Features of pathogenetic mechanisms of the interaction of virusesand platelets in patients with immune thrombocytopenia (review of literature)

Abstract

One of the urgent interdisciplinar problems of modern medicine is to study the mechanisms of development of virusinduced thrombocytopenia in patients. The aim is to sum up current knowledge of viruses and platelets interaction, how viruses affect platelet and modulate adaptive immune response. A systematic review of the articles in the Pub Med database was onducted between 2007 and 2020, using search terms: platelets, thrombocytopenia, viral infection. Current data on the study of the mechanisms of platelet interaction with different types of viruses in immune thrombocytopenia in children were analyzed. We studied activation of platelets by a viral infection and how the immune response works. We know that the immune response is a cyclic multistage process involving T-lymphocytes, B-lymphocytes, macrophages, cytokines, Nk-cells. Antiplatelet antibodies are increase platelet clearance from the blood. The combination of antibodies with platelets leads to phagocytosis. In patients with immune thrombocytopenia ІgG antibodies are produced against GP/ІІ b/ІІІ or GP/І b/ІХ glycoproteins located on the platelet surface. In this situation it is possible to produce antibodies of other subclasses of ІgG, also a complement of fixing Іg G, rarelyІg А to other glycoprotein, or to other complexes Іb ІХ, Іа/ІІа. Since megakaryocytes express glycoprotein ІІb/ІІІа, Ів as well as other platelet antigens, they become a target for autoantibodies. Viruses can interact directly with platelets and megakaryocytes. In addition, platelets can be activated by viral antigenantibody complexes and B- lymphocytes can produce antiplatelet antibodies. All of these processes are activate platelets and lead to increased consumption and remove of platelets, this causes hemorrhagic manifestation in patients.