Immune thrombocytopenic purpura
Definition
Immune thrombocytopenic purpura is a type of hemorrhagic diathesis characterized by a deficiency of red blood platelets, 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 immune thrombocytopenic purpura is suspected, anamnestic and clinical data, indicators of the general blood count, coagulogram, ELISA, microscopy of blood smears, and bone marrow puncture are evaluated. For therapeutic purposes, patients are prescribed corticosteroids, hemostatic drugs, cytostatic therapy, and splenectomy is performed.
General information
Immune thrombocytopenic purpura (immune thrombocytopenia) is a hematological pathology characterized by a quantitative deficiency of platelets in the blood, a tendency to bleed, and the development of hemorrhagic syndrome. In thrombocytopenic purpura, the level of blood platelets in the peripheral blood falls well below physiologic – 150×109 /L with a normal or slightly increased number of megakaryocytes in the bone marrow. In frequency of occurrence, thrombocytopenic purpura ranks first among other hemorrhagic diatheses. Manifests the disease usually in childhood (with a peak in the early and preschool period). In adolescents and adults, the pathology is detected 2-3 times more often among females.
Causes
In 45% of cases, idiopathic thrombocytopenic purpura develops spontaneously without apparent cause. In 40% of cases, thrombocytopenia is preceded by various infectious diseases (viral or bacterial), suffered about 2-3 weeks before. In most cases, these are infections of the upper respiratory tract of nonspecific genesis, in 20% – specific (chickenpox, measles, rubella, epidemic mumps, infectious mononucleosis, pertussis). Immune thrombocytopenic purpura can complicate the course of malaria, typhoid fever, leishmaniasis, and septic endocarditis. Sometimes, thrombocytopenic purpura is manifested against immunization – active (vaccination) or passive (administration of γ – globulin). Immunethrombocytopenic purpura can be provoked by taking medications (barbiturates, estrogens, arsenic, mercury), prolonged exposure to X-rays (radioactive isotopes), extensive surgery, trauma, and excessive insolation. Familial cases of the disease are noted.
Most variants of thrombocytopenic purpura are immune and are associated with the production of antiplatelet antibodies (IgG). The formation of immune complexes on the surface of platelets leads to rapid destruction of blood platelets, reducing their lifespan to a few hours instead of the norm of 7-10 days.
The isoimmune form of thrombocytopenic purpura may be due to the entry of “foreign” platelets into the blood during repeated transfusions of blood or platelet mass and antigenic incompatibility of maternal and fetal platelets. The heteroimmune form develops when the antigenic structure of platelets is damaged by various agents (viruses, medications). An autoimmune variant of thrombocytopenic purpura is caused by the appearance of antibodies against their own unchanged antigens of platelets 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 of the mother with immune thrombocytopenic purpura passing through the placenta.
Classification
The classification of thrombocytopenic purpura takes into account its etiologic, pathogenetic, and clinical features. There are several variants: idiopathic (Werlhoff’s disease), iso-, trans-, hetero-, and autoimmune thrombocytopenic purpura, and symptomatic Werlhoff’s complex (symptomatic thrombocytopenia).
According to its course, acute, chronic, and recurrent forms are distinguished. The acute form is more characteristic of childhood, lasts up to 6 months with normalization of platelet levels in the blood, and has no recurrences. The chronic form lasts more than 6 months and more often occurs in adult patients; recurrent has a cyclic course with recurrence of episodes of thrombocytopenia after normalization of platelet levels.
