Thrombocytopenic purpura in children

Idiopathic (autoimmune) thrombocytopenic purpura is a disease characterized by an isolated decrease in the number of platelets (less than 100,000 / mm ³ ) with a normal or increased amount of megakaryocytes in the bone marrow and the presence of antiplatelet antibodies on the surface of platelets and serum that cause increased destruction of platelets.

Epidemiology

The incidence of idiopathic thrombocytopenic purpura in children is about 1.5-2 per 100 000 children without differences in sex, with an equal frequency of acute and chronic forms. In adolescence, the number of sick girls becomes twice that of a young man.

[1], [2], [3], [4], [5], [6], [7],

Causes of the thrombocytopenic purpura in a child

In children, the cause of thrombocytopenia can be both hereditary and post-birth factors. Basically, the number of platelets decreases because of insufficient formation of them in the bone marrow from megakaryocytes - the parent cells; direct destruction in the bloodstream; or for both reasons.

Causes of insufficient platelet production:

1. Changing the parent cells (megakaryocytes) in the bone marrow in combination with a general disturbance of the hematopoiesis cycle and subsequent anomalies in the development of organs and systems.
2. Tumors of the nervous system (neuroblastoma).
3. Chromosomal diseases (Down syndrome, Edwards, Patau, Wiskott-Aldrich).
4. Taking diuretics, antidiabetic, hormonal and nitrofuran drugs during pregnancy.
5. Eclampsia and severe preeclampsia.
6. Premature birth of the fetus.

The next cause of thrombocytopenia is the destruction of platelets.

This is caused by the following:

1. Immunological pathologies.
2. Change in the structure of the vessel wall (antiphospholipid syndrome).
3. Change in the structure of platelets.
4. Inadequacy of clotting factors (hemophilia B).
5. DIC-syndrome.

Immunological reasons are:

• direct: development of antibodies to their platelets as a result of the incompatibility of the mother and the child with the platelet count of the blood group (there are platelets in the mother's blood that the child does not have). These forms cause the rejection of an "alien" agent - the destruction of platelets of the fetus and the development of thrombocytopenia.
• cross: for maternal diseases associated with autoimmune destruction of platelets, antibodies penetrating through the placenta into the fetus, cause in it the same destruction of these blood cells.
• antigen-dependent: antigens of viruses interacting with surface receptors of platelets, change their structure and cause self-destruction.
• autoimmune: development of antibodies to normal surface receptors.

[8], [9]

Symptoms of the thrombocytopenic purpura in a child

• Cumulative manifestations (ecchymosis, petechiae - pinpoint hemorrhage) - always occur
• Gastrointestinal bleeding (melena, bloody diarrhea), bleeding from the umbilical remains - occur in 5% of cases
• Nasal bleeding - about 30% of cases
• Hemorrhages in the shells of the eyeballs (prognostic probability of intracranial hemorrhages)
• Enlarged liver and spleen according to ultrasound. It is characteristic only for secondary thrombocytopenia (medicinal, viral)

Diagnostics of the thrombocytopenic purpura in a child

1. Blood
   • The content of platelets is less than 150x10 * 9 g / l (normal 150-320 x 10 * 9 g / l)
   • Duke's bleeding time

This indicator helps differentiate thrombocytopathy from hemophilia. After the puncture of the finger pad with the scarifier, the bleeding normally stops after 1.5-2 minutes. With thrombocytopathy, it lasts more than 4 minutes, while the coagulation function remains normal. When hemophilia is the opposite.

• The formation (retraction) of a full blood clot is less than 45% (in the norm of 45-60%) - an indicator characterizing the amount of platelets sufficient for stopping bleeding.

2. Myelogram: a detailed description of the number of all cells of the bone marrow, in particular, the progenitor cells of platelets. Normally, the number of megakaryocytes is 0.3-0.5 in a microlitre. When thrombocytopathy, this indicator increases to 114 in 1 μl of bone marrow substance. The life span of platelets is about 10 days. In diseases associated with their decrease in blood, these cells live much less.
3. Anamnesis
   • The presence or predisposition to autoimmune diseases in the mother
   • Violation of placental functions during pregnancy (detachment, thrombosis)
   • Fetal pathology (hypoxia, intrauterine growth retardation, prematurity, intrauterine infection)
4. Immunological analysis

Detection of a high content of antibodies to its own platelets or to certain infectious diseases (herpes simplex virus type 1, cytomegalovirus, Epstein-Barr virus)

[10], [11], [12], [13], [14], [15], [16], [17]

Treatment of the thrombocytopenic purpura in a child

Usually in 80% of children thrombocytopenic purpura disappears after six months without any medical measures. In this case, parents are required to comply with several important rules in the care of the child, in order to prevent the deterioration of health:

• Exclude traumatic sports (wrestling, gymnastics, cycling, skiing)
• use a soft toothbrush
• observe a diet that prevents constipation
• do not give the child a blood-thinning medication (aspirin)

At the time of treatment of thrombocytopenia, the child must be transferred to artificial feeding to prevent further immunization of his body with antiplatelet antibodies of the mother.

Medicamental or inpatient treatment is necessary in case of a critical reduction in the number of platelets less than 20 thousand in a microliter. In this case, the criterion for the appointment of treatment procedures should be a pronounced clinic of thrombocytopenic syndrome: massive nasal, gastrointestinal bleeding that threatens the life of the child.

Medication

1. Intravenous drip transfusion of thromboconcentrate (washed-up platelets of the mother or an antigen-compatible donor) at a dose of 10-30 ml / kg of body weight. A positive effect of the transfusion will be considered stopping bleeding in the child, increasing the number of platelets by 50-60x10 * 9 / L 1 hour after the procedure and maintaining these indicators during the day.
2. Intravenous drip infusion of normal human immunoglobulin at a dose of 800 mcg / kg for 5 days. As an immunoglobulin, such drugs as Immunovenin, Pentaglobin, Octagam are used. They give a faster but less stable effect compared to hormonal drugs (prednisolone).
3. Hemostatic drugs

• intravenous drip infusion of aminocaproic acid in a dose of 50 mg / kg once a day

4. Hormonal therapy

• oral intake of prednisolonadvazhdy per day in a dose of 2 mg / kg

Surgery

Surgical treatment means splenectomy - removal of the spleen. This operation is only indicated if hormone therapy is ineffective. We must also take into account the fact that prednisolone should still lead to a certain increase in the number of platelets, otherwise the operation will not have a significant effect on the underlying cause of the disease. After the splenectomy performed, the number of platelets may remain low, but despite this hemorrhagic syndrome completely passes.

New methods in the treatment of thrombocytopenia in children

1. The clotting factor VIIa (Novoseven)
2. Ethrombopag is a thrombopoietin receptor antagonist
3. Rituximab is a monoclonal cell agent

These substances are being intensively studied in world laboratories. To date, their effect has been partially studied in relation to the adult organism. In clinical pediatrics, their impact on the child's body has no evident practical basis.

Forecast

As mentioned earlier, thrombocytopenic purpura often enters the stage of spontaneous long-term remission and requires only regular monitoring of blood counts. It is performed after improvement of the general condition and disappearance of clinical symptoms of thrombocytopenia after 1 and 6 weeks, then after 3 and 6 months.

In the absence of severe hemorrhagic complications of thrombocytopenia in the brain, the prognosis of the disease is generally favorable.

[18], [19]