Symptoms of thrombocytopathies

Symptoms of acquired and hereditary thrombocytopathy are characterized by bleeding of the vascular-platelet (microcirculatory) type: petechiae, ecchymosis (hemorrhages into the subcutaneous fat), bleeding from the mucous membranes of the nose, gums, and genitourinary organs.

Hemorrhagic syndrome is characterized by polymorphism, asymmetry, polychromy and combined nature (petechiae or ecchymosis and bleeding from the mucous membranes), varying degrees of hemorrhage depending on the effect of exogenous platelet inhibitors. Long-term bleeding with small cuts and injuries is typical. Unlike hemophilia, hemarthrosis and muscle hematomas are not typical.

With different variants of platelet defect, the severity of the disease varies from mild bleeding (a tendency to "bruise" with minor injuries, skin hemorrhages with "rubbing" clothing, at the site of compression by rubber bands or with vigorous pressure on the limb, periodic minor nosebleeds, "familial" prolonged menstruation in women, etc.) to profuse nasal, uterine, gastrointestinal bleeding, widespread skin purpura. Minor surgical interventions often cause profuse bleeding. Cutaneous hemorrhagic syndrome can be in the form of petechiae, ecchymosis. Often, "minimal bleeding" is so common among relatives that it is explained by "familial vascular weakness", "familial sensitivity", etc. It is in patients with hereditary thrombocytopathy that bleeding usually develops as a complication after taking medications that do not cause this reaction in millions of people. They also often have nosebleeds during infections. Long-term hematuria torpid to conventional therapy can also be a manifestation of thrombocytopathy (usually in such patients in the anamnesis or at the time of examination it is possible to detect other manifestations of increased bleeding). The time of appearance of the first signs of bleeding can be very different, but most often it is early or preschool age. In spring and winter, bleeding is more pronounced. The most persistent and severe hemorrhagic syndrome of the listed hereditary thrombocytopathy is observed in thrombasthenia.

Glanzmann's thrombasthenia

The disease is based on a genetically determined decrease in the content of glycoprotein IIb-IIIa on the surface of platelet membranes, which results in the inability of platelets to bind fibrinogen, form aggregation between cells and cause retraction of the blood clot. Diagnosis of Glanzmann's thrombasthenia is based on the absence of platelet aggregation in response to the action of physiological activators (ADP, thrombin, collagen, adrenaline) and the absence or insufficient retraction of the blood clot. At the same time, platelet aggregation with ristocetin is not impaired.

Bernard-Soulier syndrome

Thrombopathy inherited in a recessive autosomal manner, the basis of which is the absence of glycoprotein b (glycocalcin) receptors on the surface membrane of platelets. The clinical picture is characterized by moderate thrombocytopenia, giant platelet sizes (up to 5-8 μm), lack of platelet aggregation in response to the addition of ristocetin, bovine fibrinogen; aggregation with ADP or collagen is preserved.

Congenital or immune form of thrombocytopenia

Congenital isoimmune thrombocytopenia occurs when the fetus has the platelet antigen PLAI and the mother does not. As a result, the pregnant woman becomes sensitized, and she synthesizes antiplatelet antibodies that penetrate the placenta to the fetus and cause platelet lysis.

Symptoms of Bernard-Soulier syndrome. In the first hours of life, petechial and small-spotted hemorrhages appear on the skin of the newborn. In a more severe course and late appearance of hemorrhagic syndrome, hemorrhages on the mucous membranes, as well as umbilical bleeding and intracranial hemorrhages may appear. An enlarged spleen is observed.

Diagnosis of Bernard-Soulier syndrome. The diagnosis is confirmed by the presence of thrombocytopenia and a positive thromboagglutination reaction of the child's blood platelets in the mother's blood serum. Thrombocytopenia lasts from 2-3 to 12 weeks, despite the fact that the hemorrhagic syndrome is stopped from the beginning of therapy in the first days of life.

Transimmune, congenital transient thrombocytopenia of the newborn

This form of thrombocytopenia develops in newborns born to mothers with idiopathic thrombocytopenic purpura. The reason for the development of this form of thrombocytopenia is that the mother's autoantibodies pass through the placenta to the fetus and cause platelet lysis. The clinical picture may be mild, thrombocytopenia is transient.

The establishment of the type of bleeding and its kind (hereditary or acquired) based on clinical and anamnestic data is supplemented by laboratory tests to assess hemostasis in order to identify thrombocytopathy, for which the following are determined: the number, size and morphology of platelets the presence of antiplatelet antibodies (in thrombocytopenia) bleeding time platelet adhesion to glass fiber, induced platelet aggregation under the influence of ADP, thrombin, arachidonic acid and other aggregators retraction of a blood clot platelet ultrastructure under electron microscopy typing of membrane receptors with specific mono- and polyclonal antibodies.

To establish the hereditary nature of thrombocytopathy and determine the type of inheritance, pedigrees are compiled with the involvement of relatives of three degrees of kinship who have increased bleeding in the examination.

In autosomal dominant inheritance, the same type of disorders in the platelet link of hemostasis are traced in manifest forms vertically in each generation; in the case of a recessive type of inheritance, the disease manifests itself in latent forms in the lateral branches of the pedigree.

Diagnosis and differential diagnosis of thrombocytopathies. Thrombocytopathies can be suspected based on the anamnesis alone. It is mandatory to compile a family tree with careful collection of information about bleeding in relatives. Endothelial tests (cuff, tourniquet, cupping, capillary resistance) are usually positive. The duration of bleeding may be increased. The number of platelets and parameters of the blood coagulation system may be normal. A final diagnosis is possible only with a laboratory study of the properties of platelets: their adhesive ability to glass and collagen (reduced only in von Willebrand disease and Bernard-Soulier disease), aggregation activity with ADP, adrenaline, thrombin, collagen, ristocetin. In this case, the examination should be carried out dynamically not only in the child, but also in his parents, as well as in "bleeding" relatives.

Athrombia, thrombocytopathy with defective release reaction are usually inherited in an autosomal dominant manner, so one of the patient's parents is sure to have a defective platelet properties. Thrombasthenia is often inherited in an autosomal recessive manner, which is why identifying a heterozygous carrier among parents can be difficult. At the same time, there are families with dominant inheritance of thrombasthenia.

Differential diagnostics are carried out with other types of hemorrhagic diathesis, primarily with von Willebrand disease (the diagnostic reference point is defective aggregation with ristocetin). Studying the state of the coagulation link of hemostasis in patients allows excluding deficiencies of I, II, III, V and X coagulation factors, which are also characterized by the microcirculatory type of bleeding.