Causes of thrombocytopenia

The causes of thrombocytopenia, due to the fact that it is predominantly an acquired disease, are often hidden in allergic reactions that may arise in connection with the use of certain medications. In this case, they speak of thrombocytopenia of allergic origin.

The consequences of taking certain medications can also be the production of specific antibodies to platelets, which leads to the development of autoimmune thrombocytopenia.

Thrombocytopenia can be caused by infection, intoxication of the body, or the development of thyrotoxicosis. This phenomenon is symptomatic thrombocytopenia.

The infection factors that mainly act as the main causes of thrombocytopenia are:

• the presence of the human immunodeficiency virus in the body,
• the development of various types of hepatitis, the progression of herpes disease and the emergence of all kinds of complications associated with it.

In addition, thrombocytopenia may appear in connection with infectious mononucleosis, as a negative consequence of influenza and other acute respiratory diseases.

However, thrombocytopenia of non-infectious origin is also noted. It can be provoked by Gaucher disease.

There is also such a way of acquiring thrombocytopenia as transmission of the disease to the child from the mother who has this disease, in the process of which autoantibodies penetrating through the placenta appear in the child's body. This phenomenon is called transimmune thrombocytopenia.

A number of physiological features of the life cycle of blood platelets determine the development of thrombocytopenia for the following reasons:

• the production of these blood platelets by the red bone marrow is insufficient, which leads to thrombocytopenia;
• high intensity of platelet destruction processes - this is called destruction thrombocytopenia;
• due to the fact that platelets are redistributed abnormally, in turn, their reduced concentration in the bloodstream is caused. In this case, this indicates redistribution thrombocytopenia.

The causes of thrombocytopenia, as we can conclude, mainly consist of the appearance of platelet autoantibodies in the body, resulting in a deficiency of blood platelets. And this is fertile ground for the development of thrombocytopenia of various types.

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Causes of thrombocytopenia in adults

Approaching the consideration of what are the causes of thrombocytopenia in adults, we note that this disease can arise as a result of the influence of two main groups of pathogenic factors. Thrombocytopenia in adults is mainly either autoimmune in nature or has the character of a disease of infectious origin.

In the first case, thrombocytopenia occurs as a specific autoimmune reaction to negative processes occurring in the body caused by the appearance of thrombocytopenic purpura or are caused by the development of Werlhof's disease. A number of infectious infections occurring in the body can provoke infectious thrombocytopenia. These include, in particular, acute respiratory viral infections, influenza, herpes, hepatitis, etc.

In addition, it should be said that there is also idiopathic thrombocytopenia, the causes of which in many cases are completely unclear and their establishment may be associated with certain difficulties. However, the frequency of its cases is significantly lower compared to the first two types of the disease. The risk of developing idiopathic thrombocytopenia is extremely small, especially with a fairly strong immune system.

The causes of thrombocytopenia in adults can be very different and any of these listed manifestations can be its fundamental prerequisite. But this disease serves as an unconditional evidence of the fact that there are some rather severe disorders of the immune system. The immune barrier in its normal healthy state is able to effectively resist various infectious attacks from the outside, and the activation of the body's defenses in this case would simply not allow any autoimmune disorders, including preventing the development of thrombocytopenia of the corresponding type.

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Causes of thrombocytopenia in children

The causes of thrombocytopenia in children can be classified into three main groups of pathogenic factors that provoke the development of this disease.

Thrombocytopenia in children is caused by destructive processes that affect a large number of platelets. Thrombocytopenia in children can also occur as a result of their insufficient production. In addition, there may be cases when the appearance of thrombocytopenia is caused by the action of a mixed set of pathogenic factors.

Intensification of platelet destruction is based on immunopathological processes of heteroimmune, isoimmune and transimmune thrombocytopenia in children. The presence of vasopathy, pulmonary hypertension, pneumonia, respiratory distress syndrome (regardless of origin), aspiration syndrome and a number of other syndromes in a child also lead to the destruction of a large number of platelets: DIC, Kasabach-Merritt, systemic inflammatory response syndrome.

Thrombocytopathies have the most detrimental effect on platelets. They are destroyed by primary, hereditary thrombocytopathies - May-Hegglin, Shwachman-Diamond, Wiskott-Aldrich, as well as secondary, drug-induced, in cases of hyperbilirubinemia, acidosis, when generalized viral infections occur, etc.

Platelet destruction is provoked by generalized and isolated thromboses as a result of trauma, with hereditary deficiency of antithrombin III, protein C, etc., which are anticoagulants, if the mother has antiphospholipid syndrome.

The phenomenon of large-scale platelet destruction is also observed during replacement blood transfusions, plasmapheresis, and hemosorption.

