Thrombocytopenic purpura is a type of hemorrhagic diathesis characterized by a deficiency of red blood platelets – platelets, more often caused by immune mechanisms. Signs of thrombocytopenic purpura are spontaneous, multiple, polymorphic hemorrhages in the skin and mucous membranes, as well as nasal, gingival, uterine and other bleeding. If thrombocytopenic purpura is suspected, anamnestic and clinical data, indicators of a general blood test, coagulograms, ELISA, microscopy of blood smears, bone marrow puncture are evaluated. For therapeutic purposes, patients are prescribed corticosteroids, hemostatic drugs, cytostatic therapy, splenectomy is performed.
Thrombocytopenic purpura (Werlhof’s disease, benign thrombocytopenia) is a hematological pathology characterized by a quantitative deficiency of platelets in the blood, accompanied by a tendency to bleeding, the development of hemorrhagic syndrome. With thrombocytopenic purpura, the level of blood plates in peripheral blood drops significantly below the physiological level – 150×109 / l with a normal or slightly increased number of megakaryocytes in the bone marrow. According to the frequency of occurrence, thrombocytopenic purpura ranks first among other bleeding diatheses. The disease usually manifests in childhood (with a peak in the early and preschool period). In adolescents and adults, pathology is 2-3 times more often detected among females.
In 45% of cases, idiopathic thrombocytopenic purpura occurs, developing spontaneously, for no apparent reason. In 40% of cases, thrombocytopenia is preceded by various infectious diseases (viral or bacterial), transferred about 2-3 weeks before. In most cases, these are infections of the upper respiratory tract of non-specific genesis, in 20% – specific (chickenpox, measles, rubella, mumps, infectious mononucleosis, whooping cough). Thrombocytopenic purpura can complicate the course of malaria, typhoid fever, leishmaniasis, septic endocarditis. Sometimes thrombocytopenic purpura manifests itself against the background of immunization – active (vaccination) or passive (administration of gamma – globulin). Thrombocytopenic purpura can be triggered by taking medications (barbiturates, estrogens, arsenic preparations, mercury), prolonged exposure to X-rays (radioactive isotopes), extensive surgery, trauma, excessive insolation. There are family cases of the disease.
Most variants of thrombocytopenic purpura have an immune nature and are associated with the production of antiplatelet antibodies (IgG). The formation of immune complexes on the platelet surface leads to the rapid destruction of blood platelets, reducing their lifespan to several hours instead of 7-10 days normally.
The isoimmune form of thrombocytopenic purpura may be due to the entry of “foreign” platelets into the blood during repeated blood transfusions or platelet mass, as well as antigenic incompatibility of maternal and fetal platelets. The heteroimmune form develops when the antigenic structure of platelets is damaged by various agents (viruses, medications). The autoimmune variant of thrombocytopenic purpura is caused by the appearance of antibodies against its own unchanged platelet antigens and is usually combined with other diseases of the same genesis (SLE, autoimmune hemolytic anemia). The development of transimmune thrombocytopenia in newborns is provoked by antiplatelet autoantibodies passing through the placenta of a mother with thrombocytopenic purpura.
Platelet deficiency in thrombocytopenic purpura may be associated with a functional lesion of megakaryocytes, a violation of the process of lacing of blood red plates. For example, the Werlhof symptom complex is caused by the ineffectiveness of hematopoiesis in anemia (B-12 deficiency, aplastic), acute and chronic leukemia, systemic diseases of the hematopoietic organs (reticulosis), bone marrow metastases of malignant tumors.
With thrombocytopenic purpura, there is a violation of the formation of thromboplastin and serotonin, a decrease in contractility and increased permeability of the capillary wall. This is associated with an elongation of the bleeding time, a violation of the processes of thrombosis and retraction of a blood clot. With hemorrhagic exacerbations, the number of platelets decreases down to single cells in the drug, during remission it is restored to a level below normal.
The classification of thrombocytopenic purpura takes into account its etiological, pathogenetic and clinical features. There are several variants – idiopathic (Werlhof’s disease), iso-, trans-, hetero- and autoimmune thrombocytopenic purpura, Werlhof’s symptom complex (symptomatic thrombocytopenia).
Acute, chronic and recurrent forms are distinguished downstream. The acute form is more typical for children, lasts up to 6 months with normalization of platelet levels in the blood, has no relapses. The chronic form lasts for more than 6 months, is more common in adult patients; recurrent – has a cyclical course with repeated episodes of thrombocytopenia after normalization of platelet levels.
Thrombocytopenic purpura is clinically manifested when the platelet level drops below 50×109/ l, usually 2-3 weeks after exposure to an etiological factor. Bleeding of the petechial-spotted (bruised) type is characteristic. In patients with thrombocytopenic purpura, painless multiple hemorrhages appear under the skin, in the mucous membranes (“dry” variant), as well as bleeding (“wet” variant). They develop spontaneously (often at night) and their severity does not correspond to the strength of the traumatic impact.
