders involving the immune mechanism.
D84. Other immunodeficiencies:
- complement defects;
- immunodeficiencies;
- secondary immunodeficiencies.
D84.9 Immunodeficiency, unspecified.
Reasons
The causes of secondary immunodeficiency states can be exogenous and endogenous.
External causes - all destructive environmental factors - poor ecological situation, chronic poisoning of the body, harmful radiation (ionizing, microwave, etc.), harmful effects of noise, dust, taking certain immunosuppressive and hormonal drugs.
Internal causes - secondary immunodeficiency and immunosuppressive states in this case are much more numerous and varied:
- children's age, up to 1 year, especially if at birth there was a low body weight, when a lack of nutrition (or artificial feeding) is added to physiological immunodeficiency;
- old age;
- pregnancy and lactation - cause physiological immunosuppression, often combined with iron deficiency anemia;
- chronic deficiency of nutrition, protein, trace elements, vitamins or water;
- injuries, operations, long recovery after them;
- chronic infections (bacterial, viral, fungal) are almost all verystrongly affect immunity (chronic hepatitis, glomerulonephritis, tuberculosis, rubella, etc. Especially, of course, HIV);
- helminthiases - cause and intensify secondary immunodeficiency states (ascariasis, trichinosis, toxoplasmosis);
- plasma loss - blood loss, burns, kidney damage;
- malignant oncological formations;
- diabetes mellitus, hyper- and hypothyroidism;
- autoimmune pathologies (rheumatoid arthritis, scleroderma, systemic lupus erythematosus, etc.), in which the own immune system targets its own organs and systems;
- taking certain types of drugs (cyclosporine, carbamazepine, valproate, azathioprine, corticosteroids, cytostatics, antibiotics);
- chronic blood loss (for example, with peptic ulcer of the gastrointestinal tract);
- chronic diarrhea;
- stress.
As we can see, secondary immunodeficiency states have completely different origins. They are caused by both exogenous and endogenous factors. They are extremely widespread and accompany both some physiological and many pathological processes. So, as a result of infections, stress, adverse environmental factors, and especially their combination, secondary immunodeficiency states occur.
Pathophysiology: the basis of manifestations of secondary immunodeficiencies is the death of cells of the immune system, which occurs in two ways. The first - according to the type of necrosis, when cells die due to damage to the membrane, and the second - according to the type of apoptosis, then deathoccurs as a result of DNA degradation under the action of its own enzymes. Also, often secondary immunodeficiency states appear due to an imbalance in the cells of the immune system, such as helper and suppressor cells.
Diagnosis
- Anamnesis, complaints, study of heredity.
- Determination of T-lymphocytes in blood, activity and number of phagocytes, spectrum of immunoglobulins.
- Test for HIV, hepatitis, helminths, etc.
- Proteinogram.
- Detection of chronic infections.
All studies are assigned by a specialist.
Treatment
Treatment tactics depend directly on the cause that caused secondary immunodeficiency states. Therapy examples:
- Under the action of adverse factors (for example, ionizing radiation), only their elimination and immunocorrection will help.
- With a lack of nutrition, protein or vitamins - adding them to the diet.
- During pregnancy and lactation - taking additional vitamins and trace elements, treating anemia (if any).
- For chronic infections and helminthiasis, first of all, sanitation of infectious foci and then immunotherapy.
- In case of autoimmune diseases, their stable remission is necessary, therefore, course hormone therapy is carried out.
- As a symptomatic treatment - replacement therapy. For example, interferons, interleukins, cytokines, plasma.
In conclusion
Primary andsecondary immunodeficiency states have completely different origins, and therefore appear at different ages.
At the same time, their pathophysiological mechanisms are very similar and follow only a few paths. And if primary immunodeficiencies are difficult to treat due to a defect in the genome, then secondary ones can be cured quite realistically. To do this, it is only necessary to establish the reason why the link of immunity fell out. Particularly flexible, in this regard, is the secondary immunodeficiency state in a child - with timely correction, the prognosis in most cases is very favorable.