Platelets begin to be produced in significantly smaller quantities against the background of some diseases. These include the TAR syndrome or megakaryocytic hypoplasia, the presence of aplastic anemia, congenital leukemia and neuroblastoma. This also includes trisomy on the 9th, 13th, 18th and 21st pairs of chromosomes.

The disruption of platelet production occurs due to the fact that during drug treatment of the mother with thiazides, tolbutamide, etc., thrombocytopoiesis occurs with reduced intensity.

A significant factor in reducing the number of platelets is the extremely low body weight of the newborn, if he has severe hemolytic disease in the antenatal period, thrombocytopoietin is not synthesized to an adequate degree, etc.

Thrombocytopenia in children, which has a mixed pathogenesis, results from the presence of polycythemia, when there was severe asphyxia, as a complication of a severe infectious infection, due to blood poisoning, due to thyrotoxicosis, etc.

The causes of thrombocytopenia in children, as we see, can be very diverse, which determines what form the disease will take and what will be the characteristic manifestations of such a disease. Newborns are most at risk in this regard. Thrombocytopenia in them occurs extremely rarely - in one case out of 10,000, but even a fatal outcome is not excluded.

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Causes of thrombocytopenia during pregnancy

Pregnancy is a time when a woman undergoes a great many changes and almost her entire body is rebuilt. The essence of such changes in relation to blood is largely that during this period, red blood cells experience a shortened lifespan. When a woman carries a child, changes also occur in the volume of circulating blood in her body. This is a phenomenon caused by the need to provide blood supply to the placenta and fetus. In such new changed conditions, the level of platelet consumption increases, which may not have time to be replenished in the required quantity. In some cases, in combination with some other unfavorable factors, this can act as a cause of thrombocytopenia during pregnancy.

The probability of occurrence and progression of such a disease increases significantly if various accompanying aggravating factors are added. These include poor blood clotting, the presence of viral infections, allergic reactions if the woman takes medications, cases of late gestosis, nephropathy, the presence of immune and autoimmune disorders, as well as unbalanced nutrition.

The greatest danger during pregnancy is immune thrombocytopenia. One of its negative consequences can be that against its background, uteroplacental insufficiency can occur. And this poses a threat of causing hypoxia and hypotrophy in the fetus. In addition, due to the greatly reduced content of platelets in the blood, there is a considerable risk of bleeding and even hemorrhages in the brain of the newborn.

The mother's existing immune and autoimmune diseases can affect the newborn in the form of thrombocytopoiesis disorders. This is accompanied by a decrease in the blood cell count, as a result of which thrombocytopenia begins to develop in its alloimmune, irranimmune, autoimmune, or heteroimmune form.

The causes of thrombocytopenia during pregnancy are thus primarily due to changes in the composition of the woman's blood, which is associated with an increased volume of circulating blood due to the need to ensure blood flow to the placenta and the fetus. The number of platelets decreases. On the other hand, the disease may arise due to other existing diseases against the background of weakened immunity.

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Causes of autoimmune thrombocytopenia

Autoimmune thrombocytopenia is the most common and widespread type of this disease. A disruption of the immune system, which occurs mainly due to reasons that are not clearly and definitely established, leads to the identification of healthy platelets as a foreign body. The response to this is the production of antibodies against them, which causes a sharp decrease in their content in the blood. Thus, autoimmune thrombocytopenia, depending on the causes that cause it, can be divided into primary and secondary. It is primary or idiopathic when the causes of autoimmune thrombocytopenia are not determined. Primary autoimmune thrombocytopenia is also divided into chronic and acute.

Autoimmune thrombocytopenia is secondary if the decrease in the level of platelets in the blood belongs to the symptom complex of some other disease. Especially if such a disease provokes significant disturbances in the functioning of the immune system.

Such negative changes appear when there are malignant lesions of the lymph nodes, with lymphoma, lymphogranulomatosis, lymphocytic leukemia. Autoimmune thrombocytopenia can occur with herpes, rubella, viral infections, HIV. It is caused by autoimmune diseases developing in various systems and organs of the body. These are granulomatous inflammation of the gastrointestinal tract, autoimmune hepatitis, autoimmune thyroiditis, ankylosing spondylitis, systemic lupus erythematosus, rheumatoid arthritis, ulcerative colitis, autoimmune hemolytic anemia or Evans-Fisher disease.

The causes of autoimmune thrombocytopenia are that the result of a failure in the immune system is the destruction of platelets by antibodies. Such a failure can occur both for unknown reasons and during the course of some autoimmune diseases. Based on this, the issue of preventing diseases that cause a significant weakening of the immune system is very relevant.

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