Hemorrhagic rashes are polymorphic (from minor petechiae and ecchymoses to large bruises and bruises) and polychromic (from bright purplish-blue to pale yellow-green depending on the time of appearance). Most often hemorrhages occur on the anterior surface of the trunk and limbs, rarely in the face and neck. Hemorrhages are also detected on the mucous membrane of the tonsils, soft and hard palate, conjunctiva and retina, tympanic membrane, in adipose tissue, parenchymal organs, serous membranes of the brain.
Intense bleeding is pathognomonic – nasal and gingival, bleeding after tooth extraction and tonsillectomy. Hemoptysis, bloody vomiting and diarrhea, blood in the urine may appear. In women, uterine bleeding in the form of menorrhagia and metrorrhagia, as well as ovulatory bleeding into the abdominal cavity with symptoms of ectopic pregnancy, usually prevail. Immediately before menstruation, skin hemorrhagic elements, nasal and other bleeding appear. Body temperature remains normal, tachycardia is possible. With thrombocytopenic purpura, there is moderate splenomegaly. With profuse bleeding, anemia of internal organs develops, hyperplasia of the red bone marrow and megakaryocytes.
The drug form manifests itself shortly after taking the drug, lasts from 1 week to 3 months with spontaneous recovery. Radiation thrombocytopenic purpura is characterized by severe hemorrhagic diathesis with the transition of the bone marrow into a hypo- and aplastic state. Infantile form (in children under 2 years old) it has an acute onset, severe, often chronic character and pronounced thrombocytopenia (9 / l).
During thrombocytopenic purpura, periods of hemorrhagic crisis, clinical and clinical-hematological remission are detected. In hemorrhagic crisis, bleeding and laboratory changes are pronounced, during the period of clinical remission against the background of thrombocytopenia, hemorrhages do not manifest. With complete remission, there is no bleeding and laboratory shifts. With thrombocytopenic purpura with a large blood loss, acute posthemorrhagic anemia is observed, with a long–term chronic form – chronic iron deficiency anemia.
The most serious complication – hemorrhage in the brain develops suddenly and progresses rapidly, accompanied by dizziness, headache, vomiting, convulsions, neurological disorders.
The diagnosis of thrombocytopenic purpura is established by a hematologist taking into account the anamnesis, the features of the course and the results of laboratory tests (clinical analysis of blood and urine, coagulogram, ELISA, microscopy of blood smears, bone marrow puncture).
Thrombocytopenic purpura is indicated by a sharp decrease in the number of platelets in the blood (9 / l), an increase in bleeding time (>30 min.), prothrombin time and APTT, a decrease in the degree or absence of clot retraction. The number of leukocytes is usually within the normal range, anemia appears with significant blood loss. At the height of the hemorrhagic crisis, positive endothelial tests (pinch, tourniquet, prick) are detected. In a blood smear, an increase in the size and a decrease in the granularity of platelets is determined. In the preparations of the red bone marrow, a normal or increased number of megakaryocytes, the presence of immature forms, the lacing of platelets in small points is detected. The autoimmune nature of purpura is confirmed by the presence of antiplatelet antibodies in the blood.
Thrombocytopenic purpura is differentiated from aplastic or infiltrative processes of the bone marrow, acute leukemia, thrombocytopathies, SLE, hemophilia, hemorrhagic vasculitis, hypo- and dysfibrinogenemia, juvenile uterine bleeding.
With thrombocytopenic purpura with isolated thrombocytopenia (platelets > 50×109 / l) without hemorrhagic syndrome, treatment is not carried out; with moderate thrombocytopenia (30-50 x109 / l), drug therapy is indicated in case of an increased risk of bleeding (arterial hypertension, gastric ulcer and duodenal ulcer). At a platelet level of 9 / l, treatment is carried out without additional indications in a hospital setting.
Bleeding is stopped by the introduction of hemostatic drugs, a hemostatic sponge is applied topically. To curb immune reactions and reduce vascular permeability, corticosteroids are prescribed in a lowering dose; hyperimmune globulins. With large blood loss, plasma transfusions and washed erythrocytes are possible. Infusions of platelet mass in thrombocytopenic purpura are not indicated.
Splenectomy is performed in patients with chronic form with relapses of heavy bleeding and hemorrhages in vital organs. It is possible to prescribe immunosuppressants (cytostatics). Treatment of thrombocytopenic purpura, if necessary, should be combined with therapy of the underlying disease.
In most cases, the prognosis of thrombocytopenic purpura is very favorable, complete recovery is possible in 75% of cases (in children – in 90%). Complications (for example, hemorrhagic stroke) are observed in the acute stage, creating a risk of death. With thrombocytopenic purpura, constant monitoring by a hematologist is required, drugs affecting the aggregation properties of platelets (acetylsalicylic acid, caffeine, barbiturates), food allergens are excluded, caution is exercised when vaccinating children, insolation is limited.
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