Modern aspects of the pathogenesis, diagnosis and therapy of hemostasis disorders in children with acute leukemias

Abstract

Patients with oncohematological diseases, both children and adults, face high risks of thrombotic and hemorrhagic complications.About 40 % of pediatric patients with acute lymphoblastic leukemia develop bleedings, and the incidence of thrombosis in this disease ranges from 1 to 36 %. Most thromboses are associated with the use of central venous catheters and the use of L-asparaginase, which leads to a significant reduction in the synthesis of coagulation proteins.Massive hemorrhages account for two-thirds of all causes of early death in pediatric patients with acute myelogenous leukemia (AML). Absolute risks of death due to bleeding and leukostasis range from 1.8 % in the total population of children with AML to 14.3 % in a population with hyperleukocytosis more than 200 × 109 /l. The risk of thrombotic complications in children with AML varies between 3.4–11 %. In patients with AML, complex systemic coagulopathies may occur, such as disseminated intravascular coagulation (DIC), excessive fibrinolysis, or nonspecific proteolysis. This scale is not yet applicable due to the lack of research on its effectiveness in the pediatric population. The laboratory diagnostics of hemostasis is difficult due to the combined nature of thrombotic and hemorrhagic complications: bleeding, thrombosis and even DIC syndrome (combining both hyper- and hypocoagulation phases) can be expected in each specific patient with hemoblastosis. Because of the long-term nature of the treatment and the varying intensity of the various treatment units, the patient’s hemostasis during disease manifestation does not allow one to predict with any certainty the complications on induction or consolidation therapy. Involving all the components of the hemostasis system – vascular, platelet and plasma – into the pathological process makes prediction and diagnosis of thrombohemorrhagic complications impossible with the help of standard hemostatic tests and a general blood test, since these tests are designed to assess the concentrations of individual proteins and the functioning of individual components of the hemostatic system, and does not assess the balance between its procoagulant and anticoagulant components. Global hemostatic tests such as thromboelastography, thrombodynamics and thrombin generation test adequately reflect hypercoagulable conditions and can serve as a basis for the development of a new set of laboratory hemostasis tests.Conflict of interest. F.I. Ataullakhanov is co-founder of HemaCore LLC, which holds several patents and patent applications that are related to the diagnostic use of Thrombodynamics® (Ataullakhanov F.I., international patent applications: PCT/CH2007/000543 filing date 02.11.2007 and РСТ/RU2012/000570 filing date 16.07.2012). None of the other authors has any competing interests to declare.