Symptoms of thrombocytopenic purpura
Thrombocytopenic purpura clinically manifests when platelet count drops below 50×109 /L, usually 2-3 weeks after exposure to the etiologic factor. Petechial-staining bleeding is characteristic. In patients with thrombocytopenic purpura, multiple painless hemorrhages under the skin and in the mucous membranes (“dry” variant) and bleeding (“wet” variant) appear. 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 polychromatic (from bright purple-blue to pale yellow-green, depending on the time of appearance). Hemorrhages most often occur on the anterior surface of the trunk and extremities, rarely in the face and neck. Hemorrhages are also determined on the mucous membrane of the tonsils, soft and hard palate, conjunctiva and retina, tympanic membrane, fatty tissue, parenchymatous organs, and 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 occur. In women, usually prevail uterine bleeding in the form of menorrhagia and metrorrhagia, as well as ovulatory bleeding into the abdomen with symptoms of ectopic pregnancy. Immediately before menstruation appears, skin hemorrhagic elements, nasal and other bleeding. Body temperature remains normal, and tachycardia is possible. In thrombocytopenic purpura, there is moderate splenomegaly. With profuse bleeding, internal organ anemia develops, and red bone marrow and megakaryocyte hyperplasia develops.
The drug-induced form manifests soon after drug administration and lasts from 1 week to 3 months with spontaneous recovery. Radiation thrombocytopenic purpura is characterized by severe hemorrhagic diathesis with bone marrow transition to hypo- and aplastic state. The infantile form (in children under two years of age) has an acute onset, severe, often chronic character, and marked thrombocytopenia (<20×109 /L).
Diagnosis
The diagnosis of immune thrombocytopenic purpura is established by a hematologist, taking into account the anamnesis, characteristics of the course, and the results of laboratory tests (clinical analysis of blood and urine, coagulogram, ELISA, microscopy of blood smears, bone marrow puncture).
Immune thrombocytopenic purpura is indicated by a sharp decrease in the number of platelets in the blood (<50×109 /L), increased bleeding time (>30 minutes), prothrombin time and ACTH, decreased degree or absence of clot retraction. The leukocyte count is usually within normal limits; anemia appears with significant blood loss. At the height of the hemorrhagic crisis, positive endothelial samples are detected. An increase in the size and decrease in the granularity of platelets determines the blood smear. Antiplatelet antibodies in the blood confirm the autoimmune nature of purpura.
Immune thrombocytopenic purpura is differentiated from aplastic or infiltrative processes of bone marrow, acute leukemia, thrombocytopathies, SLE, hemophilia, hemorrhagic vasculitis, hypo- and dysfibrinogenemia, juvenile uterine bleeding.
Treatment of immune thrombocytopenic purpura
In thrombocytopenic purpura with isolated thrombocytopenia (platelets >50×109 /L) without hemorrhagic syndrome, no treatment is performed; in moderate thrombocytopenia (30-50×109 /L), drug therapy is indicated in case of increased risk of bleeding (arterial hypertension, peptic ulcer disease). With platelet levels <20-30×109 /L, treatment is carried out without additional indications in the hospital.
Bleeding is controlled by the introduction of styptic drugs and locally used hemostatic sponges. To restrain immune reactions and reduce vascular permeability, corticosteroids in a decreasing dose and hyperimmune globulin are prescribed. With large blood loss, transfusions of plasma and washed red blood cells are possible. Platelet infusion in thrombocytopenic purpura is not indicated.
In patients with chronic form with recurrences of profuse bleeding and hemorrhage into vital organs, splenectomy is performed. Immunosuppressants (cytostatics) may be prescribed. If necessary, treatment of thrombocytopenic purpura should be combined with therapy of the underlying disease.
All these treatment options are available in more than 400 hospitals worldwide (https://doctor.global/results/diseases/immune-thrombocytopenic-purpura). For example, Splenectomy can be performed in these countries for following approximate prices:
Turkey $6.3 K in 12 clinics
China $14.7 K in 4 clinics
Germany $20.1 K in 30 clinics
Israel $20.2 K in 10 clinics
United States $51.1 K in 11 clinics
Prognosis
In most cases, the prognosis of thrombocytopenic purpura is very favorable; complete recovery is possible in 75% of cases (in children – in 90%). Complications (e.g., hemorrhagic stroke) are observed in the acute stage, creating a risk of fatal outcomes. Immune thrombocytopenic purpura requires constant monitoring by a hematologist, drugs affecting platelet aggregation properties (acetylsalicylic acid, caffeine, barbiturates), food allergens are excluded, caution is exercised when vaccinating children, and insolation is limited